Frontal-opercular aphasia

The standard nomenclature divides nonfluent aphasic syndromes with relative ly spared comprehension into Broca's aphasia and transcortical motor aphasi a. We report on a patient with a persistent nonfluent aphasia from a discre te, primarily cortical, frontal-opercular lesion who had impaired syntax bu t intact repetition and, therefore, did not conform to the traditional clas sification. Based on this patient's behavior and a review of other cases, we have divid ed the nonfluent aphasias with intact comprehension into five disorders. (1 ) Verbal akinesia-exhibiting diminished intention or drive to speak and ass ociated with medial frontal lesions (supplementary motor area and cingulate gyrus) or with lesions damaging the efferent projections from these areas. (2) Disorders of syntax-telegraphic and agrammatic utterances that may be associated with dominant pars opercularis lesions. (3) Phonemic disintegrat ion-a failure to correctly produce phonemes, which may be associated with i njury to the opercular primary motor cortex or efferent projections from th is area. (4) Defects of lexical access-patients who struggle to find words and are impaired at timed word-generation tasks. Defects of lexical access may be associated with lesions of the pars triangularis and adjacent prefro ntal cortex. (5) Mixed defects. According to this model, the traditional patient with Broca's aphasia would exhibit disorders of syntax, phonemic disintegration, and defects of lexic al access, whereas the traditional patient with transcortical motor aphasia would have verbal akinesia or defects of lexical access or both. Our patie nt had defects of lexical access and syntax, but only mild symptoms of phon emic disintegration, suggesting that his opercular primary motor cortex was relatively intact. Our patient's ability to repeat normally while his prop ositional speech remained telegraphic suggests that different neural mechan isms subserve these functions. (C) 1999 Academic Press.