The neurobehavioural rating scale-revised: sensitivity and validity in closed head injury assessment

OBJECTIVES: To investigate the factor structure and psychometric properties of the neurobehavioural rating scale-revised (NRS-R) and to determine its usefulness in clinical trials. METHODS: A consecutive series of patients sustaining severe closed head injury were evacuated to one of 11 large regional North American trauma centres and entered into a randomised, phase III, multicentre clinical trial investigating the therapeutic use of moderate hypothermia. Acute care personnel were blinded to outcome and outcome personnel were blinded to treatment condition. The Glasgow outcome scale (GOS) was the primary outcome measure. Secondary outcome measures included the disability rating scale (DRS) and the NRS-R. RESULTS: Exploratory factor analysis of NRS-R data collected at 6 months after injury (n=210) resulted in a five factor model including: (1) executive/cognition, (2) positive symptoms, (3) negative symptoms, (4) mood/affect, and (5) oral/motor. These factors showed acceptable internal consistency (0.62 to 0.88), low to moderate interfactor correlations (0.19 to 0.61), and discriminated well between GOS defined groups. Factor validity was demonstrated by significant correlations with specific neuropsychological domains. Significant change was measured from 3 to 6 months after injury for the total score (sum of all 29 item ratings) and all factor scores except mood/affect and positive symptoms. The total score and all factor scores correlated significantly with concurrent GOS and DRS scores. CONCLUSIONS: The NRS-R is well suited as a secondary outcome measure for clinical trials as its completion rate exceeds that of neuropsychological assessment and it provides important neurobehavioural information complementary to that provided by global outcome and neuropsychological measures.     

Clinical trials in head injury.

Secondary brain damage, following severe head injury is considered to be a major cause for bad outcome. Impressive reductions of the extent of brain damage in experimental studies have raised high expectations for cerebral neuroprotective treatment, in the clinic. Therefore multiple compounds were and are being evaluated in trials. In this review we discuss the pathomechanisms of traumatic brain damage, based upon their clinical importance. The role of hypothermia, mannitol, barbiturates, steroids, free radical scavengers, arachidonic acid inhibitors, calcium channel blockers, N-methyl-D-aspartate (NMDA) antagonists, and potassium channel blockers, will be discussed. The importance of a uniform strategic approach for evaluation of potentially interesting new compounds in clinical trials, to ameliorate outcome in patients with severe head injury, is proposed. To achieve this goal, two nonprofit organizations were founded: the European Brain Injury Consortium (EBIC) and the American Brain Injury Consortium (ABIC). Their aim lies in conducting better clinical trials, which incorporate lessons learned from previous trials, such that the succession of negative, or incomplete studies, as performed in previous years, will cease.     

Memory and head injury severity.

One hundred and two consecutive head injured patients were studied at 1 and 12 months after injury. Their performances were compared with a group of uninjured friends. The results indicate that impairment in memory depends on the type of task used, time from injury to testing, and on the severity of head injury (that is, degree of impaired consciousness). Head injury severity indices are more closely related to behavioural outcome early as compared with later after injury. At 1 year, only those with deep or prolonged impaired consciousness (as represented by greater than 1 day of coma, Glasgow Coma Scale of 8 or less, and post traumatic amnesia of 2 weeks or greater) are performing significantly worse than comparison subjects.     

Specificity and sensitivity of the Abeta oligomer ELISA

Abeta soluble oligomers are believed to play a key role in the development of Alzheimer's disease (AD). An enzyme-linked immunosorbent assay (ELISA) commonly used to measure these proteins uses the same monoclonal antibody as both capture and reporter antibody. The objective of this study was to examine the specificity and sensitivity of this procedure, using monoclonal anti-Abeta antibody 6E10 as capture antibody and biotinylated 6E10 as reporter antibody. At comparable concentrations of Abeta soluble oligomers and low molecular weight (LMW) Abeta peptides, optical density (OD) values were four- to five-fold higher for the oligomer preparation than for the LMW Abeta. The LMW Abeta preparation, when evaluated by western blots of gels run under native conditions, showed only one band even after storage at 4 °C for more than two months, suggesting that the ELISA was detecting Abeta monomer as well as Abeta oligomers. Possible explanations for these results are that (1) the LMW Abeta preparation may contain Abeta oligomer species below the limit of detection of western blot, but still detectable by ELISA, or (2) some nonspecific binding of the LMW Abeta to the ELISA plate may have occurred, allowing its relevant epitope to remain available for binding by the reporter antibody. Because of the possibility that this ELISA may not be oligomer-specific, it seems prudent to suggest that it should be used in combination with other methods, rather than as the sole technique, for measuring Abeta oligomers in biological specimens.     

Diffuse axonal injury in head trauma.

Diffuse axonal injury (DAI) as defined by detailed microscopic examination was found in 34 of 80 consecutive cases of head trauma surviving for a sufficient length of time to be clinically assessed by the Royal Adelaide Hospital Neurosurgery Unit. The findings indicate that there is a spectrum of axonal injury and that one third of cases of DAI recovered sufficiently to talk between the initial head injury producing coma and subsequent death. The macroscopic "marker" lesions in the corpus callosum and dorsolateral quadrants of the brainstem were present in only 15/34 of the cases and represented the most severe end of the spectrum of DAI.     

Disseminated intravascular coagulation and head injury.

Blood coagulation tests were performed on admission to the hospital and on consecutive days after severe and moderate head injury in 34 patients. Platelet counts and fibrinogen were normal at admission and raised thereafter. The partial thromboplastin time was shortened at admission and lengthened in the following days. Fibrinolytic activity was enhanced at admission. The ethanol gelation test was negative in all patients during the post-traumatic time course. It was concluded that, in the first 24 hours after injury, activated coagulation was present after head injury. In contrast with data of other authors, disseminated intravascular coagulation did not occur in these series.     

弥漫性轴索损伤在重型脑损伤中的意义

在15例闭合性脑损伤尸检中,病理诊断弥漫性轴索损伤(DAI)5例。根据病理研究结果和文献报道,分析了530例急性脑外伤病人脑CT表现,发现DAI61例。其CT表现为大脑皮髓质交界处、基底节内囊区域、胼胝体、脑干或小脑有一个或多个直径≤2cm的出血灶,脑室内出血及急性弥漫性脑肿胀。本文把DAI分为高颅压型和非高颅压型,后者又分的脑干损伤型和局灶性损伤型。这种分型对指导治疗和判断预后均有重要意义。DAI预后较差,是目前脑外伤病人死亡率高的重要原因之一。     

Remediation of attention deficits in head injury.

Head injury is associated with psychological sequelae which impair the patient's psychosocial functioning. Information processing, attention and memory deficits are seen in head injuries of all severity. We attempted to improve deficits of focused, sustained and divided attention. The principle of overlapping sources of attention resource pools was utilised in devising the remediation programme. Tasks used simple inexpensive materials. Four head injured young adult males with post concussion syndrome underwent the retraining program for one month. The patients had deficits of focused, sustained and divided attention parallel processing, serial processing, visual scanning, verbal learning and memory and working memory. After the retraining programme the deficits of attention improved in the four patients. Serial processing improved in two patients. Parallel processing and neuropsychological deficits did not improve in any patient. The symptom intensity reduced markedly and behavioural functioning improved in three of the four patients. The results supported an association between improving attention and reduction of symptom intensity. Attention remediation shows promise as a cost effective, time efficient and simple technique to improve the psychological and psychosocial functioning of the head injured patient.     

Midbrain deafness following head injury.

A patient is described who became deaf following a head injury. Postmortem examination revealed bilateral lesions of the lateral lemnisci and inferior colliculi. The clinical pattern of midbrain deafness is examined and compared with syndromes of cortical and peripheral auditory impairment.     

Amnesia following severe head injury.

This report concerns some aspects of the problem of establishing valid and reliable criteria for post-traumatic amnesia, and of relating this to other cognitive functions in the post-injury period. Of specific interest are the variability of the duration of retrograde and anterograde amnesia on attempts at repeated assessment, and the relationship between the time of return of full orientation and the end of the period of anterograde amnesia. A prospective study was undertaken of sixty consecutive patients who had suffered severe head injuries and had been admitted to the neurosurgical service of the Winnipeg General Hospital. The object of this study was to obtain information regarding organic, psychological and social indices of the future clinical course.     

Radionuclide cisternography after head injury.

Thirty-seven patients with severe head injury underwent radionuclide cisternography to detect early and late effects of trauma on cerebrospinal fluid (CSF) circulation. Thirty-one patients had subdural hematomas or hygromas and six had cerebral contusions without extracerebral masses. Cisternographic results were abnormal in 23 patients with subdural masses and normal in five who had only cerebral contusions. Of eight patients undergoing serial studies, one had persistent partial obstruction, five had partial resolution of abnormalities, and the two with progressive obstruction had their conditions improved by shunting. Angiography suggested transtentorial herniation in 11 patients with cisternal block, six of whom had clinical signs of herniation on the same side.     

The neuropsychology of moderate head injury.

Twenty four patients were tested on a battery of neuropsychological tests within one week of sustaining a moderate head injury. Their ability to process information rapidly was impaired in comparison with a control group that had sustained orthopaedic injuries. Differences between groups were not found on tests of intelligence and memory. This selective cognitive deficit may be due to brain damage associated with moderate head injury.     

Neuropsychological evaluation of mild head injury.

Neuropsychological deficits following mild head injury have been reported recently in the literature. The purpose of this study was to investigate this issue with a strict methodological approach. The neuropsychological performance of 50 mildly head injured patients was compared with that of 50 normal controls chosen with the case-control approach. No conclusive evidence was found that mild head injury causes cognitive impairment one month after the trauma.     

Anticipatory behaviour deficits in closed head injury.

Closed head injured patients demonstrated greater anticipatory behaviour deficit than cerebral vascular accident patients on a shuttlebox-analog avoidance task, even though these two groups did not differ on escape behaviour and on performance on the individual tests of the Halstead-Reitan Battery and Wechsler scales. Neither clarification of instructions, additional trials, nor enhancement of the warning cue appeared to improve the anticipatory behaviour deficit. It was concluded that anticipatory behaviour deficit should be considered a relatively dense deficit that is not identified by standard instruments. Clinical and practical implications are discussed.     

Gunshot injury to the head and spine.

The principles of management of civilian gunshot wounds (GSWs) to the head and spine have evolved directly from the experience gained in war by military neurosurgeons. The type of craniocerebral wounds being produced in urban gang warfare and suicide at tempts using handguns or rifles at close range vary considerably from the lower velocity fragment injuries which are common in modern warfare. Civilian craniocerebral GSWs are often devastating. The in-hospital mortality for civilians with penetrating craniocerebral injury is 52-95% depending on the proportion of suicide victims in the series. The most important predictive factor is the post-resuscitation Glasgow Coma Score (GCS). Many civilian victims (47%) present with GCS 3-5 and only approximately 8.1% survive. Of these survivors, 1.4% will have nil, mild or moderate disability without surgery and 4.8% with surgery. Higher post-resuscitation GCS is associated with a significantly improved survival: GCS 6-8, 35.6% and GCS 9-15, 90.5%. A selective treatment policy is recommended for the patients with GCS 3-5. There are many clinical and radiological correlates with poor outcome that help the neurosurgeon decide on operative versus supportive treatment. Early aggressive resuscitation, surgery and vigorous control of intracranial pressure offers the best chance of achieving a satisfactory outcome. Spinal GSWs are uncommon and the neurosurgeon should be aware of the principles of management and prognosis. The indication for acute spinal cord decompression is deteriorating neurological status. Steroids are not indicated for these injuries. Neurosurgeons should take an active role in formulating and supporting public policy which aims to reduce possession and usage of firearms and therefore the prevalence of gunshot injuries.