Neurologic Validity of the Wisconsin Card Sorting Test with a Pediatric Population

This study investigated the neurologic validity of the Wisconsin Card Sorting Test (WCST) with a pediatric population; that is, the ability of the test to detect dysfunction in the frontal lobes. Fifty children with diverse etiologies of brain dysfunction were classified via EEG, MRI, or CT as having left hemisphere, right hemisphere, or bilateral frontal, extrafrontal, or multifocal/diffuse regions of brain dysfunction. Findings failed to support the hypotheses that WCST performance is more impaired in frontal lesions than extrafrontal or multifocal/diffuse lesions, or that WCST performance is more impaired in left hemisphere lesions than right. Although the WCST is not helpful in localizing cerebral area of dysfunction, it may still be a clinically useful test for examining processes that children use to solve complex problems.     

Diagnostic utility of the thurstone word fluency test in neuropsychological evaluations

Abstract

Previous research has found that verbal associative fluency tasks are sensitive to the presence of cerebral lesions and more sensitive to frontal lobe and left hemisphere lesions than to other focal lesions. The present study investigated the diagnostic utility of the Thurstone Word Fluency Test (TWFT), a test of written verbal fluency, in detecting and localizing cerebral lesions. Using results from 203 brain-damaged and 134 normal subjects, we found that TWFT performance is affected by cerebral damage generally. At the same time, it is more impaired by frontal than by nonfrontal, by left than by right hemisphere, and by left frontal than by right frontal lesions. This test does not discriminate focal frontal from diffuse lesions. Stepwise discriminant function analyses indicated that the TWFT adds to the Halstead-Reitan Battery in discriminating focal frontal from nonfrontal lesions, but not in discriminating left hemisphere from right hemisphere lesions. Only markedly impaired TWFT performances had lateralizing significance.     

Late MRI after head injury in children: relationship to clinical features and outcome

To characterize the brain pathology in relation to long-term outcome after pediatric head injury, 55 children were studied by magnetic resonance imaging (MRI) at least 3 months after sustaining moderate to severe closed head injury (CHI). Thirty-nine of the patients had abnormal signal intensity consistent with residual brain lesions, including 28 children with lesions involving the frontal lobes. The clinical features of children with frontal lesions, extrafrontal lesions, and diffuse injury were compared. The analysis disclosed that children with frontal lobe lesions were more frequently disabled than children who sustained diffuse injury. Our MRI findings indicate that residual brain lesions are more common after moderate to severe CHI in children than previously thought and that the frontal lobes are most frequently involved. Further investigation is indicated to elucidate whether distinctive cognitive and behavioral sequelae are associated with frontal lobe lesions in children.     

The effects of frontal lobe lesions on goal achievement in the water jug task.

Patients with prefrontal cortex lesions are impaired on a variety of planning and problem-solving tasks. We examined the problem-solving performance of 27 patients with focal frontal lobe damage on the Water Jug task. The Water Jug task has never been used to assess problem-solving ability in neurologically impaired patients nor in functional neuroimaging studies, despite sharing structural similarities with other tasks sensitive to prefrontal cortex function, including the Tower of Hanoi, Tower of London, and Wisconsin Card Sorting Task (WCST). Our results demonstrate that the Water Jug task invokes a unique combination of problem-solving and planning strategies, allowing a more precise identification of frontal lobe lesion patients' cognitive deficits. All participants (patients and matched controls) appear to be utilizing a hill-climbing strategy that does not require sophisticated planning; however, frontal lobe lesion patients (FLLs) struggled to make required "counterintuitive moves" not predicted by this strategy and found within both solution paths. Left and bilateral FLLs were more impaired than right FLLs. Analysis of the left hemisphere brain regions encompassed by the lesions of these patients found that poor performance was linked to left dorsolateral prefrontal cortex damage. We propose that patients with left dorsolateral prefrontal cortex lesions have difficulty making a decision requiring the conceptual comparison of nonverbal stimuli, manipulation of select representations of potential solutions, and are unable to appropriately inhibit a response in keeping with the final goal.     

Brain activation during working memory after traumatic brain injury in children

Eight children with moderate to severe traumatic brain injury (TBI) and eight matched, uninjured control children underwent fMRI during an N-back task to test effects of TBI on working memory performance and brain activation. Two patterns in the TBI group were observed. Patients whose criterion performance was reached at lower memory loads than control children demonstrated less extensive frontal and extrafrontal brain activation than controls. Patients who performed the same, highest (3-back) memory load as controls demonstrated more frontal and extrafrontal activation than controls. Our findings of performance and brain activation changes in children after TBI await longitudinal investigation.     

Cerebral lateralization and cognitive deficits after congenital hemiparesis

The purpose of this study was to investigate whether and how handedness is related to the processes of cerebral lateralization and cognitive performance in children with congenital insult. Fifty-six children (31 males and 25 females) with congenital hemiparesis and 14 control subjects were investigated. Of these children, 32 had a left hemisphere lesion, and 24 children had a right hemisphere lesion. There were 30 right-handed, 23 left-handed, and three ambidextrous children in the study group. The neuropsychologic assessment was performed using the NEPSY (a developmental neuropsychological assessment of child development) test battery. We found that 41% of the hemiparetic children and 72% of the children with a left hemisphere lesion were left-handed. In children contralateral to lesion handedness (no evidence of interhemispheric transfer of functions), we found diffuse cognitive deficits with impaired language abilities and poor visuomotor and narrative memory processing. In contrast, children with ipsilateral to brain lesion handedness (interhemispheric transfer of functions) demonstrated minimal or moderate side-specific cognitive dysfunction. Right-handed children with a right hemisphere lesion had attention, spatial, and short-term memory problems; left-handed children with a left hemisphere lesion had receptive language and visuomotor difficulties. Handedness combined with neuropsychologic assessment is a reliable indicator of the processes of cerebral reorganization after early brain insult.     

Brain Activation during Working Memory after Traumatic Brain Injury in Children

Eight children with moderate to severe traumatic brain injury (TBI) and eight matched, uninjured control children underwent fMRI during an N-back task to test effects of TBI on working memory performance and brain activation. Two patterns in the TBI group were observed. Patients whose criterion performance was reached at lower memory loads than control children demonstrated less extensive frontal and extrafrontal brain activation than controls. Patients who performed the same, highest (3-back) memory load as controls demonstrated more frontal and extrafrontal activation than controls. Our findings of performance and brain activation changes in children after TBI await longitudinal investigation.     

Right and left cerebral hemisphere damage and tactile perception: performance of the ipsilateral and contralateral sides of the body

Patients with lateralized brain lesions were compared with respect to contralateral and ipsilateral tactile-perceptual difficulty as well as overall performance on such tasks. Results showed that patients with right hemisphere brain damage were more impaired on the contralateral and ipsilateral sides of the body than were patients with lesions of the left hemisphere. Total errors were also greater in the right than left brain-damaged group. Findings suggest the right hemisphere is pre-eminent in subserving tactile perception on both sides of the body.     

儿童额叶肿瘤的执行功能评价

目的探索额叶肿瘤对儿童患者的认知功能影响，确定额叶肿瘤患儿的执行功能损害特点。方法研究对象为45例儿童颅内肿瘤，年龄10～14岁，其中有25例额叶肿瘤，位于左额10例，右额15例；非额叶（颞叶、顶叶、脑室内或颞顶区）20例。所有患者均采用全麻下显微外科手术。术后病理证实：星形细胞瘤13例，室管膜瘤6例，少枝胶质细胞瘤4例，神经细胞瘤2例。运用威斯康星卡片分类测试系统对患者进行临床评价，并与30例同龄正常儿童作对照。结果威斯康星卡片（WCST）分类测试中的完成分类数（categories achieved）和持续性错误（preservative errors）两个指标在额叶肿瘤组和非额叶肿瘤组之间有统计学意义，而左额肿瘤组患者的执行功能损害较右额肿瘤组、非额叶肿瘤组和正常组差异有统计学意义，耐右额肿瘤组与非额叶肿瘤组和正常组没有统计学意义。结论左额叶肿瘤患儿存在明显的执行功能障碍，而右额肿瘤引起损害则不明显。     

Verbal and figural fluency in patients with mass lesions of the left or right frontal lobes.

Impaired verbal and figural fluency has been shown to be associated with frontal lobe dysfunction. Jones-Gotman and Milner (1977) demonstrated a double dissociation between verbal and nonverbal fluency in a small sample of patients with frontal lesions of the left or right hemisphere. The present study has examined verbal and nonverbal fluency in 25 healthy participants and 95 patients with mass lesions of the left or right frontal lobes. In comparison with healthy participants, verbal fluency was reduced in patients with frontal lesions of the left hemisphere. Patients with right-sided lesions did not differ from either the control group or from the patients with left-sided frontal mass lesions. In the figural fluency task, the performance of the groups did not differ. The finding that patients with left frontal lesions produced fewer words than healthy participants suggests an association between left frontal lobe pathology and reduced verbal fluency. The results do not support the hypothesis of a double dissociation between verbal/figural fluency and the side of lesion within the frontal lobes.     

Verbal and Figural Fluency in Patients with Mass Lesions of the Left or Right Frontal Lobes

Impaired verbal and figural fluency has been shown to be associated with frontal lobe dysfunction. Jones-Gotman and Milner (1977) demonstrated a double dissociation between verbal and nonverbal fluency in a small sample of patients with frontal lesions of the left or right hemisphere. The present study has examined verbal and nonverbal fluency in 25 healthy participants and 95 patients with mass lesions of the left or right frontal lobes. In comparison with healthy participants, verbal fluency was reduced in patients with frontal lesions of the left hemisphere. Patients with right-sided lesions did not differ from either the control group or from the patients with left-sided frontal mass lesions. In the figural fluency task, the performance of the groups did not differ. The finding that patients with left frontal lesions produced fewer words than healthy paticipants suggests an association between left frontal lobe pathology and reduced verbal fluency. The results do not support the hypothesis of a double dissociation between verbal/figural fluency and the side of lesion within the frontal lobes.     

Temporal Lobe Epilepsy and Performance on the Wisconsin Card Sorting Test

Abstract

The replicability of previous evidence for differential performance between left and right temporal lobe epileptic patients on the Wisconsin Card Sorting Test (WCST) was evaluated in a new sample of candidates for focal resection. Many subjects obtained high scores on indices of perseveration, which are commonly thought to reflect frontal dysfunction, but there were no differences in performance between patients with language-dominant and nondominant temporal foci. The findings confirm existing evidence that performance decrements on the WCST can be associated with epileptic foci and focal lesions in nonfrontal brain regions.     

The asymmetric lateralization of tactile extinction in patients with unilateral cerebral dysfunction

Two hundred and thirty-four patients with unilateral cerebral pathology and 175 control subjects were examined with a sensitive test for tactile extinction. Damage to the right hemisphere was associated with extinction slightly (but not significantly) more often than damage to the left hemisphere; the asymmetry may be due to selective exclusion of aphasics with damage to the left hemisphere. Extinction of the left side of the body, however, was significantly more common than of the right side; this asymmetry could not be accounted for by exclusion of untestable aphasics, but was a consequence of frequent ipsilateral (left side) extinction among the group with damage to the left hemisphere while the group with damage to the right hemisphere extinguished the contralateral (left) side almost exclusively. Although the hemispheres as a whole did not differ in their association with extinction, lesions in the right parietal lobe were significantly more effective in producing extinction than lesions in the left; in both cases the contralateral side of the body was affected. By contrast, lesions in the left frontal lobe were moderately but not significantly more effective in producing extinction than right frontal damage; in almost all these cases the left side of the body was affected, regardless of which frontal lobe was damaged. A relationship between extinction and pathology in the vicinity of the anterior callosum, as determined from CT scan and angiography, was found among the frontal cases. We propose an anatomical model to explain tactile extinction and its asymetric characteristics in the human. During the extinction tests a response mechanism in the left (speech) hemisphere bases its perceptual output on the relative strengths of two simultaneous sensory inputs. Damage at any point in the channel from the periphery to the response mechanism weakens one signal in comparison to the other, resulting in a response bias favouring the stronger stimulus. Tactile information from the left hand, after reaching the somatosensory zone in the right hemisphere, is transmitted to the left hemisphere by a diffuse, widespread network including the frontal lobes and the anterior callosum. This anatomical arrangement renders left-hand information more vulnerable to chance lesions than right-hand information, which has direct access to the response mechanism via a more compact projection system.     

Unirhinal olfactory identification deficits in young male patients with schizophrenia and related disorders: association with impaired memory function

We have observed discreet subgroups of male patients with psychotic disorders who have unirhinal olfactory identification deficits (microsmia). The purpose of this study was to examine the relationship between left or right nostril microsmia and performance on literalised neuropsychological tests sensitive to lesions in brain areas implicated in the pathogenesis of schizophrenia. Sixty-six male patients diagnosed with schizophrenia or related disorders were assessed with a battery of neuropsychological tests, sensitive to literalised and regional (temporal and frontal lobe) dysfunction. The University of Pennsylvania Smell Identification Test (UPSIT) was administered unirhinally and resultant scores were used to classify patients into olfactory subgroups. Neuropsychological test scores were compared amongst subgroups. A mixed design MANOVA was performed on cognitive domains with olfactory status (right microsmic; RM, n=8, left microsmic; LM, n=20, and normosmic schizophrenic controls; NSzC, n=38) as the between subject factor while hemisphere (left versus right) and domain (executive/fluency versus memory) were within-subject factors. A three-way (olfactory subgroup by hemisphere by region) interaction was observed. Non-verbal memory impairment was observed in the right and left microsmic subgroups. Verbal memory deficits were demonstrated in patients with left nostril microsmia.These results indicate that unirhinal olfactory performance may provide a meaningful manner by which to subtype patients with schizophrenia. Moreover, the data suggest that olfactory deficits in patients with schizophrenia are associated with dysfunction of temporal lobe, rather than frontal lobe abnormalities. The data are consistent with reports linking the right temporal lobe integrity to adequate olfactory processing.     

Digit repetition performance in patients with focal brain damage

Digit span forward and backward was investigated in well-matched samples of patients with discrete quadrant brain lesions. The incidence of significantly impaired digit repetition performance and the incidence of large forward and backward digit span discrepancies were also studied. Correlational data of digit span performance and various intellectual, memory, and constructional measures was examined. Approximately 60% of all brain-damaged patients showed an impairment of digit span forward, while only 5% showed a similar impairment on the digit span backward task. These data indicate that digit span forward is a more sensitive measure of brain dysfunction from focal brain lesions. No difference was found in the performance of patients with right or left hemisphere lesions; however, the low incidence of aphasia (8%) in this sample may account in part for the relatively adequate performance by the left hemisphere patients. Although the current data regarding visual constructive deficits and impaired ability to repeat digits backward is inconclusive, there did not appear to be a strong relationship between these two functions for these patients. Digit repetition performance does appear to be related to both general intellectual ability and to performance on the Wechsler Memory Scale.     

抑郁症患者弥散张量成像与认知功能的关系

目的:探讨抑郁症患者全脑白质纤维受损状况及其与认知功能的关系.方法:对 24 例抑郁症患者及 30 名健康对照者进行临床测评、常规磁共振成像(MRI)、弥散张量成像(DTI)及神经心理学检查.结果:抑郁症组在左额中回、左额上回、右额内侧回、左楔前叶、左颞上回、右扣带回等区域各向异性(FA)值较对照组显著下降(P＜0.001).抑郁症组威斯康星卡片分类测验(WCST)的分类数、总错误率明显高于对照组(P＜0.01 或 P＜0.05).两组持续注意操作测试(CPT)差异无显著性;抑郁症组 CPT 与 WCST 部分结果均呈负相关(P均＞0.05).结论:DTI 与 WCST 结果的相互印证反映重性抑郁症患者可能存在白质区域神经功能的异常,DTI 技术有助于发现影响认知改变的脑微细结构和功能的异常.     

Visual localization in patients with unilateral brain disease.

The accuracy of localization of briefly exposed single dots and pairs of dots was assessed in patients with lesions of the left and right hemispheres and in control patients without history or evidence of brain disease. A remarkably high frequency of impaired performance was found in the patients with right hemisphere lesions. The performance of the patients with left hemisphere lesions was comparable with that of the control patients. Visual field defect was associated with defective localization in the right hemisphere group but not in the left hemisphere group. Aphasic disorder and age were not related to performance level. The relationship of the findings to those of previous studies of visual localization in patients with unilateral brain disease is discussed.     

The restricted effects of right-hemisphere lesions after age one; Wechsler test data

The late effects of early and later lateralized brain lesions were studied with the Wechsler intelligence test in 50 patients with unilateral nonprogressive cerebral lesions incurred in infancy or in childhood. Results differed according to age at lesion for right but not left hemisphere patients; patients with right hemisphere lesions after age one had normal Verbal ratings impaired Performance ratings; patients with earlier right hemisphere lesions were impaired on both ratings.     

Visuospatial performance in left-handed patients with unilateral brain lesions

A test of visuospatial judgment was given to left-handed patients with lesions of either the right or left hemisphere. In right-handed patients impaired performance on the test has been found to be almost exclusively associated with right hemisphere disease, the performance of patients with left hemisphere disease being comparable to that of controls. The left-handed patients in this study showed the same performance pattern: a high proportion of patients with right hemisphere lesions performed defectively while all the patients with left hemisphere lesions performed on a normal level. Thus the findings are in accord with the conclusion that hemispheric cerebral organisation with respect to the mediation of visuospatial performance do not differ in right-handers and left-handers.     

Psychosocial outcome of TBI in children with unilateral frontal lesions.

To evaluate effects of unilateral frontal lesions on psychosocial and global outcome of traumatic brain injury (TBI) in children, Study 1 compared matched groups of 22 school aged children who had sustained TBI either with or without unilateral frontal lesions. Study 2 evaluated effects of unilateral extrafrontal lesions in 18 TBI patients as compared with 18 nonlesional TBI patients. Communication, Daily Living, and Socialization domains and the Maladaptive Behavior Scale of the Vineland Adaptive Behavior Scales (VABS) were used to assess psychosocial outcome, and the Glasgow Outcome Scale (GOS) measured global outcome. All patients underwent magnetic resonance imaging at least 3 months post injury. Children with frontal lesions had worse scores on the Daily Living and Socialization domains and a higher frequency of maladaptive behavior than those without frontal lesions, but there was no difference in cognitive function. Disability was twice as common in the frontal lesion group relative to children without frontal lesions. Volume of frontal lesion was related to the Socialization domain. Side of lesion had no effect, nor did presence of an extrafrontal lesion (Study 2). Unilateral frontal lesions adversely affect late psychosocial outcome of TBI in children.