Autosomal recessive hereditary spastic paraparesis with thin corpus callosum; report of two sisters

To describe the clinical, cognitive, neurophysiological and radiological features of autosomal recessive hereditary spastic paraparesis (ARHSP) with thin corpus callosum.

Two sisters with spastic paraparesis.

MRI brain scans demonstrated thinning of the corpus callosum. The clinical features were progressive spastic paraparesis beginning in the second decade, dysarthria, minor dystonia and chorea, distal weakness and cognitive impairment with frontal dysfunction. Motor compound action potentials are reduced and EMG demonstrated minor chronic denervation. Magnetic stimulation studies demonstrated increased threshold consistent with pyramidal system axonal loss.

AHRSP with thinned corpus callosum is a distinct clinical and genetic entity that may occur in non-Japanese individuals.