[Juvenile myoclonic epilepsy: under-diagnosed syndrome].

BACKGROUND

Juvenile myoclonic epilepsy is an idiopathic, hereditary form of epilepsy. Although juvenile myoclonic epilepsy is a well defined clinical syndrome, attempts at diagnosing it commonly fail. ETIOPATHOGENESIS: The exact cause of juvenile myoclonic epilepsy remains unknown. Clinical, morphological and metabolic data suggest a preferential role for frontal regions in this syndrome. Several major genes for juvenile myoclonic epilepsy have been identified, but these genes account for only a small proportions of juvenile myoclonic epilepsy cases, suggesting multifactorial or complex inheritance in most.

RESULTS

Juvenile myoclonic epilepsy is characterized by the triad of myoclonic jerks on awakening (all patients), generalized tonic-clonic seizures (> 90% of patients) and typical absences (about one third of patients). Seizures have an age-related onset, circadian distribution and are frequently precipitated by sleep deprivation, fatigue and alcohol intake. Intelligence is normal.

METHODS

Juvenile myoclonic epilepsy diagnosis is based upon clinical criteria and typical electroencephalographic findings (generalized pattern of spikes and/or polyspikes and waves). All other tests are normal.

UNASSIGNED

Both medical treatment and counselling are important in the management of juvenile myoclonic epilepsy. Mono-therapy with valproate is the preferred treatment. Some of the newer antiepileptic drugs have been suggested as possible alternatives. Juvenile myoclonic epilepsy has a good prognosis. Lifelong treatment is usually considered necessary in vast majority of patients due to the increased risk of relapse if treatment is discontinued.

CONCLUSIONS

Juvenile myoclonic epilepsy is a common, although under-diagnosed epileptic syndrome. The clinician should study the occurrence of myoclonic jerks and should consider atypical presentations.