Adult metachromatic leukodystrophy: three cases with normal nerve conduction velocities in a family.

Here, we report three cases of late onset metachromatic leukodystrophy (MLD) within a family. The patients presented with psychiatric disturbances and dementia. The arylsulphatase A (ASA) level in leucocytes was zero in all the patients. The cranial magnetic resonance imaging (MRI) revealed bilateral symmetrical demyelination but the nerve conduction velocities were normal in all three cases. The clinical, biochemical, imaging and electrophysiological data of the family has been discussed.