The phenylalanine loading test in the differential diagnosis of dystonia
Abstract
Early diagnosis of dopa-responsive dystonia (DRD) and its delineation from other dystonic syndromes is of great relevance because DRD is an eminently treatable condition. The possible relevance of the phenylalanine loading test (Phe-L) in differentiating DRD from primary focal and generalized dystonia was investigated. A marked difference in the phenylalanine/tyrosine ratio between patients with DRD and patients with other types of dystonia was observed. This indicates that Phe-L may be helpful in the differential diagnosis of dystonias.
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Publication History
Received: November 7, 2001
Accepted: November 5, 2002
Published online: February 25, 2003
Published in print: February 25, 2003
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