Neuromyelitis optica: Evaluation of 871 attacks and 1153 treatment courses

OBJECTIVE: Neuromyelitis optica (NMO) attacks are often severe, difficult to treat, and leave residual deficits. Here, we analyzed the frequency, sequence, and efficacy of therapies used for NMO attacks.

METHODS: Retrospective review of patient records to assess demographic/diagnostic data, attack characteristics, therapies, and the short-term remission status (complete, CR; partial, PR; no remission, NR). Inclusion criteria were NMO according to Wingerchuk's 2006 criteria or aquaporin-4 antibody-positive NMO spectrum disorder (NMOSD). Remission status was analyzed with generalized estimating equations (GEE), a patient-based statistical approach.

RESULTS: 871 attacks in 185 patients (142 NMO/43 NMOSD, 82% female) were analyzed. The 1153 treatment courses comprised high-dose intravenous steroids (HD-S, n=810), plasma exchange (PE, n=192), immunoadsorption (IA, n=38), other (n=80), and unknown (n=33) therapies. The first treatment course led to CR in 19.1%, PR in 64.5%, and NR in 16.4% of attacks. Second, third, fourth, and fifth treatment courses were given in 28.2%, 7.1%, 1.4%, and 0.5% of attacks, respectively. This escalation of attack therapy significantly improved outcome (p<0.001, Bowker's test). Remission rates were higher for isolated optic neuritis vs. isolated myelitis (p<0.001,), and for unilateral vs. bilateral optic neuritis (p=0.020). Isolated myelitis responded better to PE/IA than to HD-S as first treatment course (p=0.037). Predictors of CR in multivariate GEE analysis were age (OR=0.97; p=0.011), presence of myelitis (OR=0.38; p=0.002), CR from previous attack (OR=6.85; p<0.001), and first-line PE/IA vs. HD-S (OR=4.38; p=0.006).

INTERPRETATION: Particularly myelitis and bilateral ON have poor remission rates. Escalation of attack therapy improves outcome. PE/IA may increase recovery in isolated myelitis.