The phenylalanine loading test in the differential diagnosis of dystonia.
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.
Bandmann
O
O
Department of Neurology, Philipps-University Marburg, Germany. o.bandmann@sheffield.ac.uk
Goertz
M
M
Zschocke
J
J
Deuschl
G
G
Jost
W
W
Hefter
H
H
Müller
U
U
Zöfel
P
P
Hoffmann
G
G
Oertel
W
W
D000284:Administration, Oral; D000328:Adult; D003937:Diagnosis, Differential; D004421:Dystonia / Q000175:diagnosis* / Q000188:drug therapy; D005260:Female; D006801:Humans; D007980:Levodopa / Q000627:therapeutic use; D008297:Male; D008875:Middle Aged; D010649:Phenylalanine / Q000008:administration & dosage / Q000097:blood; D011237:Predictive Value of Tests; D012016:Reference Values; D012680:Sensitivity and Specificity; D013997:Time Factors; D014443:Tyrosine / Q000097:blood
D014443:Tyrosine; D007980:Levodopa; D010649:Phenylalanine