Anne L. Foundas

Aspiration in patients with acute stroke

OBJECTIVES To determine the frequency and clinical predictors of aspiration within 5 days of acute stroke. DESIGN Case series. SETTING Tertiary care center. PATIENTS Consecutive stroke patients (n = 55) with new neurologic deficit evaluated within 5 days of acute stroke. MAIN OUTCOME MEASURES Comparison of features identified on clinical swallowing and oromotor examinations and occurrence of aspiration (silent or overt) evident on videofluoroscopic swallow study (VSS). RESULTS Aspiration occurred in 21 of 55 patients (38%). Whereas 7 of 21 patients (33%) aspirated overtly, 14 (67%) aspirated silently on VSS. Chi-square analyses revealed that dysphonia, dysarthria, abnormal gag reflex, abnormal volitional cough, cough after swallow, and voice change after swallow were significantly related to aspiration and were predictors of the subset of patients with silent aspiration. Logistic regression revealed that abnormal volitional cough and cough with swallow, in conjunction, predicted aspiration with 78% accuracy. CONCLUSIONS Silent aspiration appears to be a significant problem in acute stroke patients because silent aspiration occurred in two thirds of the patients who aspirated. The prediction of patients at risk for aspiration was significantly improved by the presence of concurrent findings of abnormal volitional cough and cough with swallow on clinical examination.

Anomalous anatomy of speech–language areas in adults with persistent developmental stuttering

Objective: The major aim of this study was to determine whether adults with persistent developmental stuttering (PDS) have anomalous anatomy in cortical speech–language areas. The major postulate was that anomalous cerebral dominance, reflected by anomalous cortical anatomy in various regions, may put an individual at increased risk for the development of stuttering. Methods: Adults with PDS (n = 16) and controls (n = 16) matched for age, sex, hand preference, and education were studied. Volumetric MRI scans were completed. Frontal (pars triangularis, pars opercularis) and temporo-parietal areas (planum temporale, posterior ascending ramus) were measured in the left and right hemispheres and interhemispheric asymmetries were computed. Gyral variants were assessed within these perisylvian cortical speech–language areas. Results: The right and left planum temporale were significantly larger in the adults with PDS (p = 0.045), and the magnitude of the planar asymmetry was reduced (p = 0.003). Some gyral variants were unique to the adults with PDS, including a second diagonal sulcus and extra gyri along the superior bank of the sylvian fossa. In addition, anatomic subgroups emerged based on sex and hand preference. Overall, the adults with PDS had significantly more gyral variants (mean = 4.19) than controls (mean = 1.31, p < 0.0005). Conclusions: These results provide strong evidence that adults with PDS have anomalous anatomy in perisylvian speech and language areas. No one anatomic feature distinguished the groups, but multiple loci within a widely distributed neural network differed between groups. These results provide the first evidence that anatomic anomalies within perisylvian speech–language areas may put an individual at risk for the development of stuttering.

The role of the insular cortex in dysphagia.

Abstract. Recent data indicate that dysphagia may occur following unilateral cortical stroke; however, the elucidation of specific cytoarchitectonic sites that produce deglutition disorders remains unclear. In a previous study of unilateral cortical stroke patients with dysphagia, Daniels et al. [8] proposed that the insula may be important in swallowing as it was the most common lesion site in the patients studied. Therefore, 4 unilateral stroke patients with discrete lesions of the insular cortex were studied to further facilitate understanding of the role of the insula in swallowing. Dysphagia, as confirmed by videofluoroscopy, was evident in 3 of the 4 patients; all had lesions that involved the anterior insula, whereas the only patient without dysphagia had a lesion restricted to the posterior insula. These data suggest that the anterior insula may be an important cortical substrate in swallowing. The anterior insula has connections to the primary and supplementary motor cortices, the ventroposterior medial nucleus of the thalamus, and to the nucleus tractus solitarius, all of which are important regions in the mediation of oropharyngeal swallowing. Therefore, discrete lesions of the anterior insula may disrupt these connections and, thereby, produce dysphagia.

Clinical Assessment of Swallowing and Prediction of Dysphagia Severity

Dysphagia with aspiration is prevalent in acute stroke; however, noninvasive clinical screening assessments to identify patients at risk of developing aspiration are limited. This study was underta...

MRI Asymmetries of Broca's Area: The Pars Triangularis and Pars Opercularis ☆ ☆☆

Brocas area, which includes the pars triangularis (PTR) and pars opercularis (POP), is a neuroanatomic region important in speech-language production. Previous data demonstrated that PTR asymmetries are highly correlated with language dominance determined by selective hemispheric anesthesia or Wada testing, suggesting that asymmetries of the PTR may, in part, predict language dominance. The POP, however, has not been measured on volumetric magnetic resonance imaging (MRI), and therefore, it is unclear whether morphological asymmetries of the POP exist, and whether these asymmetries differ in right- and left-handers. The purpose of this study was to determine if measurable asymmetries of the POP exist on MRI, and whether the direction of the asymmetries differ in right- and left-handers. The PTR and POP were measured on volumetric MRI scans of 16 right-handers and 16 left-handers matched for age and gender. There was a significant leftward asymmetry of the PTR in right- and left-handers, although the asymmetry was reduced in the left-handers. In contrast, there was a leftward asymmetry of the POP in right-handers, and a rightward asymmetry in the left-handers. Handedness, derived from a handedness inventory, was positively correlated with POP asymmetry.

Broca's area : Nomenclature, anatomy, typology and asymmetry

In this review, we (i) describe the nomenclature of Brocas area and show how the circumscribed definition of Brocas area is disassociated from Brocas aphasia, (ii) describe in detail how the gross anatomy of Brocas area varies between people, and how the definitions vary between studies, (iii) attempt to reconcile the findings of structural asymmetry of Brocas area with the differences in methodological approaches, (iv) consider the functional significance of cytoarchitectonic definitions of Brocas area, and (v) critically elucidate the significance of circumscribed regions of cortex for language lateralisation and language development. Contrary to what has previously been reported in the literature, asymmetry of Brocas area has not been reproducibly demonstrated, particularly on a gross morphological level. This may be due to major inconsistencies in methodology (including different anatomical boundaries, measurement techniques and samples studied) or that the sulcal contours defining Brocas area are so naturally variable between people making a standard definition difficult. Cytoarchitectonic analyses more often than not report leftward asymmetry of some component of area 44 and/or area 45. If a structural asymmetry of Brocas area does exist, it is variable, which differs from that of the functional asymmetry of language, which is more consistent. One reason for this might be that the link between cellular architecture, connectivity and language function still remains to be elucidated. There is currently no convincing explanation to associate asymmetry of Brocas area with the lateralisation of language.

Cognitive neuropsychological analysis and neuroanatomic correlates in a case of acute anomia

We describe an analysis of lexical processing performed in a patient with the acute onset of an isolated anomia. Based on a model of lexical processing, we evaluated hypotheses as to the source of the naming deficit. We observed impairments in oral and written picture naming and oral naming to definition with relatively intact semantic processing across input modalities, suggesting that output from the semantic system was impaired. In contrast to previous reports, we propose that this pattern represents an impairment that arises late in semantic processing prior to accessing mode-specific verbal and graphemic output lexicons. These deficits were associated with a lesion in the posterior portion of the middle temporal gyrus or area 37, an area of supramodal association cortex that is uniquely suited as a substrate for the multimodal deficit in naming.

Aberrant auditory processing and atypical planum temporale in developmental stuttering

Objective: To learn if people with persistent developmental stuttering and atypical anatomy of their auditory temporal cortex have, when compared to control subjects, changes in fluency induced with delayed auditory feedback (DAF). Background: DAF improves fluency in many individuals who stutter, and induces dysfluency in some normal people. The planum temporale (PT), a portion of auditory temporal cortex, is anatomically atypical in some adults who stutter and atypical anatomy might induce aberrant function. Thus, the people who demonstrate the paradoxical response to DAF might be those who have atypical anatomy. Methods: Experimental subjects were adults with developmental stuttering (n = 14) and control subjects (n = 14) matched for age, sex, education, and handedness. Volumetric MRI scans of all subjects were obtained and the PT was measured in the right and left hemispheres. Based on these scans, subjects were classified as typical (leftward PT asymmetry) or atypical (rightward PT asymmetry). Prose passages were read at baseline, with non-altered feedback (NAF), and with DAF, and fluency was measured in these three conditions. Results: At baseline the adults with developmental stuttering were significantly more dysfluent than controls (p < 0.0005). Controls’ fluency did not significantly change with DAF, but DAF improved fluency in adults with developmental stuttering (p < 0.0005). In the stutter group enhanced fluency was associated with atypical (rightward) PT asymmetry, and the presence of typical (leftward) PT asymmetry was not associated with any significant change in fluency. The individuals with atypical PT asymmetry also had more severe stuttering at baseline compared to the experimental subjects with typical PT anatomy. Conclusions: In adults with persistent developmental stuttering and atypical PT anatomy, fluency is improved with DAF. These experimental subjects who showed improvement had more severe stuttering at baseline. Anomalous PT anatomy may be a neural risk for developmental stuttering in some individuals. Although a number of explanations are tenable, it may be that atypical rightward PT asymmetry may alter speech feedback, and treatment with DAF might allow these people to compensate.

Lingual Discoordination and Dysphagia following Acute Stroke: Analyses of Lesion Localization

Abstract. The mechanism and neural substrates that mediate lingual coordination during swallowing have not been well characterized. Although lingual discoordination during swallowing has been difficult to quantify, it has been defined as the random disorganization of anterior–posterior tongue movements evident in bolus propulsion. In a sample of consecutive acute stroke patients (n= 59), videofluoroscopic evaluation showed a 19% incidence of lingual discoordination during swallowing. Lingual discoordination during swallowing was not commonly associated with buccofacial apraxia, apraxia of speech, nor limb apraxia. Hemisphere and anterior–posterior localization did not predict occurrence of lingual discoordination. Lingual discoordination during swallowing occurred commonly in patients with subcortical lesions with the periventricular white matter (PVWM), the most common site of involvement. PVWM lesions may disconnect anterior and posterior cortical regions that are critical to oral control and coordination in swallowing, thereby producing lingual discoordination during swallowing. These data also suggest that the neural mechanisms that mediate lingual coordination may at least in part be independent of the neural systems that mediate buccofacial, limb, and speech praxis functions.

Ecological implications of limb apraxia: evidence from mealtime behavior.

Humans learn skilled acts in order to effectively interact with their environment. A loss of the ability to perform skilled acts is termed apraxia. Apraxia has been thought to be of theoretical interest, but the ecological implications of apraxia are controversial and have not been fully studied. We examined ten patients with unilateral left hemisphere cerebral infarctions (eight of whom were apraxic) and compared their mealtime eating behavior to a group of neurologically normal, age-matched controls. The stroke patients were less efficient in completing the meal. They made more action errors and were less organized in the sequencing of mealtime activities. Because the patients made more errors while using tools than when performing nontool actions, their deficit could not be accounted for by an elemental motor deficit. A positive relationship was found between mealtime action errors and the severity of apraxia. These findings suggest that limb apraxia may adversely influence activities of daily living.