Incorporating Measures of Cognitive Processing Speed and Brain Volume in Clinical Management of Pediatric Onset...

While cognitive processing and brain volume assessments are commonly used in multiple sclerosis (MS) research, they are not routinely incorporated into clinical care. Advances in neuroimaging software now allow for brain volume measurement to be incorporated into standard practice and guide clinical decision-making.

In this single-center, outpatient, cohort study, pediatric-onset multiple sclerosis (POMS) patients underwent at least two volumetric brain magnetic resonance imagings (MRIs) and two Symbol Digit Modalities Tests (SDMT) at least 6 months apart. Associations were analyzed using Pearson's correlation coefficient and linear regressions.

Forty patients with POMS were included. The first volumetric brain MRI occurred at a median of 2.7 years after symptom onset. At the first volumetric MRI, 12% of patients had white matter brain volumes within 1% of normative values (n = 2000 healthy controls). Whole brain volume percentile (r = 0.4, P = 0.01), white matter percentile (r = 0.4, P = 0.01), and white matter lesion volume (r = -0.4, P = 0.005) were associated with SDMT score. Annualized percent brain volume change of the hippocampus (measured a median of 1.6 years apart) significantly correlated with follow-up SDMT (r = 0.4, P = 0.02), and annualized percent brain volume change of the thalamus correlated with annual change in SDMT z-score (r = 0.4, P = 0.009).

Application of new software allows for volumetric assessment to be incorporated into clinical scans and provides clinicians with added data for patient management. This is critical for patients with POMS as the neurological examination often shows few to no abnormalities. Furthermore, a subset of POMS patients have smaller than expected brain volume which links to subsequent poorer cognitive performance.