Type of the Study: randomized double blinded placebo controlled study. Study Setting: MS outpatient clinic in Ain Shams University hospital and Dar Alshefa Hospital, they are located in Eastern Cairo and serves large sector of the ministry of health patients in Greater Cairo.~Period two years. Population patients with relapsing remittent multiple sclerosis attending to ms clinic meeting the inclusion criteria.~Sample size: 100 patients (50 patients in active group and 50 patients in placebo group).~Study Procedures:~Patients diagnosed with MS will be evaluated for inclusion and exclusion criteria using the selected screening scales. Eligible patients will be randomly assigned to one of two groups: dalfampridine ER 10mg twice daily group and placebo group for 12 consecutive weeks.~All patients will be subjected to:~Comprehensive medical history and neurological examination. Demographic information (sex, age and education years), as well as clinical characteristics of them (age at onset, duration of illness, onset of last relapse, received DMD and other medications during the study).~MRI brain and spine lesions (site & number of lesions). Check list for side effects of dalfampridine. Expanded Disability Status Scale (EDSS) (Kurtzke, 1983). The Patient Health Questionnaire (PHQ-9) Arabic translation (Kroenke et al., 2001).~Gait assessment by:~Timed 25 foot walk test (25FWT) (Motl et al., 2017).~Hauser ambulatory index (Hauser et al., 1983).~Berg balance scale (Berg et al., 1992).~Falls in last 2 weeks.~Cognitive assessment by:~Arabic validated version of the BICAM battery, which compromised the symbol digit modality test (SDMT, information processing speed), verbal learning test (VLT, verbal memory) and brief visuospatial memory teat revised (BVMT-R, visual memory) (Alboudi et al., 2020).~Montreal Cognitive Assessment (MoCA) Arabic version (Abd El-Rahman and El-Gaafary, 2009).~Frontal assessment battery (FAB) (for executive functions) (Dubois and Litvan, 2000).~Fatigue assessment by:~o Modified fatigue impact scale (MFIS) in last 4 weeks Arabic version (Farran et al., 2020).~• Assessment for gait, cognition and fatigue will be done at baseline and after 12 weeks of treatment by a blinded rater.
The only approved treatment for impaired ambulation in MS is Dalfampridine (also known as fampridine, 4-aminopyridine, 4-AP). Fampridine penetrates the blood-brain barrier and improves impaired axonal conduction by selectively blocking potassium channels. Moreover, further studies investigated the possible beneficial effect of dalfampridine on cognitive functions and fatigue.~The main objective of this study is to investigate the effect of dalfampridine on gait impairment, cognitive functions and fatigue in a sample of Egyptian patients with multiple sclerosis.