Pituitary dysfunction with reduced growth hormone (GH) secretion is common in patients following traumatic brain injury (TBI), and these patients often develop chronic symptoms including fatigue and altered cognition. We examined 18 subjects with a history of mild TBI, fatigue, and insufficient GH secretion. Subjects received GH replacement in a year-long, double-blind, placebo-controlled, crossover study, and were assessed for changes in physical performance, body composition, resting energy expenditure, fatigue, sleep, mood, and neuropsychological status. Additionally, magnetic resonance imaging (MRI) was used to assess changes in brain structure and resting state functional connectivity. GH replacement resulted in decreased fatigue, sleep disturbance, and anxiety, as well as increased resting energy expenditure, improved body composition, and altered perception of submaximal effort when performing exercise testing. Associated brain changes included increased frontal cortical thickness and gray matter volume and resting state connectivity changes in regions associated with somatosensory networks. GH replacement altered brain morphology and connectivity and reduced fatigue and related symptoms in mild TBI patients. Additional studies are needed to understand the mechanisms causing TBI-related fatigue and symptom relief with GH replacement.

Post-traumatic hypopituitarism (PTH) associated with chronic cognitive, psychiatric, and/or behavioural sequelae is common following moderate to severe traumatic brain injury (TBI). More specifically, due to a cascade of hormonal deficiencies secondary to PTH, individuals with TBI may experience debilitating fatigue that can negatively impact functional recovery, as it can limit participation in brain injury rehabilitation services and lead to an increase in maladaptive lifestyle practices. While the mechanisms underlying fatigue and TBI are not entirely understood, the current review will address the specific anatomy and physiology of the pituitary gland, as well as the association between pituitary dysfunction and fatigue in individuals with TBI.

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.

Psychiatric disorders are common following traumatic brain injury (TBI) and can include depression, anxiety, and psychosis, as well as other maladaptive behaviors and personality changes. The epidemiologic data of psychiatric disorders post-TBI vary widely, although the incidence and prevalence rates typically are higher than in the general population. Although the experience of psychiatric symptoms may be temporary and may resolve in the acute period, many patients with TBI can experience psychopathology that is persistent or that develops in the post-acute period. Long-term psychiatric disorder, along with cognitive and physical sequelae and greater risk for substance use disorders, can pose a number of life-long challenges for patients and their caregivers, as they can interfere with participation in rehabilitation as well as limit functional independence in the community. The current review of the literature considers the common psychiatric problems affecting individuals with TBI in the post-acute period, including personality changes, psychosis, executive dysfunction, depression, anxiety, and substance misuse. Although treatment considerations (pharmacological and nonpharmacological) are referred to, an extensive description of such protocols is beyond the scope of the current review. The impact of persistent psychiatric symptoms on perceived caregiver burden and distress is also discussed.

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.

The current study assessed the internal consistency, alternate forms reliability, and convergent/divergent validity of the Naming Test of the Neuropsychological Assessment Battery (NAB) in patients with acquired brain injury. Fifty-nine patients were administered the NAB Naming Test (forms 1 and 2) and the Boston Naming Test (BNT), as well as other tests of neuropsychological functioning. Forms 1 and 2 of the NAB Naming Test demonstrated adequate internal consistency and alternate forms reliability. The NAB Naming Test was significantly associated with scores from the BNT, as well as scores from tests that assess visuospatial skills, semantic fluency, and verbal memory. The divergent validity of the NAB Naming Test was demonstrated by non-significant associations with tests of attention and processing speed. BNT scores correlated significantly with the educational level and estimated premorbid intelligence but not age, whereas the NAB Naming Test scores only correlated significantly with estimated premorbid intelligence. The current study provides independent validation supporting the utility of the NAB Naming Test for patients with acquired brain injury.

Background: Balint's syndrome includes the clinical symptom triad of simultagnosia, ocular apraxia and optic ataxia. These symptoms, in combination, are rare and can be quite debilitating as they impact visuospatial skills, visual scanning and attentional mechanisms.Case Study: The literature addressing rehabilitation of individuals with Balint's syndrome is sparse. The current case report describes the outcome of a 58-year old male who presented with Balint's syndrome secondary to severe traumatic brain injury and following completion of a comprehensive post-acute brain injury rehabilitation programme. The patient was 4-months post-injury onset upon admission and received 6 months of rehabilitation services as an inpatient. The patient's comprehensive rehabilitation programme involved a 3-pronged approach including the implementation of (a) compensatory strategies, (b) remediation exercises and (c) transfer of learned skills in multiple environments and situations with implementation of psychoeducation and psychotherapy. Comprehensive neuropsychological and occupational therapy evaluations were performed at admission and at discharge in order to monitor cognitive, affective, neurological and functional change over time.Conclusions: Neuropsychological test improvements were noted on tasks that assess visuospatial functioning, although most gains were noted for functional and physical abilities.

PURPOSE:The assessment of ecological validity of neuropsychological measures is an area of growing interest, particularly in the postacute brain injury rehabilitation (PABIR) setting, as there is an increasing demand for clinicians to address functional and real-world outcomes. In the current study, we assessed the predictive value of the Screening module and the Daily Living tests of the Neuropsychological Assessment Battery (NAB) using clinician ratings from the Mayo-Portland Adaptability Inventory-4 (MPAI-4) in patients with moderate to severe traumatic brain injury.METHOD:Forty-seven individuals were each administered the NAB Screening module (NAB-SM) and the NAB Daily Living (NAB-DL) tests following admission to a residential PABIR program. MPAI-4 ratings were also obtained at admission. Linear regression analysis was used to examine the association between these functional and neuropsychological assessment measures.RESULTS:We replicated prior work (Temple at al., 2009) and expanded evidence for the ecological validity of the NAB-SM. Furthermore, our findings support the ecological validity of the NAB-DL Bill Payment, Judgment, and Map Reading tests with regards to functional skills and real-world activities.CONCLUSIONS:The current study supports prior work from our lab assessing the predictive value of the NAB-SM, as well as provides evidence for the ecological validity for select NAB-DL tests in patients with moderate to severe traumatic brain injury admitted to a residential PABIR program.

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.