291

not know why the prevalence of sexual with age only in the RCT associated difficulties that the younger the victim the It was striking subsample. of sexual difficulties after sexual was the prevalence higher relation was seen in the torture, while the opposite non-sexually tortured group. Could sexually tortured victims have been more severely tortured? In our opinion, graduating the severity of torture is difficult because severity

subsample;

we

do

was

is subjective.

Health professionals who care for torture victims should

question the victims about sexual torture and sexual diff culties, and take into consideration the age of the victim; during treatment it is essential to focus on the type of trauma

during the sexual torture; and all health professionals who examine and treat torture victims should at least have some training in sexual problems. received

We thank Dr Nils Kousgaard, Institute of Statistics, University of Copenhagen, for his valuable support in the computerisation of data and the statistical analysis; and Dr Gorm Wagner, M.D,phD, Institute of Medical Physiology B, Panum Institute, University of Copenhagen, for his comments and critical survey of the manuscript.

REFERENCES 1. Evidence of torture: studies by the Amnesty International Danish medical group. London: Ammesty International Publications, 1977.

2. Report of an Amnesty International mission to Northern Ireland, Oct 28-Dec 6, 1977. London: Amnesty International Publications, 1978. 3. Lunde I. Les agression sexuelles et la torture. 20th Congress French Criminology. Lille: Amnesty International Regie Stencil, 1981. 4. Allodi F, Cowgill G. Ethical and psychiatric aspects of torture. Can J Psychiatry 1982; 27: 98-102. 5. Domovitch E, Berger PB, Waver MJ, et al. Human torture: description and sequelae of 104 cases. Can Fam Physician 1984; 30: 827-30. 6. Lunde I, Boysen G, Genefke IK, et al. Presentation of the International Rehabilitation and Research Center for Torture Victims. Ugeskr Laeger 1985; 147: 2407-12. 7. Agger I. Seksuel tortur afkvindelige politiske fanger. Nord Sexol 1986; 4: 147-61. 8. Comisión de Derechos Humanos de El Salvador (CDHES). Torture in El Salvador. The "La Esperanza" ("HOPE") Prison, Ayutuxtepeque, San Salvador, El Salvador: Stencil, 1986. 9. Lunde I, Rasmussen OV, Lindholm J, Wagner G. Sexual and pituitary-testicular function in torture victims. Arch Sex Behav 1981; 10: 25-32. 10. Rasmussen OV, Lunde I. Evaluation of investigation of 200 torture victims. Dan Med Bul 1980; 27: 241-43. 11. Lunde I, Boysen G, Ortmann J. Rehabilitation of torture victims: treatment and research. In: Health hazards of organized violence. World Health Organisation. The Hague: Ministry of Welfare, Health and Cultural Affairs. Distribution Centre of Government Publications, 1987. 12. Hosmer DW, Lemeskow S. Applied logistic regression. New York: Wiley, 1989. 13. Agger I, Jensen SB. Den potentielle ydmygelse—Seksuel tortur af

mandlige politiske fanger: Nedbrydningsstrategier overfor mandlig potens. Nord Sexol 1988; 6: 31-54. 14. Thorvaldsen P. Torturfølger blandt latinamerikanske flygtninge i Danmark: Thesis 1986; Laegeforeninens Forlag, Copenhagen.

EPILEPSY OCTET Diagnosis of epilepsy DAVID CHADWICK

epileptic seizure is a brief and usually unprovoked stereotyped disturbance of behaviour, emotion, motor

An

or sensation which on clinical evidence results from cortical neuronal discharge. Epilepsy can only be diagnosed when seizures have recurred in an apparently spontaneous fashion. (Rarely, individuals with epilepsy may have seizures provoked by reflex stimuli-eg, visual

function,

stimuli.) The diagnosis of epilepsy is clinical, and is based on a detailed description of events experienced by the patient before, during, and after a seizure and, more importantly, on an eye-witness account. In view of the social and economic implications diagnostic errors need to be avoided. Thus the first basic rule about diagnosing epilepsy is never to make the diagnosis without incontrovertible clinical evidence. If there is any doubt, the clinician should resist the temptation to attach a label and should rely on the passage of time and the further description of symptomatic events to reach a firm conclusion. Hardly anyone with epilepsy will come to any harm from a delay in diagnosis whereas a false-positive diagnosis is gravely damaging.

However, it is not enough simply to decide that a patient’s attacks are epileptic in nature. Other considerations must be addressed. Are the seizures related to an acute encephalopathy or are they due to epilepsy? If the seizures are thought to be part of an epilepsy syndrome, an adequate classification of the seizures1 and of the syndrome2 must be attempted because this categorisation can have important prognostic, therapeutic, and aetiological implications. It may also be necessary to determine whether there is an identifiable and independently treatable aetiology for an individual’s epilepsy. Clinical

diagnosis

the start of attacks must be determined. Do without warning or are they preceded by symptoms of an epileptic aura or by faintness and syncope? Specifically, epileptic symptoms include involuntary tonic

The events

they

at

occur

ADDRESS: Associated Unit of Medical and Surgical Neurology, Walton Hospital, Liverpool L91AE, UK (Dr D. Chadwick. FRCP).

292

TABLE I-DIFFERENTIAL DIAGNOSIS OF EPILEPSY

What kind of epilepsy?

Although the diagnosis of a specific epileptic syndrome require confirmation from interictal or ictal electroencephalographic (EEG) recordings, clinical information will often be sufficient to allow a presumptive diagnosis. Thus a history of occasional nocturnal focal motor seizures involving face or upper limb in children below the age of 12 or 14 may strongly suggest Rolandic epilepsy, whereas in an adolescent the development of myoclonic jerking on awakening with occasional tonicclonic seizures points to a juvenile myoclonic epilepsy. Seizures associated with a specific epileptic aura indicate a localised onset and therefore imply a greater likelihood of a symptomatic epilepsy caused by a localised cerebral lesion. may

What is the

aetiology of the epilepsy? to 60 or 70% of people who

lateralised to one side of the body, olfactory gustatory hallucinations, and the complex perceptual changes associated with temporal lobe seizures"it is indescribable". Symptoms recorded by the patient after recovery of consciousness are also important. The presumptive diagnosis of a seizure may be secure when an individual wakes in a wet bed with a bitten tongue and complains of a headache and muscular aches and pains. Most eye witnesses will be able to give a reasonable description of a tonic-clonic (grand mal) seizure. However, it may be harder to get a satisfactory description of more minor seizures. Here, direct questioning is often important, especially to elicit the characteristic features associated with complex partial seizures-a first fixed motionless stare with subsequent automatisms that may include fidgeting repetitive movements with the hands or chewing or swallowing movements of the mouth and face. Documentation ofpostictal confusion by an eye witness may be very important. When the doctor has acquired as much clinical information as possible, he may be able to make certain or

clonic

movements or

judgments. /s it epilepsy? The first

test

will be

to

differentiate seizures from other

(table I). Syncope and pseudoseizures are most frequently mistaken for epilepsy. Once it is accepted that seizures have occurred, it is important to determine whether they are acute symptomatic events (not necessarily requiring antiepileptic drug treatment) or spontaneously occurring seizures indicating a truly epileptic disorder. Causes of acute symptomatic seizures include alcohol and other drugs, fever events

in children between 1 and 5 years, and metabolic disturbance. The hallmark of almost all these conditions is that they usually occur in patients with an acute encephalopathy who have an associated confusional state or systemic disturbance that often outlasts the seizures themselves. The presence of other associated symptoms and signs commonly indicates the correct diagnosis for which specific treatment will be required. Once a definite diagnosis of epilepsy is accepted, the patient must be counselled about the effects of the disorder on driving, employment, schooling, and leisure activities and advised about treatment and prognosis.

In up have epilepsy no specific cause can be determined. The cause may be readily apparent from clinical information alone. Epilepsy may complicate virtually any neurological condition that affects the cerebral hemispheres. A previous neurological disorder may often be the cause of the seizures. Thus the history must include direct questions about early perinatal events and development, severe head injury (especially those that are complicated by longlasting post-traumatic amnesia, depressed skull fracture, or intracerebral haematoma), and central nervous system infection. A family history of epilepsy may suggest a genetic cause when seizure disorders develop in individuals aged 5 to about 25 years.

Investigations What value is the EEG? The EEG provides valuable information that may (a) add weight to the clinical diagnosis; (b) aid the classification of epilepsy; and (c) show changes that may increase the suspicion of an underlying structural lesion. EEG as a diagnostic aid. Routine interictal EEG recording is one of the most abused investigations in clinical medicine and is unquestionably responsible for great human suffering. The diagnostic value of an interictal EEG is widely misunderstood. EEGs are often requested either to exclude or to prove a diagnosis of epilepsy-something that can seldom, if ever, be done. Between 10 and 15% of the population may have an "abnormal" EEG; most such abnormalities are mild and of no diagnostic importance. By use of more rigid defmitions of focal or generalised spike or polyspike and slow-wave abnormality in the EEG, probably only 1% of a non-epileptic population have such abnormalities.3 Waking interictal EEGs of patients with epilepsy show that about 35% consistently have specific epileptiform discharges and 50% do so on some occasion with repeated recording; about 15 % never do. Thus a single routine EEG is likely to show epileptiform abnormality in about 50% of patients with epilepsy.4 Classification of epilepsy. The EEG is especially important in two clinical settings. In patients with seizures occurring without an aura that are characterised by a brief period of absence with or without automatism, it may be difficult to differentiate typical absence seizures from complex partial seizures. The finding of generalised spike wave or focal spike activity, respectively, will clarify the diagnosis. The differentiation has important implications for treatment and prognosis. In patients with tonic-clonic seizures without an aura, especially when these occur during

293

.;:>Y" ’tJlV’ ""I "’’:::I’

I

Indications for CT scanning in patients with seizures.

Reproduced with permission from Chadwick D, Cartlidge N, Bates D. Medical neurology Edinburgh Churchill Livingstone, 1988.

sleep, the EEG can again differentiate between primary generalised epilepsies characterised by generalised spike and seizures with a focal onset in which there may be localised abnormalities. Detection of structural brain lesions. The EEG may, by demonstrating the presence of focal slow-wave abnormalities, suggest the presence of a structural lesion as a cause for a patient’s epilepsy. Such focal delta activity increases the chances of detection of a cerebral tumour on computed tomographic (CT) scanning in patients who present with epilepsy.

wave

Neurological imaging in the diagnosis of epilepsy In practical terms imaging means CT scanning. The frequency of abnormalities in CT scans of patients with epilepsy varies greatly. In surveys of patients with established epilepsy from specialist centres, 60-80% may have abnormal CT scans but most of these abnormalities are atrophic in nature. Tumours may be identified in about 10% of patients.s In patients who present with either a first seizure or early epilepsy the frequency is lowerabnormalities are detected in less than 20% of cases-but again atrophic abnormalities predominate. CT scan abnormalities are very strongly predicted by the presence of focal rather than generalised seizures, focal neurological signs, and focal EEG abnormalities. When all three are present, CT abnormalities may be found in up to 70 or 80% of cases.6 CT scanning is indicated in a group of patients with epilepsy of later onset who have focal seizures (especially simple partial seizures) with or without neurological signs and focal EEG abnormality. An algorithm for selection of patients for CT scanning is shown in the figure. It may be more important to offer CT scanning to patients whose epilepsy is unresponsive to antiepileptic drug therapy than to pursue a policy of indiscriminate CT scanning of all patients at the presentation of their epilepsy. Are other investigations indicated routinely?

In the past skull

radiographs were routinely obtained in patients presenting with epilepsy. They provide no useful

information and patients who require neurological imaging tests should undergo CT scanning. Similarly, the routine screening of haematological and biochemical indices provides an extremely low yield of clinically useful information. Such tests may be indicated in certain circumstances-eg, in patients with alcohol-related seizures-but routine use of such investigations is no substitute for adequate clinical appraisal.

Starting treatment Annegers et aF identified newly diagnosed epileptic patients in Rochester, Minnesota, from 1935 to 1974. After 20 years’ follow-up, as many as 65% had attained a remission that had lasted at least 5 years. About half these patients had successfully stopped treatment. Goodridge and Shorvon8 showed that by 15 years after the onset of seizures a similar proportion of epileptic patients in a general practice population of 6000 had achieved at least a 2-year remission; only 38% of patients were still taking antiepileptic drugs. Thus the long-term prognosis for most patients with epilepsy is good. To what extent are the start of antiepileptic treatment and its continuation responsible for this outcome? Do antiepileptic drugs merely control or do they cure the disorder? When should we start treatment and when can we stop it? Antiepileptic treatment has sometimes been advocated before the onset of seizures. Such prophylaxis may be undertaken in patients at high risk of epilepsy after head injury and craniotomy for various neurosurgical conditions, but there is no evidence that antiepileptic agents are effective in either case.9 Reports on the prognosis of a single untreated seizure are conflicting. In their retrospective general practice study, Goodridge and Shorvon found that a single seizure was followed by others in 80% of patients. Conversely, retrospective studies based on hospital populations have suggested a much lower recurrence rate-Hopkins et all’ reported a 50% risk of seizure recurrence in the 2-3 years following a first seizure. Most neurologists in the UK do not treat patients after a single seizure but prefer to await evidence of recurrence; in the USA there is a greater tendency to treat patients after single seizures, although this policy seems to be influenced

294

TABLE II-STARTING ANTIEPILEPTIC TREATMENT

supports the view that seizures should be suppressed by possible.12 Prospective randomised studies are required to compare early and delayed treatment in patients with one or two untreated seizures. Once the decision is taken to start treatment, a single drug should be introduced in a low dose, with increments if further seizures occur. The aim is to achieve control with the minimum dose. Which drugs should be chosen for which patients? The most important considerations are the comparative efficacy and toxicity of the various agents. Whilst sodium valproate appears most effective for treatment as soon as

TABLE III-CHOICE OF ANTI EPILEPTIC DRUGS

VPA=sodium valproate;

CBZ=carbamazepine; PHT=phenytoin; PHB=pheno-

idiopathic generalised epilepsies, especially juvenile myoclonic epilepsy, 13 no prospective studies have identified differences in efficacy between drugs for other types of epilepsy.14-16 Thus comparative toxicity will be the main factor determining the choice of drug. Sedative drugs (phenobarbitone, primidone, benzodiazepines) should be avoided whenever possible. Phenytoin, because of its unusual metabolism, is most likely to cause dose-related toxicity, so its use requires monitoring of blood levels, which is expensive and complicates management. For most patients the choice is therefore between carbamazepine and sodium valproate, each drug having a different spectrum of adverse effects (see M. Brodie, this series). An approach to prescribing is outlined in table III.

barbitone, ESM = ethosuximide; BZPs = benzodiazepines

defensive medicolegal considerations rather than by evidence of the efficacy of such an approach. If two or more seizures occur within a short interval antiepileptic treatment is generally thought to be necessary. But how does one define a short interval? Most doctors would include 1 year within this definition, but what if the interval between seizures is 2, 3, or 4 years? Since antiepileptic treatment is usually administered for a minimum of 2 or 3 years, is there any justification for treating patients who have had two seizures at an interval of

by

2, 3, or 4 years?

Biological and psychosocial factors that adversely influence the chance of long-term remission of epilepsy include partial seizures; seizures symptomatic of preexisting cerebral disease; long duration of epilepsy and frequent seizures; and presence of neuropsychiatric handicap. When there is any uncertainty about the need to start therapy, the presence of such adverse prognostic factors may favour treatment (table 11). Hauser et al" noted that in contrast to a 27% risk of recurrence in patients with a single seizure, the risk of further seizures in patients with two seizures rose to 60%. In previously untreated patients followed up prospectively, the longer seizures continue the less likely patients are to go into remission. Moreover, the observation that intervals between successive untreated tonic-clonic seizures decrease progressively suggests that epilepsy tends to escalate and TABLE IV-STOPPING ANTIEPILEPTIC TREATMENT —_—————————————————————————————————

Stopping treatment The fact that antiepileptic drugs have been associated with various acute idiosyncratic, dose-related, and increasingly well-documented chronic toxic and teratogenetic effects, as well as with more subtle effects on behaviour and cognitive function, is a potent argument for exploring the possibility of drug withdrawal in patients who achieve remissions lasting 2,3, or more years (table IV). The risk of such a policy is the danger of seizure recurrence, which may have important consequences for driving and employment as well as for self-esteem. Advice offered to patients varies widely. Most paediatricians and paediatric neurologists suggest a trial of withdrawal in most children who attain remission because they are worried about the impact of drugs on cognitive function and learning and are impressed by the high expectation of success. Adult neurologists tend to be much more circumspect, expressing concern about the possible effects of further seizures on driving and employment. The few studies that have been undertaken to determine the success of drug withdrawal and the factors that identify individuals who are likely to remain free of seizures are difficult to assess because there is often little information about the patients, lack of uniformity in the length of remission before withdrawal, and no information about the period over which withdrawal occurred and the length of subsequent follow-up.17 Overall, however, it seems that about 30% of patients achieving 2 or 3 years’ remission will have a recurrence of seizures on withdrawal of drugs and most seizures will occur either during the period of reduction of antiepileptic drugs or within 6 months to a year after they are stopped. Factors that influence the outcome of withdrawal are similar to those that determine whether a patient initially achieves a 2-3-year remission. Thus the prevalence of relapse in children is about 20% whereas in adults it is about 40%. The duration of epilepsy and its severity, as judged by the number or frequency of seizures before remission, are directly related to the likelihood of relapse.

295

Classification of epilepsy has important consequences. Relapse of petit mal epilepsy is rare. However, the combination of different types of seizures and the presence of secondary, generalised, or partial epilepsy probably increases the risk of relapse. The presence of neuropsychiatric or cerebral disorders affects the prognosis adversely. Whether EEG studies are helpful prognostically is controversial; only those EEGs taken at the time that treatment is withdrawn are valuable. When withdrawal is indicated it is sensible to proceed by decrements over 3-6 months.

REFERENCES

6.

Young AC, Borg Costanzi J, Mohr PD, Forbes W. Is routine computerised axial tomographic scanning in epilepsy worthwhile?

Lancet 1982; ii: 1446-47. Annegers JF, Hauser WA, Elverback LR. Remission of seizures and relapse in patients with epilepsy. Epilepsia 1979; 20: 729-37. 8. Goodridge DMG, Shorvon SD. Epileptic seizures in a population of 6000. II: treatment and prognosis. Br Med J 1983; 287: 645-47. 9. Shaw MDM, Foy PM, Chadwick D. The effectiveness of prophylactic anticonvulsants following neurosurgery. Acta Neurochir (Wien) 1983; 7.

69: 253-58.

Hopkins A, Garman A, Clarke C. The first seizure in adult life. Lancet 1988; i: 721-26. 11. Hauser WA, Rich SS, Jacobs MP, Anderson VE. Patterns of seizure occurrence and recurrence risks in patients with newly diagnosed epilepsy. Hartford, Connecticut: American Epilepsy Society 15th epilepsy international symposium: 16 (abstr). 12. Reynolds EH. Early treatment and prognosis of epilepsy. Epilepsia 1987;

10.

28: 97-106.

1. Commission

Classification and Terminology of the International League Against Epilepsy. Proposal for revised clinical and electroencephalographic classification of epileptic seizures. Epilepsia 1985; 22: 489-501. 2. Commission on Classification and Terminology of the International League Against Epilepsy. Proposal for classification of epilepsies and on

epileptic syndromes. Epilepsia 1985; 26: 268-78. 3. Zivin L, Ajmone-Marsan C. Incidence and prognostic significance of "epileptiform" activity in the EEG of non-epileptic subjects. Brain 1968; 91: 751-78. 4. Ajmone-Marsan C, Zivin L. Factors related to the occurrence of typical paroxysmal abnormalities in the EEG records of epileptic patients. Epilepsia 1970; 11: 361-81. 5. Gastaut H, Gastaut JL. Computerised transverse axial tomography in epilepsy. Epilepsia 1976; 17: 325-31.

Delgado-Escueta AV, Enrile-Bacsal F. Juvenile myoclonic epilepsy of Janz. Neurology 1984; 34: 285-94. 14. Chadwick D, Turnbull DM. The comparative efficacy of antiepileptic drugs for partial and tonic-clonic seizures. J Neurol Neurosurg Psychiatry 1985; 48: 1073-77.

13.

15. Turnbull DM, Howell D, Rawlins MD, Chadwick D. Which drug for the adult epileptic patient: phenytoin or valproate? Br Med J 1985; 290: 815-19.

16. Mattson RH, Cramer JA, Collins JF,

et al. Comparison of carbamazepine, phenobarbital, phenytoin and primidone in partial and secondary generalised tonic-clonic seizures. N Engl J Med 1985; 313:

145-51. 17. Chadwick D. In: Meldrum BM, Pedley TA, eds. The discontinuation of antiepileptic therapy. Recent advances in epilepsy 2. Edinburgh: Churchill Livingstone, 1985: 111-24.

Epilepsy in old age RAYMOND TALLIS

Epilepsy in old age was long thought to be uncommon, or even unimportant, yet there is a steep rise in the incidence of seizures after the age of 60. Hauser and Kurland’ in Rochester, Minnesota, found that the incidence rose from 11 -9/ 100 000 in the 40-59 age range to 82/100 000 in those over 60. The latter figure accords with the incidence of 77/ 100 000 observed in the Danish study of epilepsy in those over 60.2 Prevalence also rises in old age-from 7-3/1000 in the 40-59 age range to 10.2 for those over 60.1 24% of definite cases observed in the National General Practice Survey of Epilepsy and Epileptic Seizures (Hart Y, Shorvon S, unpublished observations from NGPSE) occurred in patients over the age of 60. The importance of seizures in this age group scarcely needs emphasising: a fit may seriously dent confidence and result in severe limitation of activity; in a population in whom osteoporosis is common, fits may lead to fracture; and the prolonged post-ictal states seen in elderly peopleare also hazardous.

Aetiology The

proportion of patients who present with seizures that are clinically and/or electrically partial is higher than in younger age groups (ref 2 and Hart Y, Shorvon S, unpublished)-75% in Luhdorf’s series and 69% (with a further 11 % unclassified) in the NGPSE, reflecting a higher proportion of cases with underlying focal cerebral damage.

Vascular disease is by far the commonest cause (refs 4, 5, and Hart Y, Shorvon S, unpublished). The more carefully elderly epileptic patients are studied, the higher is the proportion in whom vascular disease may be incriminated.6 This is scarcely surprising since cerebrovascular disease is common in elderly people and commonly leads to seizures.7-9 Seizures may not only follow stroke but also be the first indication of cerebrovascular disease.10 The widely varied figures for the proportion of elderly onset epilepsy associated with tumours-from 2 % to 14% (refs 2, 4, 5, and Hart Y, Shorvon S, unpublished) -reflect the different study populations and differences in extent of investigation and follow-up. A figure of 10-15% seems about right; tumours are more common as a cause of seizures than are metabolic disturbances (refs 2, 4, 5, and Hart Y, Shorvon S, unpublished). Most of the tumours in Luhdorfseries2 were metastases or inoperable gliomas, although it is premature to generalise from this observation. The role of alcohol and prescribed drugs in precipitating seizures in elderly people, or of making epilepsy more difficult to control, must not be forgotten. Important rare causes include subdural haematoma."

ADDRESS. Department of Geriatric Medicine, Clinical Sciences Building, Hope Hospital, Manchester M6 8HD, UK (Prof R C. Tallis, FRCP).