Cerebral hemodynamics after traumatic brain injury of immature brain.

These studies were designed to characterize the cerebral hemodynamic effects of fluid percussion brain injury (FPI) in the newborn pig equipped with a closed cranial window. Reductions in cerebral blood flow, pial artery diameter, and cerebral oxygenation following FPI were greater in newborn (1-3 days old) vs. juvenile (3-4 weeks old) pigs, suggesting that newborns were exquisitely sensitive to brain injury. Additionally, in piglets, there was decremented dilation to nitric oxide, cGMP, and cAMP dependent stimuli following FPI. The membrane potential of vascular muscle is an important contributor to vascular tone and the activity of K+ channels is an important regulator of membrane potential. Recent studies indicate that altered dilator responsiveness and cerebral hemodynamic control following FPI results from impaired K+ ATP sensitive (KATP) and calcium sensitive (Kca+2) channel function. Impaired KATP channel function results, at least in part, from protein kinase C activation by the peptide endothelin-1. These observations indicate that the effects of brain injury on cerebral hemodynamics in the newborn are multifaceted and multifactorial.     

自噬在创伤性脑损伤中的作用

自噬(autophagy)是真核细胞在营养与能量缺乏情况下,通过分解亚细胞成分提供生物合成原料,使蛋白质和细胞器得以循环利用的一种降解代谢途径,同时调控线粒体更新及过氧化物酶体等,从而维持细胞稳态.     

Porteus Maze performance following traumatic brain injury in children.

To investigate planning in traumatically brain injured children, the authors gave the Porteus Maze Test (PMT; S. D. Porteus, 1959) to 276 pediatric patients who had sustained a traumatic brain injury (TBI) at least 3 years previously. Sensitivity of the PMT to TBI severity, age at test, and volume of focal brain lesions detected by magnetic resonance imaging was also studied. The Peabody Picture Vocabulary Test-Revised (L. M. Dunn & L. M. Dunn, 1981) was also administered as a control measure. Results indicated that the PMT was highly sensitive to TBI severity and to volume of circumscribed prefrontal lesions. In contrast to the PMT data, receptive vocabulary was related to injury severity but not to discrete prefrontal lesions. Implications for mechanisms of cognitive deficit after TBI in children are discussed.     

Verbal IQ-performance IQ differentials in traumatic brain injury samples.

Several studies of head trauma utilizing the Wechsler Adult Intelligence Scale (WAIS) reported large sample differentials between verbal IQ (VIQ) and performance IQ (PIQ), leading some writers to claim that the VIQ is largely unaffected by traumatic brain injury (TBI), and that a superiority of VIQ over PIQ should be expected. In contrast, our review of Wechsler Adult Intelligence Scale-Revised (WAIS-R) studies indicates that although TBI sample PIQ means are often depressed relative to VIQ means, the differences are small and sometimes in the opposite direction. Possible reasons for the discrepancy between our WAIS-R review and those of an earlier review of WAIS studies are discussed. Clinically, the lack of a VIQ-PIQ difference should never be used to infer that a TBI has not occurred.     

Suicidality after traumatic brain injury: demographic,injury and clinical correlates

BACKGROUND: In spite of the high frequency of emotional distress after traumatic brain injury (TBI), few investigations have examined the extreme of such distress, namely, suicidality, and no large scale surveys have been conducted. The current study examined both the prevalence and demographic, injury, and clinical correlates of hopelessness, suicidal ideation and suicide attempts after TBI. METHODS: Out-patients (N = 172) with TBI were screened for suicidal ideation and hopelessness using the Beck Scale for Suicide Ideation and the Beck Hopelessness Scale. Data were also collected on demographic, injury, pre-morbid and post-injury psychosocial variables and included known risk factors for suicide. RESULTS: A substantial proportion of participants had clinically significant levels of hopelessness (35%) and suicide ideation (23%), and 18% had made a suicide attempt post-injury. There was a high degree of co-morbidity between suicide attempts and emotional/psychiatric disturbance. Results from regression analyses indicated that a high level of hopelessness was the most significant association of suicide ideation and a high level of suicide ideation, along with occurrence of post-injury emotional/psychiatric disturbance, were the most significant associations of post-injury suicide attempts. Neither injury severity nor the presence of pre-morbid suicide risk factors contributed to elevated levels of suicidality post-injury. CONCLUSIONS: Suicidality is a common psychological reaction to TBI among out-patient populations. Management should involve careful history taking of previous post-injury suicidal behaviour, assessment of post-injury adjustment to TBI with particular focus on the degree of emotional/psychiatric disturbance, and close monitoring of those individuals with high levels of hopelessness and suicide ideation.     

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.     

Myelin and traumatic brain injury: The copper deficiency hypothesis

Nearly two million people suffer traumatic brain injury in the US each year. These injuries alter adversely the metabolism of myelin, a major lipid material in brain, both in people and in experimental injuries of animals. A newly discovered and severe human neuropathy from copper deficiency provides evidence that some people in the US are malnourished in copper. As it is well known among copper cognoscenti that it is impossible to synthesize myelin if copper nutriture is inadequate, it seems reasonable to assume that repair will be poor in this situation. Copper status of patients should be evaluated and experiments with injured animals should be repeated with graded doses of copper to determine if copper metabolism is important in this illness.     

Myelin and traumatic brain injury: The copper deficiency hypothesis

Nearly two million people suffer traumatic brain injury in the US each year. These injuries alter adversely the metabolism of myelin, a major lipid material in brain, both in people and in experimental injuries of animals. A newly discovered and severe human neuropathy from copper deficiency provides evidence that some people in the US are malnourished in copper. As it is well known among copper cognoscenti that it is impossible to synthesize myelin if copper nutriture is inadequate, it seems reasonable to assume that repair will be poor in this situation. Copper status of patients should be evaluated and experiments with injured animals should be repeated with graded doses of copper to determine if copper metabolism is important in this illness.     

Disturbance of social cognition after traumatic orbitofrontal brain injury.

A patient with traumatic orbitomedial frontal lobe damage demonstrated good neurocognitive recovery but a lasting, profound disturbance of emotional regulation and social cognition. Initial neuropsychological findings included a complete anosmia, mildly reduced fluency and disturbed motor regulation. The impairments of fluency and motor regulation resolved, and formal measures of "frontal lobe" functioning were generally intact. However, she remained impaired on tasks requiring the interpretation of social situations, which mirrored her impairment in real life functioning. This disturbance in social cognition appeared related to difficulty appreciating and integrating the relatively subtle social and emotional cues required for the appropriate interpretation of events. The patient's presentation represents an intermediate position between patients with profound neurobehavioral deficits and patients with impaired real-life social cognition despite intact neuropsychological performance following orbitofrontal damage. Variations in the orbitofrontal behavioral syndrome may be related to extent of lesion, time post injury and the course of recovery in different patients.     

A comparison of self- and other-rated forms of the neuropsychology behavior and affect profile in a traumatic brain injury population.

The current study is the first reported use of both the other-rated and the self-rated forms of the Neuropsychology Behavior and Affect Profile (NBAP; Nelson, Satz, & D'Elia, 1994). Twenty-eight adult patients who were 7 to 27 months post predominantly mild closed head injury completed the self-report form of the NBAP, and their identified relatives/close friends completed the other-rated form of the NBAP. Patients and their relatives endorsed more items on the Inappropriateness and Depression scales for "now," as compared to "before" the injury. Only the patients endorsed more items on the Pragnosia scale for "now" as compared to "before." Comparisons of the NBAP pairs found no significant differences between the patients' self-reports and those of their significant others for "before" the injury. Patients endorsed more items on the Indifference and Pragnosia scales for "now," as compared to their relatives.     

脑微损伤的影像学进展

脑微损伤是创伤性脑损伤最常见的类型,然而,其潜在的神经生理机制尚未完全阐明,影响患者的早期诊断、治疗及预后评估。近年来,多项磁共振（MRI）新技术不断地涌现并用于评估脑微损伤,如功能磁共振、灌注MRI、弥散张量成像、定量易感性图谱、T2 mapping等。本研究综述了多模态MRI在脑微损伤中的应用,从不同的角度深入地了解脑微损伤的神经病理机制,有助于提高临床医生对脑微损伤的诊断和治疗。     

The Personality Assessment Inventory in individuals with traumatic brain injury.

This study examined the Personality Assessment Inventory (PAI) in 95 individuals who had suffered a traumatic brain injury (TBI). Participants were recruited from a rehabilitation hospital (n=60) and a military hospital (n=35); despite differences in demographics and injury characteristics groups did not differ on any of the clinical scales and were thus combined. In the combined group, the highest mean clinical scale elevations were on Somatic Complaints, Depression, and Borderline Features and the most common configural profiles, based on cluster analysis, were Cluster 1 (no prominent elevations), Cluster 6 (social isolation and confused thinking), and Cluster 2 (depression and withdrawal). Factor analysis indicated a robust three-factor solution that accounted for 74.86 percent of the variance and was similar to findings from the psychiatric and non-psychiatric populations in the standardization sample. The above findings are compared with the previous literature on psychopathology in TBI, particularly in regards to the Minnesota Multiphasic Personality Inventory-2 (MMPI-2), as well as previous psychometric research on the PAI.     

Genetic vulnerability following traumatic brain injury: the role of apolipoprotein E.

Apolipoprotein E (APOE) is thought to be responsible for the transportation of lipids within the brain, maintaining structural integrity of the microtubule within the neurone, and assisting with neural transmission. Possession of the APOE epsilon4 allele has also been shown to influence neuropathological findings in patients who die from traumatic brain injury, including the accumulation of amyloid beta protein. Previous clinical studies reporting varying outcome severities of traumatic brain injury, including cognitive and functional recovery, all support the notion that APOE epsilon4 allele possession is associated with an unfavourable outcome. Evidence from experimental and clinical brain injury studies confirms that APOE plays an important role in the response of the brain to injury.