Substance abuse, traumatic brain injury and neuropsychological outcome

The perception of Mandarin speech conveying communicative functions in Chinese heroin addicts

Drug addiction can cause severe damage to the human brain, leading to significant problems in cognitive processing, such as irritability, speech distortions, and exaggeration of negative stimuli. Speech plays a fundamental role in social interaction, including both the production and perception. The ability to perceive communicative functions conveyed through speech is crucial for successful interpersonal communication and the maintaining good social relationships. However, due to the limited number of previous studies, it remains unclear whether the cognitive disorder caused by drug addiction affects the perception of communicative function conveyed in Mandarin speech. To address this question, we conducted a perception experiment involving sixty male participants, including 25 heroin addicts and 35 healthy controls. The experiment aimed to examine the perception of three communicative functions (i.e., statement, interrogative, and imperative) under three background noise conditions (i.e., no noise, SNR [Signal to Noise Ratio] = 10, and SNR = 0). Eight target sentences were first recorded by two native Mandarin speakers for each of the three communicative functions. Each half was then combined with Gaussian White Noise under two background noise conditions (i.e., SNR = 10 and SNR = 0). Finally, 48 speech stimuli were included in the experiment with four options provided for perceptual judgment. The results showed that, under the three noise conditions, the average perceptual accuracies of the three communicative functions were 80.66% and 38% for the control group and the heroin addicts, respectively. Significant differences were found in the perception of the three communicative functions between the control group and the heroin addicts under the three noise conditions, except for the recognition of imperative under strong noise condition (i.e., SNR = 0). Moreover, heroin addicts showed good accuracy (around 50%) in recognizing imperative and poor accuracy (i.e., lower than the chance level) in recognizing interrogative. This paper not only fills the research gap in the perception of communicative functions in Mandarin speech among drug addicts but also enhances the understanding of the effects of drugs on speech perception and provides a foundation for the speech rehabilitation of drug addicts.

The negative influence of chronic alcohol abuse on acute cognitive recovery after a traumatic brain injury

OBJECTIVE

Cognitive recovery after a traumatic brain injury (TBI) may be negatively affected by a prior alcohol use disorder (AUD). This study aims to compare the cognitive recovery of patients who had comorbid TBI and AUD relative to TBI alone and investigate the influence of blood alcohol level (BAL) at hospital admission on this recovery.

METHOD

The sample consisted of 42 patients who had sustained a TBI (mild or moderate) and had an AUD diagnosis (TBI+AUD), and 42 patients who had sustained a TBI alone (TBI). The Brief Cognitive Exam in Traumatology (EXACT), designed to evaluate cognitive functions in the acute phase of TBI was administered (± 2 weeks post-injury).

RESULTS

After controlling for BAL at admission, the TBI+AUD group had a lower EXACT total score compared to the TBI group. The negative influence of age on the results was more pronounced in the TBI+AUD group. The number of intoxicated patients at admission was also higher in this group, although there was no correlation between BAL at admission and cognitive outcome.

CONCLUSION

The presence of an AUD diagnosis seems to exert a greater negative influence on cognitive recovery following a mild/moderate TBI than BAL at admission, especially in older patients.

Traumatic Brain Injury: A Forensic Approach: A Literature Review

Traumatic brain injury (TBI) is the principal cause of invalidity and death in the population under 45 years of age worldwide. This mini-review aims to systematize the forensic approach in neuropathological studies, highlighting the proper elements to be noted during external, radiological, autoptical, and histological examinations with particular attention paid to immunohistochemistry and molecular biology. In the light of the results of this mini-review, an accurate forensic approach can be considered mandatory in the examination of suspected TBI with medico-legal importance, in order to gather all the possible evidence to corroborate the diagnosis of a lesion that may have caused, or contributed to, death. From this point of view, only the use of an evidence-based protocol can reach a suitable diagnosis, especially in those cases in which there are other neuropathological conditions (ischemia, neurodegeneration, neuro-inflammation, dementia) that may have played a role in death. This is even more relevant when corpses, in an advanced state of decomposition, are studied, where the radiological, macroscopic and histological analyses fail to give meaningful answers. In these cases, immune-histochemical and molecular biology diagnostics are of fundamental importance and a forensic neuropathologist has to know them. Particularly, MiRNAs are promising biomarkers for TBI both for brain damage identification and for medico-legal aspects, even if further investigations are required to validate the first experimental studies. In the same way, the genetic substrate should be examined during any forensic examination, considering its importance in the outcome of TBI.

When Two Wrongs Make a Right: The Effect of Acute and Chronic Binge Drinking on Traumatic Brain Injury Outcomes in Young Adult Female Rats

Alcohol is the most commonly abused drug by young adults across North America. Although alcohol consumption itself incurs a risk of neurological damage, it is also a significant risk factor for traumatic brain injury (TBI). TBI among young adults is described as a modern healthcare epidemic. The drastic changes occurring within their neurological networks put young adults at greater risk for developing long-term post-traumatic deficits. Contradictory findings have been indicated regarding the effects of alcohol consumption on TBI outcomes in adults, with some studies demonstrating detrimental effects, whereas others suggest neuroprotective abilities. However, little is known about the effects of alcohol consumption on TBI outcomes during the sensitive stage of early adulthood. Young adult female Sprague-Dawley rats were randomly assigned to one of six experimental conditions: Pre-injury alcohol+TBI; Pre-injury alcohol+Sham; Pre- and Post-injury alcohol+TBI; Pre- and Post-injury alcohol+Sham; No alcohol+TBI; No alcohol+Sham. Alcohol consumption groups received an amount of 10% v/v ethanol solution based on the animals' weight. Following the injury, the rats were subjected to a behavioral test battery to assess post-concussive symptomology. Overall, chronic binge drinking significantly improved TBI outcomes related to motor coordination and balance, whereas binge drinking in general significantly decreased anxiety-like behaviors. Additionally, in many cases, chronic binge drinking appears to return the TBI animal's behavioral outcomes to levels comparable to those of the no alcohol sham animals. Thus, the results suggest that alcohol may exhibit neuroprotective abilities in the context of early adulthood TBI.

Screening questionnaires for substance abuse post brain injury: a review

OBJECTIVE

To assess the psychometric properties of the available assessment questionnaires for substance abuse studied within a brain injury population.

METHODS

A literature search was conducted on MEDLINE, PsycINFO, CINAHL, and Embase databases. Articles published in English from inception through March 2018 on the screening questionnaires used to identify substance abuse post brain injury were reviewed. Eligible primary studies had to include: adults (participants ≥18 years old) post brain injury; and report measures of diagnostic accuracy (e.g., sensitivity, specificity, and diagnostic odds ratio).

RESULTS

Six screening questionnaires were included: Alcohol Use Disorders Identification Test, Brief Michigan Alcohol Screening Test, CAGE, Drug Abuse Screening Test, Substance Abuse Screening Inventory and the Short Michigan Alcohol Screening Test (SMAST). All questionnaires, except the SMAST, used the Diagnostic and Statistical Manual of Mental Disorders as the criterion measure. While report measures of diagnostic accuracy were reported and summarized, none of the studies provided reliability information or subgroup analysis among those with brain injury.

CONCLUSIONS

Concerns of social desirability, population demographics, responsiveness to treatment effects, and administrative burden are important when selecting a questionnaire. Research examining the reliability of substance abuse screening questionnaires in the brain injury population is lacking and future research is warranted.

Impact of day-of-injury alcohol consumption on outcomes after traumatic brain injury: A meta-analysis

Although a known risk factor for traumatic brain injury (TBI), alcohol has been found to both promote and protect against secondary brain damage. However, it is presently unclear whether the cognitive, psychological and medical/functional outcomes of adults who have consumed alcohol prior to sustaining a TBI differ from those who have not. This meta-analysis examined the outcomes of groups that differed in terms of their day-of-injury (DOI) blood alcohol levels (BALs) by comparing positive with zero BAL (BAL⁺/BAL^-) and high with low BAL (BAL^high/BAL^low) samples. The PubMed, PsycINFO, EMBASE, and Scopus databases were searched from inception until the end of March 2015. Hedge's g effects (continuous data) and odds ratios (categorical data) were calculated for 27 studies that compared either the outcomes of BAL⁺ and BAL^- groups or BAL^high and BAL^low groups. BAL⁺ was associated with significantly poorer cognitive outcomes (overall and on general tests) and higher levels of disability, and BAL^high was associated with shorter stays in intensive care. More generally, however, most effect sizes were small to low-moderate in size, non-significant and inconsistent in their direction. Although DOI alcohol consumption increases the risk of sustaining a TBI, it is not consistently associated with better or worse outcomes, other than subtle cognitive deficits; the source of which remains to be determined.

Effect of cocaine use on outcomes in traumatic brain injury

Context:

Animal and molecular studies have shown that cocaine exerts a neuroprotective effect against cerebral ischemia.

Aims:

To determine if the presence of cocaine metabolites on admission following traumatic brain injury (TBI) is associated with better outcomes.

Settings and Design:

Level-1 trauma center, retrospective cohort.

Materials and Methods:

After obtaining Institutional Review Board (IRB) approval, the trauma registry was searched from 2006 to 2009 for all patients aged 15-55 years with blunt head trauma and non-head AIS <3. Exclusion criteria were pre-existing brain pathology and death within 30 min of admission. The primary outcome was in-hospital mortality; secondary outcomes were hospital length of stay (LOS), and Glasgow Outcome Score (GOS).

Statistical Analysis:

Logistic regression was used to determine the independent effect of cocaine on mortality. Hospital LOS was compared with multiple linear regression.

Results:

A total of 741 patients met criteria and had drug screens. The screened versus unscreened groups were similar. Cocaine positive patients were predominantly African-American (46% vs. 21%, P < 0.0001), older (40 years vs. 30 years, P < 0.0001), and had ethanol present more often (50.7% vs. 37.8%, P = 0.01). There were no differences in mortality (cocaine-positive 1.4% vs. cocaine-negative 2.7%, P = 0.6) on both univariate and multivariate analysis.

Conclusions:

Positive cocaine screening was not associated with mortality in TBI. An effect may not have been detected because of the low mortality rate. LOS is affected by many factors unrelated to the injury and may not be a good surrogate for recovery. Similarly, GOS may be too coarse a measure to identify a benefit.

Managing behavioral health needs of veterans with traumatic brain injury (TBI) in primary care

Traumatic brain injury (TBI) is a frequent occurrence in the United States, and has been given particular attention in the veteran population. Recent accounts have estimated TBI incidence rates as high as 20 % among US veterans who served in Afghanistan or Iraq, and many of these veterans experience a host of co-morbid concerns, including psychiatric complaints (such as depression and post-traumatic stress disorder), sleep disturbance, and substance abuse which may warrant referral to behavioral health specialists working in primary care settings. This paper reviews many common behavioral health concerns co-morbid with TBI, and suggests areas in which behavioral health specialists may assess, intervene, and help to facilitate holistic patient care beyond the acute phase of injury. The primary focus is on sequelae common to mild and moderate TBI which may more readily present in primary care clinics.

Substance use and mild traumatic brain injury risk reduction and prevention: a novel model for treatment

Traumatic brain injury (TBI) and substance use disorders (SUDs) frequently co-occur. Individuals with histories of alcohol or other drug use are at greater risk for sustaining TBI, and individuals with TBI frequently misuse substances before and after injury. Further, a growing body of literature supports the relationship between comorbid histories of mild TBI (mTBI) and SUDs and negative outcomes. Alcohol and other drug use are strongly associated with risk taking. Disinhibition, impaired executive function, and/or impulsivity as a result of mTBI also contribute to an individual's proclivity towards risk-taking. Risk-taking behavior may therefore, be a direct result of SUD and/or history of mTBI, and risky behaviors may predispose individuals for subsequent injury or continued use of substances. Based on these findings, evaluation of risk-taking behavior associated with the co-occurrence of SUD and mTBI should be a standard clinical practice. Interventions aimed at reducing risky behavior among members of this population may assist in decreasing negative outcomes. A novel intervention (Substance Use and Traumatic Brain Injury Risk Reduction and Prevention (STRRP)) for reducing and preventing risky behaviors among individuals with co-occurring mTBI and SUD is presented. Areas for further research are discussed.

Influence of alcohol on early Glasgow Coma Scale in head-injured patients

BACKGROUND

To assess the depressant effects of alcohol on the level of consciousness of patients admitted with head injuries, this study examined the changes that occur in the Glasgow Coma Scale (GCS) of traumatic brain injury patients over time.

METHODS

The records of 269 head trauma patients consecutively admitted to the neurosurgery intensive care unit were examined retrospectively. Eighty-one patients were excluded because of incomplete data. The remaining 188 patients were further divided into an intoxicated group (blood alcohol concentration [BAC] ≥ 0.08%, n = 100 [53%]) and a nonintoxicated group (BAC <0.08%, n = 88 [47%]). The GCS in the prehospital setting, in the emergency department, and the highest GCS achieved during the first 24 hours postinjury were compared.

RESULTS

The change between emergency department-GCS and the best day 1 GCS in the intoxicated group was greater than the nonintoxicated group and deemed clinically and statistically significant; median change (3 vs. 0) p < 0.001. To assess whether these results were directly related to the BAC%, piecewise regression using a general linear model was used to assess the intercept and slope of alcohol on the changes of GCS with cutting point at BAC% = 0.08. The analysis showed that, in the nonintoxicated range, the effect of alcohol was not significantly related to the changes of GCS. But in the intoxicated range, BAC% was significantly positively related to the changes of GCS.

CONCLUSION

This study concludes that the GCS increases significantly over time in alcohol intoxicated patients with traumatic brain injury.

Traumatic brain injury rates and sequelae: a comparison of prisoners with a matched community sample in Australia

AIM

To compare rates of past reported traumatic brain injury (TBI) in a prisoner sample with those in a control group drawn from the same location of usual residence.

METHOD

The prisoner group comprised a consecutive sample of men (n = 200) received into custody and screened by face-to-face interview. The control group comprised men (n = 200) matched for location of usual residence screened by telephone interview. Participants were asked about past TBIs and screened for drug and alcohol abuse, impulsivity and dissocial personality disorder.

RESULTS

Eighty-two per cent of prisoners and 71.5% of community participants reported at least one past TBI of any severity (i.e. with or without a loss of consciousness (LOC)) and 64.5% of prisoners and 32.2% of community participants reported at least one TBI associated with a LOC. Prisoners were more likely to report persisting side-effects of TBI and were much more likely to screen positive for impulsivity and dissocial personality disorder. Multivariate analyses found no significant association between TBI frequency or severity and custody/community group membership.

CONCLUSIONS

High reported rates of TBI in prisoner populations may reflect the excess of socio-demographic risk factors for TBI. Results of the current study do not support a role for TBI as causally related to criminal conduct.

Outcome prediction in mild traumatic brain injury: age and clinical variables are stronger predictors than CT abnormalities

Mild traumatic brain injury (mTBI) is a common heterogeneous neurological disorder with a wide range of possible clinical outcomes. Accurate prediction of outcome is desirable for optimal treatment. This study aimed both to identify the demographic, clinical, and computed tomographic (CT) characteristics associated with unfavorable outcome at 6 months after mTBI, and to design a prediction model for application in daily practice. All consecutive mTBI patients (Glasgow Coma Scale [GCS] score: 13-15) admitted to our hospital who were age 16 or older were included during an 8-year period as part of the prospective Radboud University Brain Injury Cohort Study (RUBICS). Outcome was assessed at 6 months post-trauma using the Glasgow Outcome Scale-Extended (GOSE), dichotomized into unfavorable (GOSE score 1-6) and favorable (GOSE score 7-8) outcome groups. The predictive value of several variables was determined using multivariate binary logistic regression analysis. We included 2784 mTBI patients and found CT abnormalities in 20.7% of the 1999 patients that underwent a head CT. Age, extracranial injuries, and day-of-injury alcohol intoxication proved to be the strongest outcome predictors. The presence of facial fractures and the number of hemorrhagic contusions emerged as CT predictors. Furthermore, we showed that the predictive value of a scheme based on a modified Injury Severity Score (ISS), alcohol intoxication, and age equalled the value of one that also included CT characteristics. In fact, it exceeded one that was based on CT characteristics alone. We conclude that, although valuable for the identification of the individual mTBI patient at risk for deterioration and eventual neurosurgical intervention, CT characteristics are imperfect predictors of outcome after mTBI.

Serum ethanol levels: predictor of survival after severe traumatic brain injury

BACKGROUND

Recent studies have suggested that moderate doses of ethanol (ETOH) before traumatic brain injury (TBI) may have a neuroprotective role.

OBJECTIVE

: The objective of this study is to investigate the effects of serum ETOH levels on outcomes after TBI. Our hypothesis was that ETOH exposure is associated with improved survival in severe TBI patients and that the serum ETOH levels on admission correlate with survival.

METHODS

All patients sustaining severe TBI (head abbreviated injury score >or=3) admitted to the Surgical Intensive Care Unit at the Los Angeles County + University of Southern California Medical Center from January 2000 to December 2005 who had a serum ETOH level measured on admission were analyzed. Patients were classified into ETOH-positive and ETOH-negative groups, according to the serum ETOH levels and compared for differences in outcomes using logistic regression to adjust for clinically and statistically relevant confounding factors.

RESULTS

During the 5-year study period, 482 severe TBI patients admitted to the Surgical Intensive Care Unit at Los Angeles County + University of Southern California Medical Center had a serum ETOH level measured on admission. A total of 47% of severe TBI patients were tested for ETOH. ETOH levels were positive in 37% (179) and negative in 63% (303) of the TBI patients. The ETOH-positive group had a higher percentage of males (91% vs. 79%, p = 0.001), lower percentage of penetrating injuries (9% vs. 20%, p = 0.002), and lower injury severity score (25.7 +/- 11.5 vs. 28.4 +/- 14.1, p = 0.05). Overall mortality was significantly lower in the ETOH-positive group at 27% versus 40% (odds ratio = 0.55, 95% confidence interval: 0.37-0.82; p = 0.004). This survival benefit remained significant after multivariable analysis (adjusted odds ratio = 0.54, 95% confidence interval: 0.31-0.92; adjusted p = 0.02). The mean serum ETOH level was significantly higher for survivors than for nonsurvivors (0.11 +/- 0.21 vs. 0.05 +/- 0.10, p < 0.001). The serum ETOH levels significantly correlated with the probability of survival (r = 0.21, p < 0.001), but this correlation was not strong as shown by the low r value.

CONCLUSION

The results of this study suggest that elevated ETOH serum levels are independently associated with higher survival in patients with severe traumatic brain injuries. Additional research is required to further investigate the mechanism and potential therapeutic implications of this association.

Early prediction of language impairment following traumatic brain injury

PRIMARY OBJECTIVE

This study investigated which factors collected early in the acute care setting (age, education, cerebral imaging, Glasgow Coma Scale score) would predict initial impairments of language comprehension and expression in patients with traumatic brain injury (TBI) of all severity.

METHODS AND PROCEDURES

Results of language tests carried out during the patients' stay in an acute tertiary trauma centre were obtained. These tests measured performance in the areas of confrontation naming, auditory comprehension, semantic and letter category naming and comprehension of verbal absurdities. Data for the predictive variables were gathered by retrospective chart review. Stepwise multiple linear regressions were carried out on the predictive variables.

MAIN OUTCOMES AND RESULTS

Education and TBI severity as measured with the GCS score were the most significant factors predicting language deficits in the acute care setting.

CONCLUSIONS

These findings will serve to guide health care professionals in predicting prognosis for cognitive-communication deficits post-TBI and in planning for appropriate resources in speech-language pathology to meet these patients' needs.

Neuropsychiatric correlates of traumatic brain injury (TBI) among Australian prison entrants

PRIMARY OBJECTIVE

To investigate the association between reported past traumatic brain injury (TBI) and demographic, neuropsychiatric and criminographic parameters among individuals recently received into custody.

RESEARCH DESIGN

A random sample of men recently received into the New South Wales (Australia) criminal justice system were screened for a history of TBI and the details of up to five separate TBI episodes were obtained. We also screened for depression, psychosis, personality disorder, drug and alcohol use, and 'social connectedness'.

MAIN OUTCOME AND RESULTS

Among the 200 study participants, 82% reported past TBI. TBI was associated with a history of engagement in contact sports, school expulsion, daily illicit drug use, depression and psychosis.

CONCLUSIONS

Past TBI is common among prisoners entering the criminal justice system and, amongst other correlates, appears to be highly associated with increased rates of major mental illness.

An update on substance use and treatment following traumatic brain injury

Traumatic brain injury (TBI) is a leading cause of mortality and morbidity among young adults. Substance abusers constitute a disproportionate percentage of these patients. A history of substance abuse predicts increased disability, poorer prognosis, and delayed recovery. While consensus in the literature indicates that substance-abuse rates decline following injury, conflicting literature shows a significant history of brain injury in addicts. We reviewed the literature on substance abuse after TBI to explore the state of knowledge on TBI as a risk factor for substance abuse. While recent reviews regarding substance abuse in TBI patients concur that substance-abuse rates decline even after mild TBI, an emerging literature suggests mild TBI may cause subtle impairments in cognitive, executive, and decision-making functions that are often poorly recognized in early diagnosis and treatment. When combined with difficulties in psychosocial adjustment and coping skills, these impairments may increase the risk for chronic substance abuse in a subset of TBI patients. Preliminary results from veterans indicate these patterns hold in a combat-related post-traumatic stress disorder population with TBI. This increasingly prevalent combination presents a specific challenge in rehabilitation. While this comorbidity presents a challenge for the successful treatment and rehabilitation of both disorders, there is sparse evidence to recommend any specific treatment strategy for these individuals. Mild TBI and substance abuse are bidirectionally related both for risks and treatment. Further understanding the neuropsychiatric pathology and different effects of different types of injuries will likely improve the implementation of effective treatments for each of these two conditions.

Alcohol and drug use following traumatic brain injury: a prospective study

PRIMARY OBJECTIVES

To establish pre-morbid alcohol and drug use in persons with TBI, relative to controls, investigate how patterns of substance use change over time following TBI and identify factors associated with heavy post-injury substance use.

METHODS AND PROCEDURES

The Alcohol Use Disorders Identification test (AUDIT) and Drug Abuse Screening Test (DAST) was completed by 121 hospital inpatients with TBI, documenting pre-injury alcohol and drug use, and 133 demographically similar controls. Participants with TBI completed these measures and the Hospital Anxiety and Depression Scale (HADS) again 1 and 2 years post-injury and 76 also completed them at 3 years.

RESULTS

Participants with TBI showed similar levels of drug and alcohol use to controls pre-injury, with 31.4% of the TBI group and 29.3% of controls drinking at hazardous levels. Alcohol and drug use declined in the first year post-injury, but increased by 2 years post-injury, with only 21.4% of participants with TBI reporting abstinence from alcohol and 25.4% drinking at hazardous levels. Only 9% showed a drug problem, but 24% had returned to some drug use. Those showing heavy alcohol use post-injury were young, male and heavy drinkers pre-injury. Drug and alcohol use was similar at 3 years post-injury.

CONCLUSIONS

More active intervention is needed to reduce alcohol and drug use following TBI.

Relationships among premorbid alcohol use, acute intoxication, and early functional status after traumatic brain injury

OBJECTIVE

To investigate the relationships among intoxication at time of injury, preinjury history of problem drinking, and early functional status in patients with traumatic brain injury (TBI).

DESIGN

Prospective cohort study.

SETTING

Acute inpatient TBI rehabilitation.

PARTICIPANTS

Participants were 1748 persons with TBI.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Blood alcohol levels (BALs) were obtained at admission to the emergency department, and a history of problem drinking was obtained through interview. Study outcomes, Disability Rating Scale (DRS), and FIM instrument scores were gathered at admission to inpatient rehabilitation.

RESULTS

Multivariate regression analysis revealed that BAL and a history of binge drinking were predictive of DRS, but not FIM, scores. A higher BAL was associated with poorer functional status on the DRS. Paradoxically, a history of binge drinking was associated with more intact functional status on the DRS.

CONCLUSIONS

The relationships among intoxication at time of injury, history of problem drinking, and early outcome after TBI were modest. Injury severity had a more significant association with TBI functional status.

Traumatic brain injury in intoxicated patients

BACKGROUND

We sought to evaluate the effect alcohol intoxication may have had in nonsurgically treated patients with severe traumatic brain injury.

METHODS

The Montreal General Hospital Traumatic Brain Injury Registry was used to identify all adult patients with a Glasgow Coma Scale score < or =8 at admission, within a 15-month period. All charts were retrospectively reviewed.

RESULTS

Twenty-three patients had toxic blood alcohol levels (BAL > or =21.7 mmol/L), 24 were alcohol negative (BAL <3 mmol/L), and 10 were alcohol-influenced or had unknown BAL. Patients were more likely to have intracranial pressure monitoring if they had multiple intracranial hemorrhages, sustained multiple injuries, or had a post-resuscitative Glasgow Coma Scale score < or =8. Intoxicated patients had a mean delay of 151 minutes more in the insertion time of an intracranial pressure monitoring device, compared with alcohol-negative patients.

CONCLUSIONS

Alcohol was a confounding factor in the treatment of some of our patients.

The Mayo Classification System for Traumatic Brain Injury Severity

PURPOSE

To develop a single TBI severity classification system based on commonly used TBI severity measures and indicators that (1) maximally uses available positive evidence to classify TBI severity in three categories: (a) Moderate-Severe (Definite) TBI, (b) Mild (Probable) TBI, (c) Symptomatic (Possible) TBI; (2) reflects current clinical knowledge and relevance; and (3) classifies a larger number of cases than single indicator systems with reasonable accuracy.

MAIN FINDINGS

The study sample of a defined population consisted of 1501 unique Olmsted County residents with at least one confirmed TBI event from 1985 to 1999. Within the sample, 1678 TBI events were confirmed. Single measures of TBI severity were not available in a large percentage of these events, i.e., Glasgow Coma Scale (GCS) was absent in 1242 (74.0%); loss of consciousness, absent in 178 (70.2%), posttraumatic amnesia (PTA), absent in 974 (58.1%), head CT, not done in 827 (49.3%). The Mayo Classification System for TBI Severity was developed to classify cases based on available indicators that included death due to TBI, trauma-related neuroimaging abnormalities, GCS, PTA, loss of consciousness and specified post-concussive symptoms. Using the Mayo system, all cases were classified. For the Moderate-Severe (Definite) TBI classification, estimated sensitivity was 89% and estimated specificity was 98%.

CONCLUSIONS

By maximally using relevant available positive evidence, the Mayo system classifies a larger number of cases than single indicator systems with reasonable accuracy. This system may be of use in retrospective research and for determination of TBI severity for planning postacute clinical care.

Measuring recovery in new learning and memory following traumatic brain injury: A mixed-effects modeling approach

Patterns of recovery from traumatic brain injury (TBI) vary greatly across individuals. Using archival data from the Traumatic Brain Injury Model Systems, recovery of memory following TBI as measured by scores on the Rey Auditory Verbal Learning Test (RAVLT) through 5 years postinjury was examined via mixed-effects modeling. Individual-level variables of age and posttraumatic amnesia duration were significant predictors of 1-year RAVLT total score. None of the variables examined predicted the trajectory of memory recovery after 1 year. Mixed-effects analyses can be helpful in determining the effect of intervention while allowing for missing data across time points.

The Effect of Moderate to Severe Traumatic Brain Injury (TBI) on Different Aspects of Memory:A Selective Review

Deficient learning and memory are frequently reported as a consequence of traumatic brain injury (TBI). Because of the diffuse nature of the injury, patients with TBI are not the ideal group for studying brain-behavior relations. Nevertheless, characterization of the memory breakdown following TBI could contribute to the assessment and rehabilitation of this patient population. It is well documented that memory is not a unitary system. Accordingly, in this article I review studies that have investigated the long-term effect of moderate to severe TBI on different memory aspects, including explicit and implicit tests of memory. This review demonstrates that TBI affects a large range of memory aspects. One of the conclusions is that the memory impairment observed in TBI patients could be viewed, at least to some degree, as a consequence of a more general cognitive deficit. Thus, unlike patients suffering from global amnesia, memory in patients with TBI is not selectively impaired. Nevertheless, it is possible to detect a subgroup of patients that do meet the criteria of amnesia. However, the most common vulnerable memory processes following TBI very much resemble the memory deficits reported in patients following frontal lobe damage, e.g., difficulties in applying active or effortful strategy in the learning or retrieval process. The suggested similarity between patients with TBI and those suffering from frontal lobe injury should be viewed cautiously; considering the nature of TBI, patients suffering from such injuries are not a homogeneous group. In view of this limitation, the future challenge in this field will be to identify subgroups of patients, either a priori according to a range of factors such as severity of injury, or a posteriori based on their specific memory deficit characteristics. Such a research approach has the potential of explaining much of the variability in findings reported in the literature on the effect of TBI on memory.

Waiting for the patient to "sober up": Effect of alcohol intoxication on glasgow coma scale score of brain injured patients

BACKGROUND

Between 35% to 50% of traumatic brain injury (TBI) patients are under the influence of alcohol. Alcohol intoxication may limit the ability of the Glasgow Coma Scale (GCS) to accurately assess severity of TBI. We hypothesized that alcohol intoxication significantly depresses GCS scores of TBI patients.

METHODS

A 10-year, retrospective analysis of a Level I trauma center registry was undertaken. The study population consisted of all blunt injured TBI patients tested for blood alcohol concentration (BAC, n = 1,075). Patients were divided into two groups; intoxicated (mean BAC 202 +/- 77 mg/dL, n = 504) and nonintoxicated (BAC = 0, n = 571). TBI was classified using ICD-9 codes as concussion alone (ICD-9 850, n = 90) and intracranial injury (ICI, ICD-9 851-854, n = 985). Severity was further classified using the Abbreviated Injury Score (AIS). Mean GCS score was compared between the two groups. Patients who were either intubated or hypotensive upon arrival were analyzed separately to rule out confounding effects on GCS score. Severely intoxicated patients (BAC >250 mg/dL, [mean +/- SD] 309 +/- 54 SD, n = 118) were similarly compared. Finally, multivariate linear regression analysis was undertaken to determine whether BAC level was an independent predictor of GCS score while controlling for confounding factors.

RESULTS

Intoxicated and nonintoxicated TBI patients were clinically similar. Alcohol intoxication had little effect on GCS score, with less than a single point difference in all types of TBI, except the most severely injured (AIS 5 injuries, GCS score difference 1.4 points). These results were not altered by endotracheal intubation, systemic hypotension, or severe intoxication. Similarly, BAC was not a significant independent predictor of GCS score in a multivariate model.

CONCLUSION

Alcohol intoxication does not result in clinically significant changes in GCS score for patients with blunt TBI. Hence, alterations in GCS score after TBI should not be attributed to alcohol intoxication, as doing so might result in inappropriate delays in monitoring and therapeutic interventions.

Traumatic brain injury and substance misuse: a systematic review of prevalence and outcomes research (1994-2004)

A systematic review of the evidence on substance misuse prevalence in patients with traumatic brain injury (TBI) and outcomes associated with this population is presented. Building upon an earlier review of the area by Corigan (1995), this review is limited to research published between 1994 and 2004. Psycinfo and Medline abstract databases were searched for English-language publications citing research from Western countries on the epidemiology and outcomes of adult TBI patients (aged 15 years or older). The majority of reviewed studies were undertaken in the USA and the investigation foci and methods used were multifarious, constraining the generalisation of the review findings. Prevalence for alcohol intoxication at time of injury in the review was found to be almost identical to that in Corrigan's review: 37-51% and 36-51%, respectively. Pre-TBI history of alcohol misuse was found to be less prevalent in the present as opposed to Corrigan's review: 37-51% and 55-66%, respectively. Outcome findings were mixed (also found by Corrigan), but mainly in the expected direction of poorer outcomes (neurological, medical, neuropsychological, and functional) in patients with pre-TBI substance misuse. Further research and implications for services are outlined.

Prediction of Outcome at Discharge From Acute Care Following Traumatic Brain Injury

OBJECTIVE

To compute outcome probabilities for persons with traumatic brain injury at discharge from acute care.

PARTICIPANTS

Three hundred thirty-nine patients with traumatic brain injury (239 mild, 48 moderate, 52 severe).

SETTING

Level I trauma center.

MAIN MEASURES

Predictor variables considered were age, education, Glasgow Coma Scale score, duration of posttraumatic amnesia, cerebral imaging results, and need for neurosurgical intervention. Outcome measures were Extended Glasgow Outcome Scale and discharge destination.

RESULTS

Logistic regressions showed that a shorter posttraumatic amnesia decreased the probability of moderate to severe disability. Moreover, discharge home was less probable for patients with positive cerebral imaging.

CONCLUSION

This model can help predict rehabilitation needs upon discharge from an acute care hospital.

Overview of traumatic brain injury patients at a tertiary trauma centre

OBJECTIVE

The goal of this study was to provide a general descriptive and cognitive portrait of a population with traumatic brain injury (TBI) at the time of their acute care stay.

MATERIAL AND METHODS

Three hundred and forty-eight TBI patients were assessed. The following data were collected for each patient: age, level of education, duration of post-traumatic amnesia, Galveston Orientation Amnesia Test score, Glasgow Coma Scale score, results of cerebral imaging, Neurobehavioral Rating Scale score, the Functional Independence Measure cognitive score and the Glasgow Outcome Scale score.

RESULTS

The clinical profile of the population revealed a mean age of 40.2 (+/-18.7) and a mean of 11.5 (+/-3.6) years of education. Most patients presented with frontal (57.6%) and temporal (40%) lesions. Sixty-two percent had post-traumatic amnesia of less than 24 hours. Seventy percent presented with mild TBI, 14% with moderate and 15% with severe TBI. The cognitive deficits most frequently observed on the Neurobehavioral Rating Scale were in the areas of attention, memory and mental flexibility as well as slowness and mental fatigability. Most patients had good cognitive outcome on the Functional Independence Measure and scores of 2 and 3 were frequent on the GOS. Forty-five percent of the patients returned home after discharge, 51.7% were referred to in or out patient rehabilitation and 3.2% were transferred to long-term care facilities.

CONCLUSION

Because of the specialized mandate of acute care institutions, the information provided here concerning characteristics of our TBI population is essential for more efficient decision-making and planning/programming with regards to care and service delivery.

The Effects of Admission Alcohol Level on Cerebral Blood Flow and Outcomes after Severe Traumatic Brain Injury

This study examined the relationship between admission serum alcohol level (ETOH) and cerebral blood flow (CBF) and outcomes in the adult traumatic brain injured (TBI) population. We hypothesized that individuals with ETOH > 100 mg/dL will have decreased blood flow on admission and poorer outcomes. Eighty subjects, age 16-65, with severe TBI (Glasgow Coma Score [GCS] </= 8) were entered into the study. Correlational analysis assessed the relationship between ETOH and admission severity of injury scores as measured by Marshall and APACHE III scores, CBF, and outcomes. Comparison of CBF and outcomes between groups based on admission serum ETOH level was conducted with analysis of variance and post hoc Scheffé analyses as well as regression analysis. There was a significant relationship between serum ETOH level and GCS (p = 0.02), but not APACHE III scores (p = 0.12) or Marshall scores (p = 0.27). There was a significant correlation between global CBF and serum ETOH level (p = 0.02). There was no statistically significant association between serum ETOH level and GOS at 3 (p = 0.97), 6 (p= 0.56), or 12 (p = 0.73) months after injury. The data indicated that serum ETOH levels > 100 mg/dL at the time of admission after a TBI were associated with a decrease in global CBF. Elevated serum ETOH level at time of injury did not, however, impact outcomes.

Alcohol abuse and traumatic brain injury: quantitative magnetic resonance imaging and neuropsychological outcome

Prior or concurrent alcohol use at the time of traumatic brain injury (TBI) was examined in terms of post-injury atrophic changes measured by quantitative analysis of magnetic resonance imaging (MRI) and neuropsychological outcome. Two groups of TBI subjects were examined: those with a clinically significant blood alcohol level (BAL) present at the time of injury (TBI + BAL) and those without a significant BAL (TBI-only). To explore the potential impact of both acute and chronic alcohol use, subjects in both groups were further clustered into one of four subgroups (NONE, MILD, MODERATE or HEAVY) based upon available information regarding their pre-injury alcohol use. One-way analysis of covariance (ANCOVA) and multiple analysis of covariance (MANCOVA) were used with subject grouping as the main factor. Age, injury severity as measured by Glasgow Coma Scale (GCS) score, years of education, total intracranial volume (TICV), and the number of days post-injury were included as covariates where appropriate. Increased general atrophy was observed in patients with (a) a positive BAL and/or (b) a history of moderate to heavy pre-injury alcohol use. In addition, performance on neuropsychological outcome variables (WAIS-R and WMS-R Index scores) was generally worse in the subgroups of patients with positive BAL and a history of preinjury alcohol use, as compared to the other TBI groups though not statistically significant. Implications of alcohol use, at the time of brain injury, are discussed.

Head injury among drug abusers: an indicator of co-occurring problems

Alcohol and other drug use has been associated with traumatic brain injury both as a contributing factor to the injury and as a complicating factor for rehabilitation. Brain injury is associated with an increase in mental health and other problems that may be related to drug and alcohol abuse and that may influence recovery. This study examined self-reports of 661 drug-abusing inmates with self-reported head injury, health problems and mental health problems. Three groups were examined for this study: those having no head injury, one head injury, and two or more head injuries. Results indicate that inmates with head injuries had a significantly greater number of health problems, higher levels of alcohol and marijuana use, and significantly more mental health problems including depression, anxiety, suicidal thinking, and difficulties in concentrating and controlling violent behavior. This study suggests that questions regarding head injuries during assessment may identify drug abusers who need a treatment approach that accommodates their co-occurring problems and difficulties with processing and complying with treatment interventions.

Rehabilitation unit staff attitudes toward substance abuse: changes and similarities between 1985 and 20011,21No commercial party having a direct financial interest in the results of the research supporting this article has or will confer a benefit on the authors or any organization with which the authors are associated.2Reprints are not available

OBJECTIVES

(1) To assess the attitudes of the members of an inpatient rehabilitation unit team toward their unit's substance abuse and tobacco use policies, and (2) to compare the findings with those of a survey 16 years earlier.

DESIGN

An anonymous repeated assessment of staff attitudes and behaviors.

SETTING

A 47-bed inpatient rehabilitation unit.

PARTICIPANTS

Rehabilitation unit nurses, occupational and physical therapists, psychologists, physicians, social workers, and speech pathologists.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURE

Change in response with time.

RESULTS

Seventy percent (89/128) of the staff members completed the survey. Seventy-two percent believed that they were "familiar or very familiar" with the unit's substance abuse policy and 51% were "concerned" or "very concerned" about their patients' alcohol and drug use. Nineteen percent reported complaints about the policy from their patients and 8% reported complaints from family members. Support for a uniform substance abuse policy remained high: 96% supported a uniform policy in both 1985 and 2001. However, only 15% believed that staff drug abuse education was adequate and only 45% believed that the current policy was "adequate" or "very adequate." (Corresponding responses in 1985 were 20% and 50%, respectively.) All but 1 respondent considered tobacco use an addiction, but only 48% believed that their patients were routinely assessed for its use.

CONCLUSION

Support for a uniform substance abuse policy remains strong. Although most team members support the policy, they believe that their education about substance abuse is inadequate. Staff members almost unanimously accept tobacco use as an addiction, but they believe that assessment and intervention efforts are poor.

Substance abuse attitudes and policies in US rehabilitation training programs: a comparison of 1985 and 2000

OBJECTIVE

To assess and compare the attitudes, beliefs, and policies of physical medicine and rehabilitation (PM&R) training programs toward substance abuse and tobacco use over the last 15 years.

DESIGN

A blinded questionnaire was sent to all US rehabilitation medicine training program directors. Results were compared with a survey conducted in 1985.

SETTING

US PM&R residency training programs with inpatient rehabilitation training.

PARTICIPANTS

Training directors or their designated agents.

INTERVENTION

A 35-item questionnaire was mailed between November 1999 and April 2000 to the 81 US training programs identified by the American Board of Physical Medicine and Rehabilitation as having rehabilitation training programs with inpatient rehabilitation units. Responses were pooled by our Survey Research Center to preserve anonymity. Training programs that did not respond received additional mailings and telephone calls to improve the response rate.

MAIN OUTCOME MEASURES

Chi-square analysis to assess changes in responses with time.

RESULTS

Forty-six of the 79 (58%) eligible training programs responded (1 program had merged, 1 did not provide inpatient rehabilitation). Programs were located in cities ranging from less than 100,000 (n = 2) to greater than a million inhabitants (n = 18). Eighty percent (37/46) of the respondents were "concerned or very concerned" about their patients' alcohol and drug use, and 69% routinely assessed patients for alcohol and drug use compared with only 25% in 1985 (P <.00001). Almost all respondents (43/46) supported written guidelines to prohibit alcohol and drug use by patients in the rehabilitation unit. Eighty-three percent had a prohibition policy, and 72% had written guidelines. Both of those rates represent increases from the 1985 response rates of 65% and 45%, respectively. Ambivalence persisted about appropriate treatment programs for persons with disabilities: in 1985, 51% of the respondents agreed that a person with a disability could be treated appropriately in a substance abuse program designed for persons without a disability; in 2000, the percentage had increased to 64%. All respondents believed that tobacco use is an addiction, but only 25% of their units offered tobacco cessation services to patients on their rehabilitation unit.

CONCLUSION

The survey results are encouraging. Since 1985, not only have substance abuse issues been recognized, but also systemic institutionalized approaches (eg, regular screening, written guidelines) have increased markedly. Tobacco is now uniformly accepted as an addiction, but screening and access to cessation programs are similar to that available for alcohol and drug treatment programs 15 years ago.

Utility of a composite measure to detect problematic alcohol use in persons with traumatic brain injury

OBJECTIVES

To examine factors complicating the study of alcohol-related effects in traumatic brain injury (TBI) patients and to evaluate a composite measure to categorize such patients according to degree of alcohol-related problems.

DESIGN

Inception cohort.

SETTING

Level I trauma center.

PATIENTS

Consecutively hospitalized adult TBI patients (n = 156; 73% men; 87% Caucasian; mean age, 30yr; mean education, 12yr). Selection criteria required objective evidence of brain trauma; minimum survival of 1 month postinjury; age 15 years or older; and English speaking.

MAIN OUTCOME MEASURES

An index of problematic drinking based on a measure created by combining blood-alcohol level, quantity-frequency of consumption, and the Short Michigan Alcoholism Screening Test. Preinjury characteristics were obtained through structured interview.

RESULTS

Participants with highly problematic drinking showed poorer premorbid psychosocial functioning, including lower educational attainment, greater likelihood of problems with the law, lower perceived social support, and greater prevalence of other substance abuse.

CONCLUSION

The composite index is useful in identifying problematic drinkers among TBI patients. Results have implications for interpreting and planning research on the role of alcohol in TBI outcomes.

A comparison of substance abuse and violence in the prediction of long-term rehabilitation outcomes after traumatic brain injury

OBJECTIVE

To determine the relative contributions of substance abuse history and violent etiology to the prediction of outcomes for individuals who sustained a traumatic brain injury (TBI) requiring inpatient rehabilitation.

DESIGN

Longitudinal study of outcomes 1 year postdischarge from rehabilitation.

SETTING

Specialized TBI acute rehabilitation unit.

PARTICIPANTS

Three hundred fifty-one individuals consecutively admitted for rehabilitation.

INTERVENTIONS

Gathered data from patients' medical records (including etiology of injury, initial Glasgow Coma Scale scores, and FIMtrade mark instrument scores at discharge), demographic details, and history of substance abuse; phone and mail survey data from individuals (Satisfaction with Life Scale [SWLS]; Community Integration Questionnaire [CIQ]).

MAIN OUTCOME MEASURES

CIQ and SWLS; relative contributions of injury etiology, demographic and injury-related dependent variables, and substance abuse history to predictive model.

RESULTS

Almost 80% of persons with injuries from violence-related causes had a history of substance abuse. Substance abuse was found to contribute to the prediction of life satisfacton and productivity, while violent etiology was not a significant contributor to predictive models.

CONCLUSION

Substance abuse history proved to be a strong predictor of long-term outcomes, while violent etiology of injury was less influential. The results of this study emphasize the need to include substance abuse history in all studies of outcomes after TBI, and to increase prevention efforts to limit the effects of such a history.

History of head injury among substance users: preliminary findings

Traumatic brain injury is associated with a variety of problems in cognitive functioning that may be related to substance use and that may influence recovery. This pilot study of 591 inmates in medium and minimum-security prisons examined self-reports of head injury, mental health problems, and health service utilization in three groups: no head injury, one head injury, and two or more head injuries. The group with multiple head injuries reported significantly more emergency room visits, more hospital admission, and number of hospital stays when compared with those with no head injury. This preliminary analysis reflects a need for additional research on brain injury among substance misusers.

The effect of cocaine on traumatic brain injury outcome: a preliminary evaluation

The effect of acute cocaine use on the functional and neuropsychological outcome of persons with traumatic brain injury, (TBI) was examined by comparing persons with TBI who tested positive for cocaine at the time of admission with persons with negative drug and alcohol screens. Subjects were matched for age, admission GCS score, level of education, and aetiology of injury (closed vs penetrating head injury). Dependent measures were: the Disability Rating Scale, the Functional Independence Measure, and selected neuropsychological tests. No group differences were found in DRS, FIM, FIM subsets, or FIM change. However, the cocaine group scored significantly lower than the no-drug group on the Rey Auditory Verbal Learning Test, but did not differ on any of the other neuropsychological tests.

The effects of acute and chronic alcohol ingestion on outcome following multiple episodes of mild traumatic brain injury in rats

OBJECTIVE

Recent studies suggest that in some circumstances, alcohol intoxication at the time of severe head injury may be neuroprotective. The objective of this study was to determine the effect of acute and chronic alcohol ingestion on outcome in rodents sustaining multiple episodes of mild traumatic brain injury while intoxicated.

METHOD

For two weeks before experimentation, adult male Sprague-Dawley rats received intoxicating levels of 95% ethanol (3 g/kg) or normal saline (NS) every other day by orogastric instillation. On the day of experimentation, the animals were randomized to receive alcohol or NS. Two hours later, the animals received either mild (1.2 +/- 0.4 ATA) fluid percussion injury (FPI) or no injury. The injured animals received a total of three episodes of FPI (once every four days). Mean reflex recovery time (RRT) was determined (seconds +/- SEM) immediately after each episode. Mean latency time (seconds +/- SEM) for Morris Water Maze (MWM) performance was assessed at post-trauma days 11-19.

RESULTS

The chronic alcohol-exposed (CA) and the non-alcohol-exposed (NA) animals intoxicated when injured had prolonged escape, righting, and corneal RRTs after each FPI compared with the nonintoxicated injured animals and the non-injured shams. However, the CA animals had significantly shorter RRTs when compared with the NA rats. All the injured animals had MWM deficits on testing days 1-6 compared with the noninjured controls. On the last two MWM testing days, the injured NA animals had significantly better MWM performance than the injured CA rats.

CONCLUSIONS

The injured intoxicated CA animals had a more rapid recovery of reflexes compared with the injured intoxicated NA animals. Despite initial MWM deficits, the injured NA rodents eventually began to learn the MWM. The injured CA rats never learned the maze. Under the conditions of this study, acute alcohol intoxication at the time of multiple episodes of minor head trauma did not provide neuroprotection for NA or CA rodents.