[An autopsied case of progressive supranuclear palsy presenting with slow progression and unusually prolonged disease duration].

A 55-year-old Japanese female with no family history of neurological disease showed gait disturbance with rigidity and resting tremor. She was initially diagnosed with Parkinson's disease, but neither laterality of symptoms nor levodopa benefit were observed. The parkinsonism and gait freezing progressed unusually slowly and she experienced frequent falls 17 years after the onset of symptoms. When neurologic examination revealed vertical gaze palsy, masked face, bradykinesia and dominant axial rigidity, the diagnosis was modified to progressive supranuclear palsy (PSP). Retrocollis, grasp reflex, and bilateral Babinski's sign developed, but resting tremor disappeared. Gastrostomy was performed 22 years after onset, after which she was still capable of walking with assistance. Tracheotomy was not performed. The patient died of an acute subarachnoid hemorrhage 24 years after onset at the age of 79. On autopsy, the brain weighed 1,050 g and showed frontal lobe atrophy. Coronal cerebral slices showed atrophy of the globus pallidus and subthalamic nucleus. Tegmental atrophy of the brainstem and depigmentation of the substantia nigra were observed. Neuropathologic examination showed severe neuron loss with gliosis in the globus pallidus, subthalamic nucleus, substantia nigra, and tegmentum of the brainstem. The Purkinje neuron layer and cerebellar dentate nucleus showed mild neuron loss. Globose-type neurofibrillary tangles were widespread, particularly in the globus pallidus, subthalamic nucleus, substantia nigra, nucleus of oculomotor nerve, locus ceruleus, and cerebellar dentate nucleus. Glial fibrillary tangles (coiled body and tuft-shaped astrocyte) and argyrophilic threads were also widespread, particularly in the frontal lobe and basal ganglia. Lewy bodies were not observed. Although, the pathologic findings were consistent with PSP, Gallyas-positive and tau-positive structures were generally small in number. According to the clinicopathological findings, we speculate that this case showed a distinct subtype of PSP with a slowly progressive clinical course and generally mild tau deposition.