Partial seizures in two cases of metachromatic leukodystrophy: electrophysiologic and neuroradiologic findings

Recurrent seizures in metachromatic leukodystrophy

The unusual presentation of juvenile onset metachromatic leukodystrophy (MLD) and frequent complex partial seizures in a patient led us to perform a retrospective study of 18 patients with MLD to identify the prevalence and type of recurrent seizures during the first 2 years of the disease. Five of 17 patients (29%) had developed recurrent seizures within 12 months of the onset of symptoms, and one patient was lost to follow-up. By 24 months after onset of symptoms, 5 patients were lost to follow-up, and 6 of the remaining 13 patients (46%) had developed recurrent seizures. In all, 7 patients, 4 with late infantile-onset and 3 with juvenile-onset disease, developed recurrent seizures. Four patients, including 3 with juvenile-onset disease had complex partial seizures. We conclude that recurrent seizures are common in MLD and may occur at any stage of the disease, particularly in patients with juvenile onset. Generalized seizures are more frequent in patients with late infantile-onset, whereas partial seizures are more common in those with juvenile-onset disease.

Leukoencephalopathy with swelling and a discrepantly mild clinical course in eight children

An identical syndrome of cerebral leukoencephalopathy and megalencephaly with infantile onset was discovered in 8 children, including 2 siblings. Neurological findings were initially normal or near normal, despite megalencephaly and magnetic resonance imaging (MRI) evidence of severe white matter affection. Slowly progressive ataxia and spasticity developed, while intellectual functioning was preserved for years after onset of the disorder. MRI characteristics included diffuse abnormality in signal intensity and swelling of the cerebral hemispheral white matter with cyst-like spaces in the frontoparietal and anterior-temporal subcortical areas. MR spectra were relatively mildly abnormal. Screening for inborn errors, especially those that cause either megalencephaly or white matter disease or both was negative. A distinguishing feature of the present disorder is the apparently severe abnormality of the cerebral white matter as demonstrated by MRI, which contrasts with the remarkably slow course of functional deterioration.