Abstract
Atypical aphasia caused by left subcortical infarction involving the anterior arcuate fasciculus was reported.
A 54-year-old right-handed woman suddenly became unable to speak with right hemiplegia. After showing mutism for 2 months, her auditory comprehension became good, and her spontaneous speech was gradually increased with occasional jargon-like utterance.
Three months after onset, she was evaluated by neuropsychological tests. Western Aphasia Battery (WAB) revealed that her spontaneous speech was mildly fluent but with short sentences, agrammatism, word-finding pauses, perseverations, and occasional semantic and phonemic paraphasias. In contrast, her voluntary speech involving naming, repeating, description of pictures, and reading kanji-words aloud, were non-fluent with frequent phonemic paraphasias, neologisms, and “conduites d'approche” . She was unable to write except for her name. Mild buccofacial apraxia was noted. Her cognition, behavior, constructional abilities were intact. By the WAB aphasia type criteria, her aphasia was categorized as Broca's aphasia or conduction aphasia.
CT scan and MRI revealed a left subcortical lesion, involving the putamen, the external capsule, the claustrum, and the arcuate fasciculus underlying the upper insula and a part of superior longitudinal fasciculus. Anterior lesions involved the arcuate fasciculus and a part of the peripheral Broca's area (the foot of inferior frontal gyrus), but sparing the lower pre-central gyrus responsible for anarthria.
The present case shows symptoms characteristic of conduction aphasia including phonemic paraphasias and repetition difficulties with “conduit d'approche” , and of Broca's aphasia including severe word-finding difficulties and perseveration. In conclusion, it is suggested that the patient's non-fluent atypical conduction aphasia consists of the phonological symptoms attributable to the lesion in the arcuate fasciculus in addition to Broca's aphasia without anarthria.
