Relevance of non-specific MRI features in multiple system atrophy

- No single MRI feature can independently diagnose MSA.
- Hyperintense lateral putaminal rim and “hot cross bun sign” were rare.
- “Morning glory sign”, corpus callosum atrophy and cerebellar atrophy were common.
- Common MRI features were found in more than two-thirds of MSA patients.

ObjectivesRarity of specific MRI features like 'hot-cross bun' sign and 'hyperintense putamen rim' reduce diagnostic utility of MRI in MSA. We therefore, studied some non-specific MRI features in addition to the specific ones, to find their diagnostic utility.Patients and methodsClinical and MRI features of 53 indoor and outdoor patients with MSA were analyzed in the context of its Parkinsonian (MSA-P) and cerebellar (MSA-C) variants.ResultsOf 53 cases (mean age: 59.53 ± 9.74 years), 16 (30.2%) had MSA-C and 37 (69.8%) had MSA-P. Midbrain atrophy was found in 37 (69.8%) MSA patients (70.3% of MSA-P and 68.8% of MSA-C), cerebellar atrophy in 45 (84.9%) MSA patients (81.1% of MSA-P and 93.8% of MSA-C), 'hot-cross bun' sign in 13 (24.5%) MSA patients (27% of MSA-P and 18.8% of MSA-C), hyperintense putamen rim in 19 (35.8%) MSA patients (37.8% of MSA-P and 31.3% of MSA-C) and corpus callosal atrophy in 39 (73.6%) MSA patients (75.7% of MSA-P and 68.8% MSA-C). The midbrain atrophy was mainly lateral tegmental and resembled a positive 'Morning glory' sign in 16 (30.2%).Conclusion“Hot cross bun” sign and “hyperintense putamen rim” sign were rarely seen in MSA. Combination of mid brain atrophy, corpus callosum atrophy and cerebellar atrophy was more commonly observed in both MSA-C and MSA-P and may be taken as of diagnostic significance.