Progressive Supranuclear Palsy

CORTICOBASAL DEGENERATION (CBD)

Corticobasal degeneration (CBD) is characterized by asymmetric cortical atrophy, neuronal cell loss, gliosis, and ballooned neurons in the central sulcus region (primary motor/primary sensory cortex), with achromatic intracytoplasmic neuronal inclusions similar to the Pick bodies seen in Pick disease/frontotemporal dementia and primary progressive aphasia. These inclusions with corresponding neuronal cell loss are found predominantly in the diencephalon, thalamus, substantia nigra, locus ceruleus, and cerebral cortex. Tau protein, ubiquitin, phosphorylated neurofilaments and, to a lesser degree, alpha-synuclein are components of such inclusions, sharing immunoreactive properties similar to that found in Pick bodies. CBD (see Plate 7-8) is characterized clinically by asymmetric dystonic posturing with superimposed stimulus-sensitive and action-induced myoclonus, giving the affected hand or limb a tremulous appearance, and by the alien limb phenomena, limb apraxia, parkinsonism, and gait and postural instability, with dementia and oculomotor disturbances manifesting later in the course of the disease.

LEWY BODY DISEASE

Lewy body disease, also known as dementia with Lewy bodies, operationally may be viewed as typical doparesponsive parkinsonism with early-onset dementia, fluctuating alertness and attention, confusion, sleep disturbances, marked sensitivity to neuroleptic or dopamine-blocking agents, and vivid and well-formed visual hallucinations. In most autopsy series, Lewy body dementia is second after Alzheimer disease as the cause of dementia, with vascular dementia a close third. The Lewy body, which is structurally and morphologically similar to that found in idiopathic Parkinson disease, is found throughout the cerebral cortex to a variable degree and in the substantia nigra. Ubiquitin, neurofilament protein, and alpha-synuclein are components of Lewy bodies. In the nucleus basalis and hippocampal formation, scattered senile plaques and neurofibrillary tangles are found with granulovacuolar degeneration simulating that observed in Alzheimer disease.

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