DESCRIPTION (provided by the PI): Primary dystonia, thought to be the third most common movement disorder, is a chronic neurological disease affecting all age groups and racial groups. Common subtypes of primary dystonia include dystonic blepharospasm, spasmodic torticollis, oromandibular dystonia, spasmodic dysphonia and focal hand dystonia (writer's cramp). Primary dystonia has adverse effects on health, employment and quality of life. There is no cure, but many forms can be effectively treated. Incorrect diagnosis at the time of presentation with dystonia is common, with estimates ranging from 50% to 90%. Correct diagnosis is often delayed for years, causing unnecessary morbidity, suffering, and greater healthcare and societal costs. Moreover, persons with dystonia are frequently misdiagnosed as malingering or as suffering from a psychiatric disorder. This serious issue has not been studied systematically. We propose to take advantage of our ongoing study in the Northern California Kaiser Permanente Medical Care Plan, which is identifying the world's largest cohort of incident cases of primary dystonia (R01 NS046340). Using computerized health utilization review and direct patient interviews we will identify and describe the frequency and characteristics of incorrect diagnosis of dystonia, including the length of time from symptom onset until diagnosis, the number and type of incorrect diagnoses, the types of medical providers seen, and the use of inappropriate treatments. We will also assess the consequences of incorrect diagnosis, including costs and adverse events, and the impact of incorrect and delayed diagnosis on patients'lives. By building on an established cohort of incident dystonia, the proposed design allows us to accomplish study aims at a fraction of the cost of conducting these studies de novo. Identifying the types of incorrect diagnoses that are made, and by whom, will provide a foundation for developing future effective interventions that can ultimately minimize this problem. If successful, this approach could be applied in other medical care settings, as well as for other rare disorders, to improve medical care and efficiency, and reduce suffering.