Recovery of naming in aphasia: relationship to fluency, comprehension and CT findings

We assessed oral naming skill after left hemisphere ischemic stroke in 54 right-handed aphasics. Initially, almost all had moderate to severe disability in oral naming. After 6 months, normal scores were achieved by one-third of the patients, all with lesions less than 60 cm3 in volume. Only 2 of 18 patients who were nonfluent at 6 months had normal naming then. Among patients with lesions less than 60 cm3 and persistently poor naming, there were two discrete lesion sites: posterior superior temporal-inferior parietal (semantic paraphasic errors) and insula-putamen (phonologic paraphasic errors). Individual variability was notable, with several patients regaining normal naming ability despite posterior temporal or insula-putamen lesions.

Mechanisms of recovery from aphasia: evidence from serial xenon 133 cerebral blood flow studies

In 21 patients who suffered aphasia resulting from left hemisphere ischemic infarction, the xenon 133 inhalation cerebral blood flow technique was used to measure cerebral blood flow within 3 months and 5 to 12 months after stroke. In addition to baseline measurements, cerebral blood flow measurements were also carried out while the patients were performing purposeful listening. In patients with incomplete recovery of comprehension and left posterior temporal-inferior parietal lesions, greater cerebral blood flow occurred with listening in the right inferior frontal region in the late studies than in the early studies. In patients with nearly complete recovery of comprehension and without left posterior temporal-inferior parietal lesions, early listening studies showed diffuse right hemisphere increases in cerebral blood flow. Later listening studies in this latter patient group showed greater cerebral blood flow in the left posterior temporal-inferior parietal region. The study provides evidence for participation of the right hemisphere in language comprehension in recovering aphasics, and for later return of function in left hemisphere regions that may have been functionally impaired early during recovery.

Recovery of single word comprehension: CT-scan correlates

9tory comprehension for single words, as measured by the BDAE Word Discrimination subtest, was studied longitudinally in a group of 37 aphasic patients. The majority of the patients had impaired performance at 1 month postonset, but recovery by Month 6 postonset was quite striking. Damage to Wernicke's area did not preclude recovery of single word comprehension to within the normal range. Only patients with very extensive left hemisphere lesions had incomplete recovery of single word comprehension.

A longitudinal study of speech fluency in aphasia: CT correlates of recovery and persistent nonfluency

The anatomic correlates of speech fluency were studied in 54 right-handed patients with aphasia due to stroke. Speech fluency was assessed at 1 month postonset and then monthly for 5 months. CTs obtained at 5 months postonset were used for lesion localization and volume determination. Persistent nonfluency was associated with lesions in the rolandic cortical region and underlying white matter. Recovery from nonfluency occurred in 6 of 27 patients. Lesions in these six patients were less extensive than lesions in patients with persistent nonfluency. Patients who were fluent by 1 month lacked extensive rolandic lesions.

Computed tomographic scan correlates of auditory comprehension deficits in aphasia: a prospective recovery study

Lesion localization and volume as assessed on computed tomography were analyzed to determine their relationships to auditory comprehension deficits following left hemisphere ischemic stroke in 39 patients. Auditory comprehension was initially tested approximately four weeks after onset, and then monthly for five months, using the Token Test, a series of commands of increasing complexity. Computed tomographic scans obtained five months after onset were used for lesion localization and volume determination. Lesions in the posterior superior temporal and infrasylvian supramarginal regions were strongly associated with poor outcome. Patients with initially preserved auditory comprehension tended to have lesions that spared these regions, whereas patients with persistent deficits had lesions that included these regions. Six of 8 patients who initially had severe deficits in auditory comprehension but recovered completely lacked lesions in these regions. Lesion volume except when very large or very small was not closely associated with outcome.

Indications for echocardiography in patients with ischemic stroke

The recent availability of two-dimensional echocardiography (2DE) has fostered the expectation that cardiac embolic sources could be identified or excluded with certitude in ischemic stroke patients. As a screening procedure, 2DE has had a low yield. In selected patients, 2DE holds promise as a useful diagnostic test. Stroke patients who may benefit from 2DE include patients under age 45, patients with suspected left atrial myxoma, and patients with known infective endocarditis, prosthetic heart valves, or rheumatic valvular heart disease. In patients with ischemic heart disease, the yield of useful information from 2DE will be low but may, on occasion, influence management.

Regional cerebral blood flow correlates of auditory processing

To study the regional cerebral blood flow (rCBF) correlates of auditory processing, we performed rCBF measurements in young, normal right-handed volunteers engaged in listening tasks. Using the xenon Xe 133 inhalation technique, rCBF was measured in 11 regions in each hemisphere. Compared with a baseline condition, significant rCBF increases in the left posterior Sylvian regions were associated with both verbal phonologic processing and nonverbal acoustic processing. Verbal semantic processing was associated with unilateral increased rCBF in the posterior Sylvian region contralateral to the hand used for response signaling. Comparison of rCBF from homologous regions of the two hemispheres also confirmed a clear difference between the rhyme detection and meaning detection tasks, with the former strongly lateralized to the left hemisphere. Thus, changes in rCBF were related to the nature of the listening task.

Echocardiography in diagnostic assessment of stroke

We assessed the use of echocardiography in the evaluation of stroke by recording M-mode and two-dimensional (2D) echocardiograms in 100 consecutive hospitalized patients. Of the 95 persons satisfactorily imaged with 2D echocardiography, 47 lacked clinical and routine laboratory evidence of heart disease; no potential embolic source or other finding that altered therapy was diagnosed by echocardiography. In the remaining 48 patients with clinical or routine laboratory evidence of heart disease, two with left ventricular thrombus as a potential embolic source were identified by 2D echocardiography. M-mode echocardiograms failed to detect the thrombus in either patient. No patients with left atrial thrombi, mitral stenosis, cardiac tumor, or vegetations suggesting endocarditis were identified. One patient had possible mitral valve prolapse. Echocardiograms in patients lacking other available evidence of heart disease are unlikely to yield findings that alter the clinical approach to patients with stroke; echocardiography in stroke patients with clinically evident heart disease may have greater clinical utility; additional study of the role of echocardiography in selected subgroups of stroke patients is indicated.

Leptomeningeal artery atherosclerosis visualized by angiography: clinical correlates

Circumscribed atherosclerotic involvement of secondary and tertiary branches of major cerebral arteries is a common angiographic finding whose nature is rarely in question. However, widespread and severe changes are unusual, and radiologic interpretation may be more difficult. We recently cared for a patient whose angiogram demonstrated extensive involvement of leptomeningeal vessels and were prompted to review the clinical courses and autopsy findings of a number of other patients with similar angiographic findings. Our observations suggest that the radiological appearance of leptomeningeal artery atherosclerosis can be confused with that of an arteritis. Atherosclerosis of leptomeningeal arteries is strongly associated with a history of arterial hypertension and seems to parallel arterial lesions thought responsible for lacunar infarction and intraparenchymal hemorrhage.