Gait Disturbance in 10-Year-Old Boy with Dravet Dyndrome, Stiripentol-associated Myopathy

Introduction: Dravet syndrome is an encephalopathy with pharmacoresistant epilepsy. The clinical signs include ataxia and crouch gait. Stiripentol is a GABAergic compound licensed for the treatment of Dravet syndrome together with valproic acid (VPA) and clobazam (CLB).

Case Report:

F.W.: An 11-year-old boy; 1st febrile seizure at 0.10 years, 1st afebrile seizure at 1.7 years. Therapy with sulthiame, VPA. Worsening of the seizure situation with lamotrigine/ oxcarbazepine. Detection of a pathogenic variant in the SCN1A gene at 6 years.

Therapy with VPA, CLB, and STP led to better seizure control.

After 2.5 years, he was exhausted during the day. A month later F.W. could barely climb stairs. VPA was reduced with increased liver enzymes and stopped without any improvement. Two months later, there was muscle weakness and ataxia.

After 8 months, creatine kinase (CK) was 1,605 U/L. There was a slight increase in CK at the beginning of the symptoms. The MRI of the thigh muscles showed muscle atrophy.

A muscle biopsy showed increased diffuse muscle fiber necrosis compatible with a drug-toxic event.

Stop of STP resulted in normalization of CK and abnormal enzymes. Clinically complete resolution was achieved after one year.

Discussion: In our patient, a necrotizing myopathy associated with STP therapy was observed, with a restitutio ad integrum after discontinuation STP.

Dravet syndrome often associated with the underlying disease led to a delayed diagnosis of the muscle weakness. In the case of elevated liver enzymes, CK should always be determined to detect a muscular damage.

Publication History

Article published online:
28 October 2021