Atrophy of optic nerve detected by transorbital sonography in patients with demyelinating diseases of the central nervous system

$\textbf {Background and purpose}$ Transorbital sonography (TOS) has emerged as promising imaging method for the diagnosis and follow-up of acute optic neuritis (ON). Available studies report an increase in the optic nerve diameter (OND) and the optic nerve sheath diameter (ONSD) in the case of a first episode of ON in the affected eye compared to either the contralateral unaffected eye or controls. However, the utility of TOS in the case of recurrent episodes of ON has never been assessed. $\bf Methods$ In our prospective cohort study, the diagnostic utility of TOS in patients with demyelinating diseases of the central nervous system was assessed, and the association between TOS, optical coherence tomography (OCT) and visual evoked potentials was examined further. $\bf Results$ Seventy-eight patients with a history of demyelinating disorders of the central nervous system (mean age 38.2 $\pm$ 14.2 years; 24% with acute ON) were included. No differences in the OND (3.2 $\pm$ 0.5 mm vs. 3.2 $\pm$ 0.4 mm) and ONSD (5.1 $\pm$ 0.8 mm vs. 5.1 $\pm$ 0.7 mm) measurements were found between patients with and without acute ON. Papillary swelling was more frequent in patients with acute ON (14.2% vs. 1.5%, $\it P$ = 0.002). Patients with a history of previous ON were found to have lower OND ($\it P$ < 0.001) and ONSD ($\it P$ = 0.007) compared to patients without a history of previous ON. TOS measurements were inversely associated with disease duration and positively correlated with OCT findings. No association with visual evoked potential measurements was found. $\bf Conclusion$ No evidence was found for TOS-sensitive differences in the OND and ONSD of patients with demyelinating diseases, according to the presence of acute ON. The association between TOS and OCT measurements deserves further investigation

Apheresis therapies for NMOSD attacks

$\bf Objective$ To analyze whether 1 of the 2 apheresis techniques, therapeutic plasma exchange (PE) or immunoadsorption (IA), is superior in treating neuromyelitis optica spectrum disorder (NMOSD) attacks and to identify predictive factors for complete remission (CR). $\bf Methods$ This retrospective cohort study was based on the registry of the German Neuromyelitis Optica Study Group, a nationwide network established in 2008. It recruited patients with neuromyelitis optica diagnosed according to the 2006 Wingerchuk criteria or with aquaporin-4 (AQP4-ab)-antibody–seropositive NMOSD treated at 6 regional hospitals and 16 tertiary referral centers until March 2013. Besides descriptive data analysis of patient and attack characteristics, generalized estimation equation (GEE) analyses were applied to compare the effectiveness of the 2 apheresis techniques. A GEE model was generated to assess predictors of outcome. $\bf Results$ Two hundred and seven attacks in 105 patients (87% AQP4-ab-antibody seropositive) were treated with at least 1 apheresis therapy. Neither PE nor IA was proven superior in the therapy of NMOSD attacks. CR was only achieved with early apheresis therapy. Strong predictors for CR were the use of apheresis therapy as first-line therapy (OR 12.27, 95% CI: 1.04–144.91, $\it {p}$ = 0.047), time from onset of attack to start of therapy in days (OR 0.94, 95% CI: 0.89–0.99, $\it {p}$ = 0.014), the presence of AQP4-abantibodies (OR 33.34, 95% CI: 1.76–631.17, $\it {p}$ = 0.019), and monofocal attack manifestation (OR 4.71, 95% CI: 1.03–21.62, $\it {p}$ = 0.046). $\bf Conclusions$ Our findings suggest early use of an apheresis therapy in NMOSD attacks, particularly in AQP4-ab-seropositive patients. No superiority was shown for one of the 2 apheresis techniques. $\textbf {Classification of evidence}$ This study provides Class IV evidence that for patients with NMOSD, neither PE nor IA is superior in the treatment of attacks