Olfactory Bulb Hyperplasia in Genetically Confirmed Infantile Alexander Disease

Abstract

Alexander Disease (AxD) is a well-known leukodystrophy with characteristic findings on brain Magnetic Resonance Imaging (MRI) including bilaterally symmetric, frontal confluent white matter signal abnormality with relative sparing of the parietal and occipital lobes, abnormal signal in the cerebellum and brainstem, as well as swelling of the deep grey nuclei. Aside from tumour-like “masses” thought to reflect collections of Glial Fibrillary Acid Protein (GFAP), there are no additional reported associations within the central nervous system in this disease. However, in our experience authors have noted that the olfactory bulbs are more prominent in patients with AxD than in age-matched controls. Here, a 12-year-old boy with genetically confirmed AxD, with classic brain parenchymal changes and large olfactory bulbs is reported. Although the clinical implications of this finding are currently unclear, identification and reporting of this potentially associated finding may have a role in the management of patients with AxD and could be valuable for treatment of unrelated medical issues.

Keywords

• brain
• leukodystrophy
• paediatrics