Relevance of non-specific MRI features in multiple system atrophy

Abstract

Objectives: Rarity 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 methods: Clinical 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.

Results: Of 53 cases (mean age: 59.53±9.74years), 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.

Keywords: Cerebellar atrophy; Corpus callosal atrophy; Hyperintense putamen rim; MRI features of MSA; Midbrain atrophy; Muliple system atrophy; ‘Hot-cross bun’ sign; ‘Morning glory’ sign.