Fever of central origin in traumatic brain injury controlled with propranolol

Evaluation and Pharmacologic Management of Paroxysmal Sympathetic Hyperactivity in Traumatic Brain Injury

OBJECTIVE

Paroxysmal sympathetic hyperactivity (PSH) can occur in up to 10% of severe traumatic brain injury (TBI) patients and is associated with poorer outcomes. A consensus regarding management is lacking. We provide a practical guide on the multi-faceted clinical management of PSH, including pharmacological, procedural and non-pharmacological interventions. In addition to utilizing a standardized assessment tool, the use of medications to manage sympathetic and musculoskeletal manifestations (including pain) is highlighted. Recent studies investigating new approaches to clinical management are included in this review of pharmacologic treatment options.

CONCLUSION

While studies regarding pharmacologic selection for PSH are limited, this paper suggests a clinical approach to interventions based on predominant symptom presentation (sympathetic hyperactivity, pain and/or muscle hypertonicity) and relevant medication side effects.

Use of baclofen and propranolol for treatment of neurogenic fever in a patient with pontine hemorrhage: A case report

Key Clinical Message

Neurogenic fever (NF) is a potentially life-threatening complication commonly seen in patients with pontine hemorrhage. This case report highlights the successful use of oral baclofen and propranolol as an effective treatment strategy to manage NF.

Abstract

Neurogenic fever (NF) is a common complication following pontine hemorrhage and poses significant challenges for clinicians in terms of diagnosis, management, and patient outcomes. This study delves into the efficacy of treatment methods involving baclofen and propranolol for neurogenic fever in patients with pontine hemorrhage. The results demonstrated a significant reduction in the duration and intensity of fever. Moreover, the treatment modality was well-tolerated and devoid of any adverse effects. These findings suggest that the use of oral baclofen and propranolol may be a promising therapeutic option for managing neurogenic fever in patients with pontine hemorrhage.

Pharmacologic Management of Central Fever: A Review of Evidence for Bromocriptine, Propranolol, and Baclofen

Objective: The purpose of this review was to evaluate the clinical data supporting bromocriptine, propranolol, and baclofen in the pharmacologic management of central fever. Data Sources: A comprehensive literature review was performed between January 2018 and August 2022 using the following keywords: "central fever" NOT "fever" OR "infection" OR "infectious" AND "neurocritical" OR "neurology" AND "treatment" AND "medication" OR "medicine" OR "drug" OR "pharmaceutical." Study Selection and Data Extraction: A total of 6 case reports met specified inclusion criteria, with 2 reporting on each of the evaluated medications. Data Synthesis: Significant heterogeneity exists regarding dosing strategies and duration of treatment with these medications for the management of central fever. Although each medication demonstrated the ability to restore normothermia, the variation in underlying cause of the fever and lack of cross-over evaluation between different medications makes a definitive treatment strategy for any of these agents elusive. Conclusions: The development of a central fever has been associated with poor outcomes in patients who have suffered a critical neurologic injury. Although their exact mechanism for this indication has not been fully elucidated, anecdotal evidence seemingly supports the use of bromocriptine, propranolol, and baclofen.

The Omnipresence of Autonomic Modulation in Health and Disease

The Autonomic Nervous System (ANS) is a critical part of the homeostatic machinery with both central and peripheral components. However, little is known about the integration of these components and their joint role in the maintenance of health and in allostatic derailments leading to somatic and/or neuropsychiatric (co)morbidity. Based on a comprehensive literature search on the ANS neuroanatomy we dissect the complex integration of the ANS: (1) First we summarize Stress and Homeostatic Equilibrium - elucidating the responsivity of the ANS to stressors; (2) Second we describe the overall process of how the ANS is involved in Adaptation and Maladaptation to Stress; (3) In the third section the ANS is hierarchically partitioned into the peripheral/spinal, brainstem, subcortical and cortical components of the nervous system. We utilize this anatomical basis to define a model of autonomic integration. (4) Finally, we deploy the model to describe human ANS involvement in (a) Hypofunctional and (b) Hyperfunctional states providing examples in the healthy state and in clinical conditions.

A pyrexic effect of FGF21 independent of energy expenditure and UCP1

OBJECTIVE

Administration of FGF21 to mice reduces body weight and increases body temperature. The increase in body temperature is generally interpreted as hyperthermia, i.e. a condition secondary to the increase in energy expenditure (heat production). Here, we examine an alternative hypothesis: that FGF21 has a direct pyrexic effect, i.e. FGF21 increases body temperature independently of any effect on energy expenditure.

METHODS

We studied the effects of FGF21 treatment on body temperature and energy expenditure in high-fat-diet-fed and chow-fed mice exposed acutely to various ambient temperatures, in high-fat diet-fed mice housed at 30 °C (i.e. at thermoneutrality), and in mice lacking uncoupling protein 1 (UCP1).

RESULTS

In every model studied, FGF21 increased body temperature, but energy expenditure was increased only in some models. The effect of FGF21 on body temperature was more (not less, as expected in hyperthermia) pronounced at lower ambient temperatures. Effects on body temperature and energy expenditure were temporally distinct (daytime versus nighttime). FGF21 enhanced UCP1 protein content in brown adipose tissue (BAT); there was no measurable UCP1 protein in inguinal brite/beige adipose tissue. FGF21 increased energy expenditure through adrenergic stimulation of BAT. In mice lacking UCP1, FGF21 did not increase energy expenditure but increased body temperature by reducing heat loss, e.g. a reduced tail surface temperature.

CONCLUSION

The effect of FGF21 on body temperature is independent of UCP1 and can be achieved in the absence of any change in energy expenditure. Since elevated body temperature is a primary effect of FGF21 and can be achieved without increasing energy expenditure, only limited body weight-lowering effects of FGF21 may be expected.

Organic features of autonomic dysregulation in paediatric brain injury - Clinical and research implications for the management of patients with Rett syndrome

Rett Syndrome (RTT) is a complex neurodevelopmental disorder with autonomic nervous system dysfunction. The understanding of this autonomic dysregulation remains incomplete and treatment recommendations are lacking. By searching literature regarding childhood brain injury, we wanted to see whether understanding autonomic dysregulation following childhood brain injury as a prototype can help us better understand the autonomic dysregulation in RTT. Thirty-one (31) articles were identified and following thematic analysis the three main themes that emerged were (A) Recognition of Autonomic Dysregulation, (B) Possible Mechanisms & Assessment of Autonomic Dysregulation and (C) Treatment of Autonomic Dysregulation. We conclude that in patients with RTT (I) anatomically, thalamic and hypothalamic function should be explored, (II) sensory issues and medication induced side effects that can worsen autonomic function should be considered, and (III) diaphoresis and dystonia ought to be better managed. Our synthesis of data from autonomic dysregulation in paediatric brain injury has led to increased knowledge and a better understanding of its underpinnings, leading to the development of application protocols in children with RTT.

Neurogenic Fever in Severe Traumatic Brain Injury Treated with Propranolol: A Case Report

The causes of intractable fever in severe traumatic brain injury (TBI) patients can be diverse. Neurogenic fever (NF) which is a rare entity can develop due to autonomic dysregulation in the absence of infection or any other cause of fever. It manifests as fever, tachycardia, paroxysmal hypertension, dilated pupils, tachypnea, and extensor posturing in cases of severe TBI, brain neoplasms or brain haemorrhage. We found propranolol to be effective in controlling many of the manifestations of neurogenic fever in our patients with severe TBI. Fever in severe TBI patients is not an uncommon phenomenon, but when intractable with negative fever workup, a central cause should be considered. Propranolol is deemed as one of the most efficacious drugs for managing NF due to dysautonomia. We want to apprise the readers about this entity and its treatment with beta-blockers.

Propranolol in yawning prophylaxis: a case report

OBJECTIVE

Yawning is a frequent behavior with circadian effects. Sometimes, its frequency is very high and it is disturbing. However, there is no evidence-based treatment for yawning.

METHOD

This is a case report of a man with severe yawning from about 2 years ago.

RESULTS

Yawning reduced after taking propranolol.

CONCLUSION

Current evidence suggests that propranolol may decrease yawning through its thermoregulation effect. It is worthwhile conducting controlled clinical trials to study whether propranolol is an effective treatment for yawning.

Risk factors related to dysautonomia after severe traumatic brain injury

BACKGROUND

Dysautonomia after severe traumatic brain injury (TBI) is a clinical syndrome affecting a subgroup of survivors and is characterized by episodes of autonomic dysregulation and muscle overactivity. The purpose of this study was to determine the incidence of dysautonomia after severe TBI in an intensive care unit setting and analyze the risk factors for developing dysautonomia.

METHODS

A consecutive series of 101 patients with severe TBI admitted in a major trauma hospital during a 2-year period were prospectively observed to determine the effects of age, sex, mode of injury, hypertension history, admission systolic blood pressure, fracture, lung injury, admission Glasgow Coma Scale (GCS) score, injury severity score, emergency craniotomy, sedation or analgesia, diffuse axonal injury (DAI), magnetic resonance imaging (MRI) scales, and hydrocephalus on the development of dysautonomia. Risk factors for dysautonomia were evaluated by using logistic regression analysis.

RESULTS

Seventy-nine of the 101 patients met inclusion criteria, and dysautonomia was observed in 16 (20.3%) of these patients. Univariate analysis revealed significant correlations between the occurrence of dysautonomia and patient age, admission GCS score, DAI, MRI scales, and hydrocephalus. Sex, mode of injury, hypertension history, admission systolic blood pressure, fracture, lung injury, injury severity score, sedation or analgesia, and emergency craniotomy did not influence the development of dysautonomia. Multivariate logistic regression revealed that patient age and DAI were two independent predictors of dysautonomia. There was no independent association between dysautonomia and admission GCS score, MRI scales, or hydrocephalus.

CONCLUSIONS

Dysautonomia frequently occurs in patients with severe TBI. A younger age and DAI could be risk factors for facilitating the development of dysautonomia.

A review of paroxysmal sympathetic hyperactivity after acquired brain injury

Severe excessive autonomic overactivity occurs in a subgroup of people surviving acquired brain injury, the majority of whom show paroxysmal sympathetic and motor overactivity. Delayed recognition of paroxysmal sympathetic hyperactivity (PSH) after brain injury may increase morbidity and long-term disability. Despite its significant clinical impact, the scientific literature on this syndrome is confusing; there is no consensus on nomenclature, etiological information for diagnoses preceding the condition is poorly understood, and the evidence base underpinning our knowledge of the pathophysiology and management strategies is largely anecdotal. This systematic literature review identified 2 separate categories of paroxysmal autonomic overactivity, 1 characterized by relatively pure sympathetic overactivity and another group of disorders with mixed parasympathetic/sympathetic features. The PSH group comprised 349 reported cases, with 79.4% resulting from traumatic brain injury (TBI), 9.7% from hypoxia, and 5.4% from cerebrovascular accident. Although TBI is the dominant causative etiology, there was some suggestion that the true incidence of the condition is highest following cerebral hypoxia. In total, 31 different terms were identified for the condition. Although the most common term in the literature was dysautonomia, the consistency of sympathetic clinical features suggests that a more specific term should be used. The findings of this review suggest that PSH be adopted as a more clinically relevant and appropriate term. The review highlights major problems regarding conceptual definitions, diagnostic criteria, and nomenclature. Consensus on these issues is recommended as an essential basis for further research in the area.

Pediatric rehabilitation: 1. Common medical conditions in children with disabilities

OBJECTIVE

This self-directed learning module focuses on the physiatric management of the common morbidities associated with pediatric traumatic brain injury and cerebral palsy. It is part of the study guide on pediatric rehabilitation in the Self-Directed Physiatric Education Program for practitioners and trainees in physical medicine and rehabilitation and pediatric medicine. The goal of this article is to enhance the learner's knowledge regarding current physiatric management of complications related with pediatric traumatic brain injury and cerebral palsy.

Paroxysmal episodic hypothalamic instability with hypothermia after traumatic brain injury

This case report describes a patient in vegetative state after severe traumatic brain injury (TBI) with hypothalamic damage and clinical manifestations of autonomic dysfunction. He also presented late onset paroxysmal hypothermia associated with mild bradycardia and hypotension. Hypothermia due to traumatic lesions of the hypothalamus is an uncommon clinical problem and few cases have been reported; no cases could be found in the literature which evidenced periodic hypothermia associated with clinical features of autonomic dysfunction after TBI. In the article, the main causes and the primary pathophysiology of hypothermia after TBI are discussed. The manifestations in this patient have been interpreted as possible consequences of autonomic dysfunction and considered atypical and rare clinical expression of acute post-traumatic hypothalamic instability.

Pharmacological management of Dysautonomia following traumatic brain injury

PRIMARY OBJECTIVE

To document and critically evaluate the likely effectiveness of pharmacological treatments used in a sample of patients with Dysautonomia and to link these findings to previously published literature.

RESEARCH DESIGN

Retrospective case control chart review.

METHODS AND PROCEDURES

Data were collected on age, sex and GCS matched subjects with and without Dysautonomia (35 cases and 35 controls). Data included demographic and injury details, physiological parameters, medication usage, clinical progress and rehabilitation outcome. Descriptive analyses were undertaken to characterize the timing and frequency of CNS active medications.

MAIN OUTCOMES AND RESULTS

Dysautonomic patients were significantly more likely to receive neurologically active medications. A wide variety of drugs were utilised with the most frequent being morphine/midazolam and chlorpromazine. Cessation of morphine/midazolam produced significant increases in heart rate and respiratory rate but not temperature. Chlorpromazine may have modified respiratory rate responses, but not temperature or heart rate.

CONCLUSIONS

The features of Dysautonomia are similar to a number of conditions treated as medical emergencies. Despite this, no definitive treatment paradigm exists. The best available evidence is for morphine (especially intravenously), benzodiazepines, propanolol, bromocriptine and possibly intrathecal baclofen. Barriers to improving management include the lack of a standardized nomenclature, formal definition or accepted diagnostic test. Future research needs to be conducted to improve understanding of Dysautonomia with a view to minimizing disability.

Long-term temperature-related morbidity after brain damage: survivor-reported experiences

PRIMARY OBJECTIVE

To determine whether temperature-related symptoms exist, long-term, in survivors of brain damage.

RESEARCH DESIGN

Scoping exercise.

METHODS AND PROCEDURES

A 'call for information', posted in the quarterly News bulletins of two major UK brain injury support groups, about any current or past temperature-related symptoms or problems that had developed since onset of brain damage.

MAIN OUTCOMES AND RESULTS

Narratives from 41 survivors revealed the nature of temperature-related morbidity, ongoing, on average, for 8 years since brain damage. Twenty-five survivors reported problems specifically related to feelings of extreme heat; in a further eight, heat-related problems occurred with bouts of 'cold'. Feelings of extreme cold only were less common (n = 8). In 20 survivors, temperature problems had adverse effects on health and personal and social relationships.

CONCLUSIONS

To the authors' knowledge, this is the first account of temperature-related problems in the form of narratives from survivors of a variety of brain injuries. The origin of abnormal somatic sensibility to temperature is currently unclear. It is plausible that the symptoms could be a 'variant' of the 'pain-thermoregulatory distress axis' well described after human stroke. In the meantime, apparently abnormal sensory and physical symptoms experienced by the survivors lack both explanation and remedy.

Paroxysmal autonomic dysregulation with fever that was controlled by propranolol in a brain neoplasm patient

Intractable fever in cancer patients is problematic and the causes of this fever can be diverse. Paroxysmal persistent hyperthermia after sudden mental change or neurologic deficit can develop via autonomic dysregulation without infection or any other causes of fever. Paroxysmal hyperthermic autonomic dysregulation is a rare disease entity. It manifests as a form of paroxysmal hypertension, fever, tachycardia, tachypnea, pupillary dilation, agitation and extensor posturing after traumatic brain injury, hydrocephalus, brain hemorrhage or brain neoplasm. We recently experienced a case of paroxysmal hyperthermia following intracerebral hemorrhage along with brain neoplasm. Extensive fever workups failed to show an infectious or inflammatory source and/or hormonal abnormality. Empirical treatments with antibiotics, antipyretics, morphine, steroid and antiepileptic agents were also ineffective. However, Propranolol, a lipophilic beta-blocker, successfully controlled the fever and stabilized the patient. Fever in cancer patients is a common phenomenon, but a central origin should be considered when the fever is intractable. Propranolol is one of the most effective drugs for treating paroxysmal hyperthermia that is due to autonomic dysregulation.

Cerebral pathophysiology and clinical neurology of hyperthermia in humans

Deliberate hyperthermia has been used clinically as experimental therapy for neoplastic and infectious diseases. Several case fatalities have occurred with this form of treatment, but most were attributable to systemic complications rather than central nervous system toxicity. Nonetheless, demyelating peripheral neuropathy and neurological symptoms of nausea, delirium, apathy, stupor, and coma have been reported. Temperatures exceeding 40 degrees C cause transient vasoparalysis in humans, resulting in cerebral metabolic uncoupling and loss of pressure-flow autoregulation. These findings may be related to the development of brain edema, intracerebral hemorrhage, and intracranial hypertension observed after prolonged therapeutic hyperthermia. Furthermore, deliberate hyperthermia critically worsens the extent of histopathological damage in animal models of traumatic, ischemic, and hypoxic brain injury. However, it is unknown whether these findings translate to episodes of spontaneous fever in neurologically injured patients. In a clinical setting fever is a strong prognostic marker of a patient's primary degree of neuronal damage, and a causal relation with long-term functional neurological outcome has not been established for most types of brain injury. Furthermore, in the neurosurgical intensive-care unit fever is extremely common whereas antipyretic therapy is only poorly effective. Therefore maintaining strict normothermia may be an impossible goal in many patients. Although there are several physiological arguments for avoiding exogenous hyperthermia in neurologically injured patients, there is no evidence that aggressive attempts at controlling spontaneous fever can improve clinical outcome.

Beta-Blocker Use is Associated With Improved Outcomes in Adult Trauma Patients

BACKGROUND

Beta-adrenoreceptor blocker (beta-blocker) therapy may improve outcomes in surgical patients by decreasing cardiac oxygen consumption and hypermetabolism. Because beta-blockers can lower the systemic blood pressure and cerebral perfusion pressure, there is concern regarding their use in patients with head injury. However, beta-blockers may protect beta-receptor rich brain cells by attenuating cerebral oxygen consumption and metabolism. We hypothesized that beta-blockers are safe in trauma patients, even if they have suffered a significant head injury.

METHODS

Using pharmacy and trauma registry data of a Level I trauma center, we identified a cohort of trauma patients who received beta-blockers during their hospital stay (beta-cohort). Trauma admissions who did not receive beta-blockers were in the control cohort. beta-blocker status, in combination with other variables associated with mortality, were placed in a stepwise multivariate logistic regression to identify independent predictors of fatal outcome.

RESULTS

In all, 303 (7%) of 4,117 trauma patients received beta-blockers. In the beta-cohort, 45% of patients were on beta-blockers preinjury. The most common reason to initiate beta-blocker therapy was blood pressure (60%) and heart rate (20%) control. The overall mortality rate was 5.6% and head injury was considered to be the major cause of death. After adjusting for age, Injury Severity Scale score, blood pressure, Glasgow Coma Scale score, respiratory status, and mechanism of injury, the odds ratio for fatal outcome was 0.3 (p < 0.001) for beta-cohort as compared with control. Decreased risk of fatal outcome was more pronounced in patients with a significant head injury.

CONCLUSIONS

beta-blocker therapy is safe and may be beneficial in selected trauma patients with or without head injury. Further studies looking at beta-blocker therapy in trauma patients and their effect on cerebral metabolism are warranted.

Prognostic influence and computed tomography findings in dysautonomic crises after traumatic brain injury

BACKGROUND

Dysautonomic crises represent a relatively unknown complication in patients with severe traumatic brain injury (TBI). Few studies have been undertaken of their pathophysiology and prognostic repercussions. We studied the prevalence of dysautonomic crises after TBI, their radiologic substrate, influence on the clinical course in the intensive care unit (ICU), and effect on neurologic recovery.

METHODS

A case-control study involving 11 patients with dysautonomic crises admitted with TBI during a span of 1 year and 26 patients admitted with TBI but no crises during the first 3 months of the same year. The initial severity was assessed from Apache II, Glasgow Coma Scale (GCS) scores, and computed tomography (CT) during the first 24 hours. Complications were assessed by the duration of ICU stay, days on mechanical ventilation, need for tracheotomy, and number of infectious complications. Neurologic recovery was assessed with the GCS at discharge from the ICU and with the Glasgow Outcome Scale 12 months later.

RESULTS

Both groups were similar at admission. The prevalence of dysautonomic crises was 9.3%. Patients with dysautonomic crises had more focal lesions on cranial CT than patients without crises, a significantly longer ICU stay, and a tendency to have a worse level of consciousness at discharge from the ICU but not 12 months later.

CONCLUSIONS

Almost 10% of patients with severe TBI have dysautonomic crises during their ICU stay. Patients with dysautonomia were more likely to have focal intraparenchymal lesions, and crises were associated with greater morbidity and a longer ICU stay. Dysautonomic crises determined a worse short-term neurologic recovery.

Development of posttraumatic hyperthermia after traumatic brain injury in rats is associated with increased periventricular inflammation

Posttraumatic hyperthermia (PTH) is a noninfectious elevation in body temperature that negatively influences outcome after traumatic brain injury (TBI). We sought to (1) characterize a clinically relevant model and (2) investigate potential cellular mechanisms of PTH. In study I, body temperature patterns were analyzed for 1 week in male rats after severe lateral fluid percussion (FP) brain injury (n=75) or sham injury (n=17). After injury, 27% of surviving animals experienced PTH, while 69% experienced acute hypothermia with a slow return to baseline. A profound blunting or loss of circadian rhythmicity (CR) that persisted up to 5 days after injury was experienced by 75% of brain-injured animals. At 2 and 7 days after injury, patterns of cell loss and inflammation were assessed in selected brain thermoregulatory and circadian centers. Significant cell loss was not observed, but PTH was associated with inflammatory changes in the hypothalamic paraventricular nucleus (PVN) by one week after injury. In brain-injured animals with altered CR, reactive astrocytes were bilaterally localized in the suprachiasmatic nucleus (SCN) and the PVN. Occasional IL-1beta+/ED-1+ macrophages/microglia were observed in the PVN and SCN exclusively in brain-injured animals developing PTH. In animals with PTH there was a significant positive correlation (r=0.788, P<0.01) between the degree of postinjury hyperthermia and the total number of cells positive for inflammatory markers within selected thermoregulatory and circadian nuclei. In study II, a separate group of animals underwent the same injury and temperature monitoring paradigm as in study I, but had additional physiologic data obtained, including vital signs, arterial blood gases, white blood cell counts, and C-reactive protein levels. All parameters remained within normal ranges after injury. These data suggest that PTH and the alteration in CR of temperature may be due, in part, to acute reactive astrocytosis and inflammation in hypothalamic centers responsible for both thermoregulation and CR.

Cyproheptadine for intrathecal baclofen withdrawal

OBJECTIVE

To evaluate the efficacy of cyproheptadine in the management of acute intrathecal baclofen (ITB) withdrawal.

DESIGN

Descriptive case series.

SETTING

University hospital with a comprehensive in- and outpatient rehabilitation center.

PARTICIPANTS

Four patients (3 with spinal cord injury, 1 with cerebral palsy) with implanted ITB infusion pumps for treatment of severe spasticity, who had ITB withdrawal syndrome because of interruption of ITB infusion.

INTERVENTIONS

Patients were treated with 4 to 8mg of cyproheptadine by mouth every 6 to 8 hours, 5 to 10mg of diazepam by mouth every 6 to 12 hours, 10 to 20mg of baclofen by mouth every 6 hours, and ITB boluses in some cases.

MAIN OUTCOME MEASURES

Clinical signs and symptoms of ITB withdrawal of varying severity were assessed by vital signs (temperature, heart rate), physical examination (reflexes, tone, clonus), and patient report of symptoms (itching, nausea, headache, malaise).

RESULTS

The patients in our series improved significantly when the serotonin antagonist cyproheptadine was added to their regimens. Fever dropped at least 1.5 degrees C, and heart rate dropped from rates of 120 to 140 to less than 100bpm. Reflexes, tone, and myoclonus also decreased. Patients reported dramatic reduction in itching after cyproheptadine. These changes were associated temporally with cyproheptadine dosing.

DISCUSSION

Acute ITB withdrawal syndrome occurs frequently in cases of malfunctioning intrathecal infusion pumps or catheters. The syndrome commonly presents with pruritus and increased muscle tone. It can progress rapidly to high fever, altered mental status, seizures, profound muscle rigidity, rhabdomyolysis, brain injury, and death. Current therapy with oral baclofen and benzodiazepines is useful but has variable success, particularly in severe cases. We note that ITB withdrawal is similar to serotonergic syndromes, such as in overdoses of selective serotonin reuptake inhibitors or the popular drug of abuse 3,4-methylenedioxymethamphetamine (Ecstasy). We postulate that ITB withdrawal may be a form of serotonergic syndrome that occurs from loss of gamma-aminobutyric acid B receptor-mediated presynaptic inhibition of serotonin.

CONCLUSION

Cyproheptadine may be a useful adjunct to baclofen and benzodiazepines in the management of acute ITB withdrawal syndrome.

Hyperthermia following traumatic brain injury: a critical evaluation

Hyperthermia, frequently seen in patients following traumatic brain injury (TBI), may be due to posttraumatic cerebral inflammation, direct hypothalamic damage, or secondary infection resulting in fever. Regardless of the underlying cause, hyperthermia increases metabolic expenditure, glutamate release, and neutrophil activity to levels higher than those occurring in the normothermic brain-injured patient. This synergism may further compromise the injured brain, enhancing the vulnerability to secondary pathogenic events, thereby exacerbating neuronal damage. Although rigorous control of normal body temperature is the current standard of care for the brain-injured patient, patient management strategies currently available are often suboptimal and may be contraindicated. This article represents a compendium of published work regarding the state of knowledge of the relationship between hyperthermia and TBI, as well as a critical examination of current management strategies.

Unexpected death and critical illness in Prader-Willi syndrome: Report of ten individuals

Individuals with Prader-Willi syndrome (PWS) generally survive into adulthood. Common causes of death are obesity related cor pulmonale and respiratory failure. We report on a case series of eight children and two adults with unexpected death or critical illness. Our data show age-specific characteristics of PWS patients with fatal or life-threatening illnesses. Under the age of 2 years, childhood illnesses in general were associated with high fever and rapid demise or near-demise. Hypothalamic dysfunction likely plays a role in exaggerated fever response, but also perhaps in central regulation of adrenal function. Below average sized adrenal glands were found in three children, which raises the possibility of unrecognized adrenal insufficiency in a subset of individuals with PWS and emphasizes the vital role of autopsy. The tub drowning death of an adult patient could be related to central hypersomnia, which has been reported in PWS. We suggest that increased risk for critical illness be considered in the discussion of anticipatory guidance for the care of infants with PWS. Since a number of children died while hospitalized, particularly close observation of PWS children who are ill enough to warrant hospital admission is recommended.

Upregulation of iNOS expression and phosphorylation of eIF-2alpha are paralleled by suppression of protein synthesis in rat hypothalamus in a closed head trauma model

When the inducible form of nitric oxide synthase (iNOS) is expressed after challenge to the nervous system, it results in abnormally high concentrations of nitric oxide (NO). Under such conditions, NO could phosphorylate the eukaryotic translation initiation factor (eIF)-2alpha, thus suppressing protein synthesis in neurons that play a role in endocrine and autonomic functions. Using the Marmarou model of traumatic brain injury (TBI), we observed a rapid increase (at 4 h after TBI) of iNOS mRNA in magno- and parvocellular supraoptic and paraventricular neurons, declining gradually by approximately 30% at 24 h and by approximately 80% at 48 h. Western analysis indicated a trend towards increased iNOS protein synthesis at 4 h, which peaked at 8 h, and tended to decrease at the later time points. At the same time points, we detected immunocytochemically the phosphorylated form of eIF-2alpha (eIF-2alpha[P]) as cytoplasmic and more often as nuclear labeling. The incidence of double-labeled [iNOS and eIF-2alpha(P)] neuronal profiles, particularly at 24 h and 48 h after TBI, was high. De novo protein synthesis assessed quantitatively after infusion of 35S methionine/cysteine was reduced by approximately 20% at 4 h, remained depressed at 24 h, and did not return to control levels up to 48 h following the trauma. The results suggest that iNOS may trigger phosphorylation of eIF-2alpha, which in turn interferes with protein synthesis at the translational (ribosomal complex) and transcriptional (chromatin) levels. The depression in protein synthesis may include downregulation of iNOS itself, which could be an autoregulatory inhibitory feedback mechanism for NO synthesis. Excessive amounts of NO may also participate in dysfunction of hypothalamic circuits that underlie endocrine and autonomic alterations following TBI.

Acute alterations of endothelin-1 and iNOS expression and control of the brain microcirculation after head trauma

The biosynthetic equilibrium between endothelin-1 (ET-1, a vasoconstricting agent) and nitric oxide (NO, a gas with vasodilating effects) is thought to play a role in the autoregulation of microvessel contractility and maintenance of adequate perfusion after traumatic brain injury. ET-1 is a constitutively expressed peptide, while the gene that encodes for the inducible nitric oxide synthase (iNOS, an enzyme responsible for the synthesis of excessive and toxic amounts of NO) is solely activated after brain injury. We employed the Marmarou acceleration impact model of brain injury (400 g from 2 m) to study the effect of closed head trauma on the rat brain microcirculation. Following head trauma we analyzed changes of cerebral cortex perfusion using laser Doppler flowmetry and ultrastructural alterations of endothelial cells. We temporally correlated these changes with the expression of ET-1 (immunocytochemistry) and iNOS (in situ hybridization) to assess the role of these vasoactive agents in vascular contractility and cortical perfusion. Cortical perfusion was reduced by approximately 50% during the second hour as compared to values during preceding time points after TBI, reached a peak minutes before 3 h, and subsequently showed a trend towards normalization. A significant reduction in the lumen of microvessels and severe distortion of their shape were observed after the fourth hour post-trauma. At the same time period ET-1 expression in endothelial cells was stronger than in microvessels of control animals. ET-1 expression was further increased at 24 h after TBI. iNOS mRNA synthesis was strongly upregulated in the same cells at 4 h but was undetectable at 24 h post trauma. Our combined functional, cellular and molecular approach supports the notion that ET-1 and iNOS are expressed differentially in time within individual endothelial cells of cortical microvessels for the control of cortical blood flow following closed head trauma. This differential expression further indicates a reciprocal interaction in the synthesis of these two molecules which may underlie the control of microvascular autoregulation.

Cognitive and functional recovery at 6 and 12 months post-TBI

Outcome studies examining recovery from traumatic brain injury (TBI) often fail to provide a clear understanding of the time course of cognitive, emotional, and behavioural recovery. The present study represents an effort to prospectively study individuals with TBI at fixed intervals, specifically 6 and 12 months post-injury with a window of +/- 1 month. Seventy-two individuals with new-onset TBI underwent neuropsychological evaluation and clinical interview at 6 and 12 months post-injury. Results revealed significant improvements in cognitive abilities, including memory, processing speed, language abilities, and constructional skills. There were significant gains in community integration and involvement in productive activities, but limitations in driving activities remained. Although individuals with mild-moderate TBI performed better than individuals with severe TBI, both groups demonstrated equivalent rates of recovery across domains. The results of this study provide important information regarding the time course of TBI recovery.

Neuroleptic malignant syndrome induced by haloperidol following traumatic brain injury

The use of neuroleptics in the acute management of traumatic brain injury (TBI) is controversial and may be detrimental to recovery. The following case report describes a patient developing neuroleptic malignant syndrome (NMS) secondary to the use of haloperidol given to control the patient's agitation. The patient began to exhibit symptoms consistent with NMS (high fever, dystonia, diaphoresis, tachycardia, and decerebrate posturing) shortly after administration of the haloperidol. Upon transfer to a rehabilitation hospital, the symptoms persisted. When NMS is suspected, the first intervention is to remove the offending agent; thus, the administration of haloperidol was suspended, and the patient was placed on Amantadine and propranolol. Amantadine was used to increase the availability of dopamine to the mid-brain region, and the propranolol was used to control the fever, which was believed to be central in origin. The patient was able to complete his rehabilitation with no further incidence of fever or agitation. The patient met or exceeded all short-term physical therapy goals and was able to complete most of the neuropsychological tasks presented. The patient returned home 38 days after admission to the rehabilitation hospital and was able to perform most activities of daily living. At the 6-months follow-up visit, the patient was considering entrance into an adult vocational school.

Incidence of fever in the rehabilitation phase following brain injury

There appears to be a high incidence of fever after brain injury. The most common cause for fever is infection. The incidence of fever occurring as a result of hypothalamic thermoregulatory dysfunction after brain injury is less clear. This study retrospectively reviewed the charts of 286 subjects with brain injuries. Subject subpopulations were divided into traumatic brain injuries, anoxic brain injuries, and brain injuries resulting from aneurysmal subarachnoid hemorrhage. Fever events were described as any core temperature greater than 99.9 degrees F. Most subjects suffered a severe brain injury and had an average acute hospital length of stay ranging from 35.4 to 60 days. The average rehabilitation length of stay ranged from 38.4 to 45.1 days. Twenty-four percent of subjects experienced fevers, with each of the populations having similar occurrence rates. Unexplained fever events were found in the traumatic brain injury (7%) and aneurysmal subarachnoid hemorrhage (8%) subpopulations only. No unexplained fever event was associated with a temperature greater than 100.8 degrees F.

Autonomic dysfunction associated with locked-in syndrome in a child

This is a report of a young boy with the unusual combination of autonomic dysfunction with locked-in syndrome following multiple shunt revisions for hydrocephalus. A review of the literature on autonomic dysfunction syndrome and the complex clinical picture of the combined syndromes in a pediatric patient are discussed. The marked effectiveness of treatment with carbidopa/levodopa over bromocriptine for both syndromes is noted.