Prognostic factors in epilepsy with eyelid myoclonia (Jeavons syndrome).

PURPOSE: To describe the prognostic factors of drug resistance in 40 patients with epilepsy with eyelid myoclonia or Jeavons syndrome. METHOD: Retrospective analysis from two French tertiary centers. RESULTS: Forty patients were enrolled (31 females and 9 males; mean age at epilepsy onset: 6.2±3.4 years [range: 1-15 years]). Half of the patients (20/40) achieved at least a one-year remission from all seizure types. In the responders, seizure freedom was achieved after a mean 13.85±13.43 years from the onset of epilepsy (range: 1-44). The presence of intellectual disability and an earlier onset of the disease (≤5 years) were the most powerful predictors of poor seizure control (P=0.003 and P=0.005, respectively). When considering the age of onset, patients with early-onset seizures (≤5 years) presented more frequently with intellectual disabilities, psychiatric comorbidities, absences, and a major risk of refractoriness (70% versus 30%, P=0.01) than patients with onset after 5 years. At the last follow-up, 15 patients (37.5%) were taking a single drug, 16 (40%) were taking two, and seven (17.5%) were taking more than two. The most frequent drugs were valproate (23/40, 57.7%), followed by levetiracetam (16/40, 40%), and lamotrigine (14/40, 35%). CONCLUSION: Patients with Jeavons syndrome present a high rate of pharmaco-resistance with the need for long-term treatment. Early onset of epilepsy and the presence of intellectual disability appeared to be the most relevant predictors of poor seizure control, suggesting the use of genetic tests to individualize specific etiologies and perhaps adapt the therapeutic strategy.

Will MRI replace the EEG for the diagnosis of nonconvulsive status epilepticus, especially focal?

Magnetic resonance imaging (MRI) can now be used to diagnose or to provide confirmation of focal nonconvulsive status epilepticus (NCSE). Approximately half of patients with status epilepticus (SE) have signal changes. MRI can also aid in the differential diagnosis with generalized NCSE when there is a clinical or EEG doubt, e.g. with metabolic/toxic encephalopathies or Creutzfeldt-Jakob disease. With the development of stroke centers, MRI is available 24h/24 in most hospitals. MRI has a higher spatial resolution than electroencephalography (EEG). MRI with hyperintense lesions on FLAIR and DWI provides information related to brain activity over a longer period of time than a standard EEG where only controversial patterns like lateralized periodic discharges (LPDs) may be recorded. MRI may help identify the ictal nature of LPDs. The interpretation of EEG tracings is not easy, with numerous pitfalls and artifacts. Continuous video-EEGs require a specialized neurophysiology unit. The learning curve for MRI is better than for EEG. It is now easy to transfer MRI to a platform with expertise. MRI is more accessible than single photon emission computed tomography (SPECT) or positron emission tomography (PET). For the future, it is more interesting to develop a strategy with MRI than SPECT or PET for the diagnosis of NCSE. With the development of artificial intelligence, MRI has the potential to transform the diagnosis of SE. Additional MRI criteria beyond the classical clinical/EEG criteria of NCSE (rhythmic versus periodic, spatiotemporal evolution of the pattern…) should now be systematically added. However, it is more complicated to move patients to MRI than to perform an EEG in the intensive care unit, and at this time, we do not know how long the signal changes persist after the end of the SE. Studies with MRI at fixed intervals and after SE cessation are necessary.

[Juvenile myoclonic epilepsy in a patient with history of infantile hemiplegia]. / Epilepsie myoclonique juvénile chez une patiente atteinte d'hémiplégie infantile.

INTRODUCTION: The 1989 International Classification of Epilepsies and Related Syndromes considers normal cognitive, neurologic and anatomic findings to be prerequisites for the diagnosis of idiopathic forms of epilepsy. CASE REPORT: We report the case of a woman with juvenile myoclonic epilepsy (JME) and a history of infantile hemiplegia. When she was a teenager, she had two generalized tonic-clonic seizures, later followed by a few seizures with loss of consciousness misinterpreted as complex partial seizures. Physical examination revealed right hemiparesis. A CT scan documented a left rolandic infarction and a wrong diagnosis of focal epilepsy was made. At 20 years, a nap video-EEG was performed. A burst of generalized spike-waves was recorded on awakening. Photic stimulation and watching a Japanese cartoon on television disclosed a marked photoparoxysmal response associated with myoclonic jerks. Myoclonic jerks were in fact known by the patients but unreported. She had jerks on roads with trees due to shade/sunlight alternance. A diagnosis of JME was made. CONCLUSION: This observation illustrates that patients' situation with a presumed genetic predisposition for JME are at equal risk for brain lesions as others subjects. Misdiagnosis of focal epilepsy may have dramatic consequences in patient with JME, as some patients will be aggravated by inadequate antiepileptic drugs.

[Lafora's disease (EPM2)]. / La maladie de Lafora (EPM2).

Lafora's disease (LD) is a comparatively frequent and particularly severe type of progressive myoclonus epilepsy. Prevalence varies, LD is seen everywhere but is more common in geographic isolates and areas with high degree of inbreeding. Onset occurs during adolescence, with generalized tonic-clonic, clonic-tonic-clonic seizures, action and resting myoclonus, negative myoclonus, and focal occipital seizures with transient amaurosis. The course is marked by prominent cognitive deterioration, which can precede seizures and myoclonus, and by the progressive, relentless increase of seizures and myoclonus. Transmission is autosomal recessive. LD is genetically heterogeneous. Mutations/deletions of the EPM2A gene, localized in 1995 on 6q24, are found in 80p.cent (product: laforin), the less common EPM2B variant is on 6p22 (product: malin), but these two localizations do not account for all cases of LD. The diagnosis of LD may be suspected on the basis of the family history, age at onset, typical appearance of symptoms, rapid worsening of cognitive function, evaluation of fairly typical EEG aspects, and can easily be confirmed by axillar skin biopsy with proof of Lafora bodies (polyglucosan aggregates) in the sweat duct cells. Other biopsies, like brain biopsy, are generally not necessary. Genetic testing is useful for diagnosis but the genetic heterogeneity cannot rule out LD when none of the known mutations are detected. Genetic counselling and prenatal diagnosis are theoretically possible when the genetic anomaly has been documented in an affected member of the family. The treatment of LD remains purely symptomatic. Drugs that may aggravate myoclonus must be avoided. Psychological and social management is of utmost importance in LD. Death occurs 4 to 10 years after onset in typical forms.

[Unverricht-Lundborg disease (PME1)]. / La maladie d'Unverricht-Lundborg (EPM1).

Unverricht-Lundborg disease (ULD) is the purest and least severe type of progressive myoclonus epilepsy (PME), and is not associated with progressive cognitive deficit. Symptoms stabilize in adulthood, with a varying degree of permanent, often severe handicap that is mostly due to myoclonus. The disorder follows an autosomal recessive transmission pattern, with onset between 8 and 15 years years of age of generalized tonic-clonic or clonic-tonic-clonic seizures, action myoclonus (massive or segmental), photosensitivity, and often ataxia. Prevalence varies, it is highest in certain isolates (Finland, La Réunion Island) and in region with higher levels of inbreeding (Maghreb). ULD is due to a deficit in cystatin B (stefin B), but the mechanisms leading to the clinical symptoms are not well understood. The causative gene, PME1, was identified in 1991 and localized to chromosome 21q22.3. The mutations are mainly expansions of the CCCCGCCCCGCG dodecamer, but less common point mutations were also found. A variant has been recently reported in a Palestinian family, with localization on chromosome 12. The diagnosis of ULD is made on the basis of family history, age at onset, geographical and ethnic context, and on the typical features of myoclonus and epilepsy, in the absence of cognitive and sensory deficits. Neurophysiological evaluation yields interesting, but unspecific results. There are no biological or pathological markers for ULD. Molecular analysis confirms the diagnosis in most patients. Genetic testing for heterozygotes and even prenatal diagnosis are possible, although seldom performed, if the mutation has been identified. In spite of intensive research, ULD has yet to reveal all of its secrets. It remains a quasi "idiopathic" type of PME, with limited progression. Clinicians and patients are still waiting for an etiologically oriented treatment, which should, ideally, be admnistered early in the course of the disease, if possible before the onset of invalidating symptoms.

Progress in pharmaceutical development presentation with improved pharmacokinetics: a new formulation for valproate.

Successful long-term treatment of patients with epilepsy requires selection of an appropriate antiepileptic regimen, optimal dosing and patient compliance. Recent advances in our understanding of the biological basis of epilepsy and in the choice of treatment options are transforming the global management of these patients. If the achievement of seizure freedom remains the primary goal of any antiepileptic treatment, issues associated with drug acceptability and tolerability, and with quality of life of patients, have gained increasing attention as major determinants of ultimate therapeutic success. Sustained-release formulations of antiepileptic drugs can be very helpful in achieving treatment objectives. Stable serum levels without marked peak-to-trough fluctuations, reduced frequency of dosing and the possibility of dosing flexibility may all improve compliance, patient satisfaction and ultimately quality of life. The efficacy of sodium valproate for the treatment of most types of epilepsy has been demonstrated extensively and this drug remains the mainstay of treatment for many clinical situations. Among the various valproate formulations, extended-release tablets have shown improved patient compliance and satisfaction. However, the tablet size and the limited dosing flexibility could be unsuitable for individualized treatment in special populations such as children, the elderly and patients with swallowing difficulties. A new sustained-release formulation of sodium valproate consisting of tasteless microspheres that can be sprinkled on semi-solid food such as yoghurt or jam has been developed. A stick pack presentation allows individualized dosing and greater convenience.

Reliability of self-monitoring of blood glucose by CSII-treated patients with type I diabetes.

The reliability of patient-generated data from self-monitoring of blood glucose (SMBG) was studied in 14 patients with type I (insulin-dependent) diabetes mellitus treated by continuous subcutaneous insulin infusion (CSII) (7 women, 7 men). The reflectance meters (Glucometer I, Ames, Elkhart, IN) used by the patients were replaced for a period of 21 days by memory-reflectance meters; patients were unaware of the memory capacity of the new meters and were instructed to continue their practice of recording the meter readings in their logbook. This study compares the data recorded in the memory-reflectance meters with those reported in the logbook. The number of SMBG measurements was different in 11 patients (differences ranging from 2 to 66). Mean glycemia was similar (8.23 +/- 0.36 mM in logbook vs. 8.49 +/- 0.48 mM in memory-reflectance meters), but both the M value and mean amplitude of glycemic excursions (MAGE) index were lower when calculated from logbook data (38 +/- 5 vs. 48 +/- 7 mM, P less than .05 and 6.91 +/- 0.43 vs. 7.72 +/- 0.52 mM, respectively; P less than .05). Overreporting (addition of phantom values in logbook) and underreporting (omission of SMBG measurements from logbook) indexes were 19 +/- 7 and 12 +/- 3%, respectively. Precision (percent of identical values in logbook and in memory-reflectance meters at the corresponding time) was 77 +/- 6.8%. The number of SMBG measurements recorded in the memory-reflectance meter was negatively correlated with glycosylated hemoglobin [HbA1c; (r = -.85, P less than .001)], whereas overreporting was positively correlated with HbA1c (r = .76, P less than .01).

Visual evoked potentials in diabetic patients.

Visual evoked potentials (VEPs) were assessed in 50 adult type I (insulin-dependent) and 19 type II (noninsulin-dependent) diabetes mellitus patients and in 54 controls. P100 wave latency was significantly longer in diabetic patients (P less than .001). Twenty-eight percent of diabetic patients had P100 wave latencies above the normal range. There was no correlation between P100 latency and type or duration of diabetes mellitus, quality of metabolic control, or presence of degenerative complications. The significance of VEP abnormalities in diabetes mellitus remains speculative.

The prevalence of retinopathy is similar in diabetes mellitus secondary to chronic pancreatitis with or without pancreatectomy and in idiopathic diabetes mellitus.

In a retrospective study, we compared the prevalence of retinopathy in two groups of 88 diabetic patients (84 men, 4 women) with either diabetes mellitus secondary to chronic pancreatitis (CP-DM group) or idiopathic diabetes mellitus (I-DM group). The patients of these two groups were pair-matched according to age (48.7 +/- 1.1 versus 48.8 +/- 1.0 yr in CP-DM and I-DM groups, respectively; mean +/- SEM), sex, duration of diabetes (7.96 +/- 0.56 versus 8.08 +/- 0.8 yr) and therapy (80 on insulin and 8 on oral hypoglycemic agents in each group). Retinopathy was assessed by bilateral ophthalmoscopic examination of the fundus after pupillary dilation in all 176 patients and by fluorescein angiography in 47 patients with CP-DM and 35 patients with I-DM. Forty-one percent of patients in the CP-DM group and 45.5% of patients in the I-DM group had diabetic retinopathy (P greater than 0.5). In each group, patients with retinopathy were older than patients without retinopathy (51.6 +/- 1.3 versus 46.7 +/- 1.8 yr in the CP-DM group, P less than 0.01, and 52.1 +/- 1.5 versus 46.0 +/- 1.2 yr in the ID-M group, P less than 0.01). They had diabetes of longer duration (10.9 +/- 1.0 versus 5.9 +/- 0.6 yr in the CP-DM group, P less than 0.001, and 10.5 +/- 1.0 versus 6.0 +/- 0.6 yr in the ID-M group, P less than 0.001). The prevalence of retinopathy increased parallel to the duration of diabetes in a similar way in both groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of propranolol and of verapamil on heart rate and blood pressure in hyperthyroidism.

Cardiac manifestations of hyperthyroidism have been attributed to enhanced sympathoadrenal activity, but thyroid hormones also have a direct positive chronotropic effect on sinoatrial cells, in which there are slow calcium channels. We evaluated the effects of verapamil on heart rate, PR and QT intervals, and blood pressure in eight patients with hyperthyroidism and compared them to those effects of propranolol. Three doses of propranolol (0.05, 0.1, and 0.2 mg/kg) and verapamil (0.1, 0.2, and 0.4 mg/kg) were injected intravenously after a 72-hr withdrawal period in a double-blind, crossover fashion. Propranolol increased the RR interval from 581 +/- 51 to 734 +/- 65 msec, whereas verapamil did not have any negative chronotropic effect despite prolonging the PR interval. Systolic blood pressure decreased from 134 +/- 5 to 119 +/- 8 mm Hg after verapamil and was not affected by propranolol. Diastolic blood pressure was depressed equally by both drugs. We conclude that verapamil is not a good alternative drug to propranolol in hyperthyroidism. Our data cannot confirm the possibility of an interaction between thyroid hormones and slow calcium channels in patients with hyperthyroidism.

Antimyoclonic effects of alcohol in progressive myoclonus epilepsy.

We studied the effect of a single oral intake of 30 to 40 grams of alcohol in 4 consecutive patients presenting with Ramsay Hunt syndrome, the most common type of degenerative progressive myoclonic epilepsy (PME) encountered in southern Europe. Clinical and polygraphic monitoring demonstrated abatement of myoclonus in all patients, although the degree of improvement varied among patients. These findings show that alcohol is a potent antimyoclonic agent. In the particular context of PME, occasional alcohol intake may help patients in their social life.

Do carbamazepine and phenytoin aggravate juvenile myoclonic epilepsy?

BACKGROUND: Juvenile myoclonic epilepsy is a frequent form of idiopathic generalized epilepsy that is usually and easily controlled by valproate monotherapy. However, juvenile myoclonic epilepsy is often misdiagnosed, and some drugs, especially carbamazepine and phenytoin, may have an aggravating effect. OBJECTIVES: To determine the risk of aggravation of juvenile myoclonic epilepsy in patients treated with carbamazepine and phenytoin. METHODS: Among 170 consecutive patients with juvenile myoclonic epilepsy (104 female, 66 male) referred between 1981 and 1998, the authors retrospectively found 40 patients (23%) who had received carbamazepine or phenytoin (duration of epilepsy at referral, 1 to 34 years; mean +/- SD, 13.8 +/- 8.5 years; follow-up, 3 to 50 years; mean +/- SD, 16.4 +/- 11 years). RESULTS: Twenty-three patients (57.5%) experienced aggravation of seizures, whereas 6 (15%) apparently benefited from these drugs. There was no effect in the remaining 11 cases (27.5%). Carbamazepine was prescribed to 28 patients: 19 (68%) had aggravated symptoms, including myoclonic status in two; 4 (14%) were improved, one in association with valproate and one in association with valproate and phenobarbital. Phenytoin was prescribed in 16 cases: 6 (38%) had aggravation and 2 (12%) were improved, including one in association with phenobarbital. Vigabatrin was given in only one case, in association with carbamazepine, and provoked a mixed absence and myoclonic status. CONCLUSIONS: Among commonly prescribed anticonvulsants, carbamazepine appears to have the strongest aggravating potential in patients with juvenile myoclonic epilepsy, whereas the aggravating effect of phenytoin is less prominent. Aggravation was mostly in the form of increased myoclonic jerks.

'De novo' absence status of late onset: report of 11 cases.

Absence status (AS) is a heterogenous epileptic syndrome that can occur at any age, usually in a context of prior epilepsy. Eleven cases of AS occurring in middle-aged patients who had no history of epilepsy were retrospectively collected over a 10-year period (10 women and one man; mean age, 58.6 years). Eight patients were receiving high doses of psychotropic drugs. Clinical and EEG presentation was similar to AS occurring in patients with prior epilepsy. Evaluation of precipitating factors revealed that AS coincided with benzodiazepine withdrawal in eight cases. Cofactors included excessive use of other psychotropic drugs, nonpsychotropic treatment, hypocalcemia, hyponatremia, and chronic alcoholism. CT demonstrated mild cerebral atrophy in six cases. There was no recurrence, even without chronic antiepileptic treatment. These data indicate that (1) most cases of "de novo" AS of middle age or late onset result from the addition of various epileptogenic factors; (2) AS can be considered a new and uncommon complication of benzodiazepine withdrawal, and (3) long-term administration of anticonvulsant medication may not be required.

Epileptic negative myoclonus.

Five patients with partial epilepsy of diverse etiology insidiously developed action-activated jerks. The disorder was limited to one arm in two patients and to the legs in another, and was multifocal in the remaining two. Each jerk was related to an EMG silent period lasting 100 to 400 msec, causing a lapse followed by resumption of posture. Simultaneous EEG-EMG recording showed each postural lapse to be time-locked with a sharp or spike and slow-wave transient over the contralateral sensorimotor cortex, where almost continuous paroxysmal activity occurred. The three patients who were able to cooperate during neurologic evaluation also exhibited motor neglect in the most affected body segment and decreased awareness of the disorder. In three patients, the phenomenon was medically resistant, and in two of them it was continuous and could be defined as epilepsia partialis continua. In the other two, medical treatment induced remission of EEG, motor, and neuropsychological abnormalities. This disabling movement disorder can be classified as "epileptic negative myoclonus" and may result from focal-discharge-related transient disruption of cortical function in the sensorimotor cortex.

Epilepsy, antiepileptic drugs, and malformations in children of women with epilepsy: a French prospective cohort study.

We conducted a prospective study of teratogenic effects of antiepileptic drugs (AEDs) in pregnant women with epilepsy in southeast France, comparing malformation rates with those collected by a birth defects registry. We evaluated isolated microcephalies separately. Malformations were seen in 7% of infants of mothers with epilepsy (IME) and in 1.36% of the general population. No significant relationship was found between type and severity of epilepsy and occurrence of malformations or isolated microcephaly. Valproate and phenytoin were the most teratogenic (all malformations). None of the malformations observed in IME whose mothers received valproate, phenytoin, or phenobarbital was seen in IME not exposed to the respective AEDs. Phenytoin plus phenobarbital was more teratogenic than phenobarbital alone. Benzodiazepines, prescribed only in combinations, had a borderline, nonspecific effect on microcephaly.

Multilobar polymicrogyria, intractable drop attack seizures, and sleep-related electrical status epilepticus.

BACKGROUND AND OBJECTIVE: Patients with cortical malformations often have intractable seizures and are candidates for epilepsy surgery. Within an unselected series of patients with various forms of cortical malformation, nine patients with multilobar polymicrogyria had electrical status epilepticus during sleep (ESES) accompanied by infrequent focal motor seizures. Eight patients also had intractable atonic drop attack seizures. Because ESES usually is accompanied by a good long-term seizure prognosis, the objective of this study was to examine ESES outcome among patients with a structural lesion that is usually highly epileptogenic and has a low seizure remission trend. METHODS: The nine patients had follow-up periods lasting 4 to 19 years. All underwent brain MRI, serial sleep EEG recordings, and cognitive testing during and after ESES. RESULTS: ESES and drop attack seizures appeared between the ages of 2 and 5 years (mean, 4 years) and ceased between the ages of 5 and 12 years (mean, 8 years). At the last visit patients were 8 to 23 years of age (mean, 14.5 years) and were either seizure free or had very infrequent focal motor seizures during sleep. Three patients were free from antiepileptic drugs. In no patient was definite cognitive deterioration apparent after ESES in comparison with earlier evaluations. CONCLUSIONS: Age-related secondary bilateral synchrony underlying ESES may be facilitated in multilobar polymicrogyria. The good seizure outcome contrasts with that usually found in the presence of cortical malformations. For children with polymicrogyria and drop attack seizures, surgical treatment of the epilepsy should be considered cautiously, and sleep EEG recordings should be performed systematically.

Hypertrophy of liver peroxisomes in type II and type IV hyperlipoproteinemia.

A morphometric study on liver biopsies from patients with primary hyperlipoproteinemia (IIa n = 4, IIb n = 7, IV n = 7) and in controls (n = 7) was performed by light and electron microscopy. We found hypertrophy of peroxisomes in all subjects with hyperlipoproteinemia. As none of our patients had been given lipid-lowering drugs, this increase in volume seems to be due to hyperlipoproteinemia. Hypertrophy of peroxisomes in hyperlipoproteinemia may constitute a response of the hepatocyte to a disturbed metabolic state. Alterations of peroxisomes in hyperlipoproteinemia may thus occur prior to any lipid-lowering therapy.

Prevalence and signification of antinuclear and anticardiolipin antibodies in patients with epilepsy.

PURPOSE: To determine the prevalence of autoantibodies in patients with epilepsy and to find a possible relationship between antinuclear antibodies (ANA) and/or anticardiolipin (aCL) antibodies and epilepsy. PATIENTS AND METHODS: One hundred sixty-three consecutive, unselected patients followed at the Centre Saint-Paul, a French medical center specialized in epilepsy, were included in the study. IgG and IgM class aCL antibodies were measured by an enzyme-linked immunosorbent assay (ELISA). IgG class ANA was detected by an indirect immunofluorescence technique with Hep2 cells as the substrate. Sera from 100 healthy blood donors, matched for age and sex, were used as controls. RESULTS: In 31 sera, IgG class a aCL antibodies were detected at a value higher than 17 GPL unit (19%, P = 0.0003); 10 of them had a value higher than 35 GPL unit. IgM class aCL antibodies were not detected at a significant value. For 6 of the 31 sera, there was a beta 2-glycoprotein I dependence. None of the patients with aCL antibodies in the serum had a past history of deep venous or arterial thrombosis. ANA were detected in the sera from 41 patients (25%, P < 0.005). The presence of autoantibodies in the serum was not statistically dependent on the type of epilepsy, the kind of antiepileptic drug, or the age or sex of the patients. CONCLUSIONS: Our study suggests that there is a relationship between epilepsy and aCL antibodies, even in the patients without systemic lupus erythematosus. Large prospective studies are needed to define the role of the aCL antibodies and ANA in pathophysiology of epilepsy.

Continuous focal spikes during REM sleep in a case of acquired aphasia (Landau-Kleffner syndrome).

We report a girl 3 years and 6 months old with onset of aphasia at age 3 years and 3 months. There was no evidence of brain damage and there were no seizures. The neuropsychological evaluation showed that the girl tended to be right-handed, that aphasia was global and that other higher cortical functions seemed to be preserved. Isolated spikes and spikes-and-wave were recorded during wake over the right temporal region with rare independent contralateral abnormalities. During polysomnography (PSG), the physiological patterns of sleep were preserved and right temporal epileptiform discharges were significantly increased in all sleep stages. Maximal activation was obtained at sleep onset and during rapid eye movement (REM) sleep periods, when focal abnormalities became continuous and spread contralaterally. Repeat PSGs showed that the activation profile retained this particular trait, although subclinical discharges tended to increase during slow wave sleep (SWS). This pattern of subclinical temporal status epilepticus during REM sleep differs from the characteristic activation profile found in the syndrome of continuous spikes-and-waves during SWS. However, this profile was transient and all epileptiform changes disappeared during clinical recovery at 18 months of follow-up.

Lafora disease is not linked to the Unverricht-Lundborg locus.

Lafora disease and Unverricht-Lundborg disease are two forms of progressive myoclonus epilepsies (PME). Recently the gene for Unverricht-Lundborg disease (EPM1) was mapped to chromosome 21q22.3. Using three highly polymorphic DNA markers (D21S212, PFKL, and D21S171) which flank the EPM1 locus, we performed linkage analysis to investigate whether or not the EPM1 gene is also implicated in Lafora disease. Linkage was excluded in three North-African pedigrees each comprising at least two affected individuals. This result suggests that differential diagnosis of Lafora disease and Unverricht-Lundborg disease may be facilitated by molecular genetic analysis.