Academic Outcome in Pediatric Stroke: A Multifaceted Approach to Exploring Challenges and Achievements

Objective

An important cause of acquired brain injury in children, pediatric stroke can engender sequelae across a wide range of cognitive domains, including language, attention, memory, and processing speed. As a result, survivors are especially vulnerable to academic difficulties and face unique challenges compared to their peers. Despite this knowledge, pediatric stroke remains an understudied neurological condition, and its impact on school functioning is poorly understood. Addressing this gap in knowledge, the present clinical research study assesses academic outcome with a multifaceted approach.

Methods

This study evaluated youth with (n = 23) and without (n = 18) histories of stroke. Families were recruited at the Hospital for Sick Children in Toronto. Participants were administered an extensive battery of neuropsychological and psychoeducational tests, quality of life questionnaires, and behavior rating scales. Medical records and school report cards provided additional data.

Results

Compared to their peers, youth with stroke exhibited more deficits in processing speed and core academic skills and were more likely to have a learning disability, an Individual Education Plan, school accommodations, and access to assistive technologies. Controlling for the effects of intelligence, a hierarchical regression suggested that processing speed and reading skills predicted grades for youth with stroke. Finally, quality of life was similar between groups, indicating comparable experiences in school environment, peer support, and social acceptance.

Conclusions

This study makes a meaningful contribution to the field of pediatric stroke and promotes a nuanced understanding of the struggles that patients encounter, what impairments they tend to incur, and how these difficulties impact academic achievement.

Breath-Hold Blood Oxygen Level-Dependent MRI: A Tool for the Assessment of Cerebrovascular Reserve in Children with Moyamoya Disease

BACKGROUND AND PURPOSE

There is a critical need for a reliable and clinically feasible imaging technique that can enable prognostication and selection for revascularization surgery in children with Moyamoya disease. Blood oxygen level-dependent MR imaging assessment of cerebrovascular reactivity, using voluntary breath-hold hypercapnic challenge, is one such simple technique. However, its repeatability and reliability in children with Moyamoya disease are unknown. The current study sought to address this limitation.

MATERIALS AND METHODS

Children with Moyamoya disease underwent dual breath-hold hypercapnic challenge blood oxygen level-dependent MR imaging of cerebrovascular reactivity in the same MR imaging session. Within-day, within-subject repeatability of cerebrovascular reactivity estimates, derived from the blood oxygen level-dependent signal, was computed. Estimates were associated with demographics and intellectual function. Interrater reliability of a qualitative and clinically applicable scoring scheme was assessed.

RESULTS

Twenty children (11 males; 12.1 ± 3.3 years) with 30 MR imaging sessions (60 MR imaging scans) were included. Repeatability was "good" on the basis of the intraclass correlation coefficient (0.70 ± 0.19). Agreement of qualitative scores was "substantial" (κ = 0.711), and intrarater reliability of scores was "almost perfect" (κ = 0.83 and 1). Younger participants exhibited lower repeatability (P = .027). Repeatability was not associated with cognitive function (P > .05). However, abnormal cerebrovascular reactivity was associated with slower processing speed (P = .015).

CONCLUSIONS

Breath-hold hypercapnic challenge blood oxygen level-dependent MR imaging is a repeatable technique for the assessment of cerebrovascular reactivity in children with Moyamoya disease and is reliably interpretable for use in clinical practice. Standardization of such protocols will allow further research into its application for the assessment of ischemic risk in childhood cerebrovascular disease.

Names and words without meaning: incidental postmorbid semantic learning in a person with extensive bilateral medial temporal damage

The authors describe a densely amnesic man who has acquired explicit semantic knowledge of famous names and vocabulary words that entered popular culture after the onset of his amnesia. This new semantic knowledge was temporally graded and existed over and above the implicit memory he demonstrated in reading speed and accuracy, familiarity ratings, and his ability to make correct guesses on unfamiliar items. However, his postmorbid knowledge was limited to verbal labels denoting famous people and words; he possessed virtually no explicit knowledge of the meaning of these words or the identities of these individuals, although there was some evidence that some of this information had been acquired at an implicit level. Findings are discussed in the context of a neural network model (J. L. McClelland, B. L. McNaughton, & R. C. O'Reilly, 1995) of semantic acquisition.

Names and words without meaning: incidental postmorbid semantic learning in a person with extensive bilateral medial temporal damage

The authors describe a densely amnesic man who has acquired explicit semantic knowledge of famous names and vocabulary words that entered popular culture after the onset of his amnesia. This new semantic knowledge was temporally graded and existed over and above the implicit memory he demonstrated in reading speed and accuracy, familiarity ratings, and his ability to make correct guesses on unfamiliar items. However, his postmorbid knowledge was limited to verbal labels denoting famous people and words; he possessed virtually no explicit knowledge of the meaning of these words or the identities of these individuals, although there was some evidence that some of this information had been acquired at an implicit level. Findings are discussed in the context of a neural network model (J. L. McClelland, B. L. McNaughton, & R. C. O'Reilly, 1995) of semantic acquisition.

Different patterns of autobiographical memory loss in semantic dementia and medial temporal lobe amnesia: a challenge to consolidation theory

Temporally graded retrograde memory loss, with a disproportionate impairment of recent relative to remote memories, is considered a hallmark of medial temporal lobe amnesia. According to consolidation theory, the hippocampal complex, which includes the hippocampal formation, parahippocampal gyrus, the entorhinal and perirhinal cortex, plays a time-limited role in memory, needed only until consolidation in the neocortex is complete (Squire, Psychological Review 1992; 99: 195-231). Recent support for this theory comes from findings of a reverse gradient in people with semantic dementia with neocortical degeneration but a relatively preserved hippocampal complex (Hodges and Graham, Neuropsychologia 1998; 36: 803-25). Consolidation theory is challenged by evidence that remote autobiographical memory is not always spared in amnesia (Nadel and Moscovitch, Current Opinion in Neurobiology 1997; 7: 217-27) and that semantic memory becomes highly personalized in semantic dementia (Snowden et al., Memory 1995; 3: 225-46). According to Nadel and Moscovitch, the hippocampal complex is needed to retain and retrieve detailed memories of autobiographical episodes no matter how old they are. To test consolidation theory against the opposing view, we investigated the role of the hippocampal complex in recent and remote autobiographical and personal semantic memory by contrasting the memory of a semantic dementia patient, EL, with that of an amnesic patient, KC, using family photographs as recall cues. KC demonstrated a complete loss of autobiographical episodes with a sparing of autobiographical facts; EL demonstrated well-preserved memory for episodes with a reverse gradient for personally relevant names. The influence of autobiographical significance on memory for names of public figures was examined further by comparing the effect that familiarity and recollection had on recognition of names of famous people and famous places. EL's memory was influenced by autobiographical significance, whereas KC's was not. We propose that the hippocampal complex plays a permanent role in the storage and retrieval of autobiographical episodes and that autobiographical significance may affect semantic representations.