Long-term dynamics of brain atrophy development in Multiple Sclerosis – a 10 year follow-up MRI study

Introduction: Brain atrophy is a known feature in multiple sclerosis (MS). Current studies suggest that atrophy may reflect the neurodegenerative and destructive components of the disease. There are indications that atrophy correlates with neurological impairment and disability, yet there is little data about its long term development. We investigated the course of brain atrophy over 10 years in 3 active MS patients who underwent MRI regularly.

Methods: We analysed clinical and MRI data over a period from 1996 to 2008 of 3 patients with MS (mean observation period 10.3 years/per subject). Patients were examined with 2 MR systems (1.5T Siemens MAGNETOM Sonata and Vision). Brain atrophy between each 2 timepoints was determined with SIENA (Structural Image Evaluation, using Normalisation, of Atrophy).

Patient 1 (Relapsing remitting MS): MRI observation 0–134 months, 6 time points.

Expanded Disability Status Scale (EDSS) constantly between 0 and 1.

Patient 2 (Relapsing Remitting MS): MRI observation 0–109 months, 8 time points.

EDSS increase from 2.5 to 5.5 during follow up.

Patient 3 (Initially RR MS to Secondary Progressive MS): MRI observation 0–117 months, 7 time points. EDSS increase from 2 to 7 during follow up.

Results: Patient 1: Brain atrophy after 54 months: 0.9%, after 57 months: 1.5%, after 94 months: 8.0%, after 120 months: 10.4% and after 134 months: 12.0%

Average value: 0.09% per month

Patient 2: Brain atrophy after 11 months: 3.9%, after 25 months: 4.7%, after 38 months 6.6%, after 64 months: 6.9%, after 73 months: 6.9%, after 90 months: 10.1% and after 109 months: 19.0%

Average value: 0.17% per month

Patient 3: Brain atrophy after 12 months: 5.8%, after 22 months: 6.4% after 31 months: 14.1%, after 71 months: 16.6%, after 102 months: 22.5% and after 117 months: 26.6%

Average value: 0.23% per month

Conclusions: Brain atrophy is a well known phenomenon to occur in MS. It is a common assumption, that brain atrophy in MS is a stable phenomenon over time. However, In this study we demonstrate that brain atrophy is not a linear process, but clearly has stepwise non-linear dynamics. This opens interesting new questions into the underlying mechanisms and relationship to the clinical features.