Involvement of the spinal posterior horn in Gerstmann-Straussler-Scheinkerdisease (PrP P102L)

Objective: The authors studied the pathomechanisms of the characteristics a ssociated with Gerstmann-Straussler-Scheinker disease (GSS). Background: GS S, associated with a missense mutation at codon 102 of the prion protein (P rP) gene (GSS102),is a hereditary disorder that presents with progressive a taxia and dementia, and is characterized by the loss of deep tendon reflexe s and painful dysesthesias of the legs in its early stage. Methods: The aut hors conducted immunohistochemical studies of the spinal cord and periphera l nervous system in one of two patients from a Japanese family with GSS102 in comparison with patients with GSS105. Results: The authors found intense PrP immunoreactivities mainly in the posterior horn of the spinal cord, bu t not in the dorsal root ganglia or peripheral nerves. In addition to PrP a myloid plaques, synaptic-type, fine granular PrP deposits were distributed in the spinal posterior horns. In contrast to the GSS102 patient;, the spin al cords of the GSS105 patients showed no granular PrP deposits. Conclusion s: The PrP abnormalities in synaptic structures of the spinal posterior hor n may cause synaptic dysfunction that leads to loss of deep tendon reflexes and painful dysesthesias in patients with GSS102.