Child's Brain I: 116-120 (1975)

Isotope Cisternography and Ventriculography in Congenital CNS Anomalies F ranz E. G lasauer Department of Neurosurgery, Edward J. Meyer Memorial Hospital, State University of New York, Buffalo, N.Y.

Key Words. Isotope cisternography • Isotope ventriculography • Congenital CNS anomalies • Hydrocephalus ■ Encephaloccle • Dandy-Walker syndrome • Poren­ cephaly Abstract. Isotope studies are well-tolerated examinations in various congenital CNS anomalies and are valuable in demonstrating the presence of associated hydro­ cephalus, abnormal accumulation of isotope associated with abnormal CSF flow or a failure of absorption. In some cases these studies may be of differential diagnostic value and a helpful indicator in the choice of surgical treatment. These tests do not disturb the CSF equilibrium which is often observed following air or other contrast studies.

The value and usefulness of isotope cisternography and ventriculo­ graphy in the study of normal and abnormal CSF flow and in the evalua­ tion of hydrocephalus has been adequately acknowledged in the literature [l-20j. Some congenital CNS anomalies are frequently associated either with hydrocephalus or disturbance in CSF flow or absorption. This pres­ entation emphasizes the significance of isotope studies in the investigation of the following congenital CNS anomalies: encephalocele, porencephaly and agenesis, hydranencephaly, Dandy-Walker syndrome, and cisterna magna cyst. Encephalocele

Downloaded by: University of Leeds 129.11.21.2 - 5/8/2018 1:18:18 AM

Congenital anomalies or defects at the base of the skull can be a source of nontraumatic CSF rhinorrhea. Nasal or frontal encephaloceles are occasionally misdiagnosed and biopsied resulting in CSF leak. Isotope

G lasaulr

117

cisternography may be the most valuable examination to establish the di­ agnosis and demonstrate the side and site of CSF leakage. Large encephaloceles in the occipital area are almost always associat­ ed with hydrocephalus. Isotope ventriculography demonstrates the pres­ ence of hydrocephalus, confirms the communication with the encephalocele sac and eliminates positional changes of the infant necessary for air or contrast studies. Porencephaly and Agenesis Porencephaly is frequently associated with communicating hydroce­ phalus and shows a tendency to progression due to increased CSF pres­ sure and an eventual decrease in CSF absorption. Pneumoencephal­ ography is usually diagnostic but may fail to demonstrate the communica­ tion with the cyst. Isotope cisternography reveals a ventricular reflux of the isotope, the size of the associated hydrocephalus, and the porence­ phalic dilatation. The isotope remains in the cyst after clearing from the ventricular system. The progression, the associated hydrocephalus and, additionally, the demonstration of lack or delay of CSF absorption all suggest the most adequate therapy, namely, a CSF shunting procedure. In cases of partial agenesis of the brain or in hemispherectomy, a large fluid-filled cavity is present. In agenesis the lateral ventricle on the nor­ mal side may be dilated. Similar to the pathophysiology in porencephaly the existing large cavity has a tendency to expand and eventually causes signs of increased intracranial pressure. At isotope ventriculography the huge cavity is filled with the radionuclide and remains unchanged for sev­ eral days indicating a lack of CSF circulation and absorption. If the con­ dition is symptomatic, again a CSF shunting procedure is the treatment of choice. Hydranencephaly

Downloaded by: University of Leeds 129.11.21.2 - 5/8/2018 1:18:18 AM

Hydranencephaly presents the image of a single fluid-filled cavity with no flow of the isotope and in fact no absorption of the material is demon­ strable. The decrease in count rate over several days is essentially due to the physical decay of the radionuclide. Some authors describe the huge monoventricle as a ‘cyclopian ventricle' which is nicely outlined by the isotope but cannot be completely outlined with air. A differential diagno­

I 18

G lasauir

sis of hydranencephaly with this method is possible by the dissipation of the radionuelide to outline a single fluid-filled cavity while in advanced obstructive hydrocephalus some ventricular outline by the isotope pers­ ists.

Dandy-Walker Syndrome and C¡sterna magna Cyst In the Dandy-Walker syndrome the fourth ventricle becomes an en­ larged cystic structure due to CSF obstruction at the foramina. In contrast, an arachnoidal cyst of the cisterna magna presents a cystic dilatation with or without communication with the fourth ventricle. The Dandy-Walker syndrome represents an obstructive hydrocephalus and is easily recognized on isotope ventriculography. The radionuclide fills the cystic fourth ventricle and persists for the duration of the study with no filling of the subarachnoid space. Isotope cisternography as a rule fails to demonstrate the hydrocephalus and associated abnormality and either a slow isotope flow into the basal cisterns or an obstruction anterior to the brain stem is observed. In the cisterna magna cyst isotope injected from below demonstrates an abnormal persisting midline accumulation in the region of the poster­ ior fossa. Usually there is no filling of the ventricular system which is of normal size and, therefore, no ventricular reflux is expected. The pres­ ence of a CSF accumulation in the posterior fossa with an obvious delay in clearing of the isotope and lack of circulation explains the symptoma­ tology and the surgical benefit of this condition. Isotope studies are very useful in the differential diagnosis of these two anomalies: isotope ventriculography demonstrates the hydrocephalus and Dandy-Walker cyst with no subarachnoid filling. In contrast, isotope cis­ ternography outlines the cisterna magna cyst but fails to enter the DandyWalker cyst. However. H arbert and M c Cullough [19] recently de­ scribed a case of Dandy-Walker cyst in which the isotope entered the cyst from below where previously air had failed.

References

Downloaded by: University of Leeds 129.11.21.2 - 5/8/2018 1:18:18 AM

I A kerman, M.; D e T ovar, G., and G uiot , G.: Abnormal CSF circulation and oc­ cult hydrocephalus in association with CSF rhinorrhea; in H arbert. McCul-

Isotope Cisternography and Ventriculography (in CNS Anomalies)

119

Downloaded by: University of Leeds 129.11.21.2 - 5/8/2018 1:18:18 AM

lough , L uessenhop and Di C hiro Cisternography and hydrocephalus. A sympo­ sium, pp. 294-302 (Thomas, Springfield 1972). 2 A lker, G. J., jr.; G i.asauer, F. E., and L eslie , E. V.: Isotope cisternography and ventriculography in hydrocephalus of children; in H arbert , M c C ullough . L uessenhop and Di C hiro Cisternography and hydrocephalus. A symposium, pp. 385-396 (Thomas, Springfield 1972). 3 A i.ker, G . J., jr.; G lasauer, F. E., and Leslie , E. V.: Long-term experience with isotope cisternography. J. ainer. med. Ass. 219: 1005-1010 (1972). 4 A shburn , W. L.; H arbert, .1. C.; Briner . W. H.. and Di C hiro , G.: Cerebro­ spinal fluid rhinorrhea studied with the gamma scintillation camera. J. nucl. Med. 9: 523-529 (1968). 5 Benson , D. F.; P atten , D. H.. and L f.M ay, M.: Hydrocephalic dementia; in H arbert, M c C ullough , L uessenhop and Di C hiro Cisternography and hydro­ cephalus. A symposium, pp. 343-355 (Thomas, Springfield 1972). 6 C astellino , R. A.; Z atz, L. M.. and D e N ardo, G. L.: Radioisotope ventriculo­ graphy in the Arnold-Chiari malformation. Radiology 93: 817-821 (1969). 7 C onway, J. J.; Y arzagaray, L„ and W elch , D.: Radionuclide evaluation of the Dandy-Walker malformation and congenital arachnoid cyst of the posterior fos­ sa. Amer. J. Roentgenol. 112: 306-314 (1971). 8 Dt C hiro , G.; A shburn , W. L., and Briner , W. H.: Technetium Tc99m serum albumin for cisternography; the use of high-specific activity technetium Tc99m serum albumin as a tracer for subarachnoidal and ventricular scint¡photography. Arch. Neurol. 19: 218-227 (1968). 9 Di C hiro , G.; A shburn , W. L.; Z eiger , L. S., and Schali., G. L.: Radioisotope encephalo-cisternography and encephalo-ventriculography. J. Neurosurg. 36: 127-132 (1972). 10 F rigeni, G.; G aini, S. M.; P aoletti, P., and V illani, R.: Isotope cisternography. Considerations on abnormal pictures. Acta neurochir. 25: 145-163 (1971). 11 F ront . D.; Beks. J. W. F., and P enning , L.: Porencephaly diagnosed by isotope cisternography. J. Neurol. Neurosurg. Psychiat. 35: 669-675 (1972). 12 F ront , D.; O verbeck, W. J., and P enning , L.: The study of infantile hydroce­ phalus with combined air and isotope ventriculography. J. Neurol. Neurosurg. Psychiat. 35: 456-462 (1972). 13 G aini. S. M.; Paoletti, P.; V illani, R.. and F rigeni, G.: High specific activity 131I and 99Tcm albumin for studying the cerebrospinal fluid circulation in in­ fantile and childhood hydrocephalus. Acta neurochir. 23: 31-46 (1970). 14 G i .asauer, F. E.: Isotope cisternography and ventriculography. Neurology (In­ dia) 16: 143-147 (1968). 15 G lasauer, F. E.; A lker, G. J.. jr., and Leslie , E. V.: Isotope cisternography and ventriculography. Evaluation of hydrocephalus in children. Amer. J. Dis. Child. 120: 109-114 (1970). 16 G oluboff , I. G.: Arachnoid cyst of the posterior fossa demonstrated by isotope cisternography. J. nucl. Med. 14: 61-62 (1973). 17 H amer, J. und P iscol, K.: Die Bedeutung des ventriculo-atrialen Shunts in der Behandlting der wachsenden Porencephalie. Acta neurochir. 24: 187-200 (1971). 18 H arbert, J. C. and J ames, A. F.., jr.: Posterior fossa abnormalities demonstrated by cisternography. J. nucl. Med. 13: 73-80 (1972).

120

G lasauer

19 H arbert. J. C. and M c C ullough , D. C.: Radionuclide studies in an unusual case of Dandy-Walker cyst. Radiology 101: 363-366 (1971). 20 O mmaya, A. K.; Di C hiro , G.; Baldwin , M., and Pennybacker, J. B.: Non-traumatic cerebrospinal fluid rhinorrhea. J. Neurol. Neurosurg. Psychiat. 31: 214-225 (1968).

Downloaded by: University of Leeds 129.11.21.2 - 5/8/2018 1:18:18 AM

F ranz E. G lasauer, Department of Neurosurgery, E. J. Meyer Memorial Hospital, 462 Grider Street, Buffalo, N Y 14215 (USA)

Isotope cisternography and ventriculography in congenital CNS anomalies.

Isotope studies are well-tolerated examinations in various congenital CNS anomalies and are valuable in demonstrating the presence of associated hydro...
516KB Sizes 0 Downloads 0 Views