Hippocampal sclerosis in severe myoclonic epilepsy in infancy: a retrospective MRI study.
OBJECTIVE
Severe myoclonic epilepsy in infancy (SMEI; Dravet's syndrome) is a malignant epilepsy syndrome characterized by early prolonged febrile convulsions (PFCs) with secondary psychomotor delay and a variety of therapy-resistant seizures. Although the initial symptoms are repeated PFCs, the MRI performed at the onset of disease shows no hippocampal structural abnormalities. We aimed to assess clinical and serial MRI data of patients with SMEI with a special attention to the temporomedial structures. To our knowledge, this is the first systematic MRI study in this disease.


METHODS
Clinical and MRI data of all SMEI patients treated in our hospitals between 1996 and 2004 were reviewed.


RESULTS
Twenty-eight MRIs from 14 children (one to four images/patient) were included. Age at disease onset was between 3 and 9 months; age at initial MRI was 5 months to 13 years. Ten of 14 patients showed hippocampal sclerosis (HS) during the course of the disease (nine unilateral, one bilateral). Six of these 10 had a normal initial MRI. Age at the first verified HS was between 14 months and 13 years. Neither complex partial seizures nor anterior temporal irritative zone was recorded in these children.


CONCLUSIONS
After initially normal structures, in most patients with SMEI, HS develops several months or years after the first PFC. These data support the hypothesis that PFC might be responsible for HS, but other factors and individual sensitivity should play a role in this process.
Siegler
Zsuzsanna
Z
Epilepsy Center, Bethesda Children's Hospital, Budapest, Hungary.
Barsi
Peter
P
Neuwirth
Magdolna
M
Jerney
Judit
J
Kassay
Maria
M
Janszky
Jozsef
J
Paraicz
Eva
E
Hegyi
Marta
M
Fogarasi
Andras
A
D000293:Adolescent; D017668:Age of Onset; D002648:Child; D002675:Child, Preschool; D004831:Epilepsies, Myoclonic / Q000175:diagnosis / Q000473:pathology*; D004833:Epilepsy, Temporal Lobe / Q000175:diagnosis; D005260:Female; D005500:Follow-Up Studies; D007839:Functional Laterality; D006624:Hippocampus / Q000473:pathology*; D006801:Humans; D007223:Infant; D008279:Magnetic Resonance Imaging / Q000706:statistics & numerical data*; D008297:Male; D012598:Sclerosis; D003294:Seizures, Febrile / Q000175:diagnosis