Juvenile Myoclonic Epilepsy Differential Diagnoses

Updated: Jun 24, 2016
  • Author: James Selph, MD; Chief Editor: Selim R Benbadis, MD  more...
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Diagnostic Considerations

One reason for inappropriate diagnosis is that patients often do not report myoclonic jerks. In most patients, juvenile myoclonic epilepsy (JME) is diagnosed after they experience a generalized tonic-clonic seizure (GTCS) and have begun to be treated with one of the usual first-line anticonvulsants, such as phenytoin or carbamazepine.

In some cases, carbamazepine increases the frequency of myoclonic seizures, often unmasking the diagnosis. Recognition of worsening with carbamazepine should lead to appropriate diagnosis and therapy. Myoclonic seizures are typically not harmful and rarely associated with any kind of injury.

Other epileptic conditions to consider include the following:

  • Epilepsy with generalized tonic-clonic seizures on awakening

  • Nocturnal generalized tonic-clonic seizures

  • Myoclonic absence epilepsy

  • Myoclonus

  • Partial seizures with secondary generalization

  • Progressive myoclonic epilepsies

As far as non-epileptic syndromes to consider, psychogenic non-epileptic spells is the primary differential consideration. Physiologic events other than epilepsies that may mimic JME include myoclonus without associated epilepsy.

Differential Diagnoses