MMPI correlates of relatively localized brain damage

Examined the MMPI correlates of relatively localized brain damage classified along dimensions of laterality and caudality. Forty patients with lateralized lesions that involved anterior or posterior cerebral areas were studied. Based on a multivariate analysis of variance, results revealed significant differences in MMPI profiles between left hemisphere and right hemisphere lesion groups. The MMPI profile for the left hemisphere lesion group is well within the normal range; the right hemisphere lesion group is beyond normal limits, primarily on scales 8 and 2. Several issues are dis cussed in an effort to integrate these findings with previous studies.     

MMPI correlates of poststroke neurobehavioral deficits.

MMPI profiles of 130 male veterans with cerebrovascular accidents were examined in relation to type and degree of neuropsychological deficit, hemispheric location of lesion, and time poststroke. Three neurobehavioral factors (Verbal, Visuospatial, Sensorimotor) were extracted from the Halstead-Reitan Battery and Wechsler Memory Scale. Canonical analyses revealed verbal impairment to be associated with greater openness in reporting emotional difficulties (Scale F) and limited social facility (Scale Hy). Sensorimotor deficits were associated with anxiety and distress (Pt) in patients with left hemisphere (LHD) but not right hemisphere damage (RHD). Although RHD and LHD patients had similar composite MMPI profiles, neuropsychological deficits in RHD were unrelated to MMPI scores. Time poststroke was independent of MMPI findings in both LHD and RHD samples.     

Reading among children with left and right brain lesions

Twenty left hemisphere lesioned and 10 right hemisphere lesioned children between 6 and 20 years old were administered a battery of tests assessing phonetic analysis and segmentation, single word decoding, reading comprehension, and spelling. Although group mean performance on all tasks was consistently below that of controls matched for age, sex, race, and social class, few differences reached statistical significance. These findings demonstrate that the majority of children with unilateral brain lesions learn to read quite adequately, evidencing considerable functional reorganization of higher cognitive abilities following brain lesions sustained early in life. Yet five left‐ and two right‐lesioned children did present marked reading deficits in contrast to 1 of the 30 control subjects. A family history for reading disorders was implicated in one left lesioned, one right lesioned and the control subject, suggesting the contribution of a genetic basis. Age of lesion onset was not found to be related to reading outcome. All left‐lesioned children with involvement of specific subcortical structures did, however, present reading disorders along with other language learning problems, suggesting that these structures may play a role in acquisition of higher cognitive functions which may be less amenable to reorganization following lesions sustained in early childhood.     

MMPI correlates of performance intellectual deficits in patients with right hemisphere lesions

This study investigated the emotional adjustment of 50 patients with focal brain damage in the right hemisphere (RHD). The impact of functional loss (as assessed by the WAIS Performance IQ) was assessed by a multivariate comparison of the composite MMPI profiles of these patients as classified into three groups: Below Average, Average, and Above Average Performance IQ. Regardless of the extent of decline in Performance-related abilities, right hemisphere impairment was associated with symptoms of mild depression, loss of initiative, anxiety, denial, and somatic preoccupations. MMPI scores were not correlated significantly with their WAIS Performance IQs. Implications for neuropsychological assessment are discussed.     

Decision strategies in neuropsychology I: determination of lateralized cerebral dysfunction.

This study addressed the issue concerning neuropsychological assessment and the determination of hemispheric lateralization. Based upon the different processing strategies employed by each hemisphere, several neuropsychological tests were hypothesized to discriminate between left hemisphere and right hemisphere damage. Lesion localization was determined by neurological examination, electroencephalography, and/or neuroradiological procedures for the 111 patients (47 right hemisphere, 64 left hemisphere) who were given a neuropsychological evaluation. Two strategies are presented for lateralizing cerebral impairment, a discriminant analysis and a decision process using one standard deviation as a cut-off point. These two strategies are compared with The Key Approach of Russell, Neuringer, and Goldstein (1970) and Simpson and Vega's WAIS Sign Test. The efficacy of decision strategies used to predict lateralization is discussed.     

Lateralized anterior and posterior lesions and performance on Digit Span and Russell's revision of the Wechsler Memory Scale

Performance on the Russell (1975) revision of the Wechsler Memory Scale and the Digit Span subtest of the Wechsler Adult Intelligence Scale by subjects with lateralized anterior and posterior lesions was investigated. Ss were right-handed men whose brain lesions were identified on the basis of neurodiagnostic tests as being lateralized to either the left or right hemisphere and restricted to either the anterior or posterior side of the central sulcus. A normal comparison group was formed of Ss suspected of having neurological damage and referred for neuropsychological testing but who had normal neurodiagnostic examinations. It was predicted that both the laterality and caudality of lesions would affect memory task performance. This prediction was fully supported for the logical memory task and partially supported for the figural memory and digit span tasks.     

Depression and hemispheric site of cerebral vascular accident

In order to investigate the possible role of left and right hemisphere neural structures in the manifestation of depression, 50 left brain damaged and 50 right brain damaged stroke inpatients were administered the Zung Depression Scale (ZD S) during the course of the rehabilitation phase of their treatment. These subjects were randomly chosen from all stroke patients receiving rehabilitation services who could be administered the ZDS. Approximately 30% of these subjects, regardless of the site of lesion, were clinically depressed. The severity of depression was independent of demographic factors and time since injury. Right brain damaged patients reported significantly more sleep disturbance, psychomotor agitation and pervasive sense of sadness. These results were discussed in light of previous findings that damaged to the left hemisphere results in greater depression. A model of reactive depression that results from neurological disability was proposed to partially account for these findings.     

Spatial localization in patients with unilateral posterior left or right hemisphere lesions

In this study, perceptual and visuomotor spatial localization were examined in patients with unilateral right (RH) or left (LH) hemisphere lesions and in a group of control subjects. Perceptual localization was measured with a position-discrimination task; in the visuomotor localization task, subjects had to point to a visual target. Both tasks were investigated in conditions with or without background visibility and with central and peripheral targets. In the visuomotor task, hand visibility was also manipulated. In both tasks, targets were presented in the left and right visual hemifield. The perceptual task revealed impairments for both LH and RH patients in the contra-lateral visual hemifield. RH patients also revealed slightly larger impairments in conditions without a visual background. In the visuomotor task, the LH patients were not impaired, whereas the RH patients were impaired in conditions without hand visibility and/or background visibility. Hence, our data strengthen the idea that spatial localization is not a unitary function and that perceptual and visuomotor localization can be selectively impaired. We suggest that one of the important factors distinguishing between localization impairments in RH and LH patients might be absolute versus relative localization.     

The perception of emotional chimeric faces in patients with depression,mania and unilateral brain damage

BACKGROUND: Judgements made on chimeric faces elicit reliably a perceptual bias to the left hemispace, presumed to be due to right hemisphere dominance for emotional processes. Major depressive illness has been shown to attenuate this bias. The aim of this work was to examine lateral perceptual bias in bipolar I and II patients in a hypomanic state and unipolar depressed patients and those with unilateral hemisphere damage following stroke. METHOD: Sixty patients with DSM-IV affective disorder (30 bipolar I or II, currently hypomanic, 30 unipolar depressives), 30 right brain-damaged patients, 30 left brain-damaged patients and 30 healthy controls were given the Happy-Sad Chimeric Faces Test. RESULTS: Right hemisphere damaged and unipolar depressed patients both showed a significantly reduced left hemispatial bias (LHB) compared to controls, bipolars and left brain-damaged patients. No significant difference in mean LHB between controls and both hypomanics and left brain-damaged patients was found. There was no significant association between LHB and clinical variables. CONCLUSIONS: The results suggest a physiological distinction between bipolar and unipolar depression. The significantly diminished left hemifacial bias in depressed patients suggests right hemisphere dysfunction.     

Brain ERPs of depressed patients to complex tones in an oddball task: Relation of reduced P3 asymmetry to physical anhedonia

Event-related potentials to binaural complex tones were recorded from 40 depressed outpatients and 22 normal control participants at 30 electrode sites. Patients did not differ from control participants in N1 or P3 amplitude but showed greater N2. N2 was greater over right than over the left hemisphere at lateral sites in patients and control participants. A P3 asymmetry was found for control participants and patients with low scores on a physical anhedonia scale, but not for patients with high anhedonia scores. Topographic (local Laplacian) maps corresponding to P3 showed greater radial current flow over right than over left central regions in control participants. Patients with high anhedonia did not show this asymmetry, whereas patients with low anhedonia showed an intermediate asymmetry. These findings support the hypothesis that anhedonic depression is associated with dysfunction of right hemisphere mechanisms mediating the processing of complex pitch information.     

Apathy and depressed mood in acquired brain damage: relationship to lesion localization and psychophysiological reactivity

BACKGROUND: Apathy is a frequent neurobehavioural sequel in patients with acquired brain damage and it may seriously affect outcome of rehabilitation. METHODS: Patients with traumatic brain injury, cerebrovascular insults and hypoxic brain injury, categorized into four lesion localization groups: left hemisphere damage (LHD); right hemisphere damage (RHD); bilateral hemispheric damage (BHD); and subcortical damage (SCD) were assessed with the Apathy Evaluation Scale (AES) and Montgomery and Asberg Depression Rating Scale (MADRS). Heart rate and electrodermal activity were recorded in an experimental situation that exposed the patients to mental stressors in order to measure psychophysiological reactivity. RESULTS: Significant differences in level of apathy were found between diagnostic groups as well as between localization subgroups. SCD and RHD patients displayed most apathy. Factor analysis of MADRS revealed a three-factor solution; depressed mood, somatic symptoms and negative symptoms. Apathy was significantly correlated with negative symptoms in all localization subgroups, except among the BHD patients. Apathy was not correlated with depressed mood or somatic symptoms. Moreover, apathy was significantly correlated with heart rate reactivity, but not with electrodermal reactivity. CONCLUSION: Apathy is common, its severity depending on diagnosis and localization of lesion. Apathy and depression in brain damaged patients share common features, but may be differentiated. The significant relationship between apathy and heart rate may provide a psychophysiological correlation of the disengagement, lack of interest and absence of emotional responsivity typically seen in apathy. The results have implications for the theoretical understanding of apathy and related negative symptoms, and for rehabilitation practice.     

Treatment response in late-onset depression: relationship to neuropsychological, neuroradiological and vascular risk factors

BACKGROUND: Late-onset depressive disorder is associated with white matter lesions and neuropsychological deficits that in some studies are linked to a poorer outcome for depression. Some white matter lesions may be vascular in origin. This study investigated the relationship between response or non-response to antidepressant monotherapy and neuropsychological function, structural brain measures and vascular factors. METHOD: This was a case control study. Fifty patients with late-onset major depressive disorder (29 who were responders to antidepressant monotherapy and 21 who were not) were compared with 35 non-depressed control subjects. Measures included assessment of vascular risk factors, neuropsychological testing and a magnetic resonance imaging (MRI) scan. RESULTS: After adjustment for depressed mood and medication at evaluation, both patient groups had significantly more impairment compared to control subjects on verbal learning tasks involving immediate or delayed recall. Patients who did not respond to antidepressant monotherapy had significantly poorer performance than controls on tests involving visuospatial ability, language, word recognition and tests of executive function, whereas there were no differences between control subjects and responders. On two tests of executive function (verbal fluency and the Stroop test) non-responders scored significantly worse than responders. There were no significant group differences on MRI measures of atrophy or of white matter lesions apart from a higher periventricular hyperintensity score in non-responders compared to controls. There were no group differences on measures of vascular disease. CONCLUSION: The results lend support to the emerging evidence that resistance to treatment in late-onset depression may be associated with impaired executive function. Subtle cerebrovascular mechanisms may be involved.     

Hemispheric specialization in the co-ordination of arm and trunk movements during pointing in patients with unilateral brain damage

During pointing movements involving trunk displacement, healthy subjects perform stereotypically, selecting a strategy in which the movement is initiated with either the hand or trunk, and where the trunk continues after the end of the hand movement. In a previous study, such temporal co-ordination was not found in patients with left-hemispheric brain lesions reaching with either their dominant paretic or with their non-dominant non-paretic arm. This co-ordination deficit may be associated in part with the presence of a lesion in the dominant left hemisphere. If so, then no deficit should be observed in patients with stroke-related damage in their non-dominant right hemisphere moving with their ipsilesional arm. To verify this, 21 right-hand dominant adults (7 who had had a stroke in the right hemisphere, 7 who had had a stroke in the left hemisphere and 7 healthy subjects) pointed to two targets located on a table in front of them in the ipsilateral and contralateral workspace. Pointing was done under three movement conditions: while not moving the trunk, while bending the trunk forward and while bending the trunk backwards. The experiment was repeated with the non-paretic arm of patients with stroke and for the right and left arms of healthy subjects. Kinematic data were recorded (Optotrak). Results showed that, compared to healthy subjects, arm-trunk timing was disrupted in patients with stroke for some conditions. As in patients with lesions in the dominant hemisphere, arm-trunk timing in those with lesions in the non-dominant hemisphere was equally more variable than movements in healthy subjects. However, patients with dominant hemisphere lesions used significantly less trunk displacement than those with non-dominant hemisphere lesions to accomplish the task. The deficit in trunk displacement was not due to problems of trunk control or sitting balance since, in control experiments, all subjects were able to move the trunk the required distance, with and without the added weight of the limb. Results support the hypothesis that the temporal co-ordination of trunk and arm recruitment during pointing movements is mediated bilaterally by each hemisphere. However, the difference in the range of trunk displacement between patients with left and right brain lesions suggests that the left (dominant) hemisphere plays a greater role than the right in the control of movements involving complex co-ordination between the arm and trunk. Electronic Publication     

Hemisphere asymmetry of alpha burst sequential organization in depression

A new quantitative EEG index based on the sequential variability of the frequency of occurrence of alpha bursts (alpha-BVI) was utilized for investigating the respective role of the two hemispheres in depression and their relationship with two clinical dimensions of this illness: psychomotor retardation and blunted affect. The EEG (at P3 and P4 referred to Fz) was recorded during rest periods in two groups of patients selected according to their scores on various clinical scales: one consisted of 12 patients characterized by psychomotor retardation (PMR group), the other of 9 patients characterized by blunted affect (BA group). A control group of 12 normal subjects was recorded in the same conditions. All subjects were dextral. The following main results were obtained: (1) in both groups of patients the right and the left alpha-BVI were, before treatment, significantly lower than those of the controls. (2) In controls, the sequential alpha burst variability was identical on both hemispheres. (3) In patients, before treatment, the right hemisphere alpha-BVI was significantly lower than the left. (4) Electro-clinical correlations were also observed: (A) in the BA group, before treatment, (a) between the degree of blunted affect and the decrease of the right alpha-BVI, (b) between ideoverbal retardation and the decrease of the left alpha-BVI (these correlations disappeared after treatment); (B) in the PMR group, ideoverbal retardation was, on the contrary, correlated to a right alpha-BVI decrease, this correlation persisting after treatment. These results are discussed according to the role of each hemisphere in depression.     

Left and right hemisphere contributions to physiognomic and verbal discrimination.

The relative contributions of the right- and left-temporal lobes in rapid recognition of faces and letters were studied in patients with anterior right- or left-temporal lobe excisions and a matched control group. On the basis of findings in patients with unilateral and bilateral brain damage, it was hypothesized that left hemisphere damage would not change the reaction time of letters analyzed by the right hemisphere and that right hemisphere damage would not change the reaction time of faces analyzed by the left hemisphere. The hypothesis was supported for letters but not for faces. Patients in the right-temporal group, particularly those with large hippocampal removals, were slow to recognize faces in both visual fields. Two possible explanations for the findings with faces are explored: One holds that right hemisphere mechanisms are involved even when a face is presented to the left hemisphere for rapid recognition; the other holds that specialized encoding is carried out by the right hemisphere during learning, with the encoded template then being used by each hemisphere independently.     

Neuropsychological functioning in major depression and responsiveness to selective serotonin reuptake inhibitors antidepressants

BACKGROUND: Only two thirds of patients with major depression (MD) respond to antidepressants. Thus, far applicable predictors of responsiveness to selective serotonergic reuptake inhibitors (SSRIs) have not been found. Cumulative evidence linking serotonergic depletion and cognition led us to hypothesize that the neuropsychological functioning of major depression patients may predict their responsiveness to SSRI antidepressants. METHODS: Fifty-five patients meeting DSM-IV criteria for major depression and strict inclusion and exclusion criteria underwent an extensive clinical and neuropsychological assessment prior to the initiation of selective serotonergic treatment. Following 6 weeks of treatment, severity of depression was reassessed, yielding a responsiveness score by which classification of each subject as a responder or nonresponder was made. The study was double blind. RESULTS: Logistic regression yielded neuropsychological indices, which significantly predicted the probability of depressed patients to respond favorably to SSRIs. Responders were characterized by better functioning in "simple" tasks and by worse functioning in "complex" tasks compared to nonresponders. No differences were found for more lateralized right or left hemisphere functions between responders and nonresponders. LIMITATIONS: Drug treatment comprised of SSRIs but was not standardized. Responsiveness was assessed following 6 weeks of treatment providing for initial amelioration rather than full remission. Placebo response was not controlled for. These limitations may influence the interpretation of the findings. CONCLUSIONS: The present findings suggest that responders and nonresponders to SSRIs might be distinguished by their neuropsychological functioning before treatment. If our findings are replicated, more efficient treatment might be practiced.     

Qualitative block design performance in epilepsy patients.

Broken configuration errors on the WAIS-R Block Design subtest have been associated with right hemisphere brain damage. This study examined whether pre-surgical epilepsy patients with seizure foci restricted to the right hemisphere would break configuration more frequently than those with left hemisphere foci. Subjects included 38 patients with unilateral right or left hemisphere epilepsy of frontal or temporal lobe origin. The left and right hemisphere groups did not differ significantly in demographic or disease variables, IQ, or Block Design standard scores. Right hemisphere patients made more broken configurations than did those with left hemisphere foci. In the right hemisphere group, more broken configurations were associated with a lower Block Design Scaled Score and Full Scale IQ. These results suggest that the observation of broken configurations in the Block Design can assist in corroborating the seizure focus and highlight the importance of qualitative Block Design analysis.     

Learning postural tasks in hemiparetic patients with lesions of left versus right hemisphere

There are a number of studies concerning difference of postural control following left or right hemisphere lesions. Few studies, however, compare the role of the right and left hemisphere in learning new postural tasks. This study aimed to address this question. Twenty patients with hemiparesis after ischemic stroke in the middle cerebral artery territory (11 with a right and 9 with a left hemispheric lesion) were investigated. All subjects were trained using two different tasks during ten training sessions. In both tasks, the subjects stood on a force platform and were taught to change the position of the center of pressure (COP) presented as a cursor on a monitor screen in front of the patient. The subjects were instructed to align the COP with the target and then move the target by shifting the COP in the indicated direction. In the “Balls” task, the position of the target (a ball) varied randomly, so the subject had to learn a general strategy of voluntary COP control. In “Bricks”, the subject always had to move the target in a single direction (downward) from the top to the bottom of the screen, so that a precise postural coordination had to be learned. The number of correctly performed trials for a session was scored. The task performance and its rate were analyzed and compared with respect to the lesion lateralization between two patient groups. The voluntary control of the COP position and learning course were initially impaired in all groups of patients in both tasks. In “Balls”, there were no differences between the two groups of patients. In contrast, in “Bricks”, there was a greater initial deficit in patients with right hemisphere lesions, while the rate of postural learning and the final performance level did not differ between the groups. With a lower initial deficit and similar rate of learning, the maximal level of the task performance was reached earlier (on the 5th day of training) in patients with left hemisphere lesions. This group stopped improving its performance during follow-up training. The results suggest that the motor structures of the right hemisphere are more involved in the precise control of COP trajectory, but not in learning. There is no difference between hemispheres in the initial performance and learning of the general strategy of voluntary COP control. Possibly, the control of specific COP trajectory needs more sensory feedback that is associated with greater involvement of the right hemisphere. This might be a reason for the greater initial impairment of this task after lesions in the right hemisphere.     

Early effects of unilateral lesions of substantia nigra on immune reactivity.

It has recently been demonstrated that central dopaminergic pathways are asymmetrically involved in the modulation of the immune response. Mitogen-induced proliferation of T lymphocytes was shown to be enhanced 4-6 weeks after right lesion of the substantia nigra (SN) in mice, when compared to left lesioned and control animals. In order to study the involvement of post lesion neuronal reorganization in these results, the same immunological parameters were determined as early as 2 weeks after right or left lesion of the SN. We showed that the lymphoproliferation induced by alpha CD3 and concanavalin A was decreased in both lesioned groups, but phytohemagglutinin-induced mitogenesis was more impaired in the right than in the left lesioned animals. Hence, the time course effects of the right lesions of SN shifted from depression to enhancement of the T lymphocyte responsiveness. This shift appeared to occur around the two weeks period following the lesion. These immunomodulatory effects of unilateral SN lesioning, which depended on time and side of lesion, were similar to those observed after hemidecortication. Based on these findings, it is reasonable to suggest that asymmetry in brain immunomodulation involves functionally related dopaminergic and cortical networks.     

Lateralized cerebral dysfunction in schizophrenia and depression: gender and medication effects.

The neuropsychological functioning of 52 schizophrenic and 39 major depressive patients was examined using the four Luria-Nebraska Neuropsychological Battery lateralization scales, with the effects of gender and medication status examined alone and in interaction with diagnosis and laterality variables. Comparisons between the diagnostic groups revealed that gender influences some aspects of neuropsychological performance, particularly those involving bilateral complex cognitive-perceptual rather than sensorimotor skills. This effect was more distinct for depressives than schizophrenics when cerebral lateralization differences were present. There was no significant left hemisphere disadvantage for schizophrenics which was gender-related. Medication status revealed no appreciable effects for depressives, although both male and female schizophrenics receiving neuroleptics showed a greater degree of complex perceptual-cognitive dysfunction compared to unmedicated schizophrenics. Level of cerebral impairment was equivalent for the right and left hemispheres for both groups. Consequently, these data are not consistent with other findings demonstrating differential hemispheric disadvantages between schizophrenia and depression.