Hemimegalencephaly - A Case for Hemispherectomy?

Abstract

Two infants are described with intractable, drug-resistant seizures from birth associated with an enlarged cerebral hemisphere. The first died at sixteen months and demonstrated arrested head growth. Histology of the abnormal hemisphere showed disturbed cortical architecture, and subcortical heterotopias with multinucleate cells resembling tuberous sclerosis cells. Continuous fitting persisted in the second infant following callosal section. Hemispherectomy was undertaken in an attempt to preserve function of the "normal" hemisphere. Seizures ceased and head growth velocity accelerated. The neuropathology of the excised hemisphere is compared with the first case. From the literature this is the first report of a favourable outcome after hemispherectomy for hemimegalencephaly. The finding of an echodense enlarged hemisphere may allow presumption of this diagnosis in a neonate with unilateral seizures. After CT scan the diagnosis may be confirmed histologically providing that a precisely orientated frontal biopsy is submitted to the neuropathologist. We suggest that very early hemispherectomy may be the treatment of choice for this condition.

Hemimegalencephaly: cranial sonographic findings in neonates

“…Total or partial hemispherectomy is now the treatment of choice, with reported prolonged survival and control of seizures. 9 Both of our cases had clinical features similar to those reported in the literature. In addition, hemimegalencephaly can occur with or without ipsilateral hemifacial hypertrophy; one of our 2 cases had such hypertrophy.…”

Hemisferectomia funcional precoce na hemimegalencefalia associada à epilepsia refratária

“…Ser refratária ao tratamento medicamentoso, o que freqüentemente ocorre na HME, é a maior indicação para o tratamento cirúrgico. King et al, em 1985, foram os primeiros a descrever a hemisferectomia com resultado favorável realizada em um lactente de 5 meses de idade que obteve controle das crises e melhora do desenvolvimento neuropsicomotor após a cirurgia 11 . Posteriormente, em 1989, Vigevano et al reportaram os resultados favoráveis de duas crianças com HME submetidas a hemisferectomia 12 .…”

Neuronal Migration Abnormalities Can Still Be Diagnosed by Computed Tomography!

“…The fre quency of seizures decreased following surgery, in each case, but no patient became entirely seizure-free. Hemispherectomy has been advocated for patients with intractable seizures associated with unilateral megalcncephaly [25]. To date, none of the 12 patients with megalencephaly in this study has had surgical treat ment.…”