Has anyone seen this? (aphasia or dysphasia is a difficulty with word finding or producing speech - its not slurred speech)
Transient high altitude expressive aphasia
Transient focal neurological deficits have been described in sojourners to high altitude. We present two cases of transient expressive aphasia in well-acclimatized high altitude climbers. We speculate that this type of transient focal neurological impairment may represent migraine aura, and we discuss other reports of transient focal neurological deficit at high altitude.
(I should say I am a neurologist)