Ventromedial prefrontal cortex modulates fatigue after penetrating traumatic brain injury (original) (raw)
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Fatigue in patients with acquired brain damage
Fatigue in patients with acquired brain damage, 2024
Fatigue is a complex, multidimensional syndrome that is prevalent in patients with acquired brain damage and has a negative impact on the neurorehabilitation process. It presents from early stages after the injury, and may persist over time, regardless of whether sequelae have resolved. Fatigue is conditioned by upper neuronal circuits, and is defined as an abnormal perception of overexertion. Its prevalence ranges from 29% to 77% after stroke, from 18% to 75% after traumatic brain injury, and from 47% to 97% after brain tumours. Fatigue is associated with factors including female sex, advanced age, dysfunctional families, history of specific health conditions, functional status (eg, fatigue prior to injury), comorbidities, mood, secondary disability, and the use of certain drugs. Assessment of fatigue is fundamentally based on such scales as the Fatigue Severity Scale (FSS). Advances have recently been made in imaging techniques for its diagnosis, such as in functional MRI. Regarding treatment, no specific pharmacological treatment currently exists; however, positive results have been reported for some conventional neurorehabilitation therapies, such as bright light therapy, neurofeedback, electrical stimulation, and transcranial magnetic stimulation. This review aims to assist neurorehabilitation professionals to recognise modifiable factors associated with fatigue and to describe the treatments available to reduce its negative effect on patients.
Fatigue and traumatic brain injury
Annales de réadaptation et de médecine physique : revue scientifique de la Société française de rééducation fonctionnelle de réadaptation et de médecine physique, 2006
Fatigue is frequent and disabling in patients with traumatic brain injury (TBI). Its mechanisms are complex and multifactorial. We performed a literature review of reports of the condition using the following key words: brain injury, depression, neuroendocrine dysfunction, and treatment. Five scales have been used to evaluate fatigue in TBI patients: the Fatigue Severity Scale, the visual analog scale (VAS) for fatigue, the Fatigue Impact Scale, the Barrow Neurological Institute (BNI) Fatigue Scale and the Cause of Fatigue (COF) Questionnaire. The BNI Fatigue Scale and the COF Questionnaire have been designed specifically for brain-injured patients. Fatigue is present in 43-73% of patients and is one of the first symptoms for 7% of them. Fatigue does not seem to be significantly related to injury severity not to time since injury. It can be related to mental effort necessary to overcome attention deficit and slowed processing ("coping hypothesis"). It can also be related t...
Clinical neurophysiology of fatigue
Clinical Neurophysiology, 2008
Fatigue is a multidimensional concept covering both physiological and psychological aspects. Chronic fatigue is a typical symptom of diseases such as cancer, multiple sclerosis (MS), Parkinson's disease (PD) and cerebrovascular disorders but is also presented by people in whom no defined somatic disease has been established. If certain criteria are met, chronic fatigue syndrome can be diagnosed. The 4-item Abbreviated Fatigue Questionnaire allows the extent of the experienced fatigue to be assessed with a high degree of reliability and validity. Physiological fatigue has been well defined and originates in both the peripheral and central nervous system. The condition can be assessed by combining force and surface-EMG measurements (including frequency analyses and muscle-fibre conduction estimations), twitch interpolation, magnetic stimulation of the motor cortex and analysis of changes in the readiness potential. Fatigue is a well-known phenomenon in both central and peripheral neurological disorders. Examples of the former conditions are multiple sclerosis, Parkinson's disease and stroke. Although it seems to be a universal symptom of many brain disorders, the unique characteristics of the concomitant fatigue also point to a specific relationship with several of these syndromes. As regards neuromuscular disorders, fatigue has been reported in patients with post-polio syndrome, myasthenia gravis, Guillain-Barré syndrome, facioscapulohumeral dystrophy, myotonic dystrophy and hereditary motor and sensory neuropathy type-I. More than 60% of all neuromuscular patients suffer from severe fatigue, a prevalence resembling that of patients with MS. Except for several rare myopathies with specific metabolic derangements leading to exercise-induced muscle fatigue, most studies have not identified a prominent peripheral cause for the fatigue in this population. In contrast, the central activation of the diseased neuromuscular system is generally found to be suboptimal. The reliability of the psychological and clinical neurophysiological assessment techniques available today allows a multidisciplinary approach to fatigue in neurological patients, which may contribute to the elucidation of the pathophysiological mechanisms of chronic fatigue, with the ultimate goal to develop tailored treatments for fatigue in neurological patients. The present report discusses the different manifestations of fatigue and the available tools to assess peripheral and central fatigue.
NeuroImage: Clinical, 2021
Following mild traumatic brain injury (mTBI), a substantial number of patients experience disabling fatigue for months after the initial injury. To date, the underlying mechanisms of fatigue remain unclear. Recently, it was shown that mTBI patients with persistent fatigue do not demonstrate increased performance fatigability (i.e., objective performance decline) during a sustained motor task. However, it is not known whether the neural activation required to sustain this performance is altered after mTBI. Methods: Blood oxygen level-dependent (BOLD) fMRI data were acquired from 19 mTBI patients (>3 months post-injury) and 19 control participants during two motor tasks. Force was recorded from the index finger abductors of both hands during submaximal contractions and a 2-minute maximal voluntary contraction (MVC) with the right hand. Voluntary muscle activation (i.e., CNS drive) was indexed during the sustained MVC using peripheral nerve stimulation. Fatigue was quantified using the Fatigue Severity Scale (FSS) and Modified Fatigue Impact Scale (MFIS). Questionnaire, task, and BOLD data were compared across groups, and linear regression was used to evaluate the relationship between BOLD-activity and fatigue in the mTBI group. Results: The mTBI patients reported significantly higher levels of fatigue (FSS: 5.3 vs. 2.6, p < 0.001). Both mTBIand control groups demonstrated significant performance fatigability during the sustained MVC, but no significant differences in task performance or BOLD-activity were observed between groups. However, mTBI patients reporting higher FSS scores showed increased BOLD-activity in the bilateral visual cortices (mainly extrastriate) and the left midcingulate gyrus. Furthermore, across all participants mean voluntary muscle activation during the sustained MVC correlated with long lasting post-contraction BOLD-activation in the right insula and midcingulate cortex. Conclusion: The fMRI findings suggest that self-reported fatigue in mTBI may relate to visual processing and effort perception. Long lasting activation associated with high levels of CNS drive might be related to changes in cortical homeostasis in the context of high effort.
Objective Measurement of Fatigue Following Traumatic Brain Injury
Journal of Head Trauma Rehabilitation, 2008
Objectives: To quantify posttraumatic brain injury (post-TBI) mental fatigue objectively by documenting changes in performance on neuropsychological tests as a result of sustained mental effort and to examine the relationship between objectively measured mental fatigue and self-reported situational and day-today fatigue. Participants: The study included 202 community-dwelling individuals with mild-severe TBI and 73 noninjured controls. Measures: Measures included Cambridge Neuropsychological Test Automated Battery, Global Fatigue Index, and situational fatigue rating. Method: Subjects were administered a 30-minute computerized neuropsychological test battery 3 times. The second and third administrations of the battery were separated by approximately 2 hours of interviews and administration of self-report measures. Results: The neuropsychological test scores were factor analyzed, yielding 3 subscales: speed, accuracy, and executive function. Situational fatigue and day-today fatigue were significantly higher in individual with TBI group than in individuals without TBI and were associated with speed subscale scores. Individuals with TBI evidenced a significant decline in performance on the accuracy subscale score. These declines in performance related to sustained mental effort were not associated with subjective fatigue in the TBI group. While practice effects on the speed and accuracy scores were observed in non-brain-injured individuals, they were not evidenced in individuals with TBI. Conclusions: Findings were largely consistent with previous literature and indicated that while subjective fatigue is associated with poor performance in individuals with TBI, it is not associated with objective decline in performance of mental tasks.
Psychological Medicine, 2008
Background. Fatigue is the central symptom in chronic fatigue syndrome (CFS) and yet very little is known about its neural correlates. The aim of this study was to explore the functional brain response, using functional magnetic resonance imaging (fMRI), to the imaginal experience of fatigue in CFS patients and controls. Method. We compared the blood oxygen level dependent (BOLD) responses of 12 CFS patients and 11 healthy controls to a novel fatigue provocation procedure designed to mimic real-life situations. A non-fatiguing anxiety-provoking condition was also included to control for the non-specific effects of negative affect. Results. During the provocation of fatigue, CFS patients reported feelings of both fatigue and anxiety and, compared to controls, they showed increased activation in the occipito-parietal cortex, posterior cingulate gyrus and parahippocampal gyrus, and decreased activation in dorsolateral and dorsomedial prefrontal cortices. The reverse pattern of findings was observed during the anxiety-provoking scenarios. Conclusions. The results may suggest that, in CFS patients, the provocation of fatigue is associated with exaggerated emotional responses that patients may have difficulty suppressing. These findings are discussed in relation to the cognitive-behavioural model of CFS.
Journal of Head Trauma Rehabilitation, 2018
Objective-Fatigue is a complex, multidimensional phenomenon that commonly occurs following traumatic brain injury (TBI). The thalamus-a structure vulnerable to both primary and secondary injury in TBI-is thought to play a pivotal role in the manifestation of fatigue. We explored how neuroimaging markers of local and global thalamic morphometry relate to the subjective experience of fatigue post-TBI. Methods-63 Veterans with history of mild TBI (mTBI) underwent structural magnetic resonance scanning (MRI) and completed questionnaires related to fatigue and psychiatric symptomatology. FMRIB's Software (FSL) was utilized to obtain whole brain and thalamic volume estimates, as well as to perform regional thalamic morphometry analyses. Results-Independent of age, sex, intracranial volume, PTSD and depressive symptoms, greater levels of self-reported fatigue was significantly associated with decreased right (p = .026) and left (p = .046) thalamic volumes. Regional morphometry analyses revealed that fatigue was significantly associated with reductions in the anterior and dorsomedial aspects of the right thalamic body (p < .05). Similar trends were observed for the left thalamic body (p < .10).
Fatigue and fatigability in neurologic illnesses: Proposal for a unified taxonomy
Neurology, 2013
Fatigue is commonly reported in many neurologic illnesses, including multiple sclerosis, Parkinson disease, myasthenia gravis, traumatic brain injury, and stroke. Fatigue contributes substantially to decrements in quality of life and disability in these illnesses. Despite the clear impact of fatigue as a disabling symptom, our understanding of fatigue pathophysiology is limited and current treatment options rarely lead to meaningful improvements in fatigue. Progress continues to be hampered by issues related to terminology and assessment. In this article, we propose a unified taxonomy and a novel assessment approach to addressing distinct aspects of fatigue and fatigability in clinical and research settings. This taxonomy is based on our current knowledge of the pathophysiology and phenomenology of fatigue and fatigability. Application of our approach indicates that the assessment and reporting of fatigue can be clarified and improved by utilizing this taxonomy and creating measures to address distinct aspects of fatigue and fatigability. We review the strengths and weaknesses of several common measures of fatigue and suggest, based on our model, that many research questions may be better addressed by using multiple measures. We also provide examples of how to apply and validate the taxonomy and suggest directions for future research. Neurology â 2013;80:409-416 GLOSSARY MG 5 myasthenia gravis; MS 5 multiple sclerosis; PD 5 Parkinson disease; TMS 5 transcranial magnetic stimulation. Fatigue is one of the most common symptoms in neurology. Our understanding of the pathophysiology of fatigue is limited for most conditions. Even the term "fatigue" is used without standard definitions or means of measurement. Not surprisingly, current treatments are nonspecifically targeted to a vaguely defined symptom with unsatisfactory outcomes. In this article, we use the term fatigue to refer to subjective sensations and fatigability to refer to objective changes in performance. We briefly review the prevalence, impact, and treatment of fatigue in neurologic disorders before discussing problems with current terminology and proposing a unifying taxonomy. We conclude by providing examples of the use of the taxonomy, demonstrating how it relates to current fatigue measures, and proposing avenues for future research.