Fronto-temporal lobar degeneration - semantic variant


This patient's primary presenting complaint was progressive deterioration in language function, most specifically relating to semantic knowledge. Striking deficits of recognition, naming and abstraction on bedside cognitive examination with fluent but empty speech, word approximations and anosognosia on mental state examination. Otherwise healthy and well with no personal or family history of medical or psychiatric illness.

A language-variant frontotemporal dementia (primary progressive aphasia) was suspected.

Structural neuroimaging demonstrated marked asymmetric temporal lobe atrophy more promininently affecting the left side - an impression that correlated to asymmetric hypometabolism on functional neuroimaging. The pathological diagnosis was frontotemporal lobar degerenation.

Clinical neuropsychology further resolved the pathological diagnosis to semantic dementia on account of preserved fluency of speech and intact repetion, but marked impairment of semantic knowledge and recognition.