[Camptocormia--segmental dystonia. Proposal of a new definition for an old disease].

Camptocormia is defined as a forced posture with a forward-bent trunk which appears during standing and sitting. It was first described in 1818 by Brodie. In the last 100 years, numerous cases were observed. A psychogenic origin was presumed in most cases. We describe four patients with typical symptoms of camptocormia who present with the clinical and electromyographical criteria of a segmental dystonia. A new classification of camptocormia is proposed including (1) the primary form, a segmental dystonia of the abdominal wall muscles and (2) secondary forms. Among other conditions (psychogenic disorder, neurosis, myopathy, myositis, Parkinson's disease, multiple-system atrophy, thoracolumbar kyphosis, paraneoplastic syndrome), camptocormia is to be considered in essential tremor. A combination of dystonia of the abdominal wall muscles and essential tremor seems possible.