Peroneal somatosensory evoked potentials in the "pure" form of hereditary spastic paraplegia.

Two patients suffering from the stationary form of hereditary spastic paraplegia, father and son, are described. While in the father the disease - probably because of congenital clubfeet - led to flexion contractures of the hip- and knee-joints, the son in contrary showed extreme genua recurvata. In spite of these contradictionary findings, neurological examination of both patients led to the diagnosis of stationary form of hereditary spastic paraplegia. Both patients had normal latencies of their somatosensory evoked peroneal cortical potentials (Peron-SEP). It is known that the progredient form of the disease leads to alterations of the Peron-SEP. So it is the opinion of the authors that this electrodiagnostic aspect might allow to distinguish between the "pure" and the progredient form of the disease in less clear cases, if these findings can be confirmed in other sibships with the "pure" form of hereditary spastic paraplegia.