Corticobasal Degeneration Corticobasal ganglionic degeneration present with asymmetric basal ganglia (akinesia, rigidity, dystonia) and cerebral cortical (apraxia, cortical sensory loss, alien limb) manifestations. We see the alien limb with parietal lobe, medial frontal lobe, and corpus callosum pathology. Dementia is a variable but may be the presenting symptom.  Oculomotor involvement like that in progressive supranuclear palsy may occur. But the major difference between PSP and corticobasal degeneration is that the latter is with limb coordination problems, and the former is with balance and walking problems.  Prognosis Survival ranges from 2.5 to 12 years, with a median of about 8 years.  Neuropathology Corticobasal degeneration pathology shows abundant ballooned, achromatic neurons, and focal cortical atrophy predominating in medial frontal and parietal lobes, plus degeneration of the substantia nigra. We also see astrocytic plaques in the cortex. corticobasal degeneration: neuro