Adult-onset subacute sclerosing panencephalitis presenting with tonic motor seizures

Subacute sclerosing panencephalitis (SSPE) is a degenerative disease of the brain caused by a persistent measles virus infection occurring mostly in childhood or early adolescence. The spectrum of epileptic phenomena associated with SSPE is wide, varying from partial or generalized tonic-clonic seizures and atypical absences to myoclonic-atonic attacks. Tonic seizures are very rare in SSPE.

Herein, we discuss a case of 25 years old male that presented with adult-onset SSPE with tonic seizures accompanying myoclonic seizures.

Patient was treated with clonazepam 5 mg/day and an isoprinosine regimen with a dose of 70 mg/kg/day. This is the fourth case of SSPE presenting with myoclonic and tonic seizures and the first case of SSPE with myoclonic and tonic seizures reported in an adult-onset case in the English literature.

Adult-onset SSPE with tonic seizures is rare and may be confusing, thus, it is important to recognize the presence of this type of tonic motor seizures in SSPE patients.