The relation between essential tremor and other movement disorders

Relação entre tremor essencial e outras desordens do movimento

THESIS

The relation between essential tremor and other movement disorders (abstract)^*

Relação entre tremor essencial e outras desordens do movimento (resumo)

Márcia Rúbia Rodrigues Gonçalves^**

The relation between essential tremor and other movement disorders (Abstract). Dissertation. São Paulo, 1996.

This manuscript reviews the controversies of the medical literature regarding the association between essential tremor and other movement disorders. Historic, genetic, epidemiological data, clinical and pathophysiologic features of essential tremor are discussed. The obstacles in the differentiation between essential tremor and Parkinson's disease tremor are also discussed.

The epidemiological data concerns two main features: the inherent risk essential tremor patients of developing Parkinson's disease and the occurrence of essential tremor in relatives of patients with Parkinson's disease. These studies are discrepant regarding the wide variation in methodological issues and threfore no conclusion is drawn from them. Neuropathology studies make evident that there is no connection between essential tremor and Parkinson's disease. The presence of tremor in patients with idiopathic or symptomatic dystonia is believed to be 15 to 40%. Dystonia subjects may present two types of tremor, namely, one type which resembles essential tremor and the other one is called dystonic tremor. Methodological issues such as the abscence of homogeneous criteria in the identification of the tremor type, the wide variation in the patient sample and distortion in the patient selection criteria, make an interpretation of the data somewhat difficult. Additionally, a genetic abnormality recorded in idiopathic dystonia which is located in cromosome 9, is not found in essential tremor subjects. The data regarding the association between essential tremor and other movement disorders other than Parkinson's disease and dystonia are insufficient to allow a more detailed analysis.

Key words: essential tremor, Parkinson's disease, dystonia.

*

Dissertação de Mestrado, Faculdade de Medicina da Universidade de São Paulo (Área: Neurologia). Orientador: Egberto Reis Barbosa.

**

Address: Rua Fradique Coutinho 1692 / 23, 05416-002 São Paulo SP. Brasil.

Publication Dates

• Publication in this collection
  10 Nov 2010
• Date of issue
  1997