Clinically Isolated Syndrome of Multiple Sclerosis: Clinical and Paraclinical Features

Clinically isolated syndrome is the first clinical attack of multiple sclerosis. Clinical signs of clinically isolated syndrome depend on anatomical location of foci/focus of demyelination and are manifested as unilateral neuritis of the optic nerve, focal supratentorial or brainstem, cerebellar syndrome or partial myelopathy. Up to 70% of patients with clinically isolated syndrome will develop multiple sclerosis in future. There are five phenotypes of clinically isolated syndrome. In case of clinically isolated syndrome lesions can be present or absent on brain MRI. Clinically isolated syndrome is relatively recently isolated in an independent nosological unit, so the number of works dealing with its features is insufficient, in Ukraine as well. The purpose of the study was to determine the clinical and structural features of the brain in patients with clinically isolated syndrome. Material and methods. We conducted a longitudinal study of 30 patients who attended Volyn Regional Clinical Hospital. We developed universal inclusion and exclusion criteria to enroll the patients into the study. This study was conducted in Ukraine for the first time. The research is an observatory, prospective, double (a patient, a researcher) examination of patients with clinically isolated syndrome of multiple sclerosis. We examined the associations between demographic, clinical, imaging features in patients with clinically isolated syndrome. MRI of the brain was performed on 1.5 T scanner Toshiba Titan Octave with a standard protocol. To assess atrophic processes, we measured 23 linear parameters for each patient twice in dynamics. Besides, 14 indices were calculated for each MRI, namely, corpus callosum index, width of lateral ventricles (right and left), width of III ventricle, frontal atrophy index, bicaudate index, and index of medial structures, Evans' index, Huckman index, ventricular parieto-occipital index and ventricular temporal index. To conduct linear measurements, RadiAnt DICOM Viewer program was used, which is available free online (https://www.radiantviewer.com/). Statistical analysis was performed by means of the program Microsoft Excel, SPSS for Windows; standard descriptive statistics were used. Routine laboratory investigations (hematological, biochemical), as a safety measures, were performed during each visit of a patient before conducting MRI of the brain. Results and discussion. 30 patients with clinically isolated syndrome were examined aged 32.07±8.54 years old. Women predominated and comprised 27 (90%) patients. The multifocal debut of the disease was observed in 18 (60%) subjects. The EDSS score at the time of clinically isolated syndrome was 2.98±0.55 points. The average time before the second attack was 6.33±3.46 months. We revealed demyelinating lesions in 30 (100%) patients. The typical localization of demyelinating lesions in patients with clinically isolated syndrome is periventricular (including corpus callosum), juxtacortical and cortical zones according to magnetic resonance imaging. Infratentorial lesions were observed much less frequently in the clinically isolated syndrome. Contrast enhancement lesions were located in periventricular regions most frequently. Limited lesions located in cerebral cortex were active. In general, despite of clinical symptoms, active lesions of demyelination were present less than in half of patients with clinically isolated syndrome.