and the United Kingdom. The focus of the Workshop was earlier and better diagnosis of PSP.
PSP affects at least 3,000 living patients across the UK, but it is believed the true figure is nearer 10,000, a discrepancy thought to be caused by misdiagnosis and nondiagnosis. PSP can mimic other neurodegenerative diseases and its early symptoms are often misleading and nonspecific. Diagnosis can and often does take well over a year from disease onset, as PSP symptoms are ill defined and often misleading. As noted in Professor Lees's introduction, clinicians at this time would be doing exceptionally well to achieve 80% accuracy with diagnosis within a year of symptom onset. Although this is obviously unsatisfactory for patients and caregivers, it is understandable that neurologists want to be certain before they give this devastating news.
Diagnosis depends on clinical acumen, but three areas in which diagnostic markers might become available to assist neurologists are serial volumetric magnetic resonance (MRI) imaging, neurobehavioural tests, and eye movement recordings.
Professor Irene Litvan, currently Raymond Lee Lebby Professor in Parkinson's disease research and Director of the Movement Disorder Programme at the University of Louisville, Kentucky, USA, made a keynote presentation on the clinical diagnosis of PSP. Together with an international panel of movement disorder specialists, Professor Litvan, formerly at the US National Institute of Health, had drawn up the now-established operational criteria for clinical diagnosis of probable and possible PSP. Professor Litvan spoke of the possibility of redefining these criteria under the headings of definite, probable, and possible PSP, and suggested symptoms to be included under each heading.
Professor Lees and Dr. Litvan covered the clinical aspects of PSP and how to apply diagnostic criteria. Professor Nigel Leigh presented an update on the large European trial of Riluzole in PSP and multiple system atrophy (MSA). Subsequent presentations re-