[Transitory cerebellar ataxia from high dosage combination thymoleptic therapy]

Transitory ataxias have repeatedly been observed and reported in connection with antidepressant medication. However, it is remarkable that exact descriptions of this particular form of ataxia are rarely included. Also, hypotheses concerning the etiology and pathophysiology of these disorders are generally lacking. They are usually given the imprecise designation of "extrapyramidal" ataxias. Two cases are presented here in which therapy-resistant endogenous depressions were treated with maprotiline/dibenzepine and maprotiline/clomipramine, respectively. In both cases, marked neurological side effects in the form of cerebellar ataxia developed. The symptoms, which occurred despite usual dosage, remitted after maprotiline treatment was discontinued for one patient and after dose reduction of both drugs for the other. The atactical and dysmetric symptoms described here are thought to result from a reversible intoxication of mainly cerebellar structures. In an attempt to explain the genesis of these ataxias, a neurophysiological and a neuropharmacological hypothesis are considered and predisposing factors as well as therapeutic consequences are discussed.