Attention and executive functioning profiles in children following perinatal arterial ischemic stroke

Perinatal arterial ischemic stroke (PAIS) is a form of childhood stroke; the majority of those affected experience neurologic sequelae, including motor, language and neurocognitive impairments. This study examines the attention and executive functioning (EF) profiles of children following PAIS, as well as the impact of age and sex. In this single-center cross-sectional study, 40 children aged 3 to 16 years (median age 7.2 years; 58% male) who have suffered a PAIS underwent a comprehensive neuropsychological battery to assess attention and EF. Parents completed behavioral questionnaires regarding real-world functioning. Composite scores were calculated for seven attention and EF domains (Attention, Working Memory, Verbal Retrieval, Inhibitory Control, Flexibility/Shifting, Planning/Organization, and Processing Speed). The results for all measured domains of attention and EF are significantly lower in the participants compared to the normative samples (p < .001), with the exception of Working Memory. However, increasing difficulty with Working Memory is associated with developing age. Older age at time of testing is also associated with a higher incidence of clinically-elevated attention deficit hyperactivity disorder (ADHD) symptoms. Sex is not associated with performance measures or parental report of functioning. The participants demonstrate mild-to-moderate attention and EF impairment compared to the normative population. Clinicians, families, and educators should be informed about the neurocognitive sequelae of PAIS and the need for close developmental surveillance in this population to identify vulnerable children and initiate appropriate therapeutic interventions in a timely fashion.     

Homotopic language reorganization in the right hemisphere after early left hemisphere injury

Speech production is inextricably linked to speech perception, yet they are usually investigated in isolation. In this study, we employed a verbal-repetition task to identify the neural substrates of speech processing with two ends active simultaneously using functional MRI. Subjects verbally repeated auditory stimuli containing an ambiguous vowel sound that could be perceived as either a word or a pseudoword depending on the interpretation of the vowel. We found verbal repetition commonly activated the audition-articulation interface bilaterally at Sylvian fissures and superior temporal sulci. Contrasting word-versus-pseudoword trials revealed neural activities unique to word repetition in the left posterior middle temporal areas and activities unique to pseudoword repetition in the left inferior frontal gyrus. These findings imply that the tasks are carried out using different speech codes: an articulation-based code of pseudowords and an acoustic-phonetic code of words. It also supports the dual-stream model and imitative learning of vocabulary.     

Revealing language deficits following stroke: the cost of doing two things at once

The costs of doing two things were assessed for a group of healthy older adults and older adults who were tested at least 6 months after a stroke. A baseline language sample was compared to language samples collected while the participants were performing concurrent motor tasks or selective ignoring tasks. Whereas the healthy older adults showed few costs due to the concurrent task demands, the language samples from the stroke survivors were disrupted by the demands of doing two things at once. The dual task measures reveal long-lasting effects of strokes that were not evident when stroke survivors were assessed using standard clinical tools.     

Right hemispatial neglect: frequency and characterization following acute left hemisphere stroke

The frequency of various types of unilateral spatial neglect and associated areas of neural dysfunction after left hemisphere stroke are not well characterized. Unilateral spatial neglect (USN) in distinct spatial reference frames have been identified after acute right, but not left hemisphere stroke. We studied 47 consecutive right handed patients within 48h of left hemisphere stroke to determine the frequency and distribution of types of right USN using cognitive testing and MRI imaging. The distribution of USN types was different from the previously reported distribution following acute right hemisphere stroke. In this left hemisphere stroke population, allocentric neglect was more frequent than egocentric neglect.     

A study of language functioning in Alzheimer patients

Language functioning in Alzheimer's disease is reviewed and the performance of 25 Alzheimer patients on a standard battery is reported. All these hospitalized patients were aphasic to some degree. As a group, they differed from normals on all language variables, and from stroke patients in terms of higher fluency and lower comprehension. Spontaneous speech showed high incidence of circumlocutions and semantic jargon, but no phonemic paraphasias or target approximations. Syllabic perseverations, shouting, inappropriate laughter, and mutism were late-appearing features. Transcortical Sensory, and Wernicke's aphasias were frequent, but Broca's and Transcortical Motor aphasias notably absent. Extent of language impairment correlated with current length of hospitalization but not age. Reading, writing, and performance scores except praxis, were lower than oral language scores. Findings were discussed in relation to previous results, methodology, and language organization in the brain.     

Role of maternal functioning and parenting skills in adolescent functioning following parental divorce

While divorce has been associated with impaired child functioning, the mechanisms within the divorce process leading to such an outcome have rarely been examined. The following hypothesis was examined: Divorce is associated with poor parental adjustment or disrupts parenting behavior, or both, which leads to poor adolescent functioning. Subjects were 121 and 93 young adolescents from intact and recently divorced families, respectively, and their mothers and teachers. Mothers completed measures assessing parental conflict and depression, observers coded parenting skills during a mother-adolescent interaction, and teachers completed measures assessing adolescent functioning. Although the magnitude of differences was not large, analyses of variance indicated that the divorced sample was functioning poorer than the married sample on all measures except interparental conflict. Path analysis suggested that parental functioning and parenting skills play a role in adolescent functioning following divorce.     

Patterns of apraxia associated with the production of intransitive limb gestures following left and right hemisphere stroke

The model of apraxia proposed by Roy (1996) states that three patterns of apraxia should be observed across pantomime and imitation conditions. In the present analysis the frequency and severity of each pattern of apraxia were examined in a consecutive sample of left-(LHD) and right-hemisphere-damaged (RHD) patients during the production of intransitive limb gestures. The results indicated that a significant proportion of LHD and RHD patients were selectively impaired in formulating the ideational component of intransitive limb gestures.     

Cortical localization of finger spelling and oral language: A case study

Finger spelling of letters and words was mapped by means of the cortical stimulation procedure in a hearing patient undergoing a left dominant anterior temporal lobe resection for relief of a seizure disorder. Finger spelling was disrupted at five sites: three overlapping with one or more oral language functions at sites in the classical posterior language area, two relating only to finger spelling in the anterior temporal region. Following the resection which included these latter sites, both short- and long-term postoperative deficits in finger spelling are described. Implications for the organization of manually based communication behavior in the left hemisphere are discussed.     

Role of the left hemisphere in sign language comprehension

We investigated the relative role of the left versus right hemisphere in the comprehension of American Sign Language (ASL). Nineteen lifelong signers with unilateral brain lesions [11 left hemisphere damaged (LHD) and 8 right hemisphere damaged (RHD)] performed three tasks, an isolated single-sign comprehension task, a sentence-level comprehension task involving simple one-step commands, and a sentence-level comprehension task involving more complex multiclause/multistep commands. Eighteen of the participants were deaf, one RHD subject was hearing and bilingual (ASL and English). Performance was examined in relation to two factors: whether the lesion was in the right or left hemisphere and whether the temporal lobe was involved. The LHD group performed significantly worse than the RHD group on all three tasks, confirming left hemisphere dominance for sign language comprehension. The group with left temporal lobe involvement was significantly impaired on all tasks, whereas each of the other three groups performed at better than 95% correct on the single sign and simple sentence comprehension tasks, with performance falling off only on the complex sentence comprehension items. A comparison with previously published data suggests that the degree of difficulty exhibited by the deaf RHD group on the complex sentences is comparable to that observed in hearing RHD subjects. Based on these findings we hypothesize (i) that deaf and hearing individuals have a similar degree of lateralization of language comprehension processes and (ii) that language comprehension depends primarily on the integrity of the left temporal lobe.     

Independent effects of bilingualism and socioeconomic status on language ability and executive functioning

One hundred and seventy-five children who were 6-years old were assigned to one of four groups that differed in socioeconomic status (SES; working class or middle class) and language background (monolingual or bilingual). The children completed tests of nonverbal intelligence, language tests assessing receptive vocabulary and attention based on picture naming, and two tests of executive functioning. All children performed equivalently on the basic intelligence tests, but performance on the language and executive functioning tasks was influenced by both SES and bilingualism. Middle-class children outperformed working-class children on all measures, and bilingual children obtained lower scores than monolingual children on language tests but higher scores than monolingual children on the executive functioning tasks. There were no interactions with either group factors or task factors. Thus, each of SES and bilingualism contribute significantly and independently to children’s development irrespective of the child’s level on the other factor.     

Psychological correlates of PTSD symptoms following stroke

This study assessed associations between a number of demographic, medical and psychological risk factors and post-traumatic stress disorder (PTSD) symptoms following stroke. Individuals (N = 102) who had experienced a stroke within the previous year participated in the study. Participants completed questionnaires containing measures of PTSD symptoms and a range of psychological risk factors (i.e., anxiety, depression, negative affect, dissociation, cognitive appraisals). Regression analyses revealed the variables under consideration were able to explain large proportions of the variance in the number (R(2) = .54, p < 0.001) and severity (R(2) = .58, p < 0.001) of PTSD symptoms. Number of strokes, negative affect and cognitive appraisals emerged as significant predictors of both the number and severity of PTSD symptoms. The present findings suggest that a significant proportion of stroke patients may benefit from the detection and treatment of PTSD symptoms.     

Development of speech and language following bilateral frontal lesions

Language and speech were studied in a young child with perinatally acquired bifrontal lesions. Bilateral frontal pathology seriously interfered with the development of intelligible speech and resulted in a persistent expressive aphasia. Analysis of the neuropsychological profile indicated impairments in intelligence and language comprehension. These deficits, however, were considered secondary to the profound speech programming disorder. The findings indicate that, despite the plasticity of the immature central nervous system, bilateral frontal injury sustained at an early age precludes the development of intelligible speech. Furthermore, structurally intact cortical regions outside the territories of the speech zones fail to mediate normal speech and language development.     

Attention and social functioning in children with malformations of cortical development and stroke

Attention and social functioning and their interrelationships have not been routinely examined in children with early brain insult (EBI). This study aimed to describe attention and social functioning in children with two types of EBI: malformations of cortical development (MCD) and stroke. Children diagnosed with MCD (n = 14, 6 males) or stroke (n = 14, 8 males) aged 8 to 14 years (M = 12 years 11 months) completed neuropsychological assessments to examine attention processes. Primary caregivers completed a questionnaire to assess executive components of children's attention and teachers completed a questionnaire to measure children's social functioning. Brain scans (MRI or CT) were coded by a pediatric neuroradiologist. Higher rates of impairments in attention and social function were found in children with EBI compared with normative expectations. Children with MCD experienced more global and clinically significant levels of impairment than children with stroke; though impairments were present in both groups. A strong association between executive components of attention and social function was observed. In addition, complex attention processes were associated with social function. The findings emphasize the reciprocity between attention, behavior and social outcomes, and the vulnerability of social function following EBI.     

Language localization in cases of left temporal lobe arachnoid cyst: evidence against interhemispheric reorganization

We investigated whether left-hemisphere arachnoid cysts lead to reorganization of the language function using PET. A group analysis demonstrated that patients showed no more right-hemisphere activation than a matched control group. Several patients had clear language localizations in the left hemisphere during language comprehension; none of the patients showed right-hemisphere activation. We conclude that left-hemisphere tissue must suffer considerable compromise before reorganization of language into the right hemisphere becomes necessary. Language activations within the left hemisphere are clearly displaced. This is consistent with mere physical displacement in some patients rather than reorganization within the left hemisphere; in others intrahemispheric reorganization cannot be excluded.