Effects of fatigue on Neuromyelitis Optica

BackgroundNeuromyelitis Optica (NMO) is an inflammatory demyelinating disorder ofthe central nervous system characterised by relapses affecting opticnerves and longitudinal extensive transverse myelitis resulting invisual and physical disabilities and often neuropathic pain. Little isknown regarding the occurrence or types of fatigue in NMO. The ModifiedFatigue Impact Scale (MFIS) (Fisk et al 1994) provides an assessment ofthe effects of fatigue in terms of physical, cognitive and psychosocialfunctioning and focuses on the ways in which fatigue affects everydaylife.ObjectiveThe aim of the study was to investigate the frequency and features offatigue in NMO.Method37 patients with a diagnosis of NMO or NMO spectrum disorder whom hadaquaporin-4 antibodies, attending the National NMO clinic at WaltonCentre, Liverpool were assessed. The MFIS is a structured self-reportquestionnaire. The patients were asked to circle the number that bestindicates how often fatigue has affected them in the last 4 weeks from achoice of never, rarely, sometimes, often and almost always.Results23/37 (62%) patients were often or almost always affected by physicalfatigue.9/37 (24%) patients were often or almost always affected by cognitivefatigue.19/37 (51%) patients were often or almost always affected bypsychosocial fatigue.16/37 (43%) patients were fatigue significantly impacted on everydaylife.ConclusionFatigue appears to affect approximately 50% people living with NMO.Transverse myelitis in NMO causes significant disability and reducedmobility. The predominance of physical fatigue is in keeping with thisand has the biggest impact on their everyday life. Interestingly,unlike multiple sclerosis, cognitive fatigue does not appear to affectthe majority patients with NMO.