title: Neuromyelitis optica and neuromyelitis optica spectrum disorder: Natural history and long-term outcome, an Indian experience.
abstract: BACKGROUND
  Neuromyelitis optica (NMO) has evolved from devic's classical description to a broader disease spectrum, from monophasic illness to a polyphasic illness with multiple recurrences, disease confined to optic nerve and spinal cord to now brain stem, cerebrum and even endocrinopathy due to hypothalamic involvement.
  
  
  OBJECTIVE
  To report, the epidemiological characteristics, clinical presentations, recurrence rate, treatment and response to therapy in 26 patients with NMO and NMO spectrum disorder among the Indian population.
  
  
  METHODS
  We performed observational, retrospective analysis of our prospectively maintained data base of patients with NMO, longitudinally extensive transverse myelitis during the period of January 2003-December 2012 who satisfied the national multiple sclerosis society (NMSS) task force criteria for diagnosis of NMO and NMO spectrum disorder.
  
  
  RESULTS
  There were 26 patients (female: male, 21:5), the mean age of onset of symptom was 27 years (range 9-58, standard deviation = 12). Twenty-one patients (80%) fulfilled NMSS criteria for NMO while rest 5 patients (20%) were considered as NMO spectrum disorder. Seven patients (27%) had a monophasic illness, 19 patients (73%) had a polyphasic illness with recurrences. The Median recurrence rate was 4/patient in the polyphasic group. 13 (50%) patient were tested for aquaporin 4 antibody, 8 (61%) were positive while 5 patients (39%) were negative. All patients received intravenous methyl prednisolone, 9 patients (35%) required further treatment for acute illness in view of unresponsiveness to steroids. Thirteen patients (50%) received disease-modifying agents for recurrences. Mean duration of follow-up was 5 years. All patients had a good outcome (modified Rankin scale, <3) except one who had poor visual recovery.
  
  
  CONCLUSIONS
  Neuromyelitis optica/NMO spectrum disorder is demyelinating disorder with female predominance, polyphasic course, myelitis being most common event although brain stem involvement is not uncommon with NMO antibody positivity in 60% patients, confirms the literature data.
authors.affiliation: Department of Neurology, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrum, Kerala, India.
authors.forename: Sujit Abajirao
authors.initials: SA
authors.lastname: Jagtap
authors.affiliation: Department of Neurology, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrum, Kerala, India.
authors.forename: Alok
authors.initials: A
authors.lastname: Mandliya
authors.affiliation: Department of Neurology, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrum, Kerala, India.
authors.forename: C
authors.initials: C
authors.lastname: Sarada
authors.affiliation: Department of Neurology, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrum, Kerala, India.
authors.forename: M D
authors.initials: MD
authors.lastname: Nair
keywords: Aquaporin-4; longitudinally extensive transverse myelitis; neuromyelitis optica; optic neuritis