AGREEMENT AMONG MOVEMENT DISORDER SPECIALISTS ON THE CLINICAL-DIAGNOSIS OF ESSENTIAL TREMOR

Even though essential tremor (ET) is the most prevalent movement disor der, there has been little agreement in the neurologic literature rega rding diagnostic criteria for ET. The authors attempted to determine t he extent and source of agreement and disagreement among neurologists regarding diagnostic criteria for clinically definite ET. The authors designed and mailed a semistructured questionnaire to 160 neurologists who specialize in movement disorders in 24 countries. The questionnai re included three sections: a list of inclusion criteria, a list of ex clusion criteria, and a List of potential clinical scenarios (for exam ple, isolated site-specific tremor and primary orthostatic tremor). Th e questionnaire was completed by 98 (61%) of 160 targeted neurologists . There was greater consensus regarding features considered unnecessar y inclusion criteria for clinically definite ET (extent of disability, disease duration, and positive family history) than for those conside red necessary inclusion criteria (postural versus action tremor). With regard to exclusion criteria, there was some consensus in terms of th e presence of Parkinson's disease, dystonia, history of hyperthyroidis m or concurrent use of tremor-inducing medications, and cerebellar sig ns. The majority of neurologists would diagnose ET in the setting of i solated head or voice tremor. There are areas of both consensus and di vergence among neurologists with regard to diagnostic criteria for ET. The choice of diagnostic criteria may vary depending on the intended use of the criteria (that is, clinical versus genetic studies). Hopefu lly, this study will foster further discussion to achieve a more gener al consensus.