ACTA NEUROCHIRURGICA
Acta Neurochirurgica 49, 259--267 (1979)
9 by Springer-Verlag 1979
Abstracts of Papers Presented at the 95th Meeting of the Society of British Neurological Surgeons Held at Plymouth on 5 and 6 April 1979 Collected by
P. R. R. Clarke
Gossman, H. (Plymouth):
Intracranial Veins and Venous Sinuses.
The paper reviewed twelve cases of clinical interest collected since the inception of the Unit in 1964. Unusual modes of injury to the venous sinuses were illustrated, and some of the possible later results of such trauma to these structures were demonstrated. Methods of treatment and investigation were discussed, including muscle embolisation of carotico-cavernous fistula and the successful excision of a Vein of Galen aneurysm in a male baby presenting with increasing head circumference. T y s o n , G., Strachan, W. E. ( P l y m o u t h ) : The Role of Calvariectomy in the Treatment of Refractory Subdural Haematomas. Seven of 48 consecutive adult patients with chronic subdural haematomas suffered progressive neurological deterioration despite repeated burr hole drainage and, in some cases, craniotomy and subdural membranectomy. These patients were treated by excision of the cranial vault overlying the recurrent haematoma. Although six of these seven patients were comatose immediately prior to calvariectomy, there were no deaths in the series, and the majority of patients eventually recovered to the most favourable outcome grade. Selection of patients for calvariectomy, mechanisms responsible for the efficacy of this procedure, and limitations of this study were discussed. S t a n w o r t h , P. A. ( O x f o r d ) : The Significance of Hyperhydrosis in Patients With Post-Traumatic Syringomyelia. Syringomyelia occurs as a late complication of cord transection in a small number of paraplegics. Hyperhydrosis is an early prominent feature of the disease. Three cases are presented to illustrate this pathology. In the first patient, excessive sweating was the presenting complaint, in the second the effect of surgery on the sweating was observed, and in the third the pathological changes were noted when the cord was examined at necropsy. The clinical and pathological significance of the features of the disease were discussed. 17"
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Chowdary, U. M., Carey, P. C., Hussein, M. M. (Dublin): Prevention of Early Recurrence of Spontaneous Subarachnoid Haernorrhage by Epsilon Arninocaproic Acid. Eighty-three patients with lumbar puncture proved diagnosis of spontaneous SAH were given EACA. Eighty-two patients with SAH were not given any antifibrinolytic drug and form the group for comparison (control group). These two groups were comparable in age and sex distribution, in the interval between SAH and admission to the Neurosurgical unit, in the neurological grading at the time of admission, and in the distributions of the lesions found on angiograms. The dose of EACA was 36gm per day in six equal doses. The clinical management of the patients was similar. Twenty-six percent of patients in the control group had recurrent haemorrhage, and 45~ of these patients died. The rate of recurrent haemorrhage in patients receiving EACA was 4%, and 33% of those who had recurrent haemorrhage died. No serious side-effect resulted. EACA was found to be an effective and safe agent in markedly reducing the early recurrence of SAH.
Forster *, D. M. C., Steiner, L., Leksell, L., Backlund, E.-O., Nor~n, G., Greitz, T. (Stockholm): The Place of Radiosurgery in the Treatment of Inoperable Cerebral Arterio-Venous Malformations. Cerebral arterio-venous malformations represent a threat to life and health. Not all cases are suitable for radical extirpation. Radiotherapy has been abandoned as ineffective by most neurosurgeons. Stereotactic radiosurgery offers precise localisation of single doses of radiation with optimal isodose configurations. To date 59 patients have been treated by this method in Stockholm. In the 28 cases in which it was possible to irradiate the whole malformation and who have been followed more than six months 15 lesions have been completely obliterated and 11 partially so far. The place of this method in the future was discussed.
Jakubowski, J., Kendall, B., Symon, L. (London): Surgical Treatment of Giant Pituitary Adenornas. The authors reviewed a personal series of 16 giant pituitary adenomas selected from 117 cases (13.6~ incidence) operated on during the last ten years. The criteria for selection were as follows: 1. Massive suprasellar extension reaching more than 4 cm above the jugum sphenoidale or within a distance of 0.6 cm of the foramina of Munro. 2. Large tumour extensions in more than two directions. All patients were treated surgically by a single team with one surgical and anaesthetic technique. The operative mortality was 18.7~ (3 patients). Multidirectional extension and invasive spread are important features of these tumours. Operability cannot be established merely by determining the size of the most prominent part of the tumour. The direction and size of each extension, any involvement of major cerebral vessels, and the degree of compression of basal structures should be evaluated before planning treatment. Detailed radiological study usually includes plain X-rays, computer tomography, angiography, and air * Royal Infirmary, Sheffield.
Abstracts of Papers Presented at the 95th Meeting
261
studies. In the final analysis risks of surgical treatment are balanced against the prospects of active long-term survival. Cases with turnout embedded in the hypothalamus and with thalamic or posterior extensions are the least favourable for surgical treatment; partial removal causes infarction and swelling of the inaccessible part of the tumour. Limited exploration for exclusion of cystic or necrotic turnout and biopsy for histological study, followed by a shunt procedure and X-ray therapy, is recommended for the treatment of this subgroup. Intracranial extensions in other directions are amenable to surgery; the size of the turnout is not of itself any contra-indication to operation.
Bean, J., Darling, J., Hoyle, N., Arigbabu, S. O., Thomas, D. G. T. (London): Leucocyte Migration Inhibition in Patients With Brain Tumours and Subarachnoid Haemorrhage. Leucocyte migration inhibition was studied in 101 patients as a n in vitro indicator of cellular immunity. Patients with gliomas, benign brain tumours, and subarachnoid haemorrhage demonstrated impaired leucocyte migration inhibition compared to control subjects. The greatest impairment occurred in patients with subarachnoid haemorrhage, while the least impairment was seen in patients with gliomas. Significant rises in inhibition of leucocyte migration in response to antigen preparations from glioma and normal brain were seen in the early postoperative period in patients with gliomas and subarachnoid haemorrhage, indicating an enhanced response in the presence of depressed general cellular immunity.
Hope, D. T., Woodco&, J. (Bristol): Doppler Imaging of Carotid Arteries. A Non-Invasive Technique ]or Delineating Carotid Stenosis. Doppler imaging of major vessels in the neck and femoral region is rapidly becoming an established technique in vascular surgical departments. With the Mobile Artery-Vein Image Scanner (MAVIS, GEC Medical) we have studied a series of patients presenting with the various manifestations of carotid stenosis, and have eventually been able to obtain images of the carotid bifurcation, comparing favourably with angiography in these patients. Following endarterectomy a number of patients have been re-scanned. The image has been of good quality and may eliminate a postoperative angiogram.
Cameron, M. (Salford): Antifibrinolytic Therapy in the Management of Ruptured Intracranial Aneurysrn. One hundred and sixty-two consecutive patients with ruptured intracranial aneurysm were studied prospectively from June 1976 to May 1978. The first group of 56 patients did not receive antifibrinolytic therapy, and the subsequent group of 106 patients were given epsilon-amino-caproic acid as part of their management. A comparison is made between the two groups with regard to the incidence of rebleeding, the mode of treatment, the timing of surgery and the grade at surgery, outcome from surgery, overall mortality, and the possible complications of EACA therapy. The results strongly suggest that the use of epsilon-aminocaproic acid fovour-
262
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ably influences the outcome from ruptured intracranial aneurysm in both surgically and conservatively managed patients.
Sing Cho So (Hong Kong): Intracraniat Arteriovenous Malformations (AVM) in Chinese. A consecutive series of 32 intracranial AVMs in Chinese over a period of 4 89 years was retrospectively studied, On average seven new cases were admitted each year. The ratio of intracranial AVM: aneurysms over the same period was 1 : 1. The incidence of small and medium size as well as deep-seated AVMs (25 small and medium size, and 23 deep-seated AVMs) is much higher than in most other reported series. This fact is probably contributory to the high incidence of haemorrhage (87.50/0) as the initial presentation. The high mortality (13 in total) can be partly explained on the basis of massive intraventricular and intracerebral haemorrhage from deep-seated small size AVMs. Because these malformations are deep-seated, once they bled death rapidly ensued, allowing no time for proper treatment to be instituted. Twelve patients were subjected to surgery. Ten had total excision of the AVM with one death, and two had ligation of the feeding arteries. The rest were managed conservatively. The possible role of increased fibrinolytic activities in deep-seated AVMs responsible for haemorrhage was briefly discussed.
Maurice-Williams, R. S. (London): Monitoring Cerebrospinal Fluid Fibrinolytic Activity After Subarachnold Haernorrhage--A Guide to the Risk of Rebleeding? Haemorrhage-induced fibrinolytic activity and its suppression with drugs have aroused interest as possibly bearing on the mechanism of aneurysmal rebleeding. The few previous attempts to monitor fibrinolytic activity were reviewed, and the results were reported of a study based on 64 patients. A radioimmunoassay technique was used to measure serially fibrin/fibrinogen degradation products in blood and CSF. This is probably a more sensitive and accurate method than those previously used, and the findings do not fully accord with those of previous workers. The main conclusions are: 1. Only the meningeal and not the systemic fibrinolytic system is significantly activated after subarachnoid haemorrhage. 2. Earlier studies failed to take account of cross antigenicity with fibrinogen, which invalidates monitoring of fibrinolytic activity in the first few days. 3. Meningeal fibrinolytic activity may be increased for several weeks after a subarachnoid haemorrhage. 4. Patients given antifibrinolytic treatment who fail to suppress fibrinolytic activity in the CSF within 21 days of the bleed have a greater risk of rebleeding than those who do not. 5. CSF FDP monitoring between days 10-20 may have a role in deciding whether marginal cases should be subjected to surgery or not.
Shephard, R. H., Vaidya, J. P. (Derby): Spinal Subarachnoid Haemorrhage With Special Reference to Arteriovenous Malforrnations. An account of thirty-two patients with spinal subarachnoid haemorrhage is presented as a retrospective study.
Abstracts of Papers Presented at the 95th Meeting
263
This paper considers the causes and radiological investigation of spinal subarachnoid haemorrhage. The condition deserves emphasis since surgical treatment is very effective in many cases. This is especially so in those patients with AVM's presenting with subarachnoid haemorrhage. Spinal subarachnoid haemorrhage is more frequent than generally supposed. Its incidence appears to increase in relation to the diligence with which it is sought. A number of investigations are required for diagnosis of the cause of the condition, its extent and operability. The study brought out the importance of adequate duration of follow-up examinations.
McFie, J. (London): Psychological Effects of Localized Cerebral Injury in Childhood. With the help of a number of neurosurgical units in Great Britain, 300 cases were ascertained of surgically verified localized cerebral lesions (principally abscesses and penetrating skull wounds) which had occurred between birth and 20 years. These patients, many of whom had by then become adults, were recalled and given a series of tests aimed at assessing the function of different corticiaI regions. It was assumed that, if a region had been psychologically active at the time of the injury, there would be a residual deficit, in contrast to the functions of uninjured regions. It was anticipated that the degree of deficit would vary with the age at which the injury had occurred; and further, that the appearance of differences between the effects of right and of left sided lesions would indicate that cerebral dominance had become established. This was a study, therefore, of the development of cerebral dominance in the child as revealed by the effects of neurosurgical lesions.
Sweet, W. H. (Boston, Mass.): Central Mechanisms of Chronic Pain. Evidence was presented that chronic intractable pain differs in its mechanisms from acute pain in man. Data from dozens of neurosurgical centres show that at least 10 types of supratentorial lesions may effectively control chronic intense pain in man. Yet they are ineffective for acute pain, and produce no objective sensory change. Data from patients with the agonizing pains associated with malignant tumours were emphasized. The 10 sites are: 1. subcaudate (preinnominate) inferior postero-mediaI frontal white matter, 2. cingulum, 3. thalamic centrum medianum-parafascicularis and neighbouring intralaminar nuclei, 4. thalamic linear lesion separating specific from nonspecific sensory relay nuclei, 5. thalamic pulvinotomy, 6. amygdalotomy, 7. fronto-thalamic tractotomy, 8. hypothalamotomy-posteromedial, 9. hypothalamotomy-periventricular nuclei, 10. hypophysectomy.
Shannon, N. (London): Benign Intracranial Hypertension. The Effects of Different Treatments on the Natural History of the Condition. Sixty-two cases of BIH diagnosed over a 13-year period have been analyzed and follow-up data obtained to determine which of the many treatment modalities used significantly influence the condition.
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Evidence drawn from the published literature and from this series suggests the condition is not only overtreated but that it is virtually impossible to assesss the influence of any treatment mode when more than one is used. While all treatment modes are described, particular attention is drawn to surgical procedures and the possible subsequent morbidity ascribable to operative treatment. Special reference is made to visual disturbance.
Phillips, J. P., Ereman, A., Gleave, J. R. W. (Cambridge): Immunological Evidence for Phagocytic Function of Normal Astrocytes and Microglia. The primary biological function of normal astroglia remains unclear. Supportive and nutritive roles have been suggested, and the possibility that astrocytes might be physiological intermediaries in the transmission of electrical impulses has also been considered. To date, there has been little suggestion and no proof that normal astrocytes are immunologically active. In contrast, a true phagocytic role for microglia is recognized. As part of an ongoing investigation of glioma immunology we have found a remarkable incidence of normal brain astrocytes appearing to have a phagocytic or immune function. With sheep and ox red cell rosetting techniques, immunological Fc receptors and receptors for Immunoglobulin G have been found on 60~ of some normal astrocytes. In addition, similar receptors and C 3 complement receptors have been identified on a significant number of microglia and astrocytoma cells. While the latter discoveries are in accord with current thinking, the presence of immune receptors on large numbers of normal astrocytes is a new finding and brings into question the primary function of glial tissue in the normal individual.
Morris, J. L., Call, W. S. (Charlottesville): Radiology in Cerebral Revascularization Procedures. The advent of the operating microscope and miniaturization of surgical material permitted the development of the microvascular procedure for superficial temporal artery to middle cerebral artery anastomosis. There is now a growing opinion that the procedure of external carotid to internal carotid (EC/IC) anastomosis is beneficial in cases of transient ischaemic attacks (TIA) and reversible ischaemic neurological deficit (RIND). There is no doubt that the number of these surgical procedures will increase, and considerable importance attaches to the radiological evaluation of these patients. We have established a comprehensive protocol for the investigation of these patients in both the pre- and post-surgical states. It is the responsibility of the radiologist at the time of initial investigation to recognize patients who may be amenable to surgical revascularization and to obtain all relevant information at that time. Postoperatively, the results of revascularization must be assessed and this includes the extent of cerebral perfusion in the previously deprived areas. It also includes reassessment of previous collateral channels and any alteration in the cerebrovascular dynamics. This report describes the investigations necessary for adequate evaluation of patients in both the pre- and post-operative states.
Abstracts of Papers Presented at the 95th Meeting
265
K e n n e m o r e , D . E. ( G r e e n v i l l e ) : Management of Spasticity in Spinal Cord and Brain Injured Patients by Percutaneous Radiofrequency Rhizotomy. A method of relieving spasticity in spinal cord and brain injured patients by percutaneous radiofrequency rhizotomy has been devised, and an experience with 75 patients over a period of 51 months is presented. The initial 25 consecutive patients are presented in detail. These patients underwent 37 procedures over a 19-month period. At the end of 27 months from the beginning of the series these patients were carefully neurologically evaluated. Twenty-one patients had little or no spasm, three patients had insignificant spasms, and one patient represented a failure. Twenty-one of these 25 patients were followed for a period of longer than one year and some of these patients have been followed for as long as 51 months. Voluntary motor function, touch, and proprioception were preserved in all patients with these functions initially intact. Bladder and bowel function, and penile erections were not affected in any patient. Five patients with eight refractory decubitus ulcers were treated successfully after rhizotomy. Three patients originally thought to have total motor lesions demonstrated voluntary movements following rhizotomy. Two patients with quadriparesis noted a marked reduction in spasticity in the arms following rhizotomy at T-12, L-1,2,3,4,5, and S-1. The procedure does not destroy the potential for motor function. Bladder and bowel function are undisturbed. The capacity for penile erections is preserved. Because no open incision and no postoperative recuperation are required the procedure may be performed upon patients who are in poor condition, and should the spasms or spasticity recur this technique lends itself well to repetition. V e r d u r a , J., R e s n i k o f f , S., C a r d e n a s , J. ( M e x i c o C i t y ) :
Lumbar
Disc Surgery. Personal Experience. With 1,000 Cases. We present our experience with one thousand cases of lumbar discs operated upon over a period of 20 years. Our material is made up of 986 cases of ruptured or herniated discs surgically treated at the L 4-L 5 and L 5-S 1 levels, eleven at the L 3-L 4, two at the L 2-L 3, and one at the L I-L 2 levels. Our criteria for surgical intervention are: 1. repeated incapacitating low back pain with definite sciatica; 2. evidence of neurological deficits (Lasuege's sign); 3. positive myelogram; 4. a serious trial and failure of conservative therapy; 5. no history of psychiatric disturbances, and 6. no litigation involved. All patients were operated upon in the lateral position under general endotracheal anesthesia. With a unilateral exposure, only a hemilaminotomy (Key-hole) of the suspected interspace was carried out with a complete and radical removal of the disc. No fusion was performed in any of our patients. We had 91~ excellent to good results, and only twenty three (2.3~ of our cases had a recurrence of signs and symptoms requiring a secondary intervention. S e n g u p t a , R. P. ( N e w c a s t l e u p o n T y n e ) : A Modified Approach for the Direct Surgical Treatment of Anterior Communicating Aneurysms. Direct surgery for the obliteration of an anterior communicating aneurysm is usually carried out by a nondominant subfrontal method and the anterior coin-
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municating region is approached by following the proximal anterior cerebral artery from the carotid bifurcation. Alternatively a midline bifrontal approach is also a method of choice for some. Although satisfactory results can be obtained by using these methods along with other advances in neurosurgery in recent times, postoperative cerebral ischaemia from vasospasm still remains the outstanding problem in aneurysm surgery. The author believes that the results of surgery can be improved further by taking account of the various anatomical and physiological factors associated with these aneurysms. By carefully study of preoperative anglograms a specific approach can be planned to suit each aneurysm. With this new method the author has operated on 160 patients with anterior communicating aneurysms, and detailed results in the first 100 consecutive patients have been analysed in this report.
Duff,
T. A. ( W i s c o n s i n ) :
Topographical Analysis of Somato-
sensory Evoked Potentials. The topographic distribution of human somatosensory evoked potentials has been studied with a 36-channel scalp electrode array. The early latency cortical potential produced by electrical stimulation of the median nerve is composed of several deflections, each possessing a unique topographic profile. The differences among these profiles, coupled with the somatotopic organization of sensorimotor cortex, provides opportunity, on the one hand, for plotting those surface shifts which result from stimulating different body parts and, on the other hand, for documenting physiological abberations caused by small lesions within the somatosensory pathway or cortex. Stimulation of face, thumb, middle, or little finger was found to produce sequential P20-wave shifts which correspond to the well-documented arrangement of body part representation in the somatosensory cortex. In addition, this recording technique has provided evidence of focal physiological abnormality resulting from relatively discrete cortical and subcortical lesions, including neoplasm, haematoma, and infarct. The goal of these studies is to develop a method for detecting neurophysiological changes produced by small lesions within any portion of the somatosensory pathway. Correlating specific types of changes with the locations of lesions should provide information about the course of afferent fibres to various cortical generators.
T e a s d a l e , G., C o w d e n , A. E., R a t c l i f f e , J. G., T h o m p s o n , J. A., D a v i e s , D., M c C r u d e n , D., M a c p h e r s o n , P., D o y l e , D . ( G l a s g o w ) :
Small Prolactinomas: Endocrinological Diagnosis and Results of Selective Excision. Dynamic tests of prolactin (PRL) secretion have been performed in women with amenorrhoea and elevated PRL. Transphenoidal exploration has identified a tumour (confirmed as a prolactinoma by immunoperoxidase staining) in 16 women, even though the pituitary fossa was radiologically normal in 8 cases. In each case the diurnal rhythm of PRL and response to metoclopramide and TRH were absent or abnormally depressed; this pattern distinguishes these tumours from functional hyperprolactinaemia. After operation PRL was normal in 14 patients. A small prolactinoma can be identified endoerinologieally and effective and selective surgery performed before it becomes a large adenoma.
Abstracts of Papers Presented at the 95th Meeting
267
Winn, H. R., Welsh, J. E., Rubio, R., Berne, R. M. (Charlottesville): Brain Adenosine During the Initial 60 Seconds of Bicuculline Seizures. A sevenfold increase in cerebral blood flow (CBF) occurs within a few seconds oi: the onset of generalized seizures induced by bicuculline, a blocker of aminobutyric acid. To study the possible role of adenosine, a vasoactive purine nucleoside, in the regulation of CBF, rats were anaesthetized with 3% halothane, tracheostomized, and paralyzed with pancuronium. A femoral artery and vein were cannulated for constant recording of blood pressure and injection of drugs. Arterial blood gases were measured, and inspired gases adjusted to maintain arterial PO2 greater than 200 mm Hg and arterial PCO2 between 30 and 40 mm Hg. Seizures were induced by intravenous bicuculline (1.2mg/kg), and the brain was sampled after 10, 20, 30, and 60 seconds of seizure by the freeze-blowing method of Veech. Control rats were treated identically, but their brains were sampled before the onset of seizures. Frozen brain tissue was analyzed for adenosine, inosine, hypoxanthine, lactate, phosphocreatine (PCr), ATP, ADP, and AMP. Within i0 seconds of the onset of seizures, adenosine was elevated to 2.90 + 0.32 (SE)nmoles/gm from control values of 0.20 + 0.07. Concentrations remained elevated and stable between 20 (2.75 + 0.77) and 60 seconds (2.07 + 0.47). Inosine increased 77% by 10 seconds from control values (3.13 + 0.72) nmoles/gm. In contrast, significant elevation in hypoxanthine was delayed until 20 seconds. At 60 seconds, inosine and hypoxanthine concentrations were 10.29 + 0.83 and 23.68 _+ 4.16 nmoles/gm. An increase in AMP at 10 seconds (39 + 5 to 67 + 13 nmoles/gm) correlated with the observed increases in adenosine, but AMP values returned toward control values by 60 seconds. PCr and ATP dropped sharply within 10 seconds, with ATP values returning to initial values by 60 seconds, whereas PCr remained depressed. Lactate became progressively elevated throughout the seizure period. The rapid increment and maintainance of adenosine levels for the first 60 seconds of seizures supports a role for adenosine in the regulation of CBF.
Butler, A. B. (Charlottesville): The Arachnoid Villus. Acutely sustained increases of CSF pressure are often associated with SAH. This study assessed the role of the various blood components in disturbing the manometric profile of outflow resistance and altering ultrastructural characteristics of proxidase transport at arachnoid villi. It was concluded that acute intracranial hypertension associated with the sudden introduction of blood into the subarachnoid space results from an immediate increase in the CSF outflow resistance. This pathological effect on the vesicular transport in arachnoid villi is mediated by macromolecular substances associated with the clotting cascade.
Acta Neurochirurgica 49, 259--267 (1979)
9 by Springer-Verlag 1979
Abstracts of Papers Presented at the 95th Meeting of the Society of British Neurological Surgeons Held at Plymouth on 5 and 6 April 1979 Collected by
P. R. R. Clarke
Gossman, H. (Plymouth):
Intracranial Veins and Venous Sinuses.
The paper reviewed twelve cases of clinical interest collected since the inception of the Unit in 1964. Unusual modes of injury to the venous sinuses were illustrated, and some of the possible later results of such trauma to these structures were demonstrated. Methods of treatment and investigation were discussed, including muscle embolisation of carotico-cavernous fistula and the successful excision of a Vein of Galen aneurysm in a male baby presenting with increasing head circumference. T y s o n , G., Strachan, W. E. ( P l y m o u t h ) : The Role of Calvariectomy in the Treatment of Refractory Subdural Haematomas. Seven of 48 consecutive adult patients with chronic subdural haematomas suffered progressive neurological deterioration despite repeated burr hole drainage and, in some cases, craniotomy and subdural membranectomy. These patients were treated by excision of the cranial vault overlying the recurrent haematoma. Although six of these seven patients were comatose immediately prior to calvariectomy, there were no deaths in the series, and the majority of patients eventually recovered to the most favourable outcome grade. Selection of patients for calvariectomy, mechanisms responsible for the efficacy of this procedure, and limitations of this study were discussed. S t a n w o r t h , P. A. ( O x f o r d ) : The Significance of Hyperhydrosis in Patients With Post-Traumatic Syringomyelia. Syringomyelia occurs as a late complication of cord transection in a small number of paraplegics. Hyperhydrosis is an early prominent feature of the disease. Three cases are presented to illustrate this pathology. In the first patient, excessive sweating was the presenting complaint, in the second the effect of surgery on the sweating was observed, and in the third the pathological changes were noted when the cord was examined at necropsy. The clinical and pathological significance of the features of the disease were discussed. 17"
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Chowdary, U. M., Carey, P. C., Hussein, M. M. (Dublin): Prevention of Early Recurrence of Spontaneous Subarachnoid Haernorrhage by Epsilon Arninocaproic Acid. Eighty-three patients with lumbar puncture proved diagnosis of spontaneous SAH were given EACA. Eighty-two patients with SAH were not given any antifibrinolytic drug and form the group for comparison (control group). These two groups were comparable in age and sex distribution, in the interval between SAH and admission to the Neurosurgical unit, in the neurological grading at the time of admission, and in the distributions of the lesions found on angiograms. The dose of EACA was 36gm per day in six equal doses. The clinical management of the patients was similar. Twenty-six percent of patients in the control group had recurrent haemorrhage, and 45~ of these patients died. The rate of recurrent haemorrhage in patients receiving EACA was 4%, and 33% of those who had recurrent haemorrhage died. No serious side-effect resulted. EACA was found to be an effective and safe agent in markedly reducing the early recurrence of SAH.
Forster *, D. M. C., Steiner, L., Leksell, L., Backlund, E.-O., Nor~n, G., Greitz, T. (Stockholm): The Place of Radiosurgery in the Treatment of Inoperable Cerebral Arterio-Venous Malformations. Cerebral arterio-venous malformations represent a threat to life and health. Not all cases are suitable for radical extirpation. Radiotherapy has been abandoned as ineffective by most neurosurgeons. Stereotactic radiosurgery offers precise localisation of single doses of radiation with optimal isodose configurations. To date 59 patients have been treated by this method in Stockholm. In the 28 cases in which it was possible to irradiate the whole malformation and who have been followed more than six months 15 lesions have been completely obliterated and 11 partially so far. The place of this method in the future was discussed.
Jakubowski, J., Kendall, B., Symon, L. (London): Surgical Treatment of Giant Pituitary Adenornas. The authors reviewed a personal series of 16 giant pituitary adenomas selected from 117 cases (13.6~ incidence) operated on during the last ten years. The criteria for selection were as follows: 1. Massive suprasellar extension reaching more than 4 cm above the jugum sphenoidale or within a distance of 0.6 cm of the foramina of Munro. 2. Large tumour extensions in more than two directions. All patients were treated surgically by a single team with one surgical and anaesthetic technique. The operative mortality was 18.7~ (3 patients). Multidirectional extension and invasive spread are important features of these tumours. Operability cannot be established merely by determining the size of the most prominent part of the tumour. The direction and size of each extension, any involvement of major cerebral vessels, and the degree of compression of basal structures should be evaluated before planning treatment. Detailed radiological study usually includes plain X-rays, computer tomography, angiography, and air * Royal Infirmary, Sheffield.
Abstracts of Papers Presented at the 95th Meeting
261
studies. In the final analysis risks of surgical treatment are balanced against the prospects of active long-term survival. Cases with turnout embedded in the hypothalamus and with thalamic or posterior extensions are the least favourable for surgical treatment; partial removal causes infarction and swelling of the inaccessible part of the tumour. Limited exploration for exclusion of cystic or necrotic turnout and biopsy for histological study, followed by a shunt procedure and X-ray therapy, is recommended for the treatment of this subgroup. Intracranial extensions in other directions are amenable to surgery; the size of the turnout is not of itself any contra-indication to operation.
Bean, J., Darling, J., Hoyle, N., Arigbabu, S. O., Thomas, D. G. T. (London): Leucocyte Migration Inhibition in Patients With Brain Tumours and Subarachnoid Haemorrhage. Leucocyte migration inhibition was studied in 101 patients as a n in vitro indicator of cellular immunity. Patients with gliomas, benign brain tumours, and subarachnoid haemorrhage demonstrated impaired leucocyte migration inhibition compared to control subjects. The greatest impairment occurred in patients with subarachnoid haemorrhage, while the least impairment was seen in patients with gliomas. Significant rises in inhibition of leucocyte migration in response to antigen preparations from glioma and normal brain were seen in the early postoperative period in patients with gliomas and subarachnoid haemorrhage, indicating an enhanced response in the presence of depressed general cellular immunity.
Hope, D. T., Woodco&, J. (Bristol): Doppler Imaging of Carotid Arteries. A Non-Invasive Technique ]or Delineating Carotid Stenosis. Doppler imaging of major vessels in the neck and femoral region is rapidly becoming an established technique in vascular surgical departments. With the Mobile Artery-Vein Image Scanner (MAVIS, GEC Medical) we have studied a series of patients presenting with the various manifestations of carotid stenosis, and have eventually been able to obtain images of the carotid bifurcation, comparing favourably with angiography in these patients. Following endarterectomy a number of patients have been re-scanned. The image has been of good quality and may eliminate a postoperative angiogram.
Cameron, M. (Salford): Antifibrinolytic Therapy in the Management of Ruptured Intracranial Aneurysrn. One hundred and sixty-two consecutive patients with ruptured intracranial aneurysm were studied prospectively from June 1976 to May 1978. The first group of 56 patients did not receive antifibrinolytic therapy, and the subsequent group of 106 patients were given epsilon-amino-caproic acid as part of their management. A comparison is made between the two groups with regard to the incidence of rebleeding, the mode of treatment, the timing of surgery and the grade at surgery, outcome from surgery, overall mortality, and the possible complications of EACA therapy. The results strongly suggest that the use of epsilon-aminocaproic acid fovour-
262
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ably influences the outcome from ruptured intracranial aneurysm in both surgically and conservatively managed patients.
Sing Cho So (Hong Kong): Intracraniat Arteriovenous Malformations (AVM) in Chinese. A consecutive series of 32 intracranial AVMs in Chinese over a period of 4 89 years was retrospectively studied, On average seven new cases were admitted each year. The ratio of intracranial AVM: aneurysms over the same period was 1 : 1. The incidence of small and medium size as well as deep-seated AVMs (25 small and medium size, and 23 deep-seated AVMs) is much higher than in most other reported series. This fact is probably contributory to the high incidence of haemorrhage (87.50/0) as the initial presentation. The high mortality (13 in total) can be partly explained on the basis of massive intraventricular and intracerebral haemorrhage from deep-seated small size AVMs. Because these malformations are deep-seated, once they bled death rapidly ensued, allowing no time for proper treatment to be instituted. Twelve patients were subjected to surgery. Ten had total excision of the AVM with one death, and two had ligation of the feeding arteries. The rest were managed conservatively. The possible role of increased fibrinolytic activities in deep-seated AVMs responsible for haemorrhage was briefly discussed.
Maurice-Williams, R. S. (London): Monitoring Cerebrospinal Fluid Fibrinolytic Activity After Subarachnold Haernorrhage--A Guide to the Risk of Rebleeding? Haemorrhage-induced fibrinolytic activity and its suppression with drugs have aroused interest as possibly bearing on the mechanism of aneurysmal rebleeding. The few previous attempts to monitor fibrinolytic activity were reviewed, and the results were reported of a study based on 64 patients. A radioimmunoassay technique was used to measure serially fibrin/fibrinogen degradation products in blood and CSF. This is probably a more sensitive and accurate method than those previously used, and the findings do not fully accord with those of previous workers. The main conclusions are: 1. Only the meningeal and not the systemic fibrinolytic system is significantly activated after subarachnoid haemorrhage. 2. Earlier studies failed to take account of cross antigenicity with fibrinogen, which invalidates monitoring of fibrinolytic activity in the first few days. 3. Meningeal fibrinolytic activity may be increased for several weeks after a subarachnoid haemorrhage. 4. Patients given antifibrinolytic treatment who fail to suppress fibrinolytic activity in the CSF within 21 days of the bleed have a greater risk of rebleeding than those who do not. 5. CSF FDP monitoring between days 10-20 may have a role in deciding whether marginal cases should be subjected to surgery or not.
Shephard, R. H., Vaidya, J. P. (Derby): Spinal Subarachnoid Haemorrhage With Special Reference to Arteriovenous Malforrnations. An account of thirty-two patients with spinal subarachnoid haemorrhage is presented as a retrospective study.
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This paper considers the causes and radiological investigation of spinal subarachnoid haemorrhage. The condition deserves emphasis since surgical treatment is very effective in many cases. This is especially so in those patients with AVM's presenting with subarachnoid haemorrhage. Spinal subarachnoid haemorrhage is more frequent than generally supposed. Its incidence appears to increase in relation to the diligence with which it is sought. A number of investigations are required for diagnosis of the cause of the condition, its extent and operability. The study brought out the importance of adequate duration of follow-up examinations.
McFie, J. (London): Psychological Effects of Localized Cerebral Injury in Childhood. With the help of a number of neurosurgical units in Great Britain, 300 cases were ascertained of surgically verified localized cerebral lesions (principally abscesses and penetrating skull wounds) which had occurred between birth and 20 years. These patients, many of whom had by then become adults, were recalled and given a series of tests aimed at assessing the function of different corticiaI regions. It was assumed that, if a region had been psychologically active at the time of the injury, there would be a residual deficit, in contrast to the functions of uninjured regions. It was anticipated that the degree of deficit would vary with the age at which the injury had occurred; and further, that the appearance of differences between the effects of right and of left sided lesions would indicate that cerebral dominance had become established. This was a study, therefore, of the development of cerebral dominance in the child as revealed by the effects of neurosurgical lesions.
Sweet, W. H. (Boston, Mass.): Central Mechanisms of Chronic Pain. Evidence was presented that chronic intractable pain differs in its mechanisms from acute pain in man. Data from dozens of neurosurgical centres show that at least 10 types of supratentorial lesions may effectively control chronic intense pain in man. Yet they are ineffective for acute pain, and produce no objective sensory change. Data from patients with the agonizing pains associated with malignant tumours were emphasized. The 10 sites are: 1. subcaudate (preinnominate) inferior postero-mediaI frontal white matter, 2. cingulum, 3. thalamic centrum medianum-parafascicularis and neighbouring intralaminar nuclei, 4. thalamic linear lesion separating specific from nonspecific sensory relay nuclei, 5. thalamic pulvinotomy, 6. amygdalotomy, 7. fronto-thalamic tractotomy, 8. hypothalamotomy-posteromedial, 9. hypothalamotomy-periventricular nuclei, 10. hypophysectomy.
Shannon, N. (London): Benign Intracranial Hypertension. The Effects of Different Treatments on the Natural History of the Condition. Sixty-two cases of BIH diagnosed over a 13-year period have been analyzed and follow-up data obtained to determine which of the many treatment modalities used significantly influence the condition.
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Evidence drawn from the published literature and from this series suggests the condition is not only overtreated but that it is virtually impossible to assesss the influence of any treatment mode when more than one is used. While all treatment modes are described, particular attention is drawn to surgical procedures and the possible subsequent morbidity ascribable to operative treatment. Special reference is made to visual disturbance.
Phillips, J. P., Ereman, A., Gleave, J. R. W. (Cambridge): Immunological Evidence for Phagocytic Function of Normal Astrocytes and Microglia. The primary biological function of normal astroglia remains unclear. Supportive and nutritive roles have been suggested, and the possibility that astrocytes might be physiological intermediaries in the transmission of electrical impulses has also been considered. To date, there has been little suggestion and no proof that normal astrocytes are immunologically active. In contrast, a true phagocytic role for microglia is recognized. As part of an ongoing investigation of glioma immunology we have found a remarkable incidence of normal brain astrocytes appearing to have a phagocytic or immune function. With sheep and ox red cell rosetting techniques, immunological Fc receptors and receptors for Immunoglobulin G have been found on 60~ of some normal astrocytes. In addition, similar receptors and C 3 complement receptors have been identified on a significant number of microglia and astrocytoma cells. While the latter discoveries are in accord with current thinking, the presence of immune receptors on large numbers of normal astrocytes is a new finding and brings into question the primary function of glial tissue in the normal individual.
Morris, J. L., Call, W. S. (Charlottesville): Radiology in Cerebral Revascularization Procedures. The advent of the operating microscope and miniaturization of surgical material permitted the development of the microvascular procedure for superficial temporal artery to middle cerebral artery anastomosis. There is now a growing opinion that the procedure of external carotid to internal carotid (EC/IC) anastomosis is beneficial in cases of transient ischaemic attacks (TIA) and reversible ischaemic neurological deficit (RIND). There is no doubt that the number of these surgical procedures will increase, and considerable importance attaches to the radiological evaluation of these patients. We have established a comprehensive protocol for the investigation of these patients in both the pre- and post-surgical states. It is the responsibility of the radiologist at the time of initial investigation to recognize patients who may be amenable to surgical revascularization and to obtain all relevant information at that time. Postoperatively, the results of revascularization must be assessed and this includes the extent of cerebral perfusion in the previously deprived areas. It also includes reassessment of previous collateral channels and any alteration in the cerebrovascular dynamics. This report describes the investigations necessary for adequate evaluation of patients in both the pre- and post-operative states.
Abstracts of Papers Presented at the 95th Meeting
265
K e n n e m o r e , D . E. ( G r e e n v i l l e ) : Management of Spasticity in Spinal Cord and Brain Injured Patients by Percutaneous Radiofrequency Rhizotomy. A method of relieving spasticity in spinal cord and brain injured patients by percutaneous radiofrequency rhizotomy has been devised, and an experience with 75 patients over a period of 51 months is presented. The initial 25 consecutive patients are presented in detail. These patients underwent 37 procedures over a 19-month period. At the end of 27 months from the beginning of the series these patients were carefully neurologically evaluated. Twenty-one patients had little or no spasm, three patients had insignificant spasms, and one patient represented a failure. Twenty-one of these 25 patients were followed for a period of longer than one year and some of these patients have been followed for as long as 51 months. Voluntary motor function, touch, and proprioception were preserved in all patients with these functions initially intact. Bladder and bowel function, and penile erections were not affected in any patient. Five patients with eight refractory decubitus ulcers were treated successfully after rhizotomy. Three patients originally thought to have total motor lesions demonstrated voluntary movements following rhizotomy. Two patients with quadriparesis noted a marked reduction in spasticity in the arms following rhizotomy at T-12, L-1,2,3,4,5, and S-1. The procedure does not destroy the potential for motor function. Bladder and bowel function are undisturbed. The capacity for penile erections is preserved. Because no open incision and no postoperative recuperation are required the procedure may be performed upon patients who are in poor condition, and should the spasms or spasticity recur this technique lends itself well to repetition. V e r d u r a , J., R e s n i k o f f , S., C a r d e n a s , J. ( M e x i c o C i t y ) :
Lumbar
Disc Surgery. Personal Experience. With 1,000 Cases. We present our experience with one thousand cases of lumbar discs operated upon over a period of 20 years. Our material is made up of 986 cases of ruptured or herniated discs surgically treated at the L 4-L 5 and L 5-S 1 levels, eleven at the L 3-L 4, two at the L 2-L 3, and one at the L I-L 2 levels. Our criteria for surgical intervention are: 1. repeated incapacitating low back pain with definite sciatica; 2. evidence of neurological deficits (Lasuege's sign); 3. positive myelogram; 4. a serious trial and failure of conservative therapy; 5. no history of psychiatric disturbances, and 6. no litigation involved. All patients were operated upon in the lateral position under general endotracheal anesthesia. With a unilateral exposure, only a hemilaminotomy (Key-hole) of the suspected interspace was carried out with a complete and radical removal of the disc. No fusion was performed in any of our patients. We had 91~ excellent to good results, and only twenty three (2.3~ of our cases had a recurrence of signs and symptoms requiring a secondary intervention. S e n g u p t a , R. P. ( N e w c a s t l e u p o n T y n e ) : A Modified Approach for the Direct Surgical Treatment of Anterior Communicating Aneurysms. Direct surgery for the obliteration of an anterior communicating aneurysm is usually carried out by a nondominant subfrontal method and the anterior coin-
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municating region is approached by following the proximal anterior cerebral artery from the carotid bifurcation. Alternatively a midline bifrontal approach is also a method of choice for some. Although satisfactory results can be obtained by using these methods along with other advances in neurosurgery in recent times, postoperative cerebral ischaemia from vasospasm still remains the outstanding problem in aneurysm surgery. The author believes that the results of surgery can be improved further by taking account of the various anatomical and physiological factors associated with these aneurysms. By carefully study of preoperative anglograms a specific approach can be planned to suit each aneurysm. With this new method the author has operated on 160 patients with anterior communicating aneurysms, and detailed results in the first 100 consecutive patients have been analysed in this report.
Duff,
T. A. ( W i s c o n s i n ) :
Topographical Analysis of Somato-
sensory Evoked Potentials. The topographic distribution of human somatosensory evoked potentials has been studied with a 36-channel scalp electrode array. The early latency cortical potential produced by electrical stimulation of the median nerve is composed of several deflections, each possessing a unique topographic profile. The differences among these profiles, coupled with the somatotopic organization of sensorimotor cortex, provides opportunity, on the one hand, for plotting those surface shifts which result from stimulating different body parts and, on the other hand, for documenting physiological abberations caused by small lesions within the somatosensory pathway or cortex. Stimulation of face, thumb, middle, or little finger was found to produce sequential P20-wave shifts which correspond to the well-documented arrangement of body part representation in the somatosensory cortex. In addition, this recording technique has provided evidence of focal physiological abnormality resulting from relatively discrete cortical and subcortical lesions, including neoplasm, haematoma, and infarct. The goal of these studies is to develop a method for detecting neurophysiological changes produced by small lesions within any portion of the somatosensory pathway. Correlating specific types of changes with the locations of lesions should provide information about the course of afferent fibres to various cortical generators.
T e a s d a l e , G., C o w d e n , A. E., R a t c l i f f e , J. G., T h o m p s o n , J. A., D a v i e s , D., M c C r u d e n , D., M a c p h e r s o n , P., D o y l e , D . ( G l a s g o w ) :
Small Prolactinomas: Endocrinological Diagnosis and Results of Selective Excision. Dynamic tests of prolactin (PRL) secretion have been performed in women with amenorrhoea and elevated PRL. Transphenoidal exploration has identified a tumour (confirmed as a prolactinoma by immunoperoxidase staining) in 16 women, even though the pituitary fossa was radiologically normal in 8 cases. In each case the diurnal rhythm of PRL and response to metoclopramide and TRH were absent or abnormally depressed; this pattern distinguishes these tumours from functional hyperprolactinaemia. After operation PRL was normal in 14 patients. A small prolactinoma can be identified endoerinologieally and effective and selective surgery performed before it becomes a large adenoma.
Abstracts of Papers Presented at the 95th Meeting
267
Winn, H. R., Welsh, J. E., Rubio, R., Berne, R. M. (Charlottesville): Brain Adenosine During the Initial 60 Seconds of Bicuculline Seizures. A sevenfold increase in cerebral blood flow (CBF) occurs within a few seconds oi: the onset of generalized seizures induced by bicuculline, a blocker of aminobutyric acid. To study the possible role of adenosine, a vasoactive purine nucleoside, in the regulation of CBF, rats were anaesthetized with 3% halothane, tracheostomized, and paralyzed with pancuronium. A femoral artery and vein were cannulated for constant recording of blood pressure and injection of drugs. Arterial blood gases were measured, and inspired gases adjusted to maintain arterial PO2 greater than 200 mm Hg and arterial PCO2 between 30 and 40 mm Hg. Seizures were induced by intravenous bicuculline (1.2mg/kg), and the brain was sampled after 10, 20, 30, and 60 seconds of seizure by the freeze-blowing method of Veech. Control rats were treated identically, but their brains were sampled before the onset of seizures. Frozen brain tissue was analyzed for adenosine, inosine, hypoxanthine, lactate, phosphocreatine (PCr), ATP, ADP, and AMP. Within i0 seconds of the onset of seizures, adenosine was elevated to 2.90 + 0.32 (SE)nmoles/gm from control values of 0.20 + 0.07. Concentrations remained elevated and stable between 20 (2.75 + 0.77) and 60 seconds (2.07 + 0.47). Inosine increased 77% by 10 seconds from control values (3.13 + 0.72) nmoles/gm. In contrast, significant elevation in hypoxanthine was delayed until 20 seconds. At 60 seconds, inosine and hypoxanthine concentrations were 10.29 + 0.83 and 23.68 _+ 4.16 nmoles/gm. An increase in AMP at 10 seconds (39 + 5 to 67 + 13 nmoles/gm) correlated with the observed increases in adenosine, but AMP values returned toward control values by 60 seconds. PCr and ATP dropped sharply within 10 seconds, with ATP values returning to initial values by 60 seconds, whereas PCr remained depressed. Lactate became progressively elevated throughout the seizure period. The rapid increment and maintainance of adenosine levels for the first 60 seconds of seizures supports a role for adenosine in the regulation of CBF.
Butler, A. B. (Charlottesville): The Arachnoid Villus. Acutely sustained increases of CSF pressure are often associated with SAH. This study assessed the role of the various blood components in disturbing the manometric profile of outflow resistance and altering ultrastructural characteristics of proxidase transport at arachnoid villi. It was concluded that acute intracranial hypertension associated with the sudden introduction of blood into the subarachnoid space results from an immediate increase in the CSF outflow resistance. This pathological effect on the vesicular transport in arachnoid villi is mediated by macromolecular substances associated with the clotting cascade.
