The relationship between oestrogen and executive functioning in ALS females with emerging Frontotemporal Lobar Degeneration (FTLD) supports a neuroendocrine model of FTLD attenuation.

OBJECTIVE: The prevalence of ALS cognitive or behavioural impairment (ci or bi) consistent with Frontotemporal Degeneration (FTLD) approachs 50%, while ∼5-10% progress to dementia. Our goal was to explore ci and bi differencs between bulbar and limb onset, as well as the neuroprotective potential of oestrogen in emerging FTLD.

METHODS: We applied Mann Whitney U to evaluate differences in cognitive and behavioural profiles between site of onset in 78 female and 83 male non-demented ALS participants classified by current consensus criteria with ci. For females, we also examined differences by oestrogen level.

FINDINGS: Between group analyses found significantly worse Letter Fluency (LF) for bulbar onset, and worse Category Fluency (CF) for bulbar females. Significantly worse performance was found for low oestrogen females for LF and Similarities, with significantly worse LF for low oestrogen bulbar onset. No significant differences were found for behavioural subgroups, while moderate-severe range traits were higher in occurrence for bulbar and low oestrogen bulbar onset.

CONCLUSIONS: Findings support our previously published mesocortical pathway associated "bottom-up" model of FTLD emergence in ALSbi, extending it with a hierarchal hypothesis involving ascending cerebellar pathways in ALSci and ALSbi, further suggesting a role for oestrogen in mitigating female FTLD progression.