[Sensory aphasia during therapy with metronidazole--an important differential diagnosis of acute cerebral ischemia]. / Sensorische Aphasie unter Therapie mit Metronidazol--eine wichtige Differenzialdiagnose der akuten zerebralen Ischämie.

HISTORY AND ADMISSION FINDINGS: A 74-year old man was admitted after neurosurgical treatment of a lumbar vertebral fracture. He had a slight paresis of the right leg in combination with bladder dysfunction. INVESTIGATIONS: There were signs of a postoperative anemia (hemoglobin 10.4 mg/dl) and mildly elevated infection parameters (CRP 2 mg/dl). Routine ECG and chest X-ray were normal. TREATMENT AND COURSE: Physical training was initiated, but diarrhea occurred 2 days after admission. As the patient had received antibiotics after the operation, a treatment with metronidazole was initiated under the suspicion of diarrhoea induced by clostridium difficile. At day 6 of treatment a hypertensive crisis (blood pressure 230/120 mmHg) developed, followed by sensory aphasia. Despite treatment at the stroke unit and blood pressure regulation, the clinical signs of aphasia persisted. MRI could not detect an acute cerebral infarction. After discontinuation of metronidazole complete reconstitution occurred within 72 h. CONCLUSION: Metronidazole should be taken into account as cause of severe neurological side effects including ischemia-like syndromes like aphasia.

Interhemispheric transfer of language in patients with left frontal cerebral arteriovenous malformation.

Cerebral arteriovenous malformations (AVMs) are frequently evaluated before therapeutic embolization by superselective injection of anesthetics into individual arterial branches so as to determine whether permanent occlusion would affect eloquent function. In Experiment 1, we used this adaptation of the Wada procedure to study three right-handed adult patients with left frontal cerebral AVMs by injecting vessels in Wernicke's and Broca's areas, respectively, and assessing language functions. The results showed that superselective testing in the inferior division of the left MCA in all three patients produced a dense Wernicke's aphasia. Injections into the left frontal regions, however, resulted in right paresis in all patients, but no language deficits including no loss of fluency. In Experiment 2, Patient 2 underwent fMRI activation for spontaneous word-list generation using multi-slice echo planar BOLD techniques at 1.5 Tesla. A voxel-by-voxel comparison of rest vs activation for each task was performed with a Z-score threshold of 2.5 SD for activated voxels. There was activation in the right hemisphere in the insula, frontal operculum pars opercularis, and inferior frontal gyrus, an area homologous to Broca's area in the left hemisphere. There was also activation in the left hemisphere in the Rolandic region, but language function was unaffected during Wada testing in this area. These data suggested that features of expressive language were no longer controlled by the left frontal lobe where the AVM was located, and provided new evidence for interhemispheric re-organization under conditions of chronic neurovascular disease.