Ultrasonography and MR Imaging in Progressive Supranuclear Palsy

Progressive supranuclear palsy (PSP) also known as Steele, Richardson and Olszewski disorder (1-4) is a neurodegenerative brain disease that has no known cause, treatment or cure. PSP has no known geographical, occupational or racial preference and affects brain cells that control walking, balance, mobility, vision, speech and swallowing. Symptoms begin on average in the early 60s, but may start as early as in the 40s: a good history and physical examination support the clinical diagnosis and latency of each feature makes us suspect a probable PSP, an atypical Parkinsonism. The diagnosis of a large number of cases of PSP is missed or delayed: 75% of the patients are never clinically diagnosed by neurologist and in most cases the median interval between onset and diagnosis is three years. Notwithstanding such differences in clinical presentation, there remains an overlap in symptoms making the differential diagnosis between such neurodegenerative disorders challenging. A few imaging techniques developed to evaluate brain anatomy and function are used extensively to improve the diagnostic accuracy of different forms of Parkinsonism. Non-invasive and safe methods can now document brain structures. Transcranial sonography (TCS) is a very low cost tool to assess the basal ganglia and mesencephalic echogenicity (5,6). Conventional magnetic resonance imaging (MRI) is a valuable tool to exclude secondary Parkinsonism. Our purpose is to define characteristic objectively measured imaging markers that point out normal biological processes, and pathogenic processes in PSP. Such markers should be sufficiently sensitive and specific to show the underlying biological disease and the pharmacological responses to therapy.