Vitamin D receptor gene BsmI (rs1544410) polymorphism: role in multiple sclerosis and genotype-phenotype correlations.

BACKGROUND: Multiple sclerosis (MS) has a complex pathophysiology which depends on many endogenous and exogenous factors. Vitamin D involvement has been largely studied in MS. The large distribution of the vitamin D receptor (VDR) in different immune cells is suggestive of an immunomodulatory role. The VDR gene polymorphisms have been proposed as potential risk factors for MS development or evolution with non-conclusive results. METHODS AND RESULTS: We conducted a cross-sectional study including patients ≥ 18 years, with a diagnosis of relapsing remitting MS according to the McDonald Criteria and having a minimum follow-up period of one year after starting a disease modifying therapy. Two study groups were compared based on the Multiple Sclerosis Severity Scale or MSSS: "a slow progressor" group for an MSSS ≤ 5, and a "fast progressor" group for an MSSS > 5. The rs1544410 VDR gene polymorphism was studied for all patients. Eighty patients were included. The fast progressor groups had a higher EDSS at onset, a higher total number of relapses, more frequent and shorter time to secondary progression. The progression profile was not statistically different between genotypes and alleles of the VDR gene polymorphism rs1544410. The CC genotype and wild-type allele exhibited a more aggressive disease phenotype with a higher number of relapses the first year, shorter time to secondary progression and cerebral atrophy on assessment. CONCLUSIONS: Our results suggest potential genotype-phenotype correlations for the rs1544410 VDR gene polymorphism in the disease course of MS. Future research on a larger scale is needed to confirm these findings.

Cognitive impairment in multiple sclerosis: Utility of electroencephalography.

OBJECTIVE: to evaluate associations between neurocognitive impairment and electroencephalography (EEG) data in Multiple Sclerosis (MS). METHODS: patients aged between 18 and 65 years, diagnosed with MS accordingly to the McDonald 2017 criteria and who were in remission for at least one month were included. Cognitive functions were evaluated by validated neuropsychological tests for Tunisian population. Electroencephalography data of each patient were analysed, Grand Total EEG (GTE) score was calculated and we evaluated their statistical links with cognitive impairment. RESULTS: Thirty five patients were included. Slower background activity was associated with presence of: reduced information processing speed (IPS) (p = 0,03), verbal memory impairment (p = 0,04) and executive dysfunction (p = 0,016). The score 3 of GTE (reactivity of background activity) was associated with reduced IPS (p = 0,007) and executive dysfunction (p = 0,014). We found a positive correlation between background activity and Tunisian Verbal Test (TVLT) (ρ =0,46 ; p = 0,005) and Symbol Digit Modalities Test (SDMT) (ρ =0,35 ; p = 0,03). Sensitivity of GTE score was 68,4% for executive dysfunction (cut-off=2,5) and 66,7% for reduced IPS (cut-off=2,5). CONCLUSIONS: Our results have shown utility of EEG in detecting cortical involvement and its correlation with cognitive impairment in MS patients. SIGNIFICANCE: EEG could be a tool for monitoring cortical involvement during MS and predict cognitive impairment.

Utility of EEG on attention deficit-hyperactivity disorder (ADHD).

OBJECTIVE: The aim of our study was to analyze electrophysiological findings in patient with Attention Deficit Hyperactivity Disorder (ADHD) by electroencephalography (EEG) recording, estimate the prevalence of epilepsy in ADHD population and assess its clinical characteristics. METHODS: We conducted a retrospective and analytic study that concerned children with ADHD, followed for at least two-years in the Tunisian National Center for School and University Medicine (NCSUM). All patients recruited underwent at the diagnosis of ADHD, neurological examination and EEG recording in the department of Neurology of Charles Nicolle Hospital. Medical data including family history, ictal semiology and ADHD features were assessed. RESULTS: Thirty patients were enrolled in our study. Mean age was 12.27 years with a sex ratio of 3.28. Mean age at diagnosis of ADHD was 6.6 years. Attention Deficit Hyperactivity Disordercombined subtype was seen in 18/30 patients, Hyperactive/ Impulsive subtype in 7/30 patients and Inattentive subtype in 5/30 patients. Epilepsy-disease was reported in 20% (Seizures preceded the diagnosis of ADHD in 3/6 cases and appeared after an average of 3.67 years in 3/6 cases). Mean age of seizure onset was 7 years. Seizure-types were generalized (motor 4/6 cases, absence-type (1/6 case)) and focal (1/6 case). Electroencephalography revealed Epileptiform discharges in 30% with frontal and left dominance. Interictal discharges were significantly associated with younger age of onset (p: 0.02), inattentive subtype (p: 0.04) and intellectual disability (p: 0.04). These discharges was not associated with epilepsy. CONCLUSION: Our results have shown that epileptiform discharges could be used as risk factor for seizures and cognitive impairment which may influence outcome in ADHD population.