Prevalence of fatigue and cognitive impairment after traumatic brain injury

BACKGROUND

Following traumatic brain injury (TBI) some patients develop lingering comorbid symptoms of fatigue and cognitive impairment. The mild cognitive impairment self-reported by patients is often not detected with neurocognitive tests making it difficult to determine how common and severe these symptoms are in individuals with a history of TBI. This study was conducted to determine the relative prevalence of fatigue and cognitive impairment in individuals with a history of TBI.

METHODS

The Fatigue and Altered Cognition Scale (FACs) digital questionnaire was used to assess self-reported fatigue and cognitive impairment. Adults aged 18-70 were digitally recruited for the online anonymous study. Eligible participants provided online consent, demographic data, information about lifetime TBI history, and completed the 20 item FACs questionnaire.

RESULTS

A total of 519 qualifying participants completed the online digital study which included 204 participants with a history of TBI of varied cause and severity and 315 with no history of TBI. FACs Total Score was significantly higher in the TBI group (57.7 ± 22.2) compared to non-TBI (39.5 ± 23.9; p<0.0001) indicating more fatigue and cognitive impairment. When stratified by TBI severity, FACs score was significantly higher for all severity including mild (53.9 ± 21.9, p<0.0001), moderate (54.8 ± 24.4, p<0.0001), and severe (59.7 ± 20.9, p<0.0001) TBI. Correlation analysis indicated that more severe TBI was associated with greater symptom severity (p<0.0001, r = 0.3165). Ancillary analysis also suggested that FACs scores may be elevated in participants with prior COVID-19 infection but no history of TBI.

CONCLUSIONS

Adults with a history of even mild TBI report significantly greater fatigue and cognitive impairment than those with no history of TBI, and symptoms are more profound with greater TBI severity.

Low growth hormone secretion associated with post-acute sequelae SARS-CoV-2 infection (PASC) neurologic symptoms: A case-control pilot study

OBJECTIVE

To determine if patients that develop lingering neurologic symptoms of fatigue and "brain fog" after initial recovery from coronavirus disease 2019 (COVID-19) have persistent low growth hormone (GH) secretion as seen in other conditions with similar symptom etiology.

DESIGN

In this case-control observational pilot study, patients reporting lingering neurologic post-acute sequelae of SARS-CoV-2 (PASC, n = 10) symptoms at least 6 months after initial infection were compared to patients that recovered from COVID-19 without lingering symptoms (non-PASC, n = 13). We compared basic blood chemistry and select metabolites, lipids, hormones, inflammatory markers, and vitamins between groups. PASC and non-PASC subjects were tested for neurocognition and GH secretion, and given questionnaires to assess symptom severity. PASC subjects were also tested for glucose tolerance and adrenal function.

RESULTS

PASC subjects reported significantly worse fatigue, sleep quality, depression, quality of life, and gastrointestinal discomfort compared to non-PASC. Although PASC subjects self-reported poor mental resilience, cognitive testing did not reveal significant differences between groups. Neurologic PASC symptoms were not linked to inflammatory markers or adrenal insufficiency, but were associated with reduced growth hormone secretion.

CONCLUSIONS

Neurologic PASC symptoms are associated with gastrointestinal discomfort and persistent disruption of GH secretion following recovery from acute COVID-19. (www.

CLINICALTRIALS

gov; NCT04860869).

Efficient assessment of brain fog and fatigue: Development of the Fatigue and Altered Cognition Scale (FACs)

Debilitating symptoms of fatigue and accompanying "brain fog" are observed among patients with various chronic health conditions. Unfortunately, an efficient and psychometrically sound instrument to assess these co-occurring symptoms is unavailable. Here, we report the development and initial psychometric properties of the Fatigue and Altered Cognition Scale (the FACs), a measure of self-reported central fatigue and brain fog. Traumatic brain injury (TBI) was chosen to model and develop the FACs due to research team expertise and established links between TBI and the symptom complex. Potential items were generated by researchers and clinicians with experience treating these symptoms, drawing from relevant literature and review of patient responses to measures from past and current TBI studies. The 20 candidate items for the FACs-ten each to assess altered cognition (i.e., brain fog) and central fatigue-were formatted on an electronic visual analogue response scale (eVAS) via an online survey. Demographic information and history of TBI were obtained. A total of 519 participants consented and provided usable data (average age = 40.23 years; 73% female), 204 of whom self-reported a history of TBI (75% reported mild TBI). Internal consistency and reliability values were calculated. Confirmatory factor analysis (CFA) examined the presumed two-factor structure of the FACs and a one-factor solution for comparison. A measurement invariance test of the two latent constructs (altered cognition, fatigue) among participants with and without TBI was conducted. All items demonstrated normal distribution. Cronbach's alpha coefficients indicated good internal consistency for both factors (α's = .95). Omega reliability values were favorable (α's = .95). CFA supported the presumed two-factor model and item loadings which outperformed the one-factor model. Measurement invariance found the two-factor structure was consistent between the two groups. Implications of these findings, study limitations, and potential use of the FACs in clinical research and practice are discussed.

Traumatic brain injury, abnormal growth hormone secretion, and gut dysbiosis

The gut microbiome has been implicated in a variety of neuropathologies with recent data suggesting direct effects of the microbiome on host metabolism, hormonal regulation, and pathophysiology. Studies have shown that gut bacteria impact host growth, partially mediated through the growth hormone (GH)/insulin-like growth factor 1 (IGF-1) axis. However, no study to date has examined the specific role of GH on the fecal microbiome (FMB) or the changes in this relationship following a traumatic brain injury (TBI). Current literature has demonstrated that TBI can lead to either temporary or sustained abnormal GH secretion (aGHS). More recent literature has suggested that gut dysbiosis may contribute to aGHS leading to long-term sequelae now known as brain injury associated fatigue and cognition (BIAFAC). The aGHS observed in some TBI patients presents with a symptom complex including profound fatigue and cognitive dysfunction that improves significantly with exogenous recombinant human GH treatment. Notably, GH treatment is not curative as fatigue and cognitive decline typically recur upon treatment cessation, indicating the need for additional studies to address the underlying mechanistic cause.

Obstructive sleep apnea during the chronic stroke recovery period: Comparison between primary haemorrhagic and ischaemic events

The present study retrospectively determined the incidence of obstructive sleep apnea (OSA) after a primary haemorrhagic event compared to an ischaemic stroke during the post-acute recovery period ( x ¯ >3 months). Consideration of medications taken during the sleep evaluation provided additional information on the association between OSA and pathophysiological conditions that may increase the risk of a repeated cardiovascular event. The medical records from 103 patients that underwent a type I fully attended overnight polysomnography as a standard evaluation procedure at a rehabilitation facility were reviewed. Diagnosis of ischaemic or primary haemorrhagic stroke was obtained from a neurological report that was typically confirmed by imaging. Medications taken at the time of the sleep study were documented. Age-adjusted assessment of sleep-disordered breathing revealed a higher incidence of apnea and hypopnea in the ischaemic stroke group (p < 0.005). Patients with ischaemic stroke were also more likely to have severe OSA (p < 0.005). In comparison, a higher percentage of patients with haemorrhagic stroke had an apnea-hypopnea index <5 events/hr (p < 0.005). Those with an ischaemic stroke were taking more lipid lowering agents (p < 0.05). Results suggest that apnea is less prevalent after a haemorrhagic stroke, independent of hypertension, compared to an ischaemic stroke. An increase in predictive values for OSA was observed for indicators of diabetes (p < 0.05). These data indicate that it is relevant to consider stroke type when determining the risk of OSA during the chronic recovery period thus facilitating new strategies for stroke recurrence prevention.

Alterations of the GH/IGF-I Axis and Gut Microbiome after Traumatic Brain Injury: A New Clinical Syndrome?

CONTEXT

Pituitary dysfunction with abnormal growth hormone (GH) secretion and neurocognitive deficits are common consequences of traumatic brain injury (TBI). Recognizing the comorbidity of these symptoms is of clinical importance; however, efficacious treatment is currently lacking.

EVIDENCE ACQUISITION

A review of studies in PubMed published between January 1980 to March 2020 and ongoing clinical trials was conducted using the search terms "growth hormone," "traumatic brain injury," and "gut microbiome."

EVIDENCE SYNTHESIS

Increasing evidence has implicated the effects of TBI in promoting an interplay of ischemia, cytotoxicity, and inflammation that renders a subset of patients to develop postinjury hypopituitarism, severe fatigue, and impaired cognition and behavioral processes. Recent data have suggested an association between abnormal GH secretion and altered gut microbiome in TBI patients, thus prompting the description of a hypothesized new clinical syndrome called "brain injury associated fatigue and altered cognition." Notably, these patients demonstrate distinct characteristics from those with GH deficiency from other non-TBI causes in that their symptom complex improves significantly with recombinant human GH treatment, but does not reverse the underlying mechanistic cause as symptoms typically recur upon treatment cessation.

CONCLUSION

The reviewed data describe the importance of alterations of the GH/insulin-like growth factor I axis and gut microbiome after brain injury and its influence in promoting neurocognitive and behavioral deficits in a bidirectional relationship, and highlight a new clinical syndrome that may exist in a subset of TBI patients in whom recombinant human GH therapy could significantly improve symptomatology. More studies are needed to further characterize this clinical syndrome.

Prevalence of growth hormone deficiency in middle-age adults recovering from stroke

Objective: The prevalence of chronic growth hormone deficiency (GHD) and its association with other hormonal deficiencies was determined in middle-aged patients post-stroke with and without consideration of body mass index (BMI).Methods: Clinical records were reviewed to determine pituitary function at least 3 months post-stroke. Patients with a history of endocrine anomalies were excluded. GHD was determined by utilizing standard peak GH cutoffs following the glucagon stimulation test. A secondary analysis was conducted with stricter BMI-adjusted cutoffs. The accuracy of IGF-1 in predicting GHD was also examined.Results: GHD was diagnosed in 54% of patients (≥5.0 μg/L), with 32% falling into the severe (≤3 μg/L) category. Patients with GHD had lower levels of FSH, T3, LH, and SHBG. Analyzes of BMI-adjusted GH levels, revealed that 14% of patients were GHD. These patients had higher prolactin. IGF-1 values were not predictive of GHD. Latency to be admitted to post-acute rehabilitation was greater in patients with GHD.Conclusions: Evidence suggests patients with stroke may be at risk for developing GHD. GHD was associated with decreased levels of other hormones. Co-morbidities for stroke and neuroendocrine dysfunction overlap and may have implications for recovery following stroke.

Abstract TP167: Prevalence of Growth Hormone Deficiency in the Chronic Phase of Recovery From Stroke

Introduction: The objective of the current retrospective study was to determine the prevalence of growth hormone deficiency (GHD) in middle-aged patients with ischemic and hemorrhagic stroke who were at least 3 months post-stroke. It was hypothesized a large percentage of patients with stroke would exhibit growth hormone deficiency, as well as, other hormone deficiencies. A secondary objective was to determine if chronic health conditions often associated with stroke were associated with neuroendocrine dysfunction.

Methods: Clinical records from 139 adult patients (from 2009-2017), who were in the post-acute phase of their recovery, were obtained to analyze findings from standard endocrine blood tests. Patients with a pre-stroke history of endocrine anomalies were excluded from the study. Growth hormone was assessed by the glucagon stimulation test (GST).

Results: GHD was identified in 54% of the patients with stroke during the chronic phase of recovery. Patients with GHD took longer to be admitted to post-acute rehabilitation compared to patients with normal GH levels. Patients with GHD also had lower levels of follicle stimulating hormone (FSH), triiodothyronine (T3), luteinizing hormone (LH) and sex hormone binding globulin. Body mass index was higher in patients with GHD.

Conclusions: There is a considerable risk of developing hypopituitarism, particularly GHD, following ischemic or hemorrhagic stroke. In this relatively large sample of middle-aged stroke patients, GHD was associated with decreased levels of T3 and gonadotrophic hormones. Co-morbidities for stroke and neuroendocrine dysfunction overlap and may have implications for recovery following stroke and warrant further investigation.

The influence of post-acute rehabilitation length of stay on traumatic brain injury outcome: a retrospective exploratory study

OBJECTIVE

Data regarding length of stay (LOS) in a rehabilitation programme after traumatic brain injury (TBI) are limited. The goal of this study was to examine the effect of LOS and disability on outcome following TBI.

METHODS

Records from patients in a multidisciplinary rehabilitation programme at least 3 months after TBI were analysed retrospectively to study the influence of LOS on functional outcome at different levels of disability. Functional status was determined by the Mayo-Portland Adaptability Inventory (MPAI) and the Community Integration Questionnaire (CIQ). Patients were further grouped by time since injury of 3-12 months or over 1 year.

RESULTS

Those with a mild and moderate disabilities and over 1 year chronicity showed improvements after 90 days of rehabilitation. Patients with a severe disability and over 1 year chronicity required at least 180 days to show improvements. Moderately and severely disabled patients with an injury chronicity of 3-12 months showed improvements in the MPAI after 90 days. However, further improvement was observed after 180 days in the severely disabled group.

CONCLUSIONS

Results suggest that both, level of disability and injury chronicity, should be considered when determining LOS. Data also show an association between LOS and changes in the MPAI and CIQ.

The Impact of Traumatic Brain Injury on Later Life: Effects on Normal Aging and Neurodegenerative Diseases

The acute and chronic effects of traumatic brain injury (TBI) have been widely described; however, there is limited knowledge on how a TBI sustained during early adulthood or mid-adulthood will influence aging. Epidemiological studies have explored whether TBI poses a risk for dementia and other neurodegenerative diseases associated with aging. We will discuss the influence of TBI and resulting medical comorbidities such as endocrine, sleep, and inflammatory disturbances on age-related gray and white matter changes and cognitive decline. Post mortem studies examining amyloid, tau, and other proteins will be discussed within the context of neurodegenerative diseases and chronic traumatic encephalopathy. The data support the suggestion that pathological changes triggered by an earlier TBI will have an influence on normal aging processes and will interact with neurodegenerative disease processes rather than the development of a specific disease, such as Alzheimer's or Parkinson's. Chronic neurophysiologic change after TBI may have detrimental effects on neurodegenerative disease.

Functional Changes after Recombinant Human Growth Hormone Replacement in Patients with Chronic Traumatic Brain Injury and Abnormal Growth Hormone Secretion

We explored the effects of recombinant human growth hormone (rhGH) replacement on physical and cognitive functioning in subjects with a moderate-to-severe traumatic brain injury (TBI) with abnormal growth hormone (GH) secretion. Fifteen individuals who sustained a TBI at least 12 months prior to study enrollment were identified as having abnormal GH secretion by glucagon stimulation testing (maximum GH response less than 8 ng/mL). Peak cardiorespiratory capacity, body composition, and muscle force testing were assessed at baseline and one year after rhGH replacement. Additionally, standardized neuropsychological tests that assess memory, processing speed, and cognitive flexibility, as well as self-report inventories related to depression and fatigue, were administered at baseline and 1 year after rhGH replacement. Comparison tests were performed with proper post hoc analyses. All analyses were carried out at α < 0.05. Peak O₂ consumption, peak oxygen pulse (estimate of cardiac stroke volume), and peak ventilation all significantly increased (p < 0.05). Maximal isometric and isokinetic force production were not altered. Skeletal muscle fatigue did not change but the perceptual rating of fatigue was reduced by ∼25% (p = 0.06). Cognitive performance did not change significantly over time, whereas self-reported symptoms related to depression and fatigue significantly improved. The observed changes suggest that rhGH replacement has a positive impact on cardiorespiratory fitness and a positive impact on perceptual fatigue in survivors of TBI with altered GH secretion.

Hypoaminoacidemia Characterizes Chronic Traumatic Brain Injury

Individuals with a history of traumatic brain injury (TBI) are at increased risk for a number of disorders, including Alzheimer's disease, Parkinson's disease, and chronic traumatic encephalopathy. However, mediators of the long-term morbidity are uncertain. We conducted a multi-site, prospective trial in chronic TBI patients (∼18 years post-TBI) living in long-term 24-h care environments and local controls without a history of head injury. Inability to give informed consent was exclusionary for participation. A total of 41 individuals (17 moderate-severe TBI, 24 controls) were studied before and after consumption of a standardized breakfast to determine if concentrations of amino acids, cytokines, C-reactive protein, and insulin are potential mediators of long-term TBI morbidity. Analyte concentrations were measured in serum drawn before (fasting) and 1 h after meal consumption. Mean ages were 44 ± 15 and 49 ± 11 years for controls and chronic TBI patients, respectively. Chronic TBI patients had significantly lower circulating concentrations of numerous individual amino acids, as well as essential amino acids (p = 0.03) and large neutral amino acids (p = 0.003) considered as groups, and displayed fundamentally altered cytokine-amino acid relationships. Many years after injury, TBI patients exhibit abnormal metabolic responses and altered relationships between circulating amino acids, cytokines, and hormones. This pattern is consistent with TBI, inducing a chronic disease state in patients. Understanding the mechanisms causing the chronic disease state could lead to new treatments for its prevention.

Pituitary dysfunction after traumatic brain injury: a clinical and pathophysiological approach

Traumatic brain injury (TBI) is a growing public health problem worldwide and is a leading cause of death and disability. The causes of TBI include motor vehicle accidents, which are the most common cause, falls, acts of violence, sports-related head traumas, and war accidents including blast-related brain injuries. Recently, pituitary dysfunction has also been described in boxers and kickboxers. Neuroendocrine dysfunction due to TBI was described for the first time in 1918. Only case reports and small case series were reported until 2000, but since then pituitary function in TBI victims has been investigated in more detail. The frequency of hypopituitarism after TBI varies widely among different studies (15-50% of the patients with TBI in most studies). The estimates of persistent hypopituitarism decrease to 12% if repeated testing is applied. GH is the most common hormone lost after TBI, followed by ACTH, gonadotropins (FSH and LH), and TSH. The underlying mechanisms responsible for pituitary dysfunction after TBI are not entirely clear; however, recent studies have shown that genetic predisposition and autoimmunity may have a role. Hypopituitarism after TBI may have a negative impact on the pace or degree of functional recovery and cognition. What is not clear is whether treatment of hypopituitarism has a beneficial effect on specific function. In this review, the current data related to anterior pituitary dysfunction after TBI in adult patients are updated, and guidelines for the diagnosis, follow-up strategies, and therapeutic approaches are reported.

Neuropsychological and physiological correlates of fatigue following traumatic brain injury

BACKGROUND

Fatigue is a common and debilitating phenomenon experienced by individuals with traumatic brain injury (TBI) that can negatively influence rate and extent of functional recovery by reducing participation in brain injury rehabilitation services and increasing maladaptive lifestyle practices. The underlying mechanisms of TBI-related fatigue are not entirely understood and focused research on symptom reduction or prevention is limited.

REVIEW

The current review of the literature suggests that the aetiology of TBI-related fatigue can be viewed as a multifactorial and complex model impacting physiological systems (i.e. endocrine, skeletal muscle and cardiorespiratory) that can be directly or indirectly influenced by neuropsychological correlates including cognitive and psychological impairment. Distinguishing central from peripheral fatigue is helpful in this regard. Potential therapeutic strategies and pharmacological agents to help alleviate fatigue in this patient population are discussed.

What are critical outcome measures for patients receiving pituitary replacement following brain injury?

There are scant prospective studies defining improvements in critical outcome measures with hormone replacement in hypopituitarism secondary to brain injury. We review the tests of cognition and physical function and summarize their use for subjects that are deficient in anterior hormone production during anterior pituitary hormone replacement in brain injury and propose these as the minimal tests that are feasible for a physician to perform in a clinical setting. We summarize the studies conducted to assess outcome measures after brain injury and also report preliminary findings for improvements in cognition and physical function in subjects with brain injury and GH deficiency.

Hyperbaric oxygen therapy for traumatic brain injury: still an enigma

With their article on the use of HBOT for post TBI dysautonomia, Lv and colleagues discuss a novel use for this form of treatment. Although HBOT has been a part of our TBI treatment armamentarium for many years, its use remains a very controversial issue. In this commentary, the science and research studies behind HBOT for TBI are reviewed, hopefully leaving the reader with an adequate knowledge base to answer a patient or family's inquiries as to the usefulness of HBOT for TBI.

Effect of growth hormone replacement therapy on cognition after traumatic brain injury

Traumatic brain injury (TBI) is a major public health issue, and yet medical science has little to offer for the persistent symptoms that prevent many of these individuals from fully re-entering society. Post-traumatic hypopituitarism, and specifically growth hormone deficiency (GHD), has been found in a large percentage of individuals with chronic moderate to severe TBI. Presently, there are no published treatment studies of hormone replacement in this population. In this study, 83 subjects with chronic TBI were screened for hypopituitarism. Forty-two subjects were found to have either GHD or GH insufficiency (GHI), of which 23 agreed to be randomized to either a year of GH replacement or placebo. All subjects completed the study with no untoward side effects from treatment. A battery of neuropsychological tests and functional measures were administered before and after treatment. Improvement was seen on the following tests: Dominant Hand Finger Tapping Test, Wechsler Adult Intelligence Scale III-Information Processing Speed Index, California Verbal Learning Test II, and the Wisconsin Card Sorting Test (executive functioning). The findings of this pilot study provide preliminary evidence suggesting that some of the cognitive impairments observed in persons who are GHD/GHI after TBI may be partially reversible with appropriate GH replacement therapy.

Manifesto for the current understanding and management of traumatic brain injury-induced hypopituitarism

Traumatic brain injury (TBI)-induced hypopituitarism remains a relevant medical problem, because it may affect a significant proportion of the population. In the last decade important studies have been published investigating pituitary dysfunction after TBI. Recently, a group of experts gathered and revisited the topic of TBI-induced hypopituitarism. During the 2-day meeting, the main issues of this topic were presented and discussed, and current understanding and management of TBI-induced hypopituitarism are summarized here.

Serum IGF-1 concentrations in a sample of patients with traumatic brain injury as a diagnostic marker of growth hormone secretory response to glucagon stimulation testing

OBJECTIVE

The diagnosis of growth hormone deficiency (GHD) in adults is established through growth hormone (GH) stimulation testing, which is often complex, expensive, time-consuming and may be associated with adverse side effects. The decision to perform GH provocative testing is influenced by clinical findings, medical history and biochemical evidence. We report in this study our experience using the glucagon stimulation test (GST) in assessing GHD in adult patients with traumatic brain injury (TBI) as it relates to baseline serum insulin-like growth factor-1 (IGF-1) concentrations.

DESIGN

A receiver operating characteristic (ROC) curve analysis was performed to determine the optimal IGF-1 cut-off for diagnosis of GHD at different potential diagnostic GST cut-off values (<3, <5, & <10 μg/l).

PATIENTS

One hundred and thirty-eight patients (98 men and 40 women) with a documented history of moderate to severe TBI were assessed for GHD using serum IGF-1 concentrations and the GST.

MEASUREMENTS

IGF-1 values were compared with peak GH values obtained following the GST.

RESULTS

An IGF-1 cut-off value of 175 μg/l minimized the misclassification of GHD patients and GH-sufficient patients and provided a sensitivity of 83% and specificity of 40%, as well as a negative predictive power of 90% considering a criterion for peak GH response of <3 μg/l.

CONCLUSIONS

Our current findings are consistent with previous work assessing peak GH response using the insulin tolerance test (ITT) in a non-TBI sample, suggesting that diagnostic accuracy may be optimized if the GST is used when obtained serum IGF-1 concentrations are below 175 μg/l. While the decision to perform provocative testing to assess GHD in adult patients should be based on the clinician's clinical impression, the findings from this retrospective study can provide useful clinical information and serve as a guide.

Traumatic brain injury: a disease process, not an event

Traumatic brain injury (TBI) is seen by the insurance industry and many health care providers as an "event." Once treated and provided with a brief period of rehabilitation, the perception exists that patients with a TBI require little further treatment and face no lasting effects on the central nervous system or other organ systems. In fact, TBI is a chronic disease process, one that fits the World Health Organization definition as having one or more of the following characteristics: it is permanent, caused by non-reversible pathological alterations, requires special training of the patient for rehabilitation, and/or may require a long period of observation, supervision, or care. TBI increases long-term mortality and reduces life expectancy. It is associated with increased incidences of seizures, sleep disorders, neurodegenerative diseases, neuroendocrine dysregulation, and psychiatric diseases, as well as non-neurological disorders such as sexual dysfunction, bladder and bowel incontinence, and systemic metabolic dysregulation that may arise and/or persist for months to years post-injury. The purpose of this article is to encourage the classification of TBI as the beginning of an ongoing, perhaps lifelong process, that impacts multiple organ systems and may be disease causative and accelerative. Our intent is not to discourage patients with TBI or their families and caregivers, but rather to emphasize that TBI should be managed as a chronic disease and defined as such by health care and insurance providers. Furthermore, if the chronic nature of TBI is recognized by government and private funding agencies, research can be directed at discovering therapies that may interrupt the disease processes months or even years after the initiating event.

Endurance training and cardiorespiratory conditioning after traumatic brain injury

OBJECTIVE

To examine the importance of cardiorespiratory conditioning after traumatic brain injury (TBI) and provide recommendations for patients recovering from TBI.

METHOD

Review of literature assessing the effectiveness of endurance training programs.

MAIN OUTCOMES AND RESULTS

A sedentary lifestyle and lack of endurance are common characteristics of individuals with TBI who have a reduction in peak aerobic capacity of 25% to 30% compared with healthy sedentary persons. Increased physical activity and exercise training improves cardiorespiratory fitness in many populations with physical and cognitive impairments. Therefore, increasing the endurance and cardiorespiratory fitness of persons with TBI would seem to have important health implications. However, review of the TBI literature reveals that there have been few well-designed, well-controlled studies of physiologic and psychological adaptations of fitness training. Also lacking are long-term follow-up studies of persons with TBI.

CONCLUSIONS

Assessing endurance capacity and cardiorespiratory fitness early in the TBI rehabilitation process merits consideration as a standard of care by professional rehabilitation societies. Also, providing effective, safe, and accessible training modalities would seem to be an important consideration for persons with TBI, given the mobility impairments many possess. Long-term follow-up studies are needed to assess the effectiveness of cardiorespiratory training programs on overall morbidity and mortality.

Treatment of sleep disorders after traumatic brain injury

STUDY OBJECTIVES

Determine whether treatment of sleep disorders identified in brain injured adults would result in resolution of those sleep disorders and improvement of symptoms and daytime function.

METHODS

Prospective evaluation of unselected traumatic brain injury patients with nocturnal polysomnography (NPSG), multiple sleep latency test (MSLT), Epworth Sleepiness Scale (ESS), and neuropsychological testing including Psychomotor Vigilance Test (PVT), Profile of Mood States (POMS), and Functional Outcome of Sleep Questionnaire (FOSQ) before and after treatment with continuous positive airway pressure (CPAP) for obstructive sleep apnea (OSA), modafinil (200 mg) for narcolepsy and posttraumatic hypersomnia (PTH), or pramipexole (0.375 mg) for periodic limb movements in sleep (PLMS).

SETTING

Three academic medical centers.

PARTICIPANTS

Fifty-seven (57) adults > or = 3 months post traumatic brain injury (TBI).

MEASUREMENTS AND RESULTS

Abnormal sleep studies were found in 22 subjects (39%), of whom 13 (23%) had OSA, 2 (3%) had PTH, 3 (5%) had narcolepsy, 4 (7%) had PLMS, and 12 had objective excessive daytime sleepiness with MSLT score < 10 minutes. Apneas, hypopneas, and snoring were eliminated by CPAP in OSA subjects, but there was no significant change in MSLT scores. Periodic limb movements were eliminated with pramipexole. One of 3 narcolepsy subjects and 1 of 2 PTH subjects had resolution of hypersomnia with modafinil. There was no significant change in FOSQ, POMS, or PVT results after treatment.

CONCLUSIONS

Treatment of sleep disorders after TBI may result in polysomnographic resolution without change in sleepiness or neuropsychological function.

Aerobic capacity and growth hormone deficiency after traumatic brain injury

CONTEXT

GH deficiency occurs in approximately 20% of all individuals who suffer from a moderate to severe traumatic brain injury.

OBJECTIVE

This study determined whether GH deficiency secondary to traumatic brain injury had an effect on aerobic capacity.

DESIGN

Subjects were screened for GH deficiency by the glucagon stimulation test and performed a maximal treadmill exercise test.

SETTING

Patients were studied in the postacute recovery phase after traumatic brain injury.

PARTICIPANTS

Thirty-five individuals were studied. Groups were formed as follows: normal GH axis, greater than 8 ng/ml response (n = 12); insufficient, GH 3-8 ng/ml response (n = 11); and deficient, less than 3 ng/ml response (n = 12).

INTERVENTION

There was no intervention.

MAIN OUTCOME MEASURE

Aerobic capacity was assessed by measuring expired gases during a graded treadmill exercise test. One-way and two-way ANOVAs were carried out on all peak and submaximal cardiorespiratory variables, respectively. Appropriate post hoc comparisons followed as necessary.

RESULTS

Significantly higher peak oxygen consumption was found in traumatic brain injury subjects with GH normal vs. GH insufficient and deficient [26.4 +/- 6.9, 20.8 +/- 4.6, and 19.7 +/- 5.0, respectively (P < 0.05)]. Submaximal oxygen consumption was significantly higher in the GH normal group. All other variables were statistically similar.

CONCLUSIONS

This study shows that individuals with traumatic brain injury with normal GH secretion have below normal aerobic capacity and those patients who have GH insufficiency/deficiency are further deconditioned. Studies of GH replacement in these subjects should be conducted to assess whether GH therapy can improve cardiorespiratory fitness and prevent secondary disability.

Cognitive Impairment in Patients With Traumatic Brain Injury and Obstructive Sleep Apnea

OBJECTIVE

To examine the impact of comorbid obstructive sleep apnea (OSA) on the cognitive functioning of traumatic brain injury (TBI) patients.

DESIGN

A case-control study. Neuropsychologic test performances of TBI patients with OSA were compared with those who did not have OSA. The diagnosis of OSA was based on standard criteria using nocturnal polysomnography.

SETTING

Three academic medical centers with level I trauma centers, accredited sleep disorders centers, and rehabilitation medicine programs.

PARTICIPANTS

Thirty-five TBI patients who were part of a project that assessed the effect of sleep disorders in a larger sample of consecutively recruited TBI patients. There were 19 patients with TBI and OSA. They were compared with 16 TBI patients without OSA who were comparable in terms of age, education, severity of injury (when available), time postinjury, and Glasgow Coma Scale scores (when available).

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

The Psychomotor Vigilance Test, Rey Complex Figure Test, Rey Auditory Verbal Learning Test, digit span test from the Wechsler Memory Scale-Revised, and finger-tapping test.

RESULTS

The TBI patients with OSA performed significantly worse than the non-sleep disordered TBI patients on verbal and visual delayed-recall measures. The groups performed comparably on motor, visual construction, and attention tests. The TBI patients with OSA made more attention lapses (reaction times >/=500ms), but showed comparable fastest and slowest reaction times on a measure of sustained attention.

CONCLUSIONS

OSA is associated with more impairment of sustained attention and memory in TBI patients. It is possible that early identification and treatment of OSA may improve cognitive, and thus potentially functional, outcomes of TBI patients with this disease.

Prevalence and consequences of sleep disorders in traumatic brain injury

STUDY OBJECTIVES

Determine prevalence and consequences of sleepiness and sleep disorders after traumatic brain injury (TBI).

METHODS

Prospective evaluation with polysomnography (PSG), multiple sleep latency test (MSLT), Epworth Sleepiness Scale (ESS) and neuropsychological testing including Psychomotor Vigilance Test (PVT), Profile of Mood States (POMS), and Functional Outcome of Sleep Questionnaire (FOSQ).

SETTING

Three academic medical centers with level I trauma centers, accredited sleep disorders centers, and rehabilitative medicine programs. Participants; Eighty-seven (87) adults at least 3 months post TBI.

MEASUREMENTS AND RESULTS

Abnormal sleep studies were found in 40 subjects (46%), including 20 (23%) with obstructive sleep apnea (OSA), 10 (11%) with posttraumatic hypersomnia (PTH), 5 (6%) with narcolepsy, and 6 (7%) with periodic limb movements in sleep (PLMS). Among all subjects, 22 (25%) were found to have objective excessive daytime sleepiness with MSLT score <10 minutes. There was no correlation between ESS score and MSLT (r = 0.10). There were no differences in age, race, sex, or education between the sleepy and non-sleepy subjects. Likewise, there were no differences in severity of injury or time after injury between sleepy and non-sleepy subjects. Sleepy subjects had a greater body mass index (BMI) than those who were not sleepy (p = 0.01). OSA was more common in obese subjects (BMI > or =30, p < 0.001). Sleepy subjects demonstrated poorer PVT scores (p < 0.05), better self-reported sleep related quality of life (FOSQ scores [p < 0.05]), and no differences in POMS.

CONCLUSIONS

There is a high prevalence of sleep disorders (46%) and of excessive daytime sleepiness (25%) in subjects with TBI. Sleepy subjects may be more impaired than comparable non-sleepy TBI subjects, yet be unaware of problems. Given the high prevalence of OSA (23%), PTH (11%), and narcolepsy (7%) in this population, there is a clinical indication for NPSG and MSLT.

Traumatic brain injury induced hypopituitarism: the need and hope of rehabilitation

Traumatic brain injury is a leading cause of death and disability in developed countries. Damage caused by focal and diffuse lesions produces symptoms involving most major medical systems as well as symptoms of neurological and psychological origin. The severity of a traumatic brain injury is difficult to assess, and therefore, an initial accurate prognosis is difficult as well. Present treatments focus on relieving symptoms without adequately addressing the underlying cause of those symptoms. Recent studies have shown anterior pituitary deficiencies to be common amongst survivors of TBI. As many symptoms ascribed to a TBI are similar to the symptoms of hypopituitarism, it is possible that treatment of these deficiencies will improve functioning and the quality of life for survivors of traumatic brain injuries.

Rehabilitation and hypopituitarism after traumatic brain injury

Traumatic brain injury (TBI) is a leading cause of death and disability in the United States (US). The severity of a TBI is difficult to assess, and therefore, accurate determination of the prognosis is difficult. The symptoms of a TBI involve most major medical systems, and share many similarities with the symptoms of hypopituitarism. Although more than two-thirds of patients with severe head injuries who die have structural abnormalities in the hypothalamus and the pituitary, pituitary function is not routinely assessed after head trauma. Thus, studies have shown that anterior pituitary hormone deficiencies are common following brain injury [Endocrinologist 11 (2001) 275; J. Clin. Endocrinol. Metab. 86 (2001) 2752]. Survivors of brain injury should be screened for such deficiencies so that replacement therapy can be initiated to optimize rehabilitation and outcome.

Excessive daytime sleepiness in adults with brain injuries

OBJECTIVES

To determine the prevalence, demographics, and causes of excessive daytime sleepiness in adults with brain injuries after the acute phase of their injury and to investigate the relations between self-report and objective measures of hypersomnolence.

DESIGN

A case series of patients enrolled consecutively into a residential rehabilitation program.

SETTING

University sleep laboratory, live-in rehabilitation center.

PATIENTS

Adults with brain injuries (n = 71); mean time +/- standard deviation from injury to study, 38 +/- 60 months.

INTERVENTIONS

A polysomnogram and Multiple Sleep Latency Test (MSLT) were performed in each subject. Each subject also completed the Epworth Sleepiness Scale (ESS) and Pittsburgh Sleep Quality Index (PSQI) questionnaires.

MAIN OUTCOME MEASURES

Sleep patterns, by polysomnogram. Daytime hypersomnolence, diagnosed by mean sleep latency on the MSLT <or= 10 minutes. Sleep apnea-hypopnea syndrome, diagnosed by Apnea-Hypopnea Index greater than 10 events/hr. Periodic limb movement disorder, diagnosed by a Periodic Leg Movement Index greater than 10 events/hr.

RESULTS

Mean sleep latency was <or= 10 minutes in 47% of the cohort and <or= 5 minutes in 18.3%. Subjects were classified into 3 groups: nonhypersomnolent (n = 38, 53%), hypersomnolent with abnormal indices (n = 12, 17%), or hypersomnolent with normal indices (n = 21, 30%). Among the 3 groups, no significant differences were present in Glasgow Coma Scale score, length of coma, or time since brain injury. No differences across groups were found in nature of the injury, gender, or medications. No significant correlation existed between the ESS or PSQI results and mean sleep latency on the MSLT.

CONCLUSIONS

Hypersomnia is common in adults with brain injuries, with a relatively high prevalence of sleep apnea-hypopnea syndrome, periodic limb movement disorder, and posttraumatic hypersomnia. Subjects with objectively measured sleepiness were not identified on self-reporting questionnaires, suggesting their inability to perceive their hypersomnolence.

Prevalence of neuroendocrine dysfunction in patients recovering from traumatic brain injury

Although hypopituitarism is a known complication of head injury, it may be underrecognized due to its subtle clinical manifestations. The nonspecific symptoms may be masked by and may contribute to the physical and psychological sequelae of brain trauma. This study examines the prevalence of neuroendocrine abnormalities in patients rehabilitating from traumatic brain injury. Seventy adults (mean age, 31.5 +/- 1.1 yr; range, 18--58; 46 men and 24 women) with traumatic brain injury an average of 49 +/- 8 months before the study (median, 13 months) underwent a series of standard endocrine tests, including serum levels of TSH, free T(4), insulin-like growth factor I, PRL, testosterone (males), and cosyntropin stimulation. Abnormal results of these tests were followed by dynamic tests of gonadotropin, TSH, and GH secretion. Glucagon stimulation testing in 48 subjects revealed GH deficiency (peak, <3 microg/L) in 14.6%. Free T(4) (n = 6; 8.6%), TSH (n = 7; 10%), or both (n = 2; 2.9%) were low in 21.7%, whereas 87% had both TSH and free T(4) below the midnormal level. Basal morning cortisol was below normal in 45.7% of subjects, whereas cosyntropin-stimulated levels were insufficient (peak, <500 nmol/L) in 7.1%. Hypogonadism and hyperprolactinemia were uncommon. In summary, pituitary hormone deficiencies were identified in a substantial proportion of patients with previous brain injury. GH deficiency, found in 15% by glucagon stimulation testing, may compound the physical and psychological complications of traumatic brain injury and interfere with rehabilitation.

The PPVT-R: validity as a quick screen of intelligence in a postacute rehabilitation setting for brain-injured adults

The utility of the Peabody Picture Vocabulary Test-Revised (PPVT-R) as a surrogate for the Wechsler Adult Intelligence Test-Revised (WAIS-R) was investigated in 61 brain-injured adult participants in a postacute rehabilitation setting. Idiographic comparison revealed substantial disagreement in clinical classification between the two instruments, and it is concluded that the PPVT-R is not a good surrogate for the WAIS-R for this purpose. In contrast, the PPVT-R was judged an adequate surrogate for the WAIS-R for the purpose of group comparison, as is common in biomedical research. Finally, contrary to prior report, the PPVT-R was demonstrated to measure more than simply Vocabulary. As such, in the absence of independent validation research, perhaps the most parsimonious conclusion regarding what the PPVT-R is measuring is that like each of the various subtests of the WAIS-R, the PPVT-R shares some of the variance of the construct termed intelligence, as well as demonstrates some unique variance that is likely comprised of error and, perhaps, a unique or different facet of intelligence.

Comparison of 650 mg aspirin and 1,000 mg acetaminophen with each other, and with placebo in moderately severe headache

Two-hundred-sixty-nine otherwise healthy persons experiencing periodic, moderately severe headache of a type that had previously responded to nonprescription medications completed this randomized, parallel, double-blind study. The three demographically similar subgroups took either 1,000 mg acetaminophen, 650 mg aspirin, or an identical placebo, for headache. Headache intensity and relief scores over the following six hours were obtained and assessed by sums of pain intensity difference and values of pain relief scores analyses. Responses for the group, and for the subgroup with tension headaches (107 persons) showed no differences between the effects of the active medications. The effects of each medication were strongly superior to placebo. There were no differences in side effects among the three treatment modalities. In persons experiencing tension-vascular headaches (162), only aspirin, at two hours, was superior to placebo, but direct comparison with acetaminophen suggested no real difference. Acetaminophen (1,000 mg) and aspirin (650 mg) are clinically similar in treating the headaches for which they are commonly taken. Recommendations for their use in treating headache should be based on individual patient suitability and on cost factors.

Symptomatic cerebral histoplasmoma. Case report

A 53-year-old man, with a past history of a thoracotomy 7 years previously, developed seizures. A computerized tomography scan with contrast medium revealed a peripheral ring-like lesion in the anterolateral part of the right parietal lobe. Pathological evaluation of the resected lesion demonstrated it to be a histoplasmoma. Although rare, a histoplasmoma should be included in the differential diagnosis of a ring-shaped lesion in a patient with previous pulmonary disease.