title: Prevalence of neuromyelitis optica spectrum disorder and phenotype distribution.
abstract: Neuromyelitis optica spectrum disorder (NMOsd) is a group of demyelinating disorders recently redefined and associated with NMO-IgG/anti-aquaporin 4 antibodies. Because NMOsd is of unknown prevalence worldwide, we conducted a retrospective, cross-sectional study of 850 patients with demyelinating disorders hospitalized in North East Tuscany from 1998 to 2006 to examine the prevalence of NMO and related disorders among unselected consecutive neurological patients with inflammatory CNS diseases and to evaluate the clinical phenotype spectrum of identified cases. Clinical data were updated after at least 2 years of follow-up. An immunofluorescence technique was used to detect NMO-IgG on rat brain tissue. Sera from other 828 neurological patients, 65 non-neurological patients and 50 healthy donors served as controls. The prevalence of NMOsd was 1.5%, with a MS:NMOsd ratio of 42.7. Among 13 NMOsd patients, 77% had long spinal cord lesions, 38% had severe optic neuritis and 23% had brain or brainstem lesions. Only 56% had clinically definite NMO at follow-up. The final EDSS score ranged from 1 to 10, mainly depending on brainstem involvement occurrence. Our findings confirm a low prevalence of NMO and related disorders among demyelinating inflammatory diseases in a Caucasian population. Moreover, this study demonstrates an unexpectedly high prevalence of limited and atypical variants of this disease, not previously documented.
authors.affiliation: Department of Neurological and Psychiatric Sciences, Careggi Hospital, Florence, Italy.
authors.forename: Elisa
authors.initials: E
authors.lastname: Bizzoco
authors.forename: Francesco
authors.initials: F
authors.lastname: Lolli
authors.forename: Anna Maria
authors.initials: AM
authors.lastname: Repice
authors.forename: Bahia
authors.initials: B
authors.lastname: Hakiki
authors.forename: Mario
authors.initials: M
authors.lastname: Falcini
authors.forename: Alessandro
authors.initials: A
authors.lastname: Barilaro
authors.forename: Rosanna
authors.initials: R
authors.lastname: Taiuti
authors.forename: Gianfranco
authors.initials: G
authors.lastname: Siracusa
authors.forename: Maria Pia
authors.initials: MP
authors.lastname: Amato
authors.forename: Tiziana
authors.initials: T
authors.lastname: Biagioli
authors.forename: Silvia
authors.initials: S
authors.lastname: Lori
authors.forename: Marco
authors.initials: M
authors.lastname: Moretti
authors.forename: Annalisa
authors.initials: A
authors.lastname: Vinattieri
authors.forename: Patrizia
authors.initials: P
authors.lastname: Nencini
authors.forename: Luca
authors.initials: L
authors.lastname: Massacesi
authors.forename: Sabrina
authors.initials: S
authors.lastname: Matà
mesh_terms: D000293:Adolescent; D000328:Adult; D017668:Age of Onset; D000368:Aged; D000369:Aged, 80 and over; D000818:Animals; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D020278:Demyelinating Autoimmune Diseases, CNS / Q000453:epidemiology / Q000503:physiopathology; D005260:Female; D006801:Humans; D007558:Italy / Q000453:epidemiology; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D009471:Neuromyelitis Optica / Q000453:epidemiology* / Q000503:physiopathology*; D043025:Oligoclonal Bands / Q000097:blood / Q000134:cerebrospinal fluid; D010641:Phenotype; D015995:Prevalence; D051381:Rats; D012189:Retrospective Studies; D012720:Severity of Illness Index; D018709:Statistics, Nonparametric; D055815:Young Adult
chemical_list: D043025:Oligoclonal Bands