Prevalence of neuromyelitis optica spectrum disorder and phenotype distribution.
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.
Bizzoco
Elisa
E
Department of Neurological and Psychiatric Sciences, Careggi Hospital, Florence, Italy.
Lolli
Francesco
F
Repice
Anna Maria
AM
Hakiki
Bahia
B
Falcini
Mario
M
Barilaro
Alessandro
A
Taiuti
Rosanna
R
Siracusa
Gianfranco
G
Amato
Maria Pia
MP
Biagioli
Tiziana
T
Lori
Silvia
S
Moretti
Marco
M
Vinattieri
Annalisa
A
Nencini
Patrizia
P
Massacesi
Luca
L
Matà
Sabrina
S
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
D043025:Oligoclonal Bands