Clinical and neuropathological features of a neurodegenerative disorder in the central nervous system with progressive head drooping (Kubisagari).

The clinical and neuropathological features of a case of a neurodegenerative disorder with pronounced and progressive head drooping, in Japanese Kubisagari, are reported. This female patient died at the age of 72 years after an approximately 20-year history of peculiar posture with progressive head drooping (Kubisagari) and lordosis (bowed posture), parkinsonism, dysphonia and slight muscle wasting of the face, tongue, neck, and distal portions of the upper extremities. She did not display mental deterioration until the terminal stage of the illness. A simple macroscopic inspection formalin-fixed sections of the central nervous system (CNS) showed prominent atrophic frontal and temporal lobes, brownish discoloration of the putamen and an atrophic pyramidal tract. Light microscopy revealed severe neuron loss with fibrillary gliosis at both the above-mentioned lobes and the putamen. Both the facial and hypoglossal nuclei had almost disappeared. Motor neurons in the spinal cord were moderately to markedly decreased. Neither Bunina nor Lewy bodies, senile plaque, nor Pick's argyrophilic neuronal inclusions were observed, but very occasionally ubiquitin-positive neurons were found in the temporal cortex. In conclusion, the hitherto-unrecognized neuropathological findings in the CNS corresponding to progressive head drooping (Kubisagari) suggest that this is a neurodegenerative disorder of the CNS, possibly an atypical form of amyotrophic lateral sclerosis.