Progressive Supranuclear Palsy | Multiple System Atrophy | Cortical-Basal Ganglionic Degeneration | Frontotemporal Dementia and Parkinsonism Linked
to Chromosome 17
Progressive supranuclear palsy (PSP), also called Steele-Richardson-Olszewski
syndrome, is a progressive, neurodegenerative condition consisting
of parkinsonism without prominent tremor, vertical gaze palsy, axial
(midline) more than appendicular (arm and leg) rigidity, early postural
instability, and poor response to levodopa (Golbe and Davis 1993; Litvan 1998; Litvan et al. 1996).
The syndrome was first described by Steele et al. (1964).
The Society for Progressive Supranuclear Palsy estimates that 20,000 people
in the United States have PSP—only 3,000–4,000
of whom have received a diagnosis—yielding an estimated
known prevalence in the United States of 1.39 per 100,000. PSP is
often associated with frequent falling, lack of eye contact, monotonous
speech, sloppy eating, and slowed mentation (Jankovic et al. 1990).
Patients may have a surprised or worried facial expression, with
raised eyebrows resulting from bradykinesia and increased tone in
facial musculature, and may have difficulty opening their eyes because
of eyelid apraxia (Jankovic 1984). There is early suppression
of vertical optokinetic nystagmus and voluntary vertical saccadic
eye movements. Later in the illness, horizontal saccades and horizontal
optokinetic nystagmus are also suppressed. Impairment of voluntary
downgaze is more specific to PSP, whereas impairment of voluntary
upgaze is nonspecific in older adults. As is expected with a supranuclear
gaze palsy, passive head movement overcomes the compromised voluntary
eye movements in PSP.