Are Dopa-responsive dystonia and Parkinson's disease related disorders? A case report.
OBJECTIVE
L-Dopa-responsive dystonia (DRD) is a hereditary dystonia characterized by an excellent response to low dosages of levodopa. DRD patients may also develop Parkinsonism which resembles idiopathic Parkinson's disease. In classical DRD no changes in the dopaminergic uptake have been observed.


METHODS
A 65-year old woman presented with clinically remarkably slowly progressing Parkinson's disease (PD) without any dystonic signs and excellent response to dopaminergic medications. We obtained a [(123)I] FP-CIT-SPECT (DaTSCAN™) in order to elucidate a striatal dopaminergic deficit.


RESULTS
We found a reduced uptake in the [(123)I] FP-CIT-SPECT (DaTSCAN™) contralateral to the more affected body side. Additionally, the patient showed a heterozygous deletion of the GHC1 gene.


CONCLUSIONS
Patients with mild parkinsonian symptoms, excellent response to low dosages of dopaminergic drugs and a reduced dopamine-transporter uptake in [(123)I] FP-CIT-SPECT might more commonly be GCH1 mutation carriers than has previously been supposed. PD patients with a positive family history of DRD and combination of these clinical symptoms should be offered genetic counselling and testing for GCH1.
Carsten
C
Eggers
Alexander E
AE
Volk
Deniz
D
Kahraman
Gereon R
GR
Fink
Barbara
B
Leube
Matthias
M
Schmidt
Lars
L
Timmermann
D000368:Aged; D000978:Antiparkinson Agents / Q000627:therapeutic use*; D003342:Corpus Striatum / Q000000981:diagnostic imaging / Q000187:drug effects / Q000473:pathology; D020821:Dystonic Disorders / Q000000981:diagnostic imaging / Q000235:genetics; D005260:Female; D006136:GTP Cyclohydrolase / Q000235:genetics; D006801:Humans; D007980:Levodopa / Q000627:therapeutic use*; D010300:Parkinson Disease / Q000000981:diagnostic imaging / Q000188:drug therapy* / Q000235:genetics; D015899:Tomography, Emission-Computed, Single-Photon; D014326:Tropanes
D000978:Antiparkinson Agents; D014326:Tropanes; C087552:2-carbomethoxy-8-(3-fluoropropyl)-3-(4-iodophenyl)tropane; D007980:Levodopa; D006136:GTP Cyclohydrolase