163
pronounced hereditary element; the gene for this syndrome may be on chromosome 6.8 Juvenile myoclonic epilepsy is a common syndrome, accounting for about 5% of all cases of epilepsy. There are three seizure types-myoclonic jerks, occurring in the morning; generalised tonic-clonic convulsions, also developing in the morning or at least before noon; and absences, which develop less frequently. Myoclonic jerks may be present years before the onset of convulsions; unless questioned specifically, patients very seldom describe the jerks, although they may greatly interfere with everyday life. Sleep deprivation and alcohol are well-established seizure-provoking factors in epilepsy in general but in this syndrome may provoke seizures to such an extent that it may be necessary for the patient to abstain completely and to adopt a rigid lifestyle with regard to sleep. An EEG obtained at the correct time-ie, in the morning after sleep deprivation-may show characteristic abnormalities in the form of polyspike-wave paroxysms. If the EEG is recorded at other times the trace may be entirely normal. Characteristic EEG changes are sometimes found in family members without seizures. Juvenile myoclonic epilepsy is often mistaken for "grand mal" epilepsy, for which the drugs most frequently used are phenytoin or carbamazepine. However, when this seizure type is caused by juvenile myoclonic epilepsy both drugs are almost ineffective and they do not influence the myoclonic jerks or the absences. The drug of choice for this syndrome is sodium valproate.9 Despite complete seizure control for many years, withdrawal of treatment is often associated with recurrence, so extended periods of treatment are called for.
To detect this syndrome any young person who presents with convulsions should be questioned about diurnal fluctuations of seizures and myoclonic jerks. If relevant, an EEG should be obtained in the morning after sleep
deprivation. The syndrome of juvenile myoclonic epilepsy therefore has implications with regard to diagnostic measures, seizure preventing behaviour, choice of treatment, and duration of therapy. REFERENCES 1. Commission
on Classification and Terminology of the International League Against Epilepsy. Proposal for revised clinical and electroencephalographic classification of epileptic seizures. Epilepsia
1981; 22: 489-501. 2. Commission on Classification and
Terminology of the Intematonal League Against Epilepsy. Proposal for classification of epilepsies and epileptic syndromes. Epilepsia 1985; 26: 268-78. 3. Commission on Classification and Terminology of the International League Against Epilepsy. Proposal for revised classification of epilepsies and epileptic syndromes. Epilepsia 1989; 30: 389-99. 4. Lombroso CT. Sylvian seizures and mid-temporal spike foci in children. Arch Neurol 1967; 17: 52-59. 5. Beaussart M. Benign epilepsy of children with rolandic (centro-temporal) paroxysmal foci. Epilepsia 1972; 13: 795-811. 6. Janz D, Christian W. Impulsiv-petit mal. Dtsch Z Nervenheilk 1957; 176: 346-86.
Janz D. Epilepsy with impulsive petit mal (juvenile myoclonic epilepsy). Acta Neurol Scand 1985; 72: 449-59. 8. Greenberg DA, Delgado-Escueta AV, Widelitg H, et al. JME may be linked to the HLA locus on human chromosome 6. Cytogenet Cell Genet 1987; 47: 623 (abstr). 9. Covanis A, Gupta AK, Jeavons PM. Sodium valproate: monotherapy and polytherapy. Epilepsia 1983; 23: 693-720. 7.
Pseudoseizures: seizures that
are not
epilepsy
TIM BETTS Pseudoseizure is an unfortunate term since it is both pejorative and wrong. A non-epileptic seizure is still a seizure, and it is usually not the patient’s fault if the doctor’s diagnosis of the cause of seizure behaviour is erroneous. Non-epileptic attack disorder (NEAD) is a better term and not accusatory. Doctors have always recognised the need to distinguish between epilepsy and non-epilepsy-the ancients claimed to be quite good at it1-and an association between strong emotions and sudden seizures has long been acknowledged. Modem technology may help to distinguish epileptic from non-epileptic attacks but will not help us to decide what to do with the patient whose seizures are not
epileptic.2 NEAD (and even pseudo status epilepticus) are more than many doctors realise and both conditions are economically and socially important. Perhaps 20% of patients referred to specialist centres for treatment of intractable epilepsy have non-epileptic attacks and have had much previous unnecessary investigation and anticonvulsant treatment. Since the diagnosis of epilepsy is often no more than an informed guess, all of us who work in this area have had the blush making experience of treating a patient’s epilepsy unquestioningly for years only to discover eventually that the seizures were something else. Conversely, a confident diagnosis of pseudoseizures may common
have to be revised to epilepsy—eg, bizarre behaviour in frontal lobe seizures is easy to misdiagnose. Often NEAD and epilepsy co-exist, which makes recognition difficult.3
Classification
My working classification of the different causes of NEAD is shown in the table. In a 20-year experience of NEAD I have encountered all the listed organic causes, often more than once, epilepsy having been diagnosed by doctors who did not know, for instance, that incontinence and injury can occur in faints, as can twitching, and that unconsciousness during a faint will be prolonged if the patient is kept propped up rather than allowed to lie flat. The various forms of acute anxiety are also easy to mistake for epilepsy, especially those involving changes in the perception of reality, or carpopedal spasm or unconsciousness.4 NEAD that are emotionally based but not related to misdignosed psychiatric illness take several distinct forms.
Department of Psychiatry, University of Birmingham, and Neuropsychiatry Clinic, Aston University, Birmingham B47ET, UK (Dr T. Betts, FRCPsych).
ADDRESS
164
NON-EPILEPTIC ATTACK DISORDERS
Organic attack disorder Neurological Cataplexy I Ilrd ventricle cyst Transient ischaemic attacks
Migraine (basilar) Benign drop attacks Cardiovascular
Fainting Stokes Adams attacks Mitral valve prolapse Atrial myxoma Aortic stenosis Other organic Insulinoma (and other hypoglycaemias)
Phaeochromocytoma Psychiatric disorder mistaken for epilepsy Hyperventilation attacks Panic attacks
Anxiety with derealisation/depersonalisation Episodic dyscontrol syndrome case
pronounced hereditary element; the gene for this syndrome may be on chromosome 6.8 Juvenile myoclonic epilepsy is a common syndrome, accounting for about 5% of all cases of epilepsy. There are three seizure types-myoclonic jerks, occurring in the morning; generalised tonic-clonic convulsions, also developing in the morning or at least before noon; and absences, which develop less frequently. Myoclonic jerks may be present years before the onset of convulsions; unless questioned specifically, patients very seldom describe the jerks, although they may greatly interfere with everyday life. Sleep deprivation and alcohol are well-established seizure-provoking factors in epilepsy in general but in this syndrome may provoke seizures to such an extent that it may be necessary for the patient to abstain completely and to adopt a rigid lifestyle with regard to sleep. An EEG obtained at the correct time-ie, in the morning after sleep deprivation-may show characteristic abnormalities in the form of polyspike-wave paroxysms. If the EEG is recorded at other times the trace may be entirely normal. Characteristic EEG changes are sometimes found in family members without seizures. Juvenile myoclonic epilepsy is often mistaken for "grand mal" epilepsy, for which the drugs most frequently used are phenytoin or carbamazepine. However, when this seizure type is caused by juvenile myoclonic epilepsy both drugs are almost ineffective and they do not influence the myoclonic jerks or the absences. The drug of choice for this syndrome is sodium valproate.9 Despite complete seizure control for many years, withdrawal of treatment is often associated with recurrence, so extended periods of treatment are called for.
To detect this syndrome any young person who presents with convulsions should be questioned about diurnal fluctuations of seizures and myoclonic jerks. If relevant, an EEG should be obtained in the morning after sleep
deprivation. The syndrome of juvenile myoclonic epilepsy therefore has implications with regard to diagnostic measures, seizure preventing behaviour, choice of treatment, and duration of therapy. REFERENCES 1. Commission
on Classification and Terminology of the International League Against Epilepsy. Proposal for revised clinical and electroencephalographic classification of epileptic seizures. Epilepsia
1981; 22: 489-501. 2. Commission on Classification and
Terminology of the Intematonal League Against Epilepsy. Proposal for classification of epilepsies and epileptic syndromes. Epilepsia 1985; 26: 268-78. 3. Commission on Classification and Terminology of the International League Against Epilepsy. Proposal for revised classification of epilepsies and epileptic syndromes. Epilepsia 1989; 30: 389-99. 4. Lombroso CT. Sylvian seizures and mid-temporal spike foci in children. Arch Neurol 1967; 17: 52-59. 5. Beaussart M. Benign epilepsy of children with rolandic (centro-temporal) paroxysmal foci. Epilepsia 1972; 13: 795-811. 6. Janz D, Christian W. Impulsiv-petit mal. Dtsch Z Nervenheilk 1957; 176: 346-86.
Janz D. Epilepsy with impulsive petit mal (juvenile myoclonic epilepsy). Acta Neurol Scand 1985; 72: 449-59. 8. Greenberg DA, Delgado-Escueta AV, Widelitg H, et al. JME may be linked to the HLA locus on human chromosome 6. Cytogenet Cell Genet 1987; 47: 623 (abstr). 9. Covanis A, Gupta AK, Jeavons PM. Sodium valproate: monotherapy and polytherapy. Epilepsia 1983; 23: 693-720. 7.
Pseudoseizures: seizures that
are not
epilepsy
TIM BETTS Pseudoseizure is an unfortunate term since it is both pejorative and wrong. A non-epileptic seizure is still a seizure, and it is usually not the patient’s fault if the doctor’s diagnosis of the cause of seizure behaviour is erroneous. Non-epileptic attack disorder (NEAD) is a better term and not accusatory. Doctors have always recognised the need to distinguish between epilepsy and non-epilepsy-the ancients claimed to be quite good at it1-and an association between strong emotions and sudden seizures has long been acknowledged. Modem technology may help to distinguish epileptic from non-epileptic attacks but will not help us to decide what to do with the patient whose seizures are not
epileptic.2 NEAD (and even pseudo status epilepticus) are more than many doctors realise and both conditions are economically and socially important. Perhaps 20% of patients referred to specialist centres for treatment of intractable epilepsy have non-epileptic attacks and have had much previous unnecessary investigation and anticonvulsant treatment. Since the diagnosis of epilepsy is often no more than an informed guess, all of us who work in this area have had the blush making experience of treating a patient’s epilepsy unquestioningly for years only to discover eventually that the seizures were something else. Conversely, a confident diagnosis of pseudoseizures may common
have to be revised to epilepsy—eg, bizarre behaviour in frontal lobe seizures is easy to misdiagnose. Often NEAD and epilepsy co-exist, which makes recognition difficult.3
Classification
My working classification of the different causes of NEAD is shown in the table. In a 20-year experience of NEAD I have encountered all the listed organic causes, often more than once, epilepsy having been diagnosed by doctors who did not know, for instance, that incontinence and injury can occur in faints, as can twitching, and that unconsciousness during a faint will be prolonged if the patient is kept propped up rather than allowed to lie flat. The various forms of acute anxiety are also easy to mistake for epilepsy, especially those involving changes in the perception of reality, or carpopedal spasm or unconsciousness.4 NEAD that are emotionally based but not related to misdignosed psychiatric illness take several distinct forms.
Department of Psychiatry, University of Birmingham, and Neuropsychiatry Clinic, Aston University, Birmingham B47ET, UK (Dr T. Betts, FRCPsych).
ADDRESS
164
NON-EPILEPTIC ATTACK DISORDERS
Organic attack disorder Neurological Cataplexy I Ilrd ventricle cyst Transient ischaemic attacks
Migraine (basilar) Benign drop attacks Cardiovascular
Fainting Stokes Adams attacks Mitral valve prolapse Atrial myxoma Aortic stenosis Other organic Insulinoma (and other hypoglycaemias)
Phaeochromocytoma Psychiatric disorder mistaken for epilepsy Hyperventilation attacks Panic attacks
Anxiety with derealisation/depersonalisation Episodic dyscontrol syndrome case
