Neuropathological and MRI findings in an acute presentation of hemiconvulsion-hemiplegia: a report with pathophysiological implications.
The mechanisms underlying the hemiconvulsion-hemiplegia-epilepsy syndrome (HHE) remain unclear. The current proposed pathogenic mechanism is a neuronal injury induced by venous thrombosis and/or hypoxia. Previous abnormalities of the brain were suggested as underlying mechanism.


METHODS
We report a patient who presented acutely with hemiconvulsion-hemiplegia (HH) syndrome, but unfortunately died. We discuss the possible pathophysiology of the HH syndrome and possible therapeutic implications utilizing the data from neuroimaging and pathological studies. Post-mortem examination was performed including immunohistochemistry and electron microscopy of the brain tissue.


RESULTS
The abnormalities in diffusion-weighted imaging indicate cytotoxic edema of the epileptic hemisphere. The pathological studies confirmed a right homogenous hemispheric edema without evidence of any malformation, inflammatory, infectious or metabolic disease. We found axonal damages in the right thalamus confirmed by anti-neurofilament staining.


CONCLUSIONS
The pathological studies suggest that cytotoxic edema is responsible for neuronal damage. In HH syndrome, two mechanisms playing a role in the development of a later epilepsy could suggest delayed cell death induced by cytotoxic edema and/or thalamic dysfunction causing a disruption of thalamo-cortical circuit. In acute presentation, the use of anti-edema therapy should be discussed to prevent the cell injury.
Auvin
Stéphane
S
Department of Pediatric Neurology, University Hospital, Lille, France. auvin@invivo.edu
Devisme
Louise
L
Maurage
Claude Alain
CA
Soto-Ares
Gustavo
G
Cuisset
Jean Marie
JM
Leclerc
Francis
F
Vallée
Louis
L
D000927:Anticonvulsants / Q000627:therapeutic use; D001927:Brain Diseases / Q000473:pathology* / Q000503:physiopathology*; D004569:Electroencephalography; D017809:Fatal Outcome; D005260:Female; D006429:Hemiplegia / Q000188:drug therapy / Q000473:pathology* / Q000503:physiopathology*; D006801:Humans; D007150:Immunohistochemistry; D007223:Infant; D008279:Magnetic Resonance Imaging; D046529:Microscopy, Electron, Transmission; D003294:Seizures, Febrile / Q000188:drug therapy / Q000473:pathology* / Q000503:physiopathology*
D000927:Anticonvulsants