Some multiple sclerosis (MS) patients who achieved no evidence of disease activity (NEDA) status still had cognitive deterioration, in a controlled, 2-year, longitudinal study done in Campinas, Brazil.
The study included 42 patients with a relapsing-remitting MS (RRMS) diagnosis and a control group of 30 age- and gender-matched healthy subjects. All patients were clinically stable (no relapse in the previous 3 months) and being treated with disease-modifying therapies (DMTs). Clinical examinations of all patients at all time-points included the Expanded Disability Status Scale (EDSS) and the Multiple Sclerosis Functional Composite (MSFC) for all individuals. Depression and health-related quality of life were assessed in all individuals, and all individuals were neuropsychologically assessed using alternate versions of the A and B Brief Repeatable Battery (BRB-N). MRI scans were done on all subjects to search for MRI activity, which was defined as new/enlarging T2 lesions or new gadolinium-enhancing lesions. Cognitive worsening was measured as the number of BRB-N domains showing deterioration based on standardized regression–based models. Deterioration was defined as values below –1.645. Patients were also assessed using the 25-foot walk (T25FW) and nine-hole peg test (9HPT), with worsening on either test defined as an increase of more than 20% relative to the baseline measurement. A patient was said to have NEDA status if there was an absence of the following four items during follow-up: relapses, disability progression, new/enlarging T2 lesions, and new gadolinium-enhancing lesions.
From the original cohort, 40 patients performed a second and third evaluation after 12 and 24 months, respectively, and 22 members of the control group were available for the second and third evaluation. Exclusion criteria were: progressive course, fulfillment of diagnostic criteria for neuromyelitis optica, EDSS greater than 5.0, any preexisting condition known to be associated with brain atrophy or any relapse or steroid therapy within 3 months preceding the clinical or MRI evaluation.
Of the cohort, 46.2% (18 patients) had no MRI activity, 67.5% (27 patients) had no combined clinical activity, but only 30.8% (12) achieved NEDA status at 2 years.
“We found that regardless of achieving NEDA status, 8.3% still had worsening T25FW, and 58.3% had deterioration in greater than or equal to two cognitive domains, suggesting that cognitive measures should be added to the NEDA concept,” according to Dr. Alfredo Damasceno and his colleagues.
“Among those 27 patients with no relapses or EDSS progression, three (11.1%) and one (3.7%) had progression on T25FW and 9HPT, respectively. Moreover, more than one-third had deterioration in greater than or equal to two or more cognitive domains, and about half of these patients still had no evidence of MRI activity,” according to the researchers.
Patients with absence of MRI activity had lower subcortical gray matter (GM) atrophy rates. Compared with controls, MS patients had more than two times higher atrophy rates of subcortical GM.
Absence of new/enlarging T2 lesions was the only predictor of cortical thinning (B = 1.85; P = .0044), subcortical GM atrophy rate (B = 2.09; P = .011), and thalamic atrophy rate (B = 2.09; P = .021).
Among the researchers’ “interpretations” of their data were: DMTs have a limited impact on overall disease worsening, and possibly, clinical/cognitive worsening in the long term is more related to neurodegenerative processes, and the absence of relapses or EDSS progression alone does not necessarily rule out disease progression.
The researchers suggested that future studies addressing NEDA include a more diverse patient population.
The researchers reported no conflicts of interest.
Read the full study in the Multiple Sclerosis Journal (doi: 10.1177/1352458515604383).