Prognostic factors in childhood-acquired brain injury.

BACKGROUND: A long-term follow-up study comparing children after anoxic brain injury (AnBI) with those after traumatic brain injury (TBI) was conducted, and prognostic factors were mapped. METHODS: A prospective historical study following long-term functional outcome after childhood brain injury was conducted in two phases. The first phase included patients suffering from moderate-severe TBI. The second phase assessed children after AnBI, and the results were compared. Functional outcome was recorded and factors influencing prognosis were outlined. RESULTS: On admission vegetative state (VS) was twice as prevalent in the AnBI subgroup. Approximately 90% of children with TBI and 60% of patients with AnBI gained independency in activities of daily living (ADL) and mobility. Long-term positive outcome, i.e., return to school and open-market employment, were higher in patients with TBI when compared with AnBI (61% and 48.1%, respectively). Significant outcome-predicting factors were VS at admission to rehabilitation, length of loss of consciousness (LOC) up to 11 days and functional independence measure (FIM) score at admission and discharge. Aetiology was not found to be a predicting factor. CONCLUSIONS: Duration of unconsciousness is the main long-term negative prognostic outcome factor. Anoxic brain damage, associated with longer periods of unconsciousness also heralds a less favourable outcome.

Dysfunction of the auditory efferent system in patients with traumatic brain injuries with tinnitus and hyperacusis.

OBJECTIVES: Tinnitus, hyperacusis and difficulty listening in background noise are common symptoms reported by patients with traumatic brain injury (TBI). The aim of this study was to explore the function of the auditory system in TBI patients with and without auditory complaints but having normal pure-tone audiograms. METHODS: The study consisted of 24 TBI patients with and 10 TBI patients without auditory complaints. In addition, 15 normal controls were included in the study. The function of the auditory system was tested by recording transient otoacoustic emissions (TEOAE) during the presentation of increasing levels of white noise in the contralateral ear. RESULTS: Most of the TBI patients with auditory complaints (87%) showed absent or significantly reduced effect of the auditory efferent system as compared with the TBI patients without auditory complaints and to normal controls. However, the global amplitude of the TEOAE was significantly higher in TBI patients with auditory complaints compared to those without. CONCLUSIONS: Due to its role in peripheral and central auditory activity, dysfunction of the efferent system may be at least partially responsible for these auditory complaints. This study underscores the importance of testing and evaluating the functional integrity of the medial efferent system by an objective and non-invasive method in patients with TBI.

Benign paroxysmal positional vertigo as the cause of dizziness in patients after severe traumatic brain injury: diagnosis and treatment.

OBJECTIVES: To identify patients with benign paroxysmal positional vertigo (BPPV) among patients with severe traumatic brain injury (TBI) and to evaluate the effectiveness of the Particle Repositioning Maneouvre (PRM). DESIGN AND METHODS: Eighteen months prospective study of 150 consecutive patients with severe TBI referred to an in-patients rehabilitation department. INTERVENTIONS: A structured interview emphasizing the possible presence of vertigo followed by a detailed neuro-otological examination. Patients diagnosed with BPPV were immediately treated with the PRM. MAIN OUTCOMES AND RESULTS: BPPV diagnosis was based on a positive Dix-Hallpike positional test. PRM efficacy was determined by repeating the positional test 1 or 2 weeks after treatment. Twenty out of 150 (13.3%) patients complained about positional vertigo. The diagnosis of BPPV was confirmed in 10 patients. Signs and symptoms were completely relieved in six patients after a single PRM, while the other four patients needed repeated treatment for complete resolution of BPPV. CONCLUSIONS: About half of the patients with severe TBI who complain about positional vertigo suffer from BPPV. These patients can be efficiently treated by physical maneouvres improving the rehabilitation outcome.

Heart rate variability (HRV) of patients with traumatic brain injury (TBI) during the post-insult sub-acute period.

OBJECTIVE: To evaluate heart rate variability (HRV) of patients with traumatic brain injury (TBI). METHODS: By a prospective study, the HRV was assessed in 20 patients with TBI during the sub-acute period post-injury (the first test was performed at a mean time post-insult of 38 days) and a matched control. The patients were examined twice, 1 month apart. The assessment included HRV (both in time and frequency domains), GCS, length of coma, brain CT, FIM and FAM. RESULTS: A significant difference was found between patients and controls concerning HRV total power, i.e. frequencies between 0.01-0.6 Hz (high frequency p = 0.003, low frequency p = 0.013, total power p = 0.034) and for standard deviation of RR interval p = 0.011. HRV changes were related more to the timing of the evaluation than to the severity of the brain damage. CONCLUSION: HRV differed of patients with TBI and in the control group. Tendency to HRV normalization changes was detected during the first 3 months after the injury, which suggests recovery of the autonomic nervous system.

Brain injury-related heterotopic bone formation: treatment strategy and results.

OBJECTIVES: Heterotopic bone formation (HO) is a phenomenon occurring in some neurologically injured patients that can adversely affect their rehabilitation. The current study aimed at evaluating functional results and recurrence rates after recurrence of such lesions. DESIGN: The results of 12 excisions of HO in 9 patients were assessed. A single-dose of 750 cGy delivered 24 hr postoperatively was used in seven of nine patients. RESULTS: One year postintervention, the arc of motion averaged 92.5 degrees in the hips, 66.6 in the knees, and 60 degrees in the elbow. Despite increased uptake on bone scans in all patients, recurrence did not occur in any patient. Ambulation levels improved in four of eight hips. Ease of personal hygiene was improved in all patients, although some patients still require assistance. CONCLUSIONS: Excision of symptomatic HO is recommended if limitation of joint motion seems to hinder the patient's rehabilitation. Some motor control is desirable to achieve significant improvement in the patient's quality of life. Increased uptake on bone scans is not a contraindication to surgical excision of HO, provided the neurologic status is stabilized.

Visual search in peripheral vision: learning effects and set-size dependence.

Feature search for a light bar with one orientation (or color) embedded in an array of bars with a very different orientation (or color) is quick, easy and independent of the number of array elements. In contrast, search for a conjunction target has a linear response time dependence on the number of distractors. Training can improve performance of both these tasks. We report that these properties may not be valid for eccentric stimulus presentation. In general, the two hemifields are not equally suited to search, and training is most effective in the weaker hemifield. In addition, the feature-search independence of set-size may not always be valid for stimulus arrays that are presented peripherally. Subjects were tested on orientation and color feature tasks, and on orientation-color conjunction search with 3 array sizes presented at fixation or eccentrically in the right or left hemifield. During a second testing session, improvement was so much greater for the non-preferred hemifield that sometimes the preference was switched. Surprisingly, preferred hemifield performance actually declined for some subjects. Thus, the hemifield preference effect seems related to competition, and perhaps an automatic attention-directing mechanism. We confirmed the central presentation set-size independence for feature search but found a great difference between large and small arrays when presentation was lateral. There are two sources of this array size effect: 1. Target eccentricity, demonstrated by comparing performance for different target locations with the same array size. 2. Target location uncertainty, seen by comparing performance for different size arrays when the target elements appeared at the same locations. Training also affected the array-size dependence, changing search performance from set-size dependent to independent or vice versa at the point of greatest training effect.

Combined motor disturbances following severe traumatic brain injury: an integrative long-term treatment approach.

Patients surviving severe traumatic brain injury (TBI) often suffer from residual impairments in motor control, communication skills, cognition and social behaviour. These distinctly hamper their capability to return to their 'pre-trauma' activity. Comprehensive and integrated rehabilitation programmes initiate, during the acute phase, a prolonged treatment process which starts at the most sophisticated medical systems. There is no clear end point for the treatment of these patients, since the recovery process and the rehabilitation activity may continue for years, even after patients return home to live with their families. The inherent inability to make a firm early prediction regarding outcome of patients and the late appearance of additional symptoms stress the need for a comprehensive close long-term follow-up. The following presentation concerns the description of the treatment strategy and long-term improvement of a 22-year-old male who suffered from very severe TBI. On admission to the emergency room, he was in the decerebrated position and his Glasgow Coma Scale (GCS) was at the lowest (3). The focus of this presentation is on the recovery of motor function. The initial motor disabilities included weakness in all four limbs, in particular left hemiplegia, and right hemiparesis with severe bilateral ataxic elements and a marked tremor of the right arm. Range of motion was limited in hips, and he suffered from stiff trunk and neck. Goals of physiotherapy were directed towards improving range of motion (ROM) and active movement. Casting, use of orthoses, biofeedback, hydrotherapy, hippotherapy, medication and nerve blocks for reducing spasticity were timely applied during the process. The motor improvement in this very severe TBI patient who is now over 3 years post-injury still continues and has a functional meaning. He has succeeded in being able to stand up by himself from a chair and is able to walk unaided and without orthoses for very short distances--up to five steps. He is able to drink soup without assistance and play a few notes on the piano. Marked cognitive improvement occurred as well. It is concluded that motor improvement may be evident over long periods of time and various timely interventions may assist in the process.

Tracheotomy in severe TBI patients: sequelae and relation to vocational outcome.

The aim of the present study was to find the influence of performing tracheotomy on outcome of severe TBI patients. TBI patients, many of them intubated during the very acute phase post-injury, who remain unconscious for more than a few days, undergo tracheotomy to provide a reliable long term artificial airway. Tracheotomy, although being a simple elective surgical procedure, may have a negative influence on the rehabilitation process. Tracheotomy was performed in 25% (n=69) of 277 consecutive severe TBI patients admitted to the rehabilitation department during 3 years. In seven patients (10%), tracheotomy was performed immediately after injury due to cranio-facial trauma, in 18 patients (29%) due to respiratory disturbances, in 42 patients (55%) after prolonged intubation, and in two patients (6%) due to combined problems. Forty-five per cent of patients with tracheotomy suffered from respiratory disturbances and 8.6% from complications of tracheotomy. Longer periods of unconsciousness and mechanical ventilation were significantly associated with respiratory complications (p<0.0001 and p<0.001, respectively). However, presence of tracheotomies per se, did not affect vocational rehabilitation.

Declarative and nondeclarative sequence learning tasks: closed-head injured patients versus control participants.

Patients who sustained closed-head injury (CHI) have been shown to have impaired memory for temporal order when measured under intentional, but not incidental, retrieval conditions. A group of 26 patients who sustained CHI and a matched control group of 26 individuals were tested on a declarative sequence learning task--"Chain Making" (CM), and a nondeclarative sequence learning task--Tower of Hanoi puzzle (TOHP). The TOHP is a problem solving task that requires planning and a strategic approach. The latter are cognitive processes known to be impaired following frontal lobe damage, as has been frequently documented in CHI patients. The goal of the present study was to test whether CHI patients' nondeclarative learning as measured by the TOHP task is preserved, as seen in amnesic patients, or impaired, as would be predicted following frontal lobe damage. Half of the participants in each group underwent active training, and the other half went through passive training of the tasks. The results demonstrate that the control group outperformed the CHI group (in most measures) in both declarative and nondeclarative sequence learning tasks. The effect of type of training differed for the two tasks: while performance of the control group on the TOHP was better under passive training (CHI patients did not improve on either one of the training modes), performance on the CM task was better under active training for both groups. The results are discussed in light of the role of the frontal lobes in memory generally, and in sequence learning particularly.

Incidence of sexual dysfunction in TBI patients during the early post-traumatic in-patient rehabilitation phase.

OBJECTIVE: The aim of the study is to find whether sexuality and intimacy dysfunction are already present at the early rehabilitation phase of TBI patients. METHODS: Forty-four consequent severe TBI patients were studied. The GCS and the duration of unconsciousness determined the initial severity of the injury. Patients' function regarding motor, language, cognition and behaviour were assessed by an interdisciplinary team. Sexuality and intimacy were evaluated by using a special closed questionnaire. RESULTS: Regarding self confidence 81% of patients described themselves as having high or average self confidences; 78% described themselves as having high or average feeling of being sexually appealing; mood level was average or high in 80% of patients. Only 7.7% of patients reported having sexual dysfunction at that phase of rehabilitation. CONCLUSIONS: Sexual dysfunction in Severe TBI patients is uncommon at the early post-traumatic phase. It is suggested that sexual dysfunction appearing during later stages of recovery is most probably related to reactive behavioural changes.

Apolipoprotein E-epsilon4 genotype predicts a poor outcome in survivors of traumatic brain injury.

OBJECTIVE: To determine the ability of apolipoprotein E (APOE) genotypes to predict days of unconsciousness and a suboptimal functional outcome in traumatic brain injury (TBI) survivors. BACKGROUND: TBI is known to be associated with neuropsychological deficits and functional disability. Recent evidence indicates that APOE plays a pivotal role in CNS response to injury. METHODS: In this prospective study the authors determined the APOE genotypes and tested their ability to predict days of unconsciousness and functional outcome after at least 6 months in 69 survivors of TBI. A good functional outcome was defined as no dysarthria, behavioral abnormalities, or dysphasia; no severe cognitive abnormalities; and the ability to live independently. RESULTS: The odds ratio of more than 7 days of unconsciousness was 5.69 in those with the APOE-epsilon4 allele compared with those without the epsilon4 allele (95% CI, 1.69 to 20.0; p = 0.001). Only 1 of 27 subjects (3.7%) with the epsilon4 allele had a good functional outcome compared with 13 of 42 (31.0%) of those without the epsilon4 allele (p = 0.006). The OR of a suboptimal outcome (fair or unfavorable) was 13.93 for those with the epsilon4 allele compared with those without the allele after controlling for age and time of unconsciousness (95% CI, 1.45 to 133.97; p = 0.02). CONCLUSION: The results demonstrate a strong association between the APOE-epsilon4 allele and a poor clinical outcome, implying genetic susceptibility to the effect of brain injury. Additional studies of TBI patients are warranted to confirm their findings.

Female TBI patients recover better than males.

The purpose of the present study was to look at possible gender differences in outcome after severe traumatic brain injury. Three hundred and thirty four consecutive patients, 72 females and 262 males, age range 5-65 years, were included in the study. Age range and severity of injury, evaluated by duration of unconsciousness, did not differ between male and female patients. Predicted outcome at the time of discharge from an in-patient rehabilitation programme was evaluated according to work capacity. Female TBI patients had a better predicted outcome (p < 0.015). It is suggested that progesterone, acting as a neuroprotective agent, may explain this difference in outcome.

Event-related potentials as an index of cognitive function during recovery from severe closed head injury.

OBJECTIVE: To evaluate the utility and neuropsychological correlates of serially performed recordings of event-related potentials (ERPs) in patients recovering from a severe closed head injury (CHI). DESIGN: Prospective longitudinal study. SETTING: Brain injury rehabilitation unit based in a national rehabilitation hospital. SUBJECTS: Sixteen patients with severe CHI (significant degree of impaired consciousness greater than 24 hours) subclassified into two severity groups according to initial Glasgow Coma Scale (GCS) score: those with initial GCS score < 9, consistent with a more severe injury; and those with initial GCS score > 8, indicating a less severe injury. METHODS: ERPs were elicited using the standard auditory P300 "oddball" detection paradigm. ERP recordings were carried out three times: 2 months after injury, 1 month later, and 2.5 months or more after the initial study. Parameters analyzed included latencies and amplitudes of the P3, N2, P2, and N1 components of the ERPs. Correlations between changes in these ERP parameters and specific neuropsychological test results were evaluated. RESULTS: Initial P3 latencies in the more severely injured group were significantly longer (P < .05) than those recorded in the less severely injured patients. In subsequent recordings, P3 latency was found to be significantly shorter compared with the initial P3 latency, and the difference in P3 latency between the two patient groups was no longer statistically significant by the time of the third recording. For the group as a whole, P3 latency decreased significantly on each repeated recording. N2 latency was found to be significantly shorter (P < .05) between the first and third recordings. Cognitive performance significantly improved between the first and third recordings. P3 latency shortening was correlated with improvement in neuropsychological test scores for short-term and long-term story recall and for word recall. N2 latency shortening was correlated with improvement in the neuropsychological test scores for word recall only. CONCLUSION: ERP recordings performed in the subacute stage after CHI may assist in evaluating injury severity. Moreover, serially performed recordings of P3 latency may be used as a physiologic index of brain activity that correlates with recovery from CHI.

A psychodynamic model of behavior after acute central nervous system damage.

This article describes a conceptual psychodynamic model for understanding the neurobehavioral manifestations of acute central nervous system damage (ACNSD) displayed by patients during the rehabilitation process. According to the proposed model, patientsO behavioral responses are viewed as their only means of emotional expression and therefore may not be considered entirely abnormal when viewed from the perspective of patientsO interpersonal contexts. An improved understanding of the dynamic processes through which recovering patients with ACNSD journey may lead to better interaction between the patient and the therapeutic environment, the interdisciplinary team, and family members. Combining this proposed psychodynamic model with an emerging understanding of the neurobehavioral foundations of aggression and depression may also lead to a more rational approach to intervention with various psychopharmacologic agents. During the rehabilitation process, understanding patients' cognitive deficits, motivational drives, and emotional needs and proper implementation of medical and environmental treatment can ultimately lead to a better psychosocial outcome.

Mapping "cognitive" event-related potentials in prolonged postcoma unawareness state.

"Cognitive" auditory event-related potentials (ERPs) were mapped to examine the putative conscious responsiveness of eight patients in a postcoma unawareness (PCU) state and of eight matched normal controls. A "passive P3" paradigm was used to evaluate waves N2, P3, and Slow Waves of the ERPs. Results showed that the signal/noise ratio of the patients' waveshapes was poorer than that of the controls. Yet, on the whole, no between-group significant differences were noted for most of the averaged characteristics of the waves. In general, in the patients, the left hemisphere was dominated by negative potentials relative to the right one, whereas in the controls, the opposite asymmetry was apparent. Thirty-eight percent of the patients had passive N2 and P3 waves, and 67% of the responders regained consciousness (versus none of the non-responders). These findings suggest that the presence of intact "cognitive" waves is compatible with a higher probability for improvement, although nondetection of certain waves at the postcoma unawareness state does not necessarily indicate the worst prognosis.

CT findings in persistent vegetative state following blunt traumatic brain injury.

The use of linear measurements in the analysis of CT scans of TBI patients was found to contribute to the understanding of brain damage and were correlated with outcome in severe traumatic close brain injured patients. The purpose of the present study was to analyse the data obtained by the linear measurements on CT studies of TBI patients who remained in persistent vegetative state following blunt head trauma. All 27 patients included in the study were reported to be neurologically normal prior to injury. Thirteen patients, 11 remaining in persistent vegetative state (responsive but unaware) and two who died, constituted the worst outcome group. Fourteen patients who regained consciousness, underwent multidisciplinary evaluation when their recovery reached a plateau and were ranked according to severity of residual symptoms and outcome. The degree of correlation with the overall vocational outcome parameter with the various radiological indices was calculated as the Spearman rank correlation coefficient, with correction for tied scores. Fisher's z transformation was used to combine results with those of our previous analysis. Three radiological parameters showed a statistically significant correlation with clinical outcome. These were the right and left septum-caudate distance and the cerebroventricular index 2; these showed Spearman rank coefficients of 0.52, 0.45 and 0.48; with two-tailed p-values under 0.01, 0.02 and 0.01 respectively. The width of the third ventricle suggested correlation with the clinical scoring. The findings of the present study point to the importance of loss of deep gray matter of the caudate nuclei and widening of the adjacent part of the lateral ventricles in catastrophic brain injury. This finding may highlight the role of localized ischemic changes, in addition to diffuse axonal injury. Values of over 8 mm for the width of the third ventricle and over 11 mm for septum caudate distance are suggestive of catastrophic and poor prognosis for recovery.

Indirect influence of modality on direct memory for words and their modality: closed-head-injured and control participants.

Twenty closed-head-injured (CHI) patients and 28 control participants were tested on recall and recognition of words. In addition, memory for modality (i.e., visual vs. auditory) of word presentation was measured directly (i.e., recognition) and indirectly (i.e, by its influence on word and modality recognition). As predicted, the CHI patients were impaired relative to controls on all of the direct memory tasks; that is, word recall, word recognition, and modality judgment. However, the CHI and control groups did not differ significantly on the magnitude of the modality effect (i.e., facilitation due to correspondence of modality in learning and test). The findings are interpreted in the theoretical framework that distinguishes between item (i.e., words) and source (i.e., modality) memory and between direct and indirect measures of memory.

Coordinate frame for pattern recognition in unilateral spatial neglect.

The present research examines the effect of spatial (object-centered) attentional constraints on pattern recognition. Four normal subjects and two right-hemisphere-damaged patients with left visual neglect participated in the study. Small, letterlike, prelearned patterns served as stimuli. Short exposure time prevented overt scanpaths during stimulus presentation. Attention was attracted to a central (midsagittal) hation point by precuing this location prior to each stimulus presentation. Minute (up to 1.5° of visual angle) rightward and leftward stimulus shifts caused attention to be allocated each time to a different location on the object space, while remaining in a fixed central position in viewercentered coordinates. The task was to decide which of several prelearned patterns was presented in each trial. In the normal subjects, best performance was achieved when the luminance centroid (LC; derived from the analysis of low-spatial frequencies in the object space) of each pattern coincided with the spatial position of the precue. In contrast, the patients with neglect showed optimal recognition performance when precuing attracted attention to locations within the object space, to the left of the LC. The normal performance suggests that the LC may serve as a center of gravity for attention allocation during pattern recognition. This point seems to be the target location where focal attention is normally directed, following a primary global analysis based on the low spatial frequencies. Thus, the LC of a simple pattern may serve as the origin point for an object-centered-coordiate-frame (OCCF), dividing it into right and left. This, in turn, serves to create a prototype description of the pattern, in its own coordinates, in memory, to be addressed during subsequent recognition tasks. The best match of the percept with the stored description may explain the observed advantage of allocating attention to the LC. The performance of the brain- damaged patients can be explained in terms of neglect operating in the OCCE.

Word recall versus reading speed: evidence of preserved priming in head-injured patients.

This study addressed a number of issues. One purpose was to test whether memory-impaired, head-injured patients show the same pattern of memory task dissociation as reported in amnesics, that is, impaired explicit and intact implicit memory performance. The second purpose of this study was to apply the distinction between the acquisition and retention aspects of memory, which has not, as yet, been investigated adequately in the study of implicit memory. The third purpose was to evaluate the contribution of intra-item and inter-item processes in implicit memory. A group of 18 head-injured (HI) patients and 18 control subjects participated in this study. Subjects read two lists of 15 words seven times: five times consecutively, once after 20 min, and after a 1-hr delay. One list was read in the same order and the other in a different order. Acquisition and retention of the information were measured explicitly (i.e., recall of words) and implicitly (i.e., priming-reading speed). The results indicated that novel information is preserved in HI as in other amnesic patient groups, only when implicit, rather than explicit, measures of memory are used. The effect of contextual manipulation (i.e., order of presentation) was interpreted to suggest similar involvement of intra-as well as inter-memory processes in implicit memory in normal and memory-impaired subjects.