803 research outputs found
Multiple system atrophy is distinguished from idiopathic Parkinson's disease bythe arginine growth hormone stimulation test
Objective: Multiple system atrophy (MSA) may be difficult to distinguish from idiopathic Parkinson’s disease (PD). Our aim
was to evaluate the accuracy of the arginine growth hormone (GH) stimulation test in distinguishing between MSA and PD in
large populations of patients.
Methods: We measured the GH response to arginine in 69 MSA (43 MSAp [parkinsonism as the main motor feature] and 26
MSAc [cerebellar features predominated]) patients, 35 PD patients, and 90 healthy control subjects. We used receiver-operating
curve analysis to establish the arginine cutoff value that best differentiated between MSA and PD.
Results: The GH response to arginine was significantly lower (p 0.01) in MSA than in either PD patients or control subjects.
At a cutoff level of 4g/L, arginine distinguished MSAp from PD with a sensitivity and specificity of 91% and MSAc from PD
with a sensitivity of 96% and specificity of 91%. The arginine test had a positive predictive value for MSA of 95%. The GH
response to arginine was not affected by disease duration or severity, MSA motor subtype, pyramidal signs, response to dopaminergic
therapy, or magnetic resonance imaging findings.
Interpretation: The GH response to arginine differentiates MSA from PD with a high diagnostic accuracy. The results suggest
an impairment of cholinergic central systems modulating GH release in MSA
The fragile X tremor ataxia syndrome in the differential diagnosis of multiplesystem atrophy: data from the EMSA Study Group
Progression of multiple system atrophy (MSA): a prospective natural history studyby the European MSA Study Group (EMSA SG)
Dopaminergic Neuronal Imaging in Genetic Parkinson's Disease: Insights into Pathogenesis
Objectives:To compare the dopaminergic neuronal imaging features of different subtypes of genetic Parkinson's Disease.Methods:A retrospective study of genetic Parkinson's diseases cases in which DaTSCAN (123I-FP-CIT) had been performed. Specific non-displaceable binding was calculated for bilateral caudate and putamen for each case. The right:left asymmetry index and striatal asymmetry index was calculated.Results:Scans were available from 37 cases of monogenetic Parkinson's disease (7 glucocerebrosidase (GBA) mutations, 8 alpha-synuclein, 3 LRRK2, 7 PINK1, 12 Parkin). The asymmetry of radioligand uptake for Parkinson's disease with GBA or LRRK2 mutations was greater than that for Parkinson's disease with alpha synuclein, PINK1 or Parkin mutations.Conclusions:The asymmetry of radioligand uptake in Parkinsons disease associated with GBA or LRRK2 mutations suggests that interactions with additional genetic or environmental factors may be associated with dopaminergic neuronal loss
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