The Characteristics of Cognitive Functions in Patients with Acute Disseminated Encephalomyelitis

Introduction: The clinical picture of acute disseminated encephalomyelitis is characterized not only by a variety of neurological signs, but also by disorders of higher cortical functions. Disorders of higher cognitive functions often remain undetected during routine examination of patients and the use of specialized neuropsychological tests enables timely diagnosis of cognitive disorders.

Methods: The assessment of cognitive impairment was carried out in 67 patients with ADEM (28 male and 39 female, aged 16 – 50, mean age - 31.6±2.3). All the patients were being treated at the Kiev city centre of multiple sclerosis (Ukraine). The diagnosis of ADEM was based on neurological examination, MRI of the brain and CSF analysis. The cognitive impairment in patients with ADEM was assessed during the first three days after the onset of the disease. The neurological status was assessed by Kurtzke an Expanded Disability Status Scale (EDSS) and Functional Systems Scores (FSS). Patients performed neuropsychological tests that enabled evaluation of short-term and long-term visual and auditory memory, various parameters of attention as well as ability to concentrate, orientation in time and space.

Results: The assessment of cognitive functions in patients with ADEM demonstrated impaired short-term and long-term memory indices according to “memorizing 10 words” test (34.6±1.5 words compared with control 42.7±1 words, P <0.001), verbal learning and delayed recall according to "California Verbal Learning Test "(12.3±1.9 words compared to control 14.6±1.1 words, P <0,01) and sustained attention and concentration according to "Symbol Digit Modalities Test "(54.5±10.2 compared to control 57.8±9.6, P> 0.05). In addition, assessment of memory, attention, orientation in time and space according to MMSE test (Mini - Mental State Examination) showed reduction of these functions in patients of the main group (27.2±0.24 points, compared with control 29.9±0.04 points, P <0.001). Demyelination foci in patients with cognitive disorders are most often localized to the periventricular regions in the frontal and parietal lobes, and in the cerebellum, where multiple demyelinating lesions are often observed.

Conclusion: We have detected cognitive disorders that require therapeutic correction in case of carrying out treatment-rehabilitation measures in patients with acute disseminated encephalomyelitis that will improve their quality of life.