Aphasia after left thalamic infarction.

We examined a 70-year-old woman who became aphasic after a left thalamic infarction. Computed tomographic scan showed injury that was largely limited to the ventral anterior and rostral ventral lateral thalamic nuclei. Speech was characterized by reduced voice volume, impaired auditory and reading comprehension, perseverations, intermittent use of jargon, fluctuations in the ability to perform confrontation naming, extraneous intrusions, verbal paraphasia, intact repetition skills, and fluent speech that was laconic but grammatically correct. We propose that the deficits after left thalamic injury can be grouped into the following four large clusters: extrapyramidal deficits (decreased or fading voice volume), deficits in lexical access (anomia, verbal paraphasia), deficits in vigilance (neologisms, intrusions, fluctuating performance, jargon, perseverations), and comprehension defects.