A 58-year-old man presented with acute
ataxia associated with a
lacunar infarction in the right paramedian pons. His
ataxia persisted with additional progressive gait difficulty and left arm clumsiness. Six months later, a follow-up neurological examination showed asymmetrical
bradykinesia,
apraxia, dystonic posturing, postural instability, and mild
ataxia of the left limbs. Cognitive examination revealed frontal executive dysfunction and visuospatial difficulties.
Dopamine transporter imaging scan demonstrated bilateral reduced uptakes in mid-to-posterior putamen, more prominent on the right side.
Levodopa-unresponsive
parkinsonism, asymmetric
limb dystonia, and
ideomotor apraxia became more conspicuous, while
limb ataxia gradually vanished. The patient became unable to walk without assistance after 1 year, and died 4 years after the symptom onset. Autopsy findings showed frontoparietal cortical
atrophy, ballooned neurons, and phosphorylated tau-positive astrocytic plaques and neuropil threads with
gliosis and neuronal loss, confirming the
corticobasal degeneration.
CONCLUSIONS: