Rare tremors and tremors occurring in other neurological disorders

Although tremor is deemed to be the commonest movement disorder, in adults the differential diagnosis usually boils down to whether the patient has Essential Tremor or Parkinson's Disease, which has likely led to an overdiagnosis of these conditions; yet, many important rare syndromes should be considered in the differential diagnosis of patients with tremor. The aim of this review is to focus on rare forms of tremor, also in view of the new tremor classification, as well as on tremor occurring in other neurological disorders to aid their recognition. Some of the conditions reviewed here are treatable and therefore should not be missed. This review includes orthostatic tremor, focal and task-specific tremors, Holmes tremor, palatal and oculopalatal tremor, cortical tremor, some genetic forms of tremor including fragile X-associated tremor/ataxia syndrome as well as tremor associated with neuromuscular disorders, multiple sclerosis and Wilson's disease, providing an array of demonstrative videos. The recognition of these disorders should aid the physician to make a correct diagnosis and guide a prompt intervention. This article is part of the Special Issue "Tremor" edited by Daniel D. Truong, Mark Hallett, and Aasef Shaikh.