These tests evaluate both parasympathetic and sympathetic components of cardiovascular regulation.

Autonomic dysfunction assessment using COMPASS-31 questionnaire (Arabic validated version) (12):The Composite Autonomic Symptom Score 31 (COMPASS-31) is a validated, self-administered questionnaire derived from the original 169-item Autonomic Symptom Profile. It provides a concise yet comprehensive evaluation of autonomic symptoms across six domains: orthostatic intolerance, vasomotor, secretomotor, gastrointestinal, bladder, and pupillomotor functions. The total weighted score ranges from 0-100, with higher scores reflecting greater autonomic symptom burden.

D. Fatigue and psychiatric symptoms

• Fatigue Severity Scale (FSS): Nine-item scale measuring the impact of fatigue on physical, occupational, and social functioning. Widely validated in MS and NMOSD cohorts.
• Hamilton Depression Rating Scale (HAM-D)&Hamilton Anxiety Rating Scale (HAM-A): Clinician-administered tools that quantify depression and anxiety severity, respectively. Inclusion is important given the known bidirectional relationship between autonomic dysfunction and mood disorders.

E. Quality of life. o The SF-36 is a generic health-related quality of life tool with 36 items covering eight domains (physical functioning, role limitations due to physical/emotional health, pain, vitality, mental health, social functioning, and general health).

A. Neuroimaging: Brain and Spinal MRI

o MRI will be reviewed for lesion load (number and volume) and lesion topography (anatomical distribution).

Assessments will be performed by a neuroradiologist blinded to clinical