Hemimegalencephaly: what happens when children get older?
OBJECTIVE
Hemimegalencephaly (HME) is a rare congenital malformation of cortical development, usually associated with developmental delay and severe epilepsy. This condition has rarely been reported in adults. The aim of this study was to examine and compare neurological findings in adult patients with HME.


METHODS
We retrospectively examined adult patients with HME by evaluating the presence of neurocutaneous disorders, current cognitive development, seizure control, and documentation of therapies for seizure management and outcomes.


RESULTS
Five patients were included in the study (three males, two females; mean age 23 y 9 mo [SD 6 y 1 mo], range 18-34 y). Four patients had HME that was associated with neurocutaneous syndromes and the remaining patient had isolated HME. Two patients required surgical treatment for seizures in childhood. One patient had no intellectual disability, while one had mild, and three severe intellectual disability. All patients presented motor deficits ranging from mild hemiparesis in two patients to non-ambulation in one patient. Patients in whom seizure onset occurred after the 7 years of age had better seizure control and psychomotor development in adulthood than patients in whom seizure onset occurred in the first year of life.


CONCLUSIONS
In our small sample of adults with HME, age at seizure onset, cognitive disability, and seizure control were found to be associated.
Division of Neurology, Epilepsy Genetics Program, Toronto Western Hospital, Krembil Neuroscience Centre, University of Toronto, Toronto, ON, Canada.
Nicky
N
Wu
Felippe
F
Borlot
Anfal
A
Ali
Timo
T
Krings
Danielle M
DM
Andrade
D000328:Adult; D017668:Age of Onset; D001921:Brain / Q000473:pathology; D018450:Disease Progression; D005260:Female; D006801:Humans; D008607:Intellectual Disability / Q000209:etiology; D008279:Magnetic Resonance Imaging; D008297:Male; D054220:Malformations of Cortical Development / Q000150:complications / Q000175:diagnosis* / Q000473:pathology; D020752:Neurocutaneous Syndromes / Q000150:complications; D010291:Paresis / Q000209:etiology; D011379:Prognosis; D011597:Psychomotor Performance; D012189:Retrospective Studies; D012640:Seizures / Q000209:etiology / Q000601:surgery; D012720:Severity of Illness Index; D055815:Young Adult