Pontine Diameter in MRI- A Tool for Early Diagnosis of Multiple System Atrophy (MSA)

Author(s): Mappilaveetil Sayed Jabir1 , Anjamparuthikal Aboobekar Haris2

BACKGROUND As clinical features of degenerative Parkinsonism can overlap, early differentiation of MSA is difficult. So, we studied pontine diameter in patients of Multiple System Atrophy in comparison with other causes of Degenerative Parkinsonism [(Progressive Supranuclear Palsy (PSP), Parkinson’s disease, Corticobasal syndrome (CBS)] as a tool for early diagnosis of MSA. We wanted to investigate the usefulness of pontine diameter in midsagittal sections of MRI for differentiation of MSA from neurodegenerative parkinsonism. METHODS Patients who presented to the neurology department with clinical features of degenerative Parkinsonism were included; 120 patients who met the inclusion criteria underwent MRI imaging in a 1.5 tesla machine and midsagittal T1 images were read to obtain pontine diameter. Comparison was made between pontine diameter of MSA (n=30) with Progressive Supranuclear Palsy (n=30), Parkinson’s disease (n=30) and Corticobasal syndrome (n=4). RESULTS Mean age of onset in MSA is 58.63 with a SD of 3.891. Mean age of patients in progressive supranuclear palsy is 59.47 with a standard deviation of 3.86. Mean disease duration in PSP was 2.97 with an SD of 1.035; whereas, the disease duration was higher in MSA and PD with a mean of 3.56 and 3.96 respectively. In multiple system atrophy, the mean pontine diameter was 14.96 with an SD of 0.88. Mean pontine diameter is lower in MSA when compared to other groups and is statistically significant (p<0.001). This shows that pons is significantly atrophied in MSA when compared to other parkinsonian syndromes. CONCLUSIONS Pontine diameter is significantly lower in MSA when compared to PSP, PD, CBS and Control Group. So pontine diameter in MRI can be useful tool for differentiating MSA from other causes of degenerative parkinsonism.