Microstructural injury to the optic nerve with vigabatrin treatment in West syndrome: A DTI study

Abstract

To evaluate optic nerve injury associated with vigabatrin treatment in children with West syndrome using diffusion tensor imaging. Thirty-five children with West syndrome (aged 9 days-22 months) were retrospectively analyzed and grouped as follows: (1) vigabatrin with symmetrical thalamic abnormalities, (2) vigabatrin without thalamic abnormalities, and (3) controls on other anti-seizure medications. Fractional anisotropy and apparent diffusion coefficient values of the optic nerves were assessed. ROC curves were used to determine fractional anisotropy thresholds for optic nerve injury. fractional anisotropy values in group 1 were significantly lower than those in the control group (P < 0.05), while apparent diffusion coefficient values showed no significant differences. fractional anisotropy values increased significantly after vigabatrin discontinuation (P < 0.05). ROC analysis yielded an fractional anisotropy cut-off value of 304 with 63.6% sensitivity and 100% specificity. fractional anisotropy values are a sensitive imaging biomarker for detecting vigabatrin-related optic nerve injury in West syndrome, particularly when thalamic abnormalities are present. These changes appear reversible after stopping vigabatrin.

Keywords: Cytotoxic oedema; Nuclear magnetic resonance; Optic nerve integrity; Vigabatrin.

Fig.1

The red color was marked as the picking point of the right optic tract, and the green color was marked as the picking point of the left optic tract.

Fig.2

The female patient with West syndrome, was started on VGB at a dose of 75.0 mg/kg per day at the age of six months, with a cumulative VGB dose of approximately 141.5 g. A. DWI sequence showed bilateral thalamic symmetrical hyper-intensity, heterogeneous. B. DWI sequences showed abnormal hyper-intensity in the bilateral symmetric globus pallidum, medial geniculate body, and lateral geniculate body with slightly less uniform signal. C. Long arrows refer to retinopathy, and triangles refer to the optic disc.

Fig.3

The ROC curve is drawn according to the results, and within the confidence interval, AUC-LOFA is 0.92 and AUC-ROFA is 0.86, the cut-off value 304 is measured.