Related Experiment Video
Updated: Jul 20, 2026
Behavioral Assessments of Spontaneous Locomotion in a Murine MPTP-induced Parkinson's Disease Model
Published on: January 7, 2019
Multiple system atrophy is distinguished from idiopathic Parkinson's disease by the arginine growth hormone
Maria Teresa Pellecchia1, Katia Longo1, Rosario Pivonello2
1Departments of Neurological Sciences, University of Naples "Federico II," Naples.
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 4 microg/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.
Insights
The arginine growth hormone (GH) stimulation test accurately distinguishes Multiple System Atrophy (MSA) from Parkinson's disease (PD). This test shows high sensitivity and specificity, aiding in diagnosing these neurodegenerative conditions.
Area of Science:
- Neuroscience
- Endocrinology
- Clinical Diagnostics
Background:
- Multiple System Atrophy (MSA) and idiopathic Parkinson's disease (PD) share overlapping symptoms, complicating differential diagnosis.
- Accurate differentiation is crucial for appropriate patient management and treatment.
Purpose of the Study:
- To assess the diagnostic accuracy of the arginine growth hormone (GH) stimulation test in distinguishing between MSA and PD.
- To evaluate the test's utility in large patient cohorts.
Main Methods:
- Measured GH response to arginine in 69 MSA patients (including MSAp and MSAc subtypes), 35 PD patients, and 90 controls.
- Employed receiver-operating curve analysis to determine the optimal cutoff value for differentiation.
Main Results:
- MSA patients exhibited significantly lower GH response to arginine compared to PD patients and controls (p < 0.01).
- An arginine cutoff of 4 microg/L achieved high sensitivity and specificity (91-96%) in differentiating MSA subtypes from PD.
- The test demonstrated a positive predictive value of 95% for MSA.
Conclusions:
- The arginine GH stimulation test is a highly accurate method for differentiating MSA from PD.
- Findings suggest impaired cholinergic systems modulating GH release in MSA.
Related Concept Videos
01:24Parkinson's Disease: Treatment
Parkinson's Disease is primarily a result of the loss of dopaminergic neurons in the substantia nigra pars compacta. The cornerstone of its...
01:15Parkinson's Disease: Overview
01:24Parkinson Disease ll: Pathophysiology
01:24Parkinson Disease l: Introduction
01:15Myasthenia Gravis: Diagnostic Tests
The edrophonium test is a diagnostic tool for myasthenia gravis. It involves...
01:11Alterations in Muscle Tone lll