PubMed1998
Autosomal dominant hereditary spastic paraplegia (HSP) is genetically classified into three types, all of which are characterized by insidiously progressive spasticity of the lower extremities. Patients with a complicated form of autosomal recessive HSP associated with hypoplasia of the corpus callosum have been reported by Iwabuchi et al. Here we report a 64-year-old patient with a pure form of autosomal dominant HSP with thinning of the corpus callosum. He had been well until 12 years of age, when spasticity and weakness of the lower extremities began to develop. His symptoms gradually worsened and he had difficulty in walking at the age of 44. When he was 56 years old, he visited our hospital. Eleven family members over five generations have been affected, and anticipation, i.e., an apparent decrease in age of onset, has been observed. On admission, he had mild cataracts, equinovarus and pes cavus, and neurological examination revealed spastic paraplegia. However, the intelligence test was normal, and nystagmus, ataxia of the extremities, involuntary movement, orthostatic hypotension or urinary disturbance was not observed. Trinucleotide repeat diseases, such as Huntington's disease, spinocerebellar ataxia type 1, spinocerebellar ataxia type 2, Machado-Joseph disease and dentatorubral-pallidoluysian atrophy, were excluded by DNA analysis. Brain MRI at the age of 64 revealed marked thinning of the corpus callosum. We considered this patient had a pure form of HSP. However, thinning of the corpus callosum has never been reported in autosomal dominant HSP.