This is a prospective observational cohort study that included 42 patients presented with first clinical manifestations suggestive of demyelinating disease. The study was conducted over a period of 2 years and consecutive patients from both sexes attending the outpatient clinic of Neurology department were enrolled if their age ranged from 18 to 50 years, had no better explanation of his/her neurological event, and had the ability to tolerate the investigations or clinical assessment (patients with severe visual affection, unable to read/write, or with severe weakness were excluded).
All patients were subjected to full neurological evaluation and assessed using Expanded Disability Status Scale (EDSS) [13]. According to the functional systems involved, the patients were categorized as monofocal/multifocal presentation [14]. Cognitive assessment was done using the Arabic version of Montreal Cognitive Assessment (MoCA) test to detect mild cognitive impairment [3], validated in 2018 [15].
Serum samples were withdrawn for laboratory assessment to exclude better explanation as complete blood picture, liver functions, kidney functions, ESR, thyroid function tests, vasculitic profile as antinuclear antibody (ANA), antineutrophil cytoplasmic antibodies (ANCA), anti-Ds DNA, anti-cardiolipin antibodies, lupus anticoagulant, tumor markers, and serum aquaporin 4 (if needed). Serum chitinase 3-like 1 protein (CHI3L1) samples were collected from patients at least 28 days from the onset of the clinical attack in 3-milliliter (ml) blood samples withdrawn on plain tubes. The samples were allowed to clot and sera were separated and put at − 20 °C until assay. Chitinase 3-like 1 was measured by enzyme immunoassay technique using Rand D kit, Lot P126705 purchased from R and D systems. The CSF-oligoclonal bands (OCB) and IgG index were collected from patient’s data.
Transcranial sonography (TCS) was used to assess brain parenchyma by Philips IU22 machine, using phased array (2–3.5 MHZ) and linear probe (MHZ) respectively, through trans-temporal and trans-orbital approach respectively. Patients were placed in supine position, with examiner on patient’s head; room was darkened. TCS was done through trans-temporal approach parallel to orbito-meatal line; 2 standard planes were assessed, first the mesencephalic plane for visualization of midbrain structures as substantia nigra (after visualization of the brain stem, resembling a “butterfly” shape, the picture was frozen and then enlarged by 2–3 times. After manual tracing of the substantia nigra, planimetric evaluation of its area was performed the average of 3 planimetric measurements was taken). Values were then classified as normal, hyperechogenic, and hypoechogenic. Secondly, the diencephalic plane was assessed for measurement of width of third ventricle and frontal horn of lateral ventricle (normal or dilated). At thalamus level, after tilting the ultrasound beam by approximately 10° up from the position of the mesencephalon, evaluation was related to the diameter of the third ventricle and the width of the frontal horn of the lateral ventricle on the opposite side. We used the Egyptian cut-off values [16], the unilateral substantia nigra measured surface area of echogenicity was considered normal if ≤0.19 cm2, the bilateral sum of substantia nigra measured surface area of echogenicity was considered hypo-echoic if ≤0.15 cm2, and third ventricle diameter was considered dilated if ≥0.23cm. The left frontal horn of lateral ventricle was considered dilated if >0.37cm, and the right frontal horn of lateral ventricle was considered dilated if >0.36cm. TCS examinations were performed by 2 independent investigators who were blinded to the clinical data of the patients. A structure was only regarded as abnormal on TCS if the findings of both investigators agreed.
Brain imaging was done for all patients at presentation, on Philips Interna 1.5T, Philips, Achieva 1.5T and GE signa 0.2T systems, axial T1, T2, and FLAIR, and sagittal T2/FLAIR, post contrast axial and sagittal T1, and MRI spinal cord (was done when needed) (cervical cord or other levels, either with contrast or not). It was assessed for lesions typical or atypical for MS, dissemination in space (DIS), and dissemination in time (DIT) according to the 2010 revised McDonald criteria [17]. All MRI assessments were performed by a single rater blinded to clinical data.
The 42 recruited patients were then classified into two groups, patients with clinically isolated syndrome (group 1), who presented with first demyelinating event not fulfilling 2010 revised McDonald criteria [17], and patients with first attack of multiple sclerosis (group 2) who presented with first demyelinating event fulfilling 2010 revised McDonald criteria. CIS patients were followed for 1 year for appearance of new symptoms or worsening of already present symptoms lasting at least for 24 h. Follow-up MRI brain was done at 6 and 12 months; after follow-up period, patients were classified into two groups, patients who remained as CIS (group of MS non-convertor) and patients who converted to MS (McDonald criteria 2017 criteria for MS diagnosis [17] (group of MS convertor).
Signs of neuroinflammation assessed included CSF OCB, IgG index, Chitinase 3-like 1 protein (CHI3L1), brain MRI T2 lesion load, and enhancing white matter lesions, while signs of neurodegeneration evaluated included cognitive dysfunction assessed by MOCA, markers of brain atrophy detected by parenchymatous transcranial sonography, hyper-echogenicity of SN and or dilated third ventricle and frontal horn of lateral ventricle, and T1 black holes in brain MRI.
Statistical analysis
Data were coded and entered using the statistical package SPSS the Statistical Package of Social Science Software program (IBM SPSS Statistics for Windows, Version 23.0. Armonk, NY: IBM Corp.). Data was summarized using mean, standard deviation, median, minimum, and maximum in quantitative data and using frequency (count) and relative frequency (percentage) for categorical data. Comparisons between quantitative variables were done using the non-parametric Kruskal-Wallis and Mann-Whitney tests. For comparing categorical data, chi-square (χ2) test was performed. Exact test was used instead when the expected frequency is less than 5. Logistic regression was done to detect independent predictors of conversion. P-values less than 0.05 were considered as statistically significant. All participants in the study provided informed verbal consent.
