Cognitive impairment in adult Alexander disease

Alexander disease (AxD) is a rare progressive astrogliopathy and leukodystrophy caused by heterozygous pathogenic variants in the gene encoding glial fibrillary acidic protein (GFAP). Cognitive problems in AxD have long been recognized, but domain-specific neuropsychological descriptions of adult-onset Alexander disease (AO-AxD) remain sparse. We report a genetically confirmed 53-year-old man with AO-AxD who underwent comprehensive neuropsychological assessment because of progressive cognitive and behavioral complaints. The profile was characterized by deficient verbal episodic memory retrieval and reduced set-shifting efficiency, with relatively preserved recognition memory, language, visuospatial abilities, and most attentional measures. Structural MRI showed characteristic medullary and upper cervical cord involvement but only limited supratentorial white matter abnormalities. To contextualize the case, we reviewed published AO-AxD reports with domain-specific neuropsychological testing. The available literature remains limited and heterogeneous, but suggests that cognitive manifestations in AO-AxD may include retrieval-based memory deficits, executive inefficiency, and visuospatial difficulties. We discuss these findings in relation to white matter dementia, fronto-subcortical and fronto-hippocampal network dysfunction, and potential astrocyte-mediated mechanisms.