Personality Changes Associated with Localized Brain Injury in Elderly Populations

Emotional disturbances following brain damage have been frequently reported in the literature. However, systematic investigation of these disorders and their specific causes were not common until the last 30 years. However, the number of research studies into this area remains slight compared to the voluminous literature on the cognitive effects of brain injury. The completed research has fallen into 3 major areas: (1) The study of clients with localized brain injuries to evaluate whether the site of the injury predicts the emotional reactions; (2) the effect of time poststroke on personality changes; and (3) the relation of neuropsychological deficits to emotional changes. This paper provides a comprehensive review of the research that has been completed in this area with elderly subjects along with an analysis of the current state of the knowledge in this area. Future directions for research to further our understanding are discussed.     

Long-term ability to interpret facial expression after traumatic brain injury and its relation to social integration

There is considerable evidence that individuals with traumatic brain injury (TBI) experience problems interpreting the emotional state of others. However, the functional implications of these changes have not been fully investigated. A study of 13 individuals with severe TBI and an equal number of matched controls found that TBI participants had significantly more difficulty interpreting facial expression and matching emotions to social situations. A significant relationship was also established between social integration and ability to interpret facial expression for TBI participants. These results support the inclusion of therapy targeting this area within rehabilitation programs for individuals with TBI.     

DNA methylation and behavioral changes induced by neonatal spinal transection

Although the importance of epigenetic mechanisms in behavioral development has been gaining attention in recent years, research has largely focused on the brain. To our knowledge, no studies to date have investigated epigenetic changes in the developing spinal cord to determine the dynamic manner in which the spinal epigenome may respond to environmental input during behavioral development. Animal studies demonstrate that spinal cord plasticity is heightened during early development, is somewhat preserved following neonatal transection, and that spinal injured animals are responsive to sensory feedback. Because epigenetic alterations have been implicated in brain plasticity and are highly responsive to experience, these alterations are promising candidates for molecular substrates of spinal plasticity as well. Thus, the current study investigated behavioral changes in the development of weight-bearing locomotion and epigenetic modifications in the spinal cord of infant rats following a neonatal low-thoracic spinal transection or sham surgery on postnatal day (P)1. Specifically, global levels of methylation and methylation status of the brain-derived neurotrophic factor (Bdnf) gene, a neurotrophin heavily involved in both CNS and behavioral plasticity, particularly in development, were examined in lumbar tissue harvested on P10 from sham and spinal-transected subjects. Behavioral results demonstrate that compared to shams, spinal-transected subjects exhibit significantly reduced partial-weight bearing hindlimb activity. Molecular data demonstrate group differences in global lumbar methylation levels as well as exon-specific group differences in Bdnf methylation. This study represents an initial step toward understanding the relationship between epigenetic mechanisms and plasticity associated with spinal cord and locomotor development.     

Synergistic influences of sensory and central stimuli on non-voluntary rhythmic arm movements

In recent years, neuromodulation of the cervical spinal circuitry has become an area of interest for investigating rhythmogenesis of the human spinal cord and interaction between cervical and lumbosacral circuitries, given the involvement of rhythmic arm muscle activity in many locomotor tasks. We have previously shown that arm muscle vibrostimulation can elicit non-voluntary upper limb oscillations in unloading body conditions. Here we investigated the excitability of the cervical spinal circuitry by applying different peripheral and central stimuli in healthy humans. The rationale for applying combined stimuli is that the efficiency of only one stimulus is generally limited. We found that low-intensity electrical stimulation of the superficial arm median nerve can evoke rhythmic arm movements. Furthermore, the movements were enhanced by additional peripheral stimuli (e.g., arm muscle vibration, head turns or passive rhythmic leg movements). Finally, low-frequency transcranial magnetic stimulation of the motor cortex significantly facilitated rhythmogenesis. The findings are discussed in the general framework of a brain-spinal interface for developing adaptive central pattern generator-modulating therapies.     

Alcohol,head injury,and neuropsychological function

Evidence is reviewed indicating that the extent of alcohol abuse alone cannot account for the neuropsychological deficits observed in alcoholics, and that alcohol abuse and head injury may interact in some patients to influence neuropsychological status. Alcohol abuse both increases the risk for head trauma and potentiates the resulting brain injury, which can lead to negative neuropsychological consequences. Clinicians involved in the treatment of addiction should assess patients for history of head injury, and neuropsychological deficits consequent to both head injury and ethanol. These deficits may limit patient ability to comply with addiction rehabilitation programs. Conversely, clinicians in acute care and rehabilitation of the sequelae of head trauma should routinely assess their patients for substance abuse, because such abuse can have a significant impact on recovery from brain injury.     

Noncontingent reinforcement as treatment for food refusal and associated self-injury

We examined the use of noncontingent reinforcement to decrease self-injury and increase bite acceptance in a child who exhibited food refusal. First, a brief functional analysis suggested that self-injury was maintained by escape from food presentation. Next, we evaluated an intervention that involved noncontingent access to a video during feeding sessions. Results of the intervention showed a decrease in self-injury and an increase in bite acceptance.     

Fear of Physical Harm: Factor Structure and Psychometric Properties of the Injury/Illness Sensitivity Index

Three fundamental fears—anxiety sensitivity, fear of negative evaluation, and injury/illness sensitivity—are believed integral components of anxiety-related psychopathologies. S. Taylor (1993) performed a cumulative factor analysis on measures of these and found them factorially distinct. Subsequently, separate factor analyses have been performed on measures of anxiety sensitivity and fear of negative evaluation. No such analysis exists for the Injury/Illness Sensitivity Index (ISI; S. Taylor, 1993). The ISI, an 11-item self-report questionnaire intended to measure fear of illness and injury, has the potential to inform the understanding of mechanisms underlying anxiety-associated chronic health conditions. The primary purpose of this study was to assess the factor structure and psychometric properties of the ISI. A principal components analysis with oblique rotation, conducted on data from 122 participants, suggests the ISI comprises two distinct lower order factors—Fear of Illness and Fear of Injury—that load onto a higher order factor of Fear of Physical Harm.     

Broad-Perspective Perceptual Disorder of the Right Hemisphere

Traditional accounts of right-posterior brain injury describe a syndrome of low-level perceptual sequelae producing marked acute dependency and transient safety concerns. The syndrome is also held to spare cognition and to carry a generally favorable long-term prognosis. The present paper reviews publications and anecdotal data that challenge this picture. Recent theoretical expositions and empirical studies stipulate three major cognitive functions of the right posterior association cortex: processing novel input, guiding reactions to emergencies, and anticipating consequences. Appearing benign after acute recovery, the impairment of these processes produces vocational, social and marital dysfunctions that increase as a function of chronicity, ultimately becoming more broadly disabling than focal injuries in other cortical loci. The unique symptom picture and serious implications suggest that the long-term syndrome should be labeled (Broad-Perspective Perceptual Disorder) and incorporated in future clinical taxonomies, underscoring the need for extraordinary long-term assistance and specialized therapeutics. Procedures for assessment and differential diagnosis are outlined.     

Depression After Mild Traumatic Brain Injury: A Review of Current Research

Research pertaining to the occurrence of depression and/or depression symptomatology after a Mild Traumatic Brain Injury (MTBI) was reviewed. We found that methodological differences such as the criteria used to assess MTBI and depression, time that elapsed since brain injury, and control group variations confounded comparisons across studies. Nevertheless, the studies are consistent with at least a 35% prevalence of, and left frontal damage with depression after MTBI, an overlap of symptoms of depression and Postconcussion Syndrome (PCS), and indicate that depression can continue for many years following the injury. Our conclusion is that MTBI is the triggering event for a set of pathophysiological changes and a concomitant depressive episode in a vulnerable subset of the population. Due to a paucity of research, it cannot be definitively concluded that the underlying substrates of depression seen after MTBI and clinical depression are the same. Implications for future investigations are discussed.     

脑外伤后患者的认知障碍

本文对83例脑外伤患者在智力、记忆、信息处理速度及语言流畅性等方面进行了研究.结果表明:脑外伤损害了患者的高级皮质功能,使其在相当长的时期内,仍遗留有智力、记忆、注意、信息处理速度及语言流畅性等方面的障碍,只是轻、重程度不等而已。从中我们选出相对比较灵敏的测验,做为今后研究脑外伤病人心理功能障碍的方法,并拟定出脑外伤病人心理功能的评定指标。