Visual evoked potentials in two forms of hereditary spastic paraplegia.

Visual evoked potentials (VEPs) were used to study two forms of hereditary spastic paraplegia. We recorded the VEP in 6 homozygotes and 5 obligate heterozygotes in one family with recessively transmitted disease and in 5 persons with dominantly transmitted hereditary spastic paraplegia. The VEPs in the affected persons from both families were similar; both had delayed conduction times and changes in the wave form. The VEPs of the obligate heterozygotes were indistinguishable from those of the unaffected control subjects. Comparison of our findings with those of other disease processes that affect the VEPs suggest that the conduction delays in our patients' VEPs may be associated with changes in myelin.