PRELIMINARY NINDS NEUROPATHOLOGIC CRITERIA FOR STEELE-RICHARDSON-OLSZEWSKI SYNDROME (PROGRESSIVE SUPRANUCLEAR PALSY)

We present the preliminary neuropathologic criteria for progressive su pranuclear palsy (PSP) as proposed at a workshop held at the National Institutes of Health, Bethesda, MD, April 24 and 25, 1993. The criteri a distinguish typical, atypical, and combined PSP. A semiquantitative distribution of neurofibrillary tangles is the basis for the diagnosis of PSP. A high density of neurofibrillary tangles and neuropil thread s in the basal ganglia and brainstem is crucial for the diagnosis of t ypical PSP. Tau-positive astrocytes or their processes in areas of inv olvement help to confirm the diagnosis. Atypical cases of PSP are vari ants in which the severity or distribution of abnormalities deviates f rom the typical pattern. Criteria excluding the diagnosis of typical a nd atypical PSP are large or numerous infarcts, marked diffuse or foca l atrophy, Lewy bodies, changes diagnostic of Alzheimer's disease, oli godendroglial argyrophilic inclusions, Pick bodies, diffuse spongiosis , and prion protein-positive amyloid plaques. The diagnosis of combine d PSP is proposed when other neurologic disorders exist concomitantly with PSP.