[Unusual causes of gait disorders].

Gait disorder is a common complaint in general practice, in particular in the elderly, and more than one cause frequently interact to produce various abnormalities of gait, including neurological, orthopedic, rhumatologic or ophthalmologic conditions, among others. The most frequent etiologies of gait impairment include sensory deficits, cervical myelopathy, vascular encephalopathy, parkinsonism and normal pressure hydrocephalus. In a particular individual, several of them may contribute to alter gait and, as a general rule, the treatment of these well-established conditions is generally considered difficult. Besides them, a number of rare and underrecognized neurological conditions may also produce a gait disorder as their initial, main or exclusive feature, including dopa-responsive dystonia, stiff-person syndrome, orthostatic tremor, primary progressive freezing gait and cursive epilepsy. In this review article, the clinical, therapeutic and other characteristics of these conditions are revisited and a typical illustrative case is reported for each. Since most of these conditions are responsive to specific treatments, we believe that a better knowledge of these unusual forms of gait disorder may allow general practitioners to identify them more accurately, to assess them and to improve therapeutic strategies.