Chronic hematoma superimposed to a large frontotemporal arachnoid cyst: evidence against crowding of audioverbal memory.

We report a patient with a chronic subdural/epidural hematoma superimposed to a large arachnoid cyst occupying the left frontotemporal region. Both were discovered accidentally because of a trigeminal neuralgia and concomitant subjective memory complaints. Patient's sudden selective audioverbal memory impairment probably links to a primary cortical tone deregulation and expressed through deficits of arousal-mediating structures subtly impacted by the hematoma's progression. This case illustrates that in early-onset asymmetrical brain damage (usually left), language, audioverbal memory in particular, should not always come to dominate intact hemisphere function. A severity-threshold may exist below which inter-hemispheric reorganization of audioverbal memory is unlikely.