Dan Hoofien

Bilateral hippocampal lesion and a selective impairment of the ability for mental time travel

Mental time travel allows individuals to mentally project themselves backwards and forwards in subjective time. This case report describes a young woman suddenly rendered amnesic as a result of bilateral hippocampal damage following an epileptic seizure and brain anoxia. Her neuropsychological profile was characterized by a high-average general level of cognitive functioning, selective deficit in episodic memory of past events and a significant difficulty to envisage her personal future. This case provides clinical support for the concept of mental time travel with its retrospective and prospective components and for the hippocampus being its critical neural substrate.

Comparison of the predictive power of socio-economic variables, severity of injury and age on long-term outcome of traumatic brain injury: sample-specific variables versus factors as predictors.

The primary objective of this study was to measure the predictive power of pre-injury socio-economic status (SES), severity of injury and age variables on the very long-term outcomes of traumatic brain injury (TBI). By applying a within-subjects retroactive follow-up design and a factor analysis, the study also compared the relative power of sample-specific predictors to that of more commonly used variables and conceptually based factors. Seventy-six participants with severe TBI were evaluated at an average of 14 years post-injury with an extensive neuropsychological battery. The results show that pre-injury SES variables predict long-term cognitive, psychiatric, vocational, and social/familial functioning. Measures of severity of injury predict daily functioning, while age at injury fails to predict any of these variables. Sample-specific predictors were more powerful than more commonly used predictors. Implications regarding long-term clinically based and conceptually based prediction, and those regarding comparisons of predictors across samples are further discussed.

Hyperbaric Oxygen Therapy Can Improve Post Concussion Syndrome Years after Mild Traumatic Brain Injury - Randomized Prospective Trial

Background Traumatic brain injury (TBI) is the leading cause of death and disability in the US. Approximately 70-90% of the TBI cases are classified as mild, and up to 25% of them will not recover and suffer chronic neurocognitive impairments. The main pathology in these cases involves diffuse brain injuries, which are hard to detect by anatomical imaging yet noticeable in metabolic imaging. The current study tested the effectiveness of Hyperbaric Oxygen Therapy (HBOT) in improving brain function and quality of life in mTBI patients suffering chronic neurocognitive impairments. Methods and Findings The trial population included 56 mTBI patients 1–5 years after injury with prolonged post-concussion syndrome (PCS). The HBOT effect was evaluated by means of prospective, randomized, crossover controlled trial: the patients were randomly assigned to treated or crossover groups. Patients in the treated group were evaluated at baseline and following 40 HBOT sessions; patients in the crossover group were evaluated three times: at baseline, following a 2-month control period of no treatment, and following subsequent 2-months of 40 HBOT sessions. The HBOT protocol included 40 treatment sessions (5 days/week), 60 minutes each, with 100% oxygen at 1.5 ATA. “Mindstreams” was used for cognitive evaluations, quality of life (QOL) was evaluated by the EQ-5D, and changes in brain activity were assessed by SPECT imaging. Significant improvements were demonstrated in cognitive function and QOL in both groups following HBOT but no significant improvement was observed following the control period. SPECT imaging revealed elevated brain activity in good agreement with the cognitive improvements. Conclusions HBOT can induce neuroplasticity leading to repair of chronically impaired brain functions and improved quality of life in mTBI patients with prolonged PCS at late chronic stage. Trial Registration ClinicalTrials.gov NCT00715052

Hope, dispositional optimism and severity of depression following traumatic brain injury.

Primary objective: To investigate the extent in which two coping variables—hope and dispositional optimism—are related to depression severity amongst individuals who have sustained traumatic brain injury (TBI). Methods and procedures: Sixty-five participants were administered the Beck Depression Inventory (BDI), the Adult Hope Scale (AHS), the Life Orientation Test-Revised (LOT-R) and a demographic and injury-related data questionnaire. In addition, relevant injury-related data was collected from the medical records. Main outcomes and results: High levels of depression were experienced in the study sample, while hope and dispositional optimism were significantly lower in comparison to the general population. The correlation patterns indicate that both hope and dispositional optimism negatively correlated with participants’ depression levels and that they showed significant positive correlations with each other. In the case of mild depression, the hope-Pathways sub-scale of the AHS was the only variable negatively correlated to it, while in moderate-to-severe depression all coping variables were negatively correlated to it. Regression analysis revealed that the AHS and LOT-R, but not the demographic and injury-related variables, predicted depression severity. Conclusions: Clinical implications in referring persons with TBI with mild vs. severe depression to rehabilitation programmes are discussed.

Unawareness of Cognitive Deficits and Daily Functioning Among Persons With Traumatic Brain Injuries

This study examines levels of unawareness of cognitive deficits and their relationship to functional outcome among persons with traumatic brain injury (TBI). Data from 61 persons with TBI and 34 family members consisting of various measures were used. The results suggest that awareness of cognitive deficits is not differentially distributed along a concrete- continuum of cognitive domains. Awareness in this sample was significantly related to psychiatric symptomatology and partially associated with behavior disturbances and daily functioning, but not with vocational outcomes. Persons with TBI who over-estimated their cognitive abilities were found to function worse on most outcome measures, except vocation, than persons who did not overestimate their abilities.

Automatic temporal order judgment : the effect of intentionality of retrieval on closed-head-injured-patients

Closed-head-injured (CHI) and control groups were tested on a temporal order task under intentional and incidental retrieval conditions. Subjects were given five presentations of a list of nouns. In the incidental retrieval condition, subjects were told that they were to remember the words but that the order was not important. In the intentional retrieval condition, subjects were given the words in an order different from that in which they were originally presented and were asked to reorder the words to match the original order. For both conditions we compared the order in which words were recalled to the order in which they were originally presented. The results suggest that temporal order memory had more effortful characteristics in the intentional than in the incidental retrieval condition. The two groups did not differ significantly in the incidental retrieval condition. However, while the control group showed a significant improvement in the intentional retrieval condition. CHI groups performance did not significantly change. This study highlights two major points: (1) intentionality at the retrieval stage determines the effortfulness with which information is processed; (2) the more automatic the tasks, the better it is preserved following closed-head injury.

Improvement of memory impairments in poststroke patients by hyperbaric oxygen therapy.

OBJECTIVE Several recent studies have shown that hyperbaric oxygen (HBO₂) therapy carry cognitive and motor therapeutic effects for patients with acquired brain injuries. The goal of this study was to address the specific effects of HBO₂ on memory impairments after stroke at late chronic stages. METHOD A retrospective analysis was conducted on data of 91 stroke patients 18 years or older (mean age ∼60 years) who had either ischemic or hemorrhagic stroke 3-180 months before HBO₂ therapy (M = 30-35 months). The HBO₂ protocol included 40 to 60 daily sessions, 5 days per week, 90 min each, 100% oxygen at 2ATA, and memory tests were administered before and after HBO₂ therapy using NeuroTraxs computerized testing battery. Assessments were based on verbal or nonverbal, immediate or delayed memory measures. The cognitive tests were compared with changes in the brain metabolic state measured by single-photon emission computed tomography. RESULTS Results revealed statistically significant improvements (p < .0005, effect sizes medium to large) in all memory measures after HBO₂ treatments. The clinical improvements were well correlated with improvement in brain metabolism, mainly in temporal areas. CONCLUSIONS Although further research is needed, the results illustrate the potential of HBO₂ for improving memory impairments in poststroke patients, even years after the acute event.

The Delis–Kaplan Executive Function System Sorting Test as an evaluative tool for executive functions after severe traumatic brain injury: A comparative study

Neuropsychological tests are often used to evaluate executive function (EF) deficits in patients suffering traumatic brain injuries (TBIs). This study compared the sensitivity of three such tests—namely, the Delis–Kaplan Executive Function System Sorting Test (D-KEFS ST), the Wisconsin Card Sorting Test (WCST), and the Trail Making Test (TMT)—in differentiating between severe TBI patients and healthy controls. The differences between the two groups were significant for 5/5 variables evaluated through the D-KEFS ST, for 4/6 variables evaluated through the WCST, and for 2/2 variables evaluated through the TMT. Receiver operating characteristic analysis revealed that the variables “attempted sorts” in the D-KEFS ST and completion time in Part B of the TMT were the most powerful predictors of group assignment, with cutoff points of 9.5 sorts and 84.5 seconds, respectively. Our results highlight the possible value of the D-KEFS ST in the evaluation of postinjury EF deficits in TBI patients.

Comparison of two patient-controlled analgesia techniques on neuropsychological functioning in the immediate postoperative period

Pain may contribute to cognitive decline, which is a common complication in the early postoperative period. We compared the effects of two common pain management techniques, intravenous patient-controlled analgesia (PCA-IV) and patient-controlled epidural analgesia (PCEA), on cognitive functioning in the immediate postoperative period. Patients hospitalized for elective surgery were randomly assigned to one of the treatment groups (30 patients per group). A battery of objective, standardized neuropsychological tests was administered preoperatively and 24 hours after surgery. Pain intensity was also evaluated. Nonoperated volunteers served as controls. Patients of the PCA-IV group exhibited significantly higher pain scores than did patients of the PCEA group. PCA-IV patients exhibited significant deterioration in the postoperative period in all the neuropsychological measures, while the PCEA patients exhibited significant deterioration only in one cognitive index, compared to controls.

The sorting test of the D‐KEFS in current and weight restored anorexia nervosa patients

OBJECTIVE Efforts have been made to characterize executive functions (EF) in anorexia nervosa (AN) both in the acute stage of the illness and after weight gain, yet many questions remain. The question of verbal versus visuo-perceptual stimuli in this regard has not been adequately addressed. The aim of this study is to further examine EF in women with past and present AN and to compare their performances in verbal and visual modalities with women who have never suffered from an eating disorder. METHOD Thirty-five underweight AN patients, 33 weight-restored patients symptom-free for at least 2 years, and 48 healthy female controls completed the Delis-Kaplan Executive Function System Sorting Test, so as to evaluate their EF. RESULTS No differences were observed between the scores of women with current and past AN. Both groups scored lower than controls on most test variables. However, while in the visuo-perceptual domain the performance of the AN groups was worse than that of controls, in the verbal domain they performed similarly to them. DISCUSSION Women with a past or present diagnosis of AN show difficulties in visuo-perceptual EF, whereas verbal EF seem to be preserved. There may be a dissociation between verbal and visuo-perceptual EF that persists after weight restoration.