Radiological characteristics of neuromyelitis optica spectrum disorder in Kuwait

Neuromyelitis optica spectrum disorder (NMOSD) is an inflammatory demyelinating disorder of the central nervous system that predominantly targets optic nerves and spinal cord. Studies of NMOSD are scarce in the Middle East.

To evaluate the MRI characteristics of NMOSD patients in Kuwait.

This is an observational, retrospective study on NMOSD patients who attended the MS clinic. Patients who fulfilled the 2015 diagnostic criteria of NMOSD were included. Patients` clinical, radiological and serological data were extracted from the medical records. The radiological variables were compared according to gender and AQP4 serostatus.

Forty-two patients fulfilling the NMOSD diagnostic criteria. The mean age and mean age of onset were 32.6 ± 11.4 and 28.9 ± 9.8 years respectively. Females represented 83.3 % of the cohort with female-to-male ratio of 5:1. Thirty-one patients (73.8 %) tested positive for AQP4 antibody. Nineteen patients (45.2 %) had bilateral optic nerve involvement, while chiasmal involvement was seen in 8 (19.0 %) patients. Spinal cord was involved in 36 (85.7 %) patients; of whom 27 (64.3 %) had LETM. The most common spinal segment involved was the cervical (72.2 %) followed by the dorsal (25.0 %) regions. The brain was involved in 39 (92.8 %) patients and the periventricular region around fourth and lateral ventricles was the most commonly involved site (n = 35; 83.3 %), along with periaqueductal (n = 25; 61.9 %) and corpus callosal (n = 24; 57.1 %) regions. Isolated area postrema involvement was observed in 9 (21.4 %) patients.

This is the first study describing the radiological characteristics of NMOSD in Kuwait. Although our data is comparable with the previous international studies, a higher percentage of bilateral optic nerve, brain, and callosal involvement was observed. Further multicenter studies with a larger cohort are needed to confirm our results.