Evaluation of cognitive function in neuromyelitis optica patients

Purpose: Neuromyelitis optica is an inflammatory disease of the central nervous system which is characterized by optic neuritis and LETM. Cognitive function impairment is an important component that has effects on social life, daily life activities and working effectivity regardless of physical disability. There are few studies on cognitive impairment in NMO patients. The purpose of this study is to assess the factors that may be related with the frequency and level of cognitive function impairment bu performing cognitive function tests like BRB-N, BDI and ACE-R in Turkish NMO patients. Material and methods: The files of 22 patients who are followed in Istanbul Bilim University neurology polyclinic with NMO suitable for study criteria and has had BDI, BRB-N and ACE-R tests while being followed are evaluated retrospectively after ethical council approval. The cases who are under 5 percentile in the normal values of BRB-N test were diagnosed with cognitive impairment, other cases were taken as not impaired and by this process, the frequency of cognitive impairment is obtained. The groups with and without cognitive impairment were compared according to age, sex, level of disease, level of education, pathologic findings on cranial MRI, NMO Ig existence and EDSS score. The relation of the clinical, radiological and demographic values and patients' depression level was evaluated. The specificity and sensitivity of ACE-R test on detecting cognitive impairment were assessed through ACE-R test results. Results in our study were evaluated with SPSS 20 statistics program and all statistic results with a p less than 0,05 were taken as significant. Results: The mean age of the patients was 42,86±10,98, changing between 23 and 65. 45,5% (n=10) of the patients had cognitive impairment and 50% (n=11) had depression. The group with cognitive impairment had significantly older age, lower educational status, higher EDSS and BDI scores (p<0,05). Gender was not a affecting factor on cognitive function. Patients with cognitive impairment had significantly lower PASAT, SPART short term memory, SRT long term memory, SRT short term memory, SDMT and verbal fluency scores than non cognitive impairment group. SPART long term memory scores did not show significant difference between groups (p>0,05). The mostly affected cognitive profile was found to be memory impairment, attention and processing dysfunction. When the specificity and sensitivity of ACE-R test on NMO patients were evaluated, diagnostic level of the test was found to be statistically good since it can detect cognitive impairment with a sensitivity of 88% and specificity of 75% on a cut off level of 82,5. Conclusion: In our study, approximately half of the patients had depression or cognitive impairment. It has been concluded that ACE-R test can be used to detect cognitive impairment in NMO patients. Since cognitive impairment and depression are frequent in NMO patients, for their quality of life, it is important for the patients to be assessed on these aspects of the disease.