The Role of Brodmann Area 47 in Acute Stroke Patients with Language Impairment

A recent study in chronic stroke patients found that left Brodmann area 47 was among the most commonly lesioned area (more commonly than Brodmann area 44/45) in patients with chronic deficits in reading, naming, and repetition. We hypothesized that the same would not be true in acute stroke; that left BA 44 and 45 would be more commonly associated with these acute lexical deficits. We confirmed this hypothesis and speculate that left BA 47 is an area is critical for recovery of lexical production, perhaps because it can assume lexical production when BA 44/45 are damaged when it is spared

Areas of Right Hemisphere Ischemia Associated with Impaired Comprehension of Affective Prosody in Acute Stroke

We studied 25 participants within 24 hours of acute right hemisphere ischemic stroke and 17 age and education matched hospitalized controls on tests of comprehension of affective prosody. Stroke patients were significantly more impaired than controls in identifying sarcasm versus sincerity in sentences and identifying affective prosody in sentences, monosyllables, and asyllabic utterances, and in discriminating differences in affective prosody in sentences. Impairments in prosodic comprehension were most associated with acute tissue dysfunction in right posterior frontal cortex, posterior inferior temporal cortex, and thalamus

Asyntactic comprehension and working memory in Broca's aphasia

We hypothesized that in acute stroke, some patients show structure-specific, task-independent deficits in sentence comprehension, with chance level of accuracy on passive reversible sentences, more impaired comprehension of object-cleft than subject-cleft sentences, and more impaired comprehension of reversible than irreversible sentences in both sentence-picture matching and enactment tasks, but that this pattern of "asyntactic comprehension" is associated with impaired working memory rather than dysfunctional tissue in Broca's area as previously proposed. We found that the pattern did exist, but was often independent of both impaired working memory and ischemia in Broca’s area (which were less often independent of one another)

Patterns of Decline on Language Testing in Primary Progressive Aphasia

The aim of this study was to investigate patterns of decline on language testing in subtypes of primary progressive aphasia (PPA) and to examine the effects of other variables on rate of decline. Forty-six patients with PPA (mean age = 66.9 + 6.6; 27 female; mean education = 16.4 + 2.8) completed language testing. PPA subtypes were not distinguishable by rapidity of decline; however, there were different patterns of performance on language testing. Age and education did not affect rate of decline on any test. These results have implications for patient/family education regarding language deterioration and future planning

Disentangling the Neuroanatomical Correlates of Perseveration from Unilateral Spatial Neglect

Perseverative behavior, manifest as re-cancelling or re-visiting targets, is distinct from spatial neglect. Perseveration is thought to reflect frontal or parietal lobe dysfunction, but the neuroanatomical correlates remain poorly defined and the interplay between neglect and perseveration is incompletely understood. We enrolled 87 consecutive patients with diffusion-weighted, perfusion-weighted imaging, and spatial neglect testing within 24 hours of right hemisphere ischemic stroke. The degrees of spatial neglect and perseveration were analyzed. Perseveration was apparent in 46% (40/87) of the patients; 28% (24/87) showed perseveration only; 18% (16/87) showed both perseveration and neglect; and 3% (3/87) showed neglect only. Perseverative behaviors occur in an inverted “U” shape: little neglect was associated with few perseverations; moderate neglect with high perseverations; and in severe neglect targets may not enter consciousness and perseverative responses decrease. Brodmann areas of dysfunction, and the caudate and putament, were assessed and volumetrically measured. In this study, the caudate and putamen were not associated with perseveration. After controlling for neglect, and volume of dysfunctional tissue, only Brodmann area 46 was associated with perseveration. Our results further support the notion that perseveration and neglect are distinct entities; while they often co-occur, acute dorsolateral prefrontal cortex ischemia is associated with perseveration specifically

Acute recovery of oral word production following stroke: Patterns of performance as predictors of recovery

Background: Impairments in oral word production are common at the onset of stroke. The identification of factors that predict early recovery has important implications for identifying those at greater risk of continued impaired functioning, and the management of the patient's care following discharge

Neuroanatomical correlates of oral reading in acute left hemispheric stroke

Oral reading is a complex skill involving the interaction of orthographic, phonological, and semantic processes. Functional imaging studies with non-impaired adult readers have identified a widely distributed network of frontal, inferior parietal, posterior temporal, and occipital brain regions involved in the task. However, while functional imaging can identify cortical regions engaged in the process under examination, it cannot identify those brain regions essential for the task. The current study aimed to identify those neuroanatomical regions critical for successful oral reading by examining the relationship between word and nonword oral reading deficits and areas of tissue dysfunction in acute stroke. We evaluated 91 patients with left hemisphere ischemic stroke with a test of oral word and nonword reading, and magnetic resonance diffusion-weighted and perfusion-weighted imaging, within 24–48 hours of stroke onset. A voxel-wise statistical map showed that impairments in word and nonword reading were associated with a distributed network of brain regions, including the inferior and middle frontal gyri, the middle temporal gyrus, the supramarginal and angular gyri, and the middle occipital gyrus. In addition, lesions associated with word deficits were found to be distributed more frontally, while nonword deficits were associated with lesions distributed more posteriorly

Patterns of reading performance in acute stroke: A descriptive analysis

Abstract. One of the main sources of information regarding the underlying processes involved in both normal and impaired reading has been the study of reading deficits that occur as a result of brain damage. However, patterns of reading deficits found acutely after brain injury have been little explored. The observed patterns of performance in chronic stroke patients might reflect reorganization of the cognitive processes underlying reading or development of compensatory strategies that are not normally used to read. Method: 112 acute left hemisphere stroke patients were administered a task of oral reading of words and pseudowords within 1-2 days of hospital admission; performance was examined for error rate and type, and compared to that on tasks involving visual lexical decision, visual/auditory comprehension, and naming. Results: Several distinct patterns of performance were identified. Although similarities were found between the patterns of reading performance observed acutely and the classical acquired dyslexias generally identified more chronically, some notable differences were observed. Of interest was the finding that no patient produced any pure semantic errors in reading, despite finding such errors in comprehension and naming

Patterns of reading performance in acute stroke: A descriptive analysis

One of the main sources of information regarding the underlying processes involved in both normal and impaired reading has been the study of reading deficits that occur as a result of brain damage. However, patterns of reading deficits found acutely after brain injury have been little explored. The observed patterns of performance in chronic stroke patients might reflect reorganization of the cognitive processes underlying reading or development of compensatory strategies that are not normally used to read. Method: 112 acute left hemisphere stroke patients were administered a task of oral reading of words and pseudowords within 1–2 days of hospital admission; performance was examined for error rate and type, and compared to that on tasks involving visual lexical decision, visual/auditory comprehension, and naming. Results: Several distinct patterns of performance were identified. Although similarities were found between the patterns of reading performance observed acutely and the classical acquired dyslexias generally identified more chronically, some notable differences were observed. Of interest was the finding that no patient produced any pure semantic errors in reading, despite finding such errors in comprehension and naming