Anoxic encephalopathy: neuroradiological and neuropsychological findings.

The effects of anoxic brain injury are examined in 12 patients. Neuroradiological as well as neuropsychological findings are discussed and clinical guidelines offered. The most common neuropsychological profile associated with anoxic brain injury is one in which there is generalized cognitive impairment but with particular deficits in memory function. The common neuropathological findings are manifested by a pattern of diffuse cerebral atrophy as identified by neuroimaging techniques. A detailed case study is presented.     

Neuropsychological outcome and quantitative neuroimaging in mild head injury.

Four cases of well-documented mild traumatic brain injury (Glasgow Coma scores > or = 13) in whom preinjury neuroimaging studies were available (three with computerized tomography and one with magnetic resonance [MR] imaging) were examined in terms of postinjury MR imaging and neuropsychological outcome. All scans were subjected to quantitative analysis by measuring ventricular volumes and calculating a ventricle-to-brain ratio. Since ventricular measurements provide an index of parenchymal integrity, any systematic increase in postinjury ventricle size would be an indication of tissue loss. In addition to using the preinjury scan for a within-subject design in comparing postinjury changes, similar MR measures were obtained on a group of medical controls. Despite neuropsychological findings that suggested significant sequelae, quantitative postinjury MR studies did not show differences between preinjury neuroimaging or medical control subjects.     

Three-dimensional image analysis of trauma-induced degenerative changes: an aid to neuropsychological assessment.

A single case study is presented that depicts three-dimensional (3D) reconstruction of the day of injury computerized tomogram (CT) findings with the degenerative changes identified by magnetic resonance imaging (MR) 18 months postinjury. The method allows the clinician to examine 3D changes in the ventricular system as an aid in identifying regions of structural damage in one view rather than the need to view multiple images with the traditional two-dimensional (2D) presentation of CT or MR images. In this case study the neuropsychological deficits implicated generalized cerebrocortical dysfunction and the 3D image analysis correspondingly indicated generalized parenchymal tissue loss. This type of methodology is discussed in terms of furthering the neuropsychological-neuroimaging interface.     

Commentary and perspectives on R.M. Allen's "The test performance of the brain injured"

Significant advances have occurred in the study of the neuropsychology of head injury since R.M. Allen's (1947) paper. These include better conceptualization of brain-behavior relationships, advances in neuropsychological instruments, normative data and assessment paradigms, structural and functional brain imaging techniques, greater understanding of the mechanisms of brain injury, and the classification and quantification of brain injury. However, because of conceptual and methodological problems there has been a relative lack of progress in understanding the etiology of symptoms in mild head injury. To date, studies of mild head injury have produced widely mixed findings. Further, orthopedic injury, chronic pain, litigation, and other conditions may also produce cognitive and behavioral changes similar to those seen in mild head injury. The authors outline a study design with two control groups (other injury and noninjury) contrasted with mild closed head injury to resolve the issue of whether functional changes following an injury are due to a specific head injury effect or to more general injury factor(s). Results of extant studies using this design are discussed, along with future directions for neuropsychological assessment.     

Anoxic versus traumatic brain injury: amount of tissue loss, not etiology, alters cognitive and emotional function

Research in neuropsychology suggests that the etiology of a neurologic injury determines the neuropathological and neuropsychological changes. This study compared neuropsychological outcome in subjects who had traumatic brain injury (TBI) with subjects who had anoxic brain injury (ABI), who were matched for age, gender, and ventricle-to-brain ratio. There were no group differences for morphologic or neuropsychological measures. Both groups exhibited impaired memory, attention, and executive function, as well as slowed mental processing speed. Intelligence correlated with whole brain volume, and measures of memory correlated with hippocampal atrophy. There was no unique contribution of hippocampal atrophy on neuropsychological outcome between the groups. In the absence of localized lesions, the amount of neural tissue loss, rather than etiology, may be the critical factor in neuropsychological outcome.     

Neurobiology and neuropathology underlie the neuropsychological deficits associated with traumatic brain injury.

The neurobiological and neuropathological bases that underlie the neuropsychological deficits associated with traumatic brain injury (TBI), including mild TBI, are further reviewed. The article provides an update on neuroimaging methods and findings in the study of TBI since the author's published address of the 1999 Distinguished Neuropsychologist Award of the National Academy of Neuropsychology (see Bigler, 2001a). The review addresses and answers criticisms raised about the interface of neuroimaging abnormalities and neuropsychological deficits, particularly in mild TBI. The article provides further guidelines in making the link between neuroimaging findings and neuropsychological outcome in the clinical practice of neuropsychology. The article also opines on the future role and importance that neuroimaging will play in neuropsychological practice, particularly functional neuroimaging methods.     

Cerebral energy metabolism following ESWL brain injury model and effects of cerebral protective drugs.

The goal of this study was to introduce a new method inducing an experimental brain injury model using ESWL(Extracorporeal Shock Wave Lithotripsy) and to evaluate findings of localized lesions on 1H MR imaging and the response of cerebral energy metabolism using a 31P MR spectroscope to the ESWL brain injury in cats. This study also examined effects of cerebral protective drugs. 1) There were no statistically significant changes in pH at all measurement points. 2) In the trauma group, initial decrease of PCr/Pi was seen at 30 to 60 minutes with return to control levels by 2 hours after injury(P < 0.05), followed by a second decline at 4 hours which lasted until 8 hours after injury. 3) Significant recovery in PCr/Pi(P < 0.05) was observed in both the THAM and dexamethasone treated groups at all measurement points and in the mannitol treated group only temporary recovery at 30 and 60 minutes (P < 0.05). 4) High intensity signals were seen on 1H MR imaging in traumatized animals. This study demonstrated the immediate and persistent recovery of cerebral energy metabolism using THAM or dexamethasone and an immediate but transient effect with mannitol in traumatized animals.     

A history of sport-related concussion on event-related brain potential correlates of cognition

Over the past decade, a growing body of research has detailed persistent changes to neuroelectric indices of cognition in amateur and professional athletes with a concussion history. Here, we review the relevant neuroelectric findings on this relationship while considering the duration from the last concussive event. Collectively, the findings support a negative relation of concussive injury to neuroelectric indices of brain health and cognition in the presence of normal clinical findings. The results suggest that event-related brain potentials are especially well-suited for identifying aspects of cognition that remain dysfunctional for an extended period of time, which are otherwise unidentified using standard neuropsychological tests. Such findings also suggest the need for additional research to fully elucidate the extent to which concussive injuries negatively impact brain health and cognition.     

Neuropsychological testing defines the neurobehavioral significance of neuroimaging-identified abnormalities.

Three cases are presented in patients all of whom sustained focal left frontal traumatic injury to the brain. Although each case was selected because of a neuroimaging-identified frontal lesion, the point is made that the behavioral significance of such lesions is defined by the neuropsychological examination process, and not the specific size, location, or type of lesion. While neuroimaging information is critical to the comprehensive evaluation of the neurologic patient, neuroimaging findings alone have only limited predictive ability with regard to neurobehavioral syndromes. The key role of information from neuropsychological test data, combined with neuroimaging findings to fully evaluate the neurologic patient, is made.     

Distinguished Neuropsychologist Award Lecture 1999. The lesion(s) in traumatic brain injury: implications for clinical neuropsychology.

This paper overviews the current status of neuroimaging in neuropsychological outcome in traumatic brain injury (TBI). The pathophysiology of TBI is reviewed and integrated with expected neuroimaging and neuropsychological findings. The integration of clinical and quantitative magnetic resonance (QMR) imaging is the main topic of review, but these findings are integrated with single photon emission computed tomography (SPECT) and magnetoencephalography (MEG). Various clinical caveats are offered for the clinician.     

Theory of mind in schizophrenia: A critical review

Introduction. In neuropsychological research, “organic personality disorder”, lack of social insight, and executive dysfunctions have been identified in patients with prefrontal brain injury. The assessment of personality change has, in particular, been a methodological challenge in this field of research. The aim of the present pilot study was to examine personality aspects in patients with prefrontal brain injury from a neuropsychological as well as a psychodynamic point of view.

Methods. A total of 13 adults with personality change as a manifest sequel after sudden onset brain injury were assessed with neuropsychological tests of executive functions, with the European Brain Injury Questionnaire (EBIQ), and with the Karolinska Psychodynamic Profile (KAPP), which to our knowledge has not previously been used as part of a neuropsychological assessment. The personality profiles of the brain‐injured patients were compared to the personality profile of a group of 65 brain‐healthy individuals.

Results. The personality organisation of the prefrontally brain‐injured patients was significantly disturbed and close to a borderline personality organisation, as defined by the KAPP.

Conclusions. The results of the pilot study suggest that prefrontal brain systems may support the integration of self‐functions and play a central role for inter‐personal relations. Future research regarding the relation between brain dysfunction, executive and cognitive deficit, and personality disorder needs to be carried out in larger samples to substantiate the hypothesis of a relationship between prefrontal brain systems and self‐functions.     

Pre- and post-stroke MRI and neuropsychological studies in sickle cell disease: a case study.

The case of a patient with sickle cell disease is presented in which neuropsychological and magnetic resonance imaging studies were completed prior to and after a right hemispheric stroke. The contribution of a new MR perfusion technique in understanding the neurological complications in this patient is discussed. This case illustrates the complex pathophysiology of neuropsychological deficits in SCD and underscores the need to develop models that better reflect this complexity.     

Correlation of MR imaging findings and open exploration of medial patellofemoral ligament injuries in acute patellar dislocations

The purpose of this investigation was to correlate magnetic resonance (MR) images of medial patellofemoral ligament (MPFL) injuries with gross macroscopic findings. Twenty-seven knees with MPFL injury following an initial patellar dislocation were examined using axial proton-density and T2-weighted fast spin-echo MR imaging. MR findings were subsequently correlated with open exploration. MPFL injury was observed in 26 (96%) of the 27 knees. From the MR images, discontinuity, irregularity and/or high-signal intensity changes anterior to the femoral attachment were seen in 13 (82%) of the 16 knees with substantial-tear type injuries of the MPFL. In 8 (80%) of the 10 knees with avulsion-tear type injuries, detachment of the MPFL from the femoral attachment, accompanied with or without high-signal intensity changes, was confirmed. MPFL injury types could be accurately diagnosed on 21 (81%) out of 26 knees using MR imaging. MR imaging was an acceptable method in diagnosing MPFL injury types.     

Multi‐echo susceptibility‐weighted imaging and histology of open‐field blast‐induced traumatic brain injury in a rat model

Blast‐induced traumatic brain injury is on the rise, predominantly as a result of the use of improvised explosive devices, resulting in undesirable neuropsychological dysfunctions, as demonstrated in both animals and humans. This study investigated the effect of open‐field blast injury on the rat brain using multi‐echo, susceptibility‐weighted imaging (SWI). Multi‐echo SWI provided phase maps with better signal‐to‐noise ratio (SNR) and contrast‐to‐noise ratio (CNR), making it a sensitive technique for brain injury. Male Sprague‐Dawley rats were subjected to a survivable blast of 180 kPa. The visibility of blood vessels of varying sizes improved with multi‐echo SWI. Reduced signal intensity from major vessels post‐blast indicates increased deoxyhaemoglobin. Relative cerebral blood flow was computed from filtered phase SWI images using inferred changes in oxygen saturation from major blood vessels. Cerebral blood flow decreased significantly at day 3 and day 5 post‐blast compared with that pre‐blast. This was substantiated by the upregulation of β‐amyloid precursor protein (β‐APP), a marker of ischaemia, in the neuronal perikaya of the cerebral cortex, as observed by immunofluorescence, and in the cortical tissue by western blot analysis. Our findings indicate the presence of brain ischaemia in post‐blast acute phase of injury with possible recovery subsequently. Our results from cerebrovascular imaging, histology and staining provide an insight into the ischaemic state of the brain post‐blast and may be useful for prognosis and outcome. Copyright © 2015 John Wiley & Sons, Ltd.     

The clinical significance of cerebral atrophy in traumatic brain injury.

The neuropsychological effects of traumatic brain injury (TBI) as they relate to the chronic neuropathological chang.es of cortical atrophy and ventricular enlargement are reviewed. Computerized tomography (CT) and magnetic resonance imaging (MRI) methods are excellent at detecting many of these changes and results from these diagnostic methods should be incorporated in the interpretation of neuropsychological outcome in TBI patients. Several Clinical guidelines are presented on the relationship between TBI induced atrophy and neurobehavioral outcome.     

Depression and neuropsychological test performance in acute spinal cord injury patients: lack of correlation.

Factors which have been causally related to neuropsychological deficits in acute spinal cord injury (SCI) patients include advanced age, limited educational level, acute traumatic brain injury, alcohol and/or substance abuse. Concomitant depression may impair motivation, prolong reaction time, and produce fatigue during neuropsychological testing, resulting in impaired performance. To test the hypothesis that abnormal neuropsychologic test results may be associated with depression, the Zung Self-Rating Depression Scale (ZUNG) and a comprehensive, predominantly motor-free neuropsychological test battery were administered to 66 acute SCI patients approximately 8 weeks following injury. Spinal cord injury groups were dichotomized based on their ZUNG scores. Comparison of neuropsychological test scores between SCI groups failed to demonstrate any impairment in neuropsychological performance, within the limits of the test battery administered, suggesting that cognitive performance in this sample of acute SCI patients may not be influenced by the presence of depression.     

Acquired brain injury: combining social psychological and neuropsychological perspectives

This theoretical paper reviews an emerging literature which attempts to bring together an important area of social psychology and neuropsychology. The paper presents a rationale for the integration of the social identity and clinical neuropsychological approaches in the study of acquired brain injury (ABI). The paper begins by reviewing the social and neuropsychological perspectives of ABI. Subsequently, theoretical and empirical studies that demonstrate the social influences on neuropsychology and the inherently social nature of mind are considered. Neuropsychological understandings of social identities and their potential relationships to the variability in ABIs are also discussed. The values of these understandings to ABI rehabilitation are then examined. The paper concludes by suggesting an agenda for future research that integrates the social identity and neuropsychological paradigms so that psychology might grow in its store of applicable knowledge to enhance support and rehabilitation for those with ABI.     

Short-term neuropsychological outcome following uncomplicated mild TBI: effects of day-of-injury intoxication and pre-injury alcohol abuse

Research suggests that individuals who are intoxicated at the time of traumatic brain injury (TBI) have worse cognitive outcome compared with those who are sober. Worse outcome in patients with day-of-injury intoxication might (a) be related to the increased magnitude of brain injury resulting from a variety of negative responses not present following TBI in nonintoxicated individuals, or (b) reflect the effect of pre-injury alcohol abuse that is prevalent in individuals intoxicated at the time of injury. Most studies in this area have focused on patients with moderate to severe TBIs, and on medium- to long-term neuropsychological outcome. The purpose of this study was to examine the relative contributions of day-of-injury intoxication versus pre-injury alcohol abuse on short-term cognitive recovery following mild TBI. Participants were 169 patients with uncomplicated mild TBIs who were assessed on 13 cognitive measures within 7 days postinjury. The prevalence of intoxication at the time of injury was 54.4%. The prevalence of possible pre-injury alcohol abuse was 46.2%. Overall, the results suggest that pre-injury alcohol abuse, compared with day-of-injury alcohol intoxication, had the most influence on short-term neuropsychological outcome from uncomplicated mild TBI. However, the influence of pre-injury alcohol abuse was considered small at best.     

Specificity of verbal learning impairment and recovery in a marijuana-dependent male: The effects of sustained marijuana abstinence

Introduction. We present the case of a young adult in treatment for marijuana dependence, with recurrent depression and a history of possible traumatic brain injury, complaining of concentration, memory, and initiation problems.

Methods. The patient was assessed longitudinally during treatment with a brief neuropsychological battery, as well as measures of marijuana use and mood.

Results. Testing at treatment baseline revealed performance that was generally in the high average range or higher on measures of reaction time and attention, with a selective impairment in verbal learning (borderline to extremely low range). Following 8 weeks of abstinence from marijuana, his verbal learning recovered to expected levels (high average range), with signs of improved learning strategy, efficiency, rate, and capacity. However, his reaction time and attention showed minimal evidence of change.

Conclusions. This finding is consistent with the literature that demonstrates that marijuana-associated neurocognitive impairments may be most pronounced in the domain of verbal learning and may remit with abstinence. The clinical implications of these case findings and recommendations for neuropsychological assessment of marijuana abusers are discussed.