A Critical Review of the Pathophysiology of Dysautonomia Following Traumatic Brain Injury

Risk factors and clinical outcomes of basilar artery occlusion presenting with paroxysmal sympathetic hyperactivity as the initial manifestation: a prospective study

BACKGROUND

Paroxysmal sympathetic hyperactivity (PSH) has been linked to a worse clinical prognosis in patients with traumatic brain injury. We aimed to identify the risk factors and clinical features associated with basilar artery occlusion (BAO) presenting with PSH as the first clinical presentation.

METHODS

This study recruited patients with acute BAO who received endovascular therapy (EVT) at two stroke centers in China. PSH Assessment Measure ≥8 was included in the PSH+ group, while those with a score below 8 were classified as the PSH- group. Clinical data and radiological findings were compared between the two groups. A binary logistic regression model was employed to identify independent risk factors for PSH.

RESULTS

101 participants were enrolled, of whom 19 (18.8%) presented with PSH as the initial manifestation of BAO. Worse prognosis (modified Rankin Scale score of 4-6) at day 90 occurred in 14 (73.7%) of the PSH+ patients and 42 (51.2%) of the PSH- patients (P=0.076). The 90-day mortality rate was higher in the PSH+ group with 12 (63.2%) participants, compared with 31 (37.8%) participants in the PSH- group (P=0.044). A significantly increased risk of PSH was found in patients with midbrain involvement (OR 6.53, 95% CI 1.56 to 27.30, P=0.01) and a high baseline National Institutes of Health Stroke Scale (NIHSS) score (OR 1.15, 95% CI 1.01 to 1.31, P=0.037).

CONCLUSIONS

Patients with BAO presenting with PSH as the initial clinical manifestation experience a higher risk of 90-day mortality, despite undergoing EVT. Midbrain infarction and baseline NIHSS score may be significant risk factors for PSH following BAO.

Takotsubo syndrome linked to paroxysmal sympathetic hyperactivity as a postoperative complication after brain tumor removal: a case report and literature review

Paroxysmal sympathetic hyperactivity (PSH) is a relatively common syndrome typically observed following traumatic brain injury (TBI). It manifests through a combination of non-specific symptoms that collectively define its presentation. Linked to sympathetic hyperactivity, takotsubo syndrome is a cardiomyopathy marked by left ventricular dysfunction and may coincide with PSH. While various factors can lead to the simultaneous occurrence of these syndromes, a notably rare scenario involves their manifestation after brain tumor removal. The nonspecific nature of PSH symptoms and of the cardiac dysfunction in takotsubo syndrome pose challenges in accurately diagnosing these conditions in an intensive care unit (ICU) setting. They often overlap with more prevalent diagnoses like sepsis, pulmonary embolism, and acute heart failure. Thus, it is crucial for clinicians dealing with these patients to be aware that symptoms indicating sympathetic activity surge and left heart failure might prompt consideration of takotsubo syndrome and PSH. This study presents the case of an 8-year-old girl who developed takotsubo syndrome associated with sympathetic hyperactivity following the surgical removal of a bulbar tumor. To the best of our knowledge, this is the tenth case of PSH following brain tumor removal in a pediatric patient and the first reported case of occurrence of takotsubo linked to PSH after brain tumor removal. We offer a detailed account of the patient's clinical journey in the ICU, accompanied by a comprehensive review of relevant literature to identify similar cases. The significance of this case study lies in emphasizing the potential occurrence of takotsubo syndrome due to PSH and underscores the importance of early diagnosis and management due to their association with unfavorable clinical outcomes.

Bispectral Index Monitoring in the Nursing of Patients With Paroxysmal Sympathetic Hyperactivity

AIM

To investigate the clinical nursing effect of bispectral index (BIS) monitoring for paroxysmal sympathetic hyperactivity (PSH) patients in the neurosurgical intensive care unit (NICU).

METHODS

From January 2022 to June 2023, a total of 30 patients with PSH secondary to moderate to severe craniocerebral injury in the NICU were monitored for BIS. The patients' paroxysmal sympathetic hyperactivity-assessment measure (PSH-AM) scores were recorded. PSH patients generally appear in 3 states: calm state, seizure state, and postmedication state. Thirty PSH patients' BIS values were recorded during the calm period, during the seizure state, and postmedication state, and these 3 different stages' BIS values were divided into groups A, B, and C, using the Kruskal-Wallis H test to compare groups.

RESULTS

The Kruskal-Wallis H test yielded a value of H=22.599, P <0.001. H0 was rejected against the test standard of α=0.05, and the BIS values of groups A, B, and C differed. The BIS values of group A and group B differed after a pairwise comparison, and the difference was statistically significant (adjusted P =0.001). Group B and group C had different BIS values, and the difference was statistically significant (adjusted P =0.001); group A and Group C had no difference in BIS values, and the difference was not statistically significant (adjusted P =1.00).

CONCLUSIONS

Taking BIS value as the nursing observation index for PSH patients can make nursing work more objective, reasonable, and accurate, reduce the inducing factors of PSH attack, further reduce the attack of PSH, save nursing resources, and help guide the safety assessment of sedative use.

Stellate ganglion block catheter for paroxysmal sympathetic hyperactivity: calming the 'neuro-storm'

BACKGROUND

Paroxysmal sympathetic hyperactivity (PSH) is an autonomic disorder affecting patients with severe acquired brain injury characterized by intermittent sympathetic discharges with limited therapeutic options. We hypothesized that the PSH pathophysiology could be interrupted via stellate ganglion blockade (SGB).

CASE PRESENTATION

A patient with PSH after midbrain hemorrhage followed by hydrocephalus obtained near-complete resolution of sympathetic events for 140 days after SGB.

CONCLUSION

SGB is a promising therapy for PSH, overcoming the limitations of systemic medications and may serve to recalibrate aberrant autonomic states.

Paroxysmal Sympathetic Hyperactivity in Stroke

OBJECTIVE

Paroxysmal sympathetic hyperactivity (PSH) is a life-threatening neurological emergency associated with severe brain injury. Stroke-related PSH, particularly post-aneurysmal subarachnoid hemorrhage (aSAH) PSH, has been relatively understudied and is often misdiagnosed as an aSAH-related hyperadrenergic crisis. This study aims to clarify the feature of stroke-related PSH.

METHODS

This study discusses the case of a patient with post-aSAH PSH and identifies 19 articles (25 cases) on stroke-related PSH by searching the PubMed database from 1980 to 2021.

RESULTS

In the total cohort, 15 (60.0%) patients were male and the average age was 40.1 ± 16.6 years. The primary diagnoses included intracranial hemorrhage (13 cases, 52.0%), cerebral infarction (7 cases, 28.0%), subarachnoid hemorrhage (4 cases, 16.0%), and intraventricular hemorrhage (1 case, 4.0%). The sites of stroke damage were predominantly the cerebral lobe (10 cases, 40.0%), basal ganglia (8 cases, 32.0%), and the pons (4 cases, 16.0%). The median time of PSH onset after admission was 5 (1-180) days. Most cases employed combination therapy with sedation drugs, beta-blockers, gabapentin, and clonidine. On the Glasgow Outcome Scale, outcomes included death (4 cases, 21.1%), vegetative state (2 cases, 10.5%), severe disability (7 cases, 36.8%), and in only one case (5.3%) was a good recovery noted.

CONCLUSIONS

The clinical features and treatment of post-aSAH PSH differed from those of aSAH-related hyperadrenergic crises. Early diagnosis and treatment can prevent severe complications. PSH should be acknowledged as a potential complication of aSAH. Differential diagnosis can aid in developing individualized treatment plans and improving patient prognosis.

Paroxysmal Sympathetic Hyperactivity After Acquired Brain Injury: An Integrative Literature Review

BACKGROUND

Paroxysmal sympathetic hyperactivity may occur in patients with acute brain injury and is associated with physical disability, poor clinical outcomes, prolonged hospitalization, and higher health care costs.

OBJECTIVE

To comprehensively review current literature and provide information about paroxysmal sympathetic hyperactivity for nurses.

METHODS

An integrative literature review was conducted according to Whittemore and Knafl's method. The search was conducted from October 2020 through January 2021. The main targets of the literature search were definition, incidence rate, causes, clinical characteristics, pathophysiology, diagnosis, and treatment of paroxysmal sympathetic hyperactivity in pediatric and adult patients. The results were reported using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines.

RESULTS

The most characteristic clinical features of paroxysmal sympathetic hyperactivity are hypertension, tachycardia, tachypnea, hyperthermia, diaphoresis, and abnormal motor posturing. Reported incidence rates of paroxysmal sympathetic hyperactivity in patients with brain injury range from 8% to 33%. Various diagnostic criteria have been proposed; most are based on clinical symptoms. Ruling out other causes of the signs and symptoms of paroxysmal sympathetic hyperactivity is important because the signs and symptoms are nonspecific. The major goals of paroxysmal sympathetic hyperactivity management are avoidance of stimuli that may trigger a paroxysmal episode, inhibition of sympathetic overactivity, and prevention of damage to other organs.

CONCLUSIONS

Critical care nurses should be aware of the signs and symptoms of paroxysmal sympathetic hyperactivity in patients with acute brain injury. Early identification is important to ensure timely treatment for patients with paroxysmal sympathetic hyperactivity.

Weathering the storm: a single-institution experience with paroxysmal sympathetic hyperactivity after brain tumor resection in pediatric patients

OBJECTIVE

Paroxysmal sympathetic hyperactivity (PSH) is a complication of severe traumatic or hypoxic brain injury characterized by transient episodes of tachycardia, tachypnea, hypertension, hyperthermia, diaphoresis, and/or dystonic posturing. Posttraumatic "sympathetic storms" are associated with poor outcomes. PSH rarely occurs after brain tumor resection in pediatric patients; only 4 cases have been published since 1929. Thus, the authors sought to report their experience with postcraniotomy PSH in pediatric brain tumor patients.

METHODS

A retrospective study of patients younger than 18 years of age who underwent craniotomy for brain tumor resection at a single center by a single surgeon over a 7-year period was performed. A clinical diagnosis of postoperative PSH was recorded. Recorded outcomes included the interval between surgery and initiation of cytotoxic therapy, need for long-term CSF diversion, length of hospital stay, and survival.

RESULTS

Of the 150 patients who were included for analysis, 4 patients were diagnosed with postoperative PSH for an overall occurrence of 2.7%. PSH patients were younger than non-PSH patients (1.8 ± 0.4 years vs 9.2 ± 5.3 years, p = 0.010) and tended to have intraventricular tumors close to the thalamus, basal ganglia, and/or brainstem. PSH patients experienced longer hospital admissions (44.3 ± 23.4 days vs 6.8 ± 9.4 days, p = 0.001), a shorter interval between surgery and initiation of cytotoxic cancer-directed therapy (14.3 ± 8.0 days vs 90.7 days ± 232.9 days, p = 0.011), and increased need for long-term CSF diversion compared with non-PSH patients (75% vs 25%, p = 0.005). At the last follow-up, 50% of PSH patients had died compared with 13% of non-PSH patients (p = 0.094).

CONCLUSIONS

PSH is a rare postoperative complication that may affect young children with periventricular tumors and is associated with poorer clinical outcomes. Increasing awareness of this condition is vital to improving patient outcomes.

Early transient dysautonomia predicts the risk of infantile epileptic spasm syndrome onset: A prospective cohort study

Background

Infantile epileptic spasm syndrome (IESS) is an age-dependent epileptic encephalopathy with a significant risk of developmental regression. This study investigates the association between heart rate variability (HRV) in infants at risk of IESS and the clinical onset of IESS.

Methods

Sixty neonates at risk of IESS were prospectively followed from birth to 12 months with simultaneous electroencephalogram (EEG) and electrocardiogram recordings for 60 min at every 2-month interval. HRV metrics were calculated from 5 min time-epoch during sleep including frequency domain measures, Poincare analysis including cardiac vagal index (CVI) and cardiac sympathetic index (CSI), and detrended fluctuation analysis (DFA α1, DFA α2). To assess the effect of each HRV metric at the 2-month baseline on the time until the first occurrence of either hypsarrhythmia on EEG and/or clinical spasm, univariate cox-proportional hazard models were fitted for each HRV metric.

Results

Infantile epileptic spasm syndrome was diagnosed in 20/60 (33%) of the cohort in a 12-month follow-up and 3 (5%) were lost to follow-up. The median age of developing hypsarrhythmia was 25 (7-53) weeks and clinical spasms at 24 (8-40) weeks. Three (5%) patients had clinical spasms without hypsarrhythmia, and 5 (8%) patients had hypsarrhythmia before clinical spasms at the initial presentation. The infants with high CSI (hazard ratio 2.5, 95% CI 1.2-5.2, P = 0.01) and high DFA α1 (hazard ratio 16, 95% CI 1.1-240, P = 0.04) at 2 months were more likely to develop hypsarrhythmia by the first year of age. There was a trend toward decreasing CSI and DFA α1 and increasing CVI in the first 8 months of age.

Conclusion

Our data suggest that relative sympathetic predominance at an early age of 2 months may be a potential predictor for developing IESS. Hence, early HRV patterns may provide valuable prognostic information in children at risk of IESS allowing early detection and optimization of cognitive outcomes. Whether early intervention to restore sympathovagal balance per se would provide clinical benefit must be addressed by future studies.

Traumatic brain injury alters the gut-derived serotonergic system and associated peripheral organs

Most efforts to understand the pathology of traumatic brain injury (TBI) have been centered on the brain, ignoring the role played by systemic physiology. Gut-derived serotonin is emerging as a major regulator of systemic homeostasis involving various organs and tissues throughout the body. Here, we shed light on the roles occupied by gut-derived serotonin and its downstream metabolic targets in the systemic pathogenesis of TBI. Male C57BL/6J mice were subjected to a fluid percussion injury (FPI) and RT-qPCR was used to examine mRNA levels in intestine, liver, and adipose tissue. In the intestinal tract, TBI transiently downregulated enteric neuronal markers Chat and Nos1 in the duodenum and colon, and altered colonic genes related to synthesis and degradation of serotonin, favoring an overall serotonin downregulation. There also was a decrease in serotonin fluorescence intensity in the colonic mucosa and reduced circulating blood serotonin levels, with concurrent alterations in serotonin-associated gene expression in downstream tissues after TBI (i.e., upregulation of serotonin receptor Htr2a and dysregulation of genes associated with lipid metabolism in liver and adipose). Levels of commensal bacterial species were also altered in the gut and were associated with TBI-mediated changes in the colonic serotonin system. Our findings suggest that TBI alters peripheral serotonin homeostasis, which in turn may impact gastrointestinal function, gut microbiota, and systemic energy balance. These data highlight the importance of building an integrative view of the role of systemic physiology in TBI pathogenesis to assist in the development of effective TBI treatments.

Paroxysmal Sympathetic Hyperactivity in Adult Patients with Brain Injury: A Systematic Review and Meta-Analysis

BACKGROUND

Paroxysmal sympathetic hyperactivity (PSH) is a syndrome of excessive sympathetic activity, mainly occurring in severe traumatic brain injury. However, few studies have reported the frequency of PSH and its related risk factors in adult patients with brain injury.

METHODS

We performed this systematic review and meta-analysis to estimate the combined incidence of PSH and the associated risk factors in adult patients with brain injury. This study was registered with the PROSPERO international prospective register of systematic reviews (https://www.crd.york. ac.uk/PROSPERO/Identifier: CRD 42021260493), and a systematic search was conducted of the scientific databases Embase, PubMed, Web of Science, Cochrane Library, and Google Scholar. All identified observational studies regarding the incidence and risk factors of PSH in adult patients with brain injury were included. Two authors extracted data independently; data were analyzed by STATA version 16.

RESULTS

The search yielded 9 studies involving 1643 adult patients. PSH was detected in 438 patients. The combined incidence of PSH in adult patients with brain injury was 27.4% (95% confidence interval [CI], 0.190-0.358). The risk factors include patients' age (SMD = -0.592; I² = 77.5%; 95% CI, -1.027 to -0.156; P = 0.008), traffic accident (odds ratio [OR], 1.783; I² =18.0%; 95% CI, 1.128-2.820; P = 0.013), admission Glasgow Coma Scale score (SMD = -1.097; I² =28.3%; 95% CI, -1.500 to -0.693; P = 0.000), hydrocephalus (OR, 3.936; I² =67.9%; 95% CI, 1.144-13.540; P = 0.030), and diffuse axonal injury (OR, 4.747; I² =71.1%; 95% CI, 1.221-18.463; P = 0.025) and were significantly associated with the presence of PSH after brain injury.

CONCLUSIONS

PSH occurs in nearly a quarter of adult patients with brain injury. Patient's age, traffic accident, admission Glasgow Coma Scale score, hydrocephalus, and diffuse axonal injury were risk factors for PSH in adult patients with brain injury. These findings may contribute to novel strategies for early diagnosis and interventions that aid in the rehabilitation of patients with brain injury.

Paroxysmal sympathetic hyperactivity syndrome in tuberculous meningitis with paradoxical reaction

Introduction and importance

Paroxysmal sympathetic hyperactivity syndrome is frequently reported in traumatic brain injury. However, it may occur in non-traumatic brain injury, such as tuberculous meningitis with hydrocephalus.

Case presentation

We reported a 38-year-old male who presented with acute decrease of consciousness and hemiparesis that was developed during antitubercular drugs therapy. CT Scan showed hydrocephalus and granuloma lesion. Emergency ventriculoperitoneal shunting were performed. During treatment, the patient developed paroxysmal sympathetic syndrome during treatment that was controlled based on symptom elimination and prevention.

Clinical discussion

Brain tuberculosis remains a difficult problem for clinicians. Even when antitubercular drugs are administered according to protocol, paradoxical reactions can occur. If hydrocephalus develops, ventriculoperitoneal shunting is one of the options for lowering intracranial pressure. Paroxysmal sympathetic hyperactivity may occur in brain tuberculosis and should be detected as soon as possible to avoid serious morbidity.

Conclusion

Paroxysmal sympathetic hyperactivity may be developed in brain tuberculosis. Early identification and treatment are mandatory.

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Paroxysmal sympathetic hyperactivity (PSH) syndrome may be observed in non-traumatic brain injury

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Treatment of PSH was based on symptoms elimination and symptoms prevention.

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Paradoxical reaction in tuberculosis, characterized by the appearance of new clinical symptoms during antitubercular drug therapy

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Ventriculoperitoneal shunting to reduce intracranial pressure in hydrocephalus following meningitis tuberculosis

Spontaneous Hyperventilation Is Common in Patients with Spontaneous Cerebellar Hemorrhage, and Its Severity Is Associated with Outcome

Background: The spontaneous hyperventilation (SHV) accompanying spontaneous cerebellar hemorrhage has yet to attract a sufficient amount of attention. This study aimed to analyze the incidence of SHV in spontaneous cerebellar hemorrhage patients and its risk factors as well as its association with the outcome. Methods: We retrospectively reviewed the medical records of all spontaneous cerebellar hemorrhage patients who underwent surgical treatment at Tongji Hospital from July 2018 to December 2020. Arterial blood gas (ABG) test results and clinical characteristics, including demographics, comorbidities, imaging features, laboratory tests, and therapy choices, were collected. The Glasgow Outcome Scale was used to assess the outcome at two weeks and six months after admission. Results: A total of 147 patients were included, and of these patients 44.9% had spontaneous hyperventilation. Hypertension (OR, 3.175; CI, 1.332–7.569), usage of sedation drugs (OR, 3.693; CI, 1.0563–8.724), and hypernatremia (OR, 2.803; CI, 1.070–7.340) seemed to positively correlate to SHV occurrence. Hematoma removal had an inverse association with SHV (OR, 0.176; CI, 0.068–0.460). Patients with poor and good outcomes had significant differences in pH, PaCO₂, and HCO₃⁻ values, and the severity of SHV was associated with the PaCO₂ level. Conclusions: Spontaneous hyperventilation is common in patients with spontaneous cerebellar hemorrhage, and its severity is associated with the outcome.

Relationship between hyperhidrosis and hypothalamic injury in patients with mild traumatic brain injury

Hyperhidrosis is clinical symptom of various diseases and is an important clinical feature of paroxysmal sympathetic hyperactivity (PSH). Traumatic brain injury (TBI) is known to be most common condition associated with PSH, and PSH has been mainly reported in moderate and severe TBI. However, very little has been reported on PSH or hyperhidrosis in mild TBI patients. In this study, we used diffusion tensor imaging (DTI) to investigate the relationship between hyperhidrosis and hypothalamic injury in patients with mild TBI. Seven patients with hyperhidrosis after mild TBI and 21 healthy control subjects were recruited for this study. The Hyperhidrosis Disease Severity Scale was used for evaluation of sweating at the time of DTI scanning. The fractional anisotropy and apparent diffusion coefficient DTI parameters were measured in the hypothalamus. In the patient group, the fractional anisotropy values for both sides of the hypothalamus were significantly lower than those of the control group (P < .05). By contrast, the apparent diffusion coefficient values for both sides of the hypothalamus were significantly higher in the patient group than in the control group (P < .05). In conclusion, we detected hypothalamic injuries in patients who showed hyperhidrosis after mild TBI. Based on the results, it appears that hyperhidrosis in patients with mild TBI is related to hypothalamic injury.

Paroxysmal sympathetic hyperactivity concurrent with hypothalamic injury in a patient with intracerebral hemorrhage: A case report

BACKGROUND

Paroxysmal sympathetic hyperactivity (PSH) is characterized by exacerbated sympathetic discharge following severe brain injury. Here, we reports a patient diagnosed with PSH after ICH concurrent with hypothalamic injury, as demonstrated by diffusion tensor imaging (DTI).

METHODS

A 27-year-old man patient was diagnosed with spontaneous intraventricular hemorrhage and intracerebral hemorrhage in both frontal lobes. Two months after onset, brain magnetic resonance imaging of the brain revealed a leukomalactic lesion in the hypothalamus. Three months after the onset, he presented with intermittent high fever, tachycardia, tachypnea, systolic hypertension, diaphoresis, and aggravated rigidity. Infection was ruled out by a physical examination, laboratory tests, and radiological studies. After administrating morphine and bromocriptine, the clinical manifestations improved dramatically.

RESULTS

PSH after intracranial hemorrhage concurrent with the hypothalamic injury. Fractional anisotropy and mean diffusivity values of DTI were obtained in the hypothalamus. No significant difference in fractional anisotropy value was observed between the patient and control group (10 age-matched healthy male subjects) (P > .05). On the other hand, the mean diffusivity value was higher in the patient group than in the control group (P < .05), indicating hypothalamic injury.

CONCLUSION

PSH concurrent with hypothalamic injury was observed in a patient with stroke. This study suggests that DTI can be a useful imaging method for evaluating the hypothalamic state of patients presenting with PSH after brain injury.

Characteristics and Outcomes of Paroxysmal Sympathetic Hyperactivity in Anti-NMDAR Encephalitis

Background

To explore the clinical characteristics and prognosis of autonomic dysfunction and paroxysmal sympathetic hyperactivity (PSH), and evaluate the efficacy of drugs used to suppress PSH episode in anti-NMDAR encephalitis patients.

Methods

Patients who met the diagnostic criteria of anti-NMDAR encephalitis were enrolled from January 2012 to August 2018 and followed up for 2 years. PSH was diagnosed according to the PSH-Assessment Measure. The demographics data, clinical features, auxiliary tests results, treatments, and outcomes were prospective collected and analyzed.

Results

A total of 132 anti-NMDAR encephalitis patients were enrolled, of which 27.3% and 9.1% experienced autonomic dysfunction and probable PSH respectively. Cardiac autonomic dysfunction was the most common subtype (77.8%). Patients with a higher incidence of ovarian teratoma, mechanical ventilation, neurological intensive care unit admission, and elevated glucose and NMDAR antibody titer in the CSF were more likely to exhibit autonomic dysfunction or PSH. Episodes of PSH can be suppressed by monotherapy in patients without prior sedative drug use with an efficacy of 90%. No significant difference was observed between the prognosis of patients with or without autonomic dysfunction, or between the PSH versus non-PSH groups after 6 months and even during long-term follow-up. However, patients with cardiac autonomic dysfunction had poor prognosis at 6 months.

Conclusion

PSH is a common clinical condition in patients with anti-NMDAR encephalitis, especially in severe cases, and can be effectively managed by several drug monotherapies. Despite necessitating longer hospital stay, autonomic dysfunction or PSH do not seem to compromise the neurological recovery of patients.

Paroxysmal sympathetic hyperactivity following acute diffuse brain swelling due to traumatic brain injury: a case report with good clinical outcome

Background

Paroxysmal sympathetic hyperactivity (PSH) may occur after acquired brain injury. The clinical presentation of PSH results from increased sympathetic overdrive, including transient paroxysms of tachycardia, hypertension, hyperventilation, hyperthermia, dystonic posturing, and excessive sweating. The exact pathophysiology of PSH, however, remains unclear, and no definitive treatment is available. Herein, the authors report a case of PSH in a male patient who experienced acute brain swelling after acquired head injury, for which a good clinical outcome was achieved due to multimodal treatment. The ensuing discussion also addresses the pathophysiology of PSH.

Case presentation

An 18-year-old man was transported to the authors’ hospital after experiencing a traumatic brain injury. On admission, computed tomography revealed cerebral herniation due to diffuse brain edema in the left parietal lobe. Emergency decompressive craniotomy and internal decompression were performed. After surgery, anti-edema therapy (glycerol and mannitol) was continued. Ten days postoperatively, PSH was diagnosed in accordance with the PSH assessment score (20 points). Vecuronium, fentanyl, morphine, propofol, dexmedetomidine, and a calcium channel blocker were administered; however, the drug effect was insufficient. Thirty-two days postsurgery, the patient gradually recovered from the adrenergic symptoms of PSH, and head computed tomography performed 32 days after surgery revealed improvement in diffuse brain edema. Ultimately, the patient fully recovered and lived independently at home.

Conclusions

Considering the pathophysiology of PSH, cerebral contusion, acute brain swelling, and secondary mechanisms of brain injury may trigger sympathetic nerve-enhancing regions and cause hyperexcitation of the sympathetic nervous system, resulting in PSH. The outcome of the present case demonstrates that PSH can be reversed if it is identified early and before it becomes irreversible, that is, post the development of hypoxic encephalopathy or widespread brain damage. Appropriate management, including decompression craniotomy for brain swelling and multidisciplinary treatment, leads to good clinical outcomes.

Dynamic Temporal Relationship Between Autonomic Function and Cerebrovascular Reactivity in Moderate/Severe Traumatic Brain Injury

There has been little change in morbidity and mortality in traumatic brain injury (TBI) in the last 25 years. However, literature has emerged linking impaired cerebrovascular reactivity (a surrogate of cerebral autoregulation) with poor outcomes post-injury. Thus, cerebrovascular reactivity (derived through the pressure reactivity index; PRx) is emerging as an important continuous measure. Furthermore, recent literature indicates that autonomic dysfunction may drive impaired cerebrovascular reactivity in moderate/severe TBI. Thus, to improve our understanding of this association, we assessed the physiological relationship between PRx and the autonomic variables of heart rate variability (HRV), blood pressure variability (BPV), and baroreflex sensitivity (BRS) using time-series statistical methodologies. These methodologies include vector autoregressive integrative moving average (VARIMA) impulse response function analysis, Granger causality, and hierarchical clustering. Granger causality testing displayed inconclusive results, where PRx and the autonomic variables had varying bidirectional relationships. Evaluating the temporal profile of the impulse response function plots demonstrated that the autonomic variables of BRS, ratio of low/high frequency of HRV and very low frequency HRV all had a strong relation to PRx, indicating that the sympathetic autonomic response may be more closely linked to cerebrovascular reactivity, then other variables. Finally, BRS was consistently associated with PRx, possibly demonstrating a deeper relationship to PRx than other autonomic measures. Taken together, cerebrovascular reactivity and autonomic response are interlinked, with a bidirectional impact between cerebrovascular reactivity and circulatory autonomics. However, this work is exploratory and preliminary, with further study required to extract and confirm any underlying relationships.

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.

CT features of confirmed and presumed gastric wall edema in dogs

Postcontrast computed tomographic (CT) characteristics of gastrointestinal (GI) wall edema in humans have been described as GI wall thickening with a thickened submucosal layer and thin enhanced inner and outer layers. Published studies describing CT features of gastric wall edema in dogs are currently lacking. The aim of this retrospective, case series was to describe CT features of gastric wall edema in a group of dogs. Medical records were searched for dogs with postcontrast abdominal CT scans and a diagnosis of gastric wall edema based on histopathology (group I) or CT characteristics consistent with those reported in humans (group II). Clinical diagnosis, mean serum albumin concentration, and histopathological diagnosis were recorded. The following CT characteristics were recorded: numbers of wall layers, attenuation and contrast enhancement, presence of blood vessels, locations, distribution, and thickness. Twelve dogs (3 in group I and 9 in group II) were included. The most common clinical finding was hypoalbuminemia. In group I, a well-defined three-layer appearance with a non-enhancing fluid-attenuating middle layer was observed in three dogs and thin blood vessels in the middle layer in two dogs. In group II, nine dogs had a three-layer appearance with a non-enhancing fluid-attenuating middle layer. Locations of gastric wall thickening were diffuse in two, focal concentric in six, and focal asymmetric in four dogs. Findings supported including gastric wall edema as a differential diagnosis for dogs with hypoalbuminemia and CT characteristics of a three-layer appearance in the gastric wall, with a non-enhancing fluid-attenuating middle layer and thin blood vessels.

Relationship between mild traumatic brain injury and the gut microbiome: A scoping review

There is increasing evidence for the important role of gut microbiota (GMB) in the development and progression of neurologic pathologies. Some studies have shown that modifying the microbiome profile can confer benefits to patients. Mild traumatic brain injury (mTBI) is a common occurrence in the general population. Although most patients recover, in a minority, disabling symptoms can persist for several months. We carried out a review of the literature to assess the effect of mTBI on GMB and to determine whether alleviating dysbiosis can improve clinical outcomes in mTBI patients. We performed searches in Medline/PubMed and Embase using the keywords "MTBI" AND "microbiome" OR "microbiota". Additional articles were identified by manual searches and using the Google search engine. In animal models, a clear perturbation of GMB was reported following TBI and probiotic supplementation (Lactobacillus acidophilus or Clostridium butyricum) improved neurologic function. There were no studies on changes in GMB after mTBI in humans; however, pre- or probiotic supplementation reduced the infection rate in patients with severe TBI and shortened the time spent in the intensive care unit without conferring any neurologic benefits. Thus, although the findings from animal models are promising, clinical studies are needed to determine whether therapeutic strategies that restore gut microbiome profile can improve long-term outcomes of patients with mTBI.

Paroxysmal sympathetic hyperactivity during traumatic brain injury

Traumatic brain injury (TBI) is one of the leading causes of disability, morbidity, and mortality worldwide. Some of the more common etiologies of TBI include closed head injury, penetrating head injury, or an explosive blast head injury. Neuronal damage in TBI is related to both primary injury (caused by mechanical forces), and secondary injury (caused by the subsequent tissue and cellular damages). Recently, it has been well established that Paroxysmal Sympathetic Hyperactivity (PSH), also known as "Sympathetic Storm", is one of the main causes of secondary neuronal injury in TBI patients. The clinical manifestations of PSH include recurrent episodes of sympathetic hyperactivity characterized by tachycardia, systolic hypertension, hyperthermia, tachypnea with hyperpnea, and frank diaphoresis. Given the diverse manifestations of PSH and its notable impact on the outcome of TBI patients, we have comprehensively reviewed the current evidence and discussed the pathophysiology, clinical manifestations, time of onset and duration of PSH during TBI. This article reviews the different types of head injuries that most commonly lead to PSH, possible approaches to manage and minimize PSH complications in TBI and the current prognosis and outcomes of PSH in TBI patients.

Modeling Brain-Heart Crosstalk Information in Patients with Traumatic Brain Injury

Background

Traumatic brain injury (TBI) is an extremely heterogeneous and complex pathology that requires the integration of different physiological measurements for the optimal understanding and clinical management of patients. Information derived from intracranial pressure (ICP) monitoring can be coupled with information obtained from heart rate (HR) monitoring to assess the interplay between brain and heart. The goal of our study is to investigate events of simultaneous increases in HR and ICP and their relationship with patient mortality..

Methods

In our previous work, we introduced a novel measure of brain–heart interaction termed brain–heart crosstalks (ct_np), as well as two additional brain–heart crosstalks indicators [mutual information (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$mi_{ct}$$\end{document}mict) and average edge overlap (ω_ct)] obtained through a complex network modeling of the brain–heart system. These measures are based on identification of simultaneous increase of HR and ICP. In this article, we investigated the relationship of these novel indicators with respect to mortality in a multicenter TBI cohort, as part of the Collaborative European Neurotrauma Effectiveness Research in TBI high-resolution work package.

Results

A total of 226 patients with TBI were included in this cohort. The data set included monitored parameters (ICP and HR), as well as laboratory, demographics, and clinical information. The number of detected brain–heart crosstalks varied (mean 58, standard deviation 57). The Kruskal–Wallis test comparing brain–heart crosstalks measures of survivors and nonsurvivors showed statistically significant differences between the two distributions (p values: 0.02 for \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$mi_{ct}$$\end{document}mict, 0.005 for ct_np and 0.006 for ω_ct). An inverse correlation was found, computed using the point biserial correlation technique, between the three new measures and mortality: − 0.13 for ct_np (p value 0.04), − 0.19 for ω_ct (p value 0.002969) and − 0.09 for \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$mi_{ct}$$\end{document}mict (p value 0.1396). The measures were then introduced into the logistic regression framework, along with a set of input predictors made of clinical, demographic, computed tomography (CT), and lab variables. The prediction models were obtained by dividing the original cohort into four age groups (16–29, 30–49, 50–65, and 65–85 years of age) to properly treat with the age confounding factor. The best performing models were for age groups 16–29, 50–65, and 65–85, with the deviance of ratio explaining more than 80% in all the three cases. The presence of an inverse relationship between brain–heart crosstalks and mortality was also confirmed.

Conclusions

The presence of a negative relationship between mortality and brain–heart crosstalks indicators suggests that a healthy brain–cardiovascular interaction plays a role in TBI.

Sepsis or sympathetics? Paroxysmal sympathetic hyperactivity after pontine stroke

A 64-year-old man from nursing home with a pontine stroke 3 months ago, ventilator-dependent, presented with episodic fever, tachycardia and tachypnoea occurring several times a day. He was evaluated for sepsis and pulmonary embolism and was treated empirically with broad-spectrum antibiotics. But these episodes persisted. Due to the episodic nature and typical symptoms of sympathetic overactivity, in the setting of prior brain injury, paroxysmal sympathetic hyperactivity was considered. His antibiotics were discontinued, and he was treated symptomatically with baclofen and bromocriptine, which resulted in a partial reduction of these episodes.

Admission Features Associated With Paroxysmal Sympathetic Hyperactivity After Traumatic Brain Injury: A Case-Control Study

OBJECTIVES

Paroxysmal sympathetic hyperactivity occurs in a subset of critically ill traumatic brain injury patients and has been associated with worse outcomes after traumatic brain injury. The goal of this study was to identify admission risk factors for the development of paroxysmal sympathetic hyperactivity in traumatic brain injury patients.

DESIGN

Retrospective case-control study of age- and Glasgow Coma Scale-matched traumatic brain injury patients.

SETTING

Neurotrauma ICU at the R. Adams Cowley Shock Trauma Center of the University of Maryland Medical System, January 2016 to July 2018.

PATIENTS

Critically ill adult traumatic brain injury patients who underwent inpatient monitoring for at least 14 days were included. Cases were identified based on treatment for paroxysmal sympathetic hyperactivity with institutional first-line therapies and were confirmed by retrospective tabulation of established paroxysmal sympathetic hyperactivity diagnostic and severity criteria. Cases were matched 1:1 by age and Glasgow Coma Scale to nonparoxysmal sympathetic hyperactivity traumatic brain injury controls, yielding 77 patients in each group.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Admission characteristics independently predictive of paroxysmal sympathetic hyperactivity included male sex, higher admission systolic blood pressure, and initial CT evidence of diffuse axonal injury, intraventricular hemorrhage/subarachnoid hemorrhage, complete cisternal effacement, and absence of contusion. Paroxysmal sympathetic hyperactivity cases demonstrated significantly worse neurologic outcomes upon hospital discharge despite being matched for injury severity at admission.

CONCLUSIONS

Several anatomical, epidemiologic, and physiologic risk factors for clinically relevant paroxysmal sympathetic hyperactivity can be identified on ICU admission. These features help characterize paroxysmal sympathetic hyperactivity as a clinical-pathophysiologic phenotype associated with worse outcomes after traumatic brain injury.

Disruption of intestinal barrier and endotoxemia after traumatic brain injury: Implications for post-traumatic epilepsy

OBJECTIVE

Traumatic brain injury (TBI) may lead to the disruption of the intestinal barrier (IB), and to the escape of products of commensal gut bacteria, including lipopolysaccharide (LPS), into the bloodstream. We examined whether lateral fluid percussion injury (LFPI) and post-traumatic epilepsy (PTE) are associated with the increased intestinal permeability and endotoxemia, and whether these events in turn are associated with PTE.

METHODS

LFPI was delivered to adult male Sprague-Dawley rats. Before, 1 week, and 7 months after LFPI, the IB permeability was examined by measuring plasma concentration of fluorescein isothiocyanate-labeled dextran (FD4) upon its enteral administration. Plasma LPS concentration was measured in the same animals, using enzyme-linked immunosorbent assay. PTE was examined 7 months after LFPI, with use of video-EEG (electroencephalography) monitoring.

RESULTS

One week after LFPI, the IB disruption was detected in 14 of 17 and endotoxemia - in 10 of 17 rats, with a strong positive correlation between FD4 and LPS levels, and between plasma levels of each of the analytes and the severity of neuromotor deficit. Seven months after LFPI, IB disruption was detected in 13 of 15 and endotoxemia in 8 of 15 rats, with a strong positive correlation between plasma levels of the two analytes. Five of 15 LFPI rats developed PTE. Plasma levels of both FD4 and LPS were significantly higher in animals with PTE than among the animals without PTE. The analysis of seven rats, which were examined repeatedly at 1 week and at 7 months, confirmed that late IB disruption and endotoxemia were not due to lingering of impairments occurring shortly after LFPI.

SIGNIFICANCE

LFPI leads to early and remote disruption of IB and a secondary endotoxemia. Early and late perturbations may occur in different subjects. Early changes reflect the severity of acute post-traumatic motor dysfunction, whereas late changes are associated with PTE.

Incidence of Paroxysmal Sympathetic Hyperactivity after Traumatic Brain Injury in a Tertiary Care ICU: A Retrospective Cohort Study

Background Paroxysmal sympathetic hyperactivity (PSH) is an understudied complication of traumatic brain injury (TBI). PSH usually presents with transient rise in sympathetic outflow, leading to increased blood pressure, heart rate, temperature, respiratory rate, sweating, and posturing activity. We retrospectively analyzed the incidence of PSH in TBI using PSH-assessment measure (PSH-AM) scale.

Methods This single-center retrospective cohort study was conducted in traumatic head injury patients admitted in the intensive care unit from January 1, 2016 to December 31, 2019 in a tertiary care center. The data was collected from the hospital database after obtaining approval from the hospital ethics committee.

Results A total of 287 patients (18–65 years of age) were admitted to intensive care unit (ICU) with TBI out of which 227 patients were analyzed who had ICU stay for more than 14 days. PSH was diagnosed in 70 (30.8%) patients. Mean age of PSH positive patients was 40 ± 18 and 49 ± 11 years for PSH negative patients (p < 0.001). The age group between 40 and 50 years had a higher incidence of PSH. The age and Glasgow coma score (GCS) were significantly associated with the occurrence of PSH. The GCS score demonstrated good accuracy for predicting the occurrence of PSH with AUC 0.83, 95% CI of 0.775 to 0.886, and a p-value of 0.001.

Conclusion We observed that the incidence of PSH was 30.8% in the patients with TBI. Age and GCS were found to have a significant association for predicting the occurrence of PSH. The patients who developed PSH had a longer length of hospital stay in ICU.

Functional plasticity of cardiac efferent neurons contributes to traumatic brain injury-induced cardiac autonomic dysfunction

Traumatic brain injury (TBI) frequently causes cardiac autonomic dysfunction (CAD), irrespective of its severity, which is associated with an increased morbidity and mortality in patients. Despite the significance of probing the cellular mechanism underlying TBI-induced CAD, animal studies on this mechanism are lacking. In the current study, we tested whether TBI-induced CAD is associated with functional plasticity in cardiac efferent neurons. In this regard, TBI was induced by a controlled cortical impact in rats. Assessment of heart rate variability and baroreflex sensitivity indicated that CAD was developed in the sub-acute period after moderate and severe TBI. The cell excitability was increased in the stellate ganglion (SG) neurons and decreased in the intracardiac ganglion (ICG) neurons in TBI rats, compared with the sham-operated rats. The transient A-type K+ (KA) currents, but not the delayed rectifying K+ currents were significantly decreased in SG neurons in TBI rats, compared with sham-operated rats. Consistent with these electrophysiological data, the transcripts encoding the Kv4 α subunits were significantly downregulated in SG neurons in TBI rats, compared with sham-operated rats. TBI causes downregulation and upregulation of M-type K+ (KM) currents and the KCNQ2 mRNA transcripts, which may contribute to the hyperexcitability of the SG neurons and the hypoexcitability of the ICG neurons, respectively. In conclusion, the key cellular mechanism underlying the TBI-induced CAD may be the functional plasticity of the cardiac efferent neurons, which is caused by the regulation of the KA and/or KM currents.

A narrative review of pharmacologic approaches to symptom management of pediatric patients diagnosed with anti-NMDA receptor encephalitis

Anti-N-Methyl-D-Aspartate Receptor Encephalitis (ANMDARE) is one of the most common autoimmune encephalitis in the pediatric population. Patients with ANMDARE initially present with a prodrome of neuropsychiatric symptoms followed by progressively worsening seizures, agitation, and movement disorders. Complications can include problems such as aggression, insomnia, catatonia, and autonomic instability. Due to the complexity of this disease process, symptom management can be complex and may lead to significant polypharmacy. The goal of this review is to educate clinicians about the challenges of managing this disorder and providing guidance in symptom management.

Altered physiology of gastrointestinal vagal afferents following neurotrauma

The adaptability of the central nervous system has been revealed in several model systems. Of particular interest to central nervous system-injured individuals is the ability for neural components to be modified for regain of function. In both types of neurotrauma, traumatic brain injury and spinal cord injury, the primary parasympathetic control to the gastrointestinal tract, the vagus nerve, remains anatomically intact. However, individuals with traumatic brain injury or spinal cord injury are highly susceptible to gastrointestinal dysfunctions. Such gastrointestinal dysfunctions attribute to higher morbidity and mortality following traumatic brain injury and spinal cord injury. While the vagal efferent output remains capable of eliciting motor responses following injury, evidence suggests impairment of the vagal afferents. Since sensory input drives motor output, this review will discuss the normal and altered anatomy and physiology of the gastrointestinal vagal afferents to better understand the contributions of vagal afferent plasticity following neurotrauma.

Autonomic Hyperactivity

PURPOSE OF REVIEW

Autonomic hyperactivity is a relatively common consequence of severe acute brain injury and can also be seen with spinal cord and peripheral nerve disorders. This article reviews basic pathophysiologic concepts regarding autonomic hyperactivity, its various forms of clinical presentation, and practical management considerations.

RECENT FINDINGS

Paroxysmal sympathetic hyperactivity is most common after traumatic brain injury but can also occur after other forms of severe acute diffuse or multifocal brain injury. Formal criteria for the diagnosis and severity grading of paroxysmal sympathetic hyperactivity have now been proposed. A growing body of literature is beginning to elucidate the mechanisms underlying this disorder, but treatment remains based on observational data. Our mechanistic understanding of other distinct forms of autonomic hyperactivity, such as autonomic dysreflexia after traumatic spinal cord injury and dysautonomia after Guillain-Barré syndrome, remains rudimentary, yet clinical experience shows that their appropriate management can minimize the risk of serious complications.

SUMMARY

Syndromes of autonomic hyperactivity can result from injury at all levels of the neuraxis. Much more research is needed to refine our understanding of these disorders and guide optimal management decisions.

Sex as a Biological Variable in Preclinical Modeling of Blast-Related Traumatic Brain Injury

Approaches to furthering our understanding of the bioeffects, behavioral changes, and treatment options following exposure to blast are a worldwide priority. Of particular need is a more concerted effort to employ animal models to determine possible sex differences, which have been reported in the clinical literature. In this review, clinical and preclinical reports concerning blast injury effects are summarized in relation to sex as a biological variable (SABV). The review outlines approaches that explore the pertinent role of sex chromosomes and gonadal steroids for delineating sex as a biological independent variable. Next, underlying biological factors that need exploration for blast effects in light of SABV are outlined, including pituitary, autonomic, vascular, and inflammation factors that all have evidence as having important SABV relevance. A major second consideration for the study of SABV and preclinical blast effects is the notable lack of consistent model design—a wide range of devices have been employed with questionable relevance to real-life scenarios—as well as poor standardization for reporting of blast parameters. Hence, the review also provides current views regarding optimal design of shock tubes for approaching the problem of primary blast effects and sex differences and outlines a plan for the regularization of reporting. Standardization and clear description of blast parameters will provide greater comparability across models, as well as unify consensus for important sex difference bioeffects.

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.

[HYpertension due to sympathetic hyperactivity after severe head injury]

We present the case of a 34-year-old patient with severe head trauma and severe brain involvement. The patient deteriorated progressively and required several reinterventions for bleeding and brain herniation. We were consulted by neurosurgery due to irregular blood pressure control despite treatment with calcium antagonists. The patient had associated diaphoresis, tachypnoea and tachycardia, together with persistent high-grade fever with no microbiological evidence. Laboratory tests showed normal kidney function, with no proteinuria and no signs of left ventricular hypertrophy to suggest previous arterial hypertension. This led us to consider sympathetic hyperactivity syndrome as a first possible diagnosis due to severe neurological damage. In line with this suspicion, antihypertensive therapy was initiated which included non-cardioselective beta-blockers, alpha-2 agonists, benzodiazepines and GABA receptor agonists. Thus, we were able to improve the labile blood pressure levels, which supports the diagnosis.

Clinical significance of increased peripheral venous blood adipocyte-specific protein FABP4 after joint replacement

A new method of diagnosing fat embolism (FE) at the molecular level was proposed, and the diagnostic value of adipocyte-specific protein fatty acid-binding protein 4 (Homo sapiens [human]) gene ID = 2167 (FABP4) for FE was preliminarily explored. Eight joint replacement patients, 5 internal medicine patients, and 6 healthy persons were recruited. Serum of internal medicine patients, healthy people, and patients before and 24 hours after joint replacement were taken as study samples. Subcutaneous adipose, intra-articular adipose and intramedullary yellow bone marrow of patients undergoing joint replacement were taken as study samples. The level of FABP4 in the above samples was detected by enzyme-linked immunoassay. Normal distribution was tested. Paired sample T test was used for self-control. Univariate analysis of variance was used for multigroup comparison.There was no significant difference in serum FABP4 level between healthy persons, medical patients, and preoperative patients. The FABP4 level in yellow bone marrow and subcutaneous adipose was significantly higher than that in serum of healthy people, medical patients, and preoperative patients. FABP4 level in the serum after joint replacement was significantly higher than that before joint replacement. FABP4 may be a specific indicator of FE diagnosis, but further studies are needed to confirm its clinical value.

Risk factors and clinical features of paroxysmal sympathetic hyperactivity after spontaneous intracerebral hemorrhage

BACKGROUND AND PURPOSE

Paroxysmal sympathetic hyperactivity (PSH) is a rare complication of spontaneous intracerebral hemorrhage (ICH).We aimed to evaluate the risk factors and clinical features for PSH after ICH.

METHODS

From January 1, 2013 to April 1, 2018, patients with ICH were consecutively included in this observational study. Baseline characteristics were compared in patients with and without PSH. Multivariate logistic regression analysis was used to determine the risk factors associated with PSH development. Clinical features of patients with PSH were also analyzed.

RESULTS

There were 548 patients with ICH included and a total of 15 (2.7%) patients were identified with PSH. In univariate analysis, PSH development was associated with the following: previous hemorrhagic stroke, pupils abnormity, admission Glasgow Coma Scale (GCS) score, hematoma volume, liver function abnormity, neutrophil count and early tracheostomy. Multivariate logistic regression analysis showed that a significantly increased risk of PSH was found in patients with previous hemorrhagic stroke (odds ratio [OR], 4.176; 95% confidence interval [CI], 1.111-15.698), admission GCS score (OR, 0.703; 95% CI, 0.548-0.902) and early tracheostomy (OR, 8.317; 95%CI, 1.755-39.412).The most common symptoms of PSH were hyperthermia (80%) and hyperhidrosis (80%).The median Intensive Care Unit stays and Glasgow Outcome Scale at discharge were 34 (19-46) and 2 (1.5-3), respectively.

CONCLUSIONS

PSH is characterized by a cluster of symptoms and abnormal vital signs, which may lead to poor outcomes in ICH. The present study suggests that previous hemorrhagic stroke, admission GCS score and early tracheostomy may be the significant risk factors for PSH after ICH.

Identification and Management of Paroxysmal Sympathetic Hyperactivity After Traumatic Brain Injury

Paroxysmal sympathetic hyperactivity (PSH) has predominantly been described after traumatic brain injury (TBI), which is associated with hyperthermia, hypertension, tachycardia, tachypnea, diaphoresis, dystonia (hypertonia or spasticity), and even motor features such as extensor/flexion posturing. Despite the pathophysiology of PSH not being completely understood, most researchers gradually agree that PSH is driven by the loss of the inhibition of excitation in the sympathetic nervous system without parasympathetic involvement. Recently, advances in the clinical and diagnostic features of PSH in TBI patients have reached a broad clinical consensus in many neurology departments. These advances should provide a more unanimous foundation for the systematic research on this clinical syndrome and its clear management. Clinically, a great deal of attention has been paid to the definition and diagnostic criteria, epidemiology and pathophysiology, symptomatic treatment, and prevention and control of secondary brain injury of PSH in TBI patients. Potential benefits of treatment for PSH may result from the three main goals: eliminating predisposing causes, mitigating excessive sympathetic outflow, and supportive therapy. However, individual pathophysiological differences, therapeutic responses and outcomes, and precision medicine approaches to PSH management are varied and inconsistent between studies. Further, many potential therapeutic drugs might suppress manifestations of PSH in the process of TBI treatment. The purpose of this review is to present current and comprehensive studies of the identification of PSH after TBI in the early stage and provide a framework for symptomatic management of TBI patients with PSH.

Ghrelin as an anti-inflammatory and protective agent in ischemia/reperfusion injury

Ischemia/reperfusion (I/R) continue to be the most frequent cause of damaged tissues. Injured tissues resulted from the first ischemic insult, which is determined by the interruption in the blood supply, followed by subsequent impairment induced by reperfusion. In addition, ischemia-reperfusion injury is mediated by tumor necrosis factor (TNF) and other cytokines that activate complements and proteases responsible for free radical production. However, earlier studies have reported the protective roles of bioactive peptides during ischemia reperfusion injury. In fact, ghrelin is a peptide hormone discovered since 1999 as GH secretagogue and its production was identified in gastric X/A-like endocrine cells in rats and P/D1 type cells in humans. To date, this peptide receives growing attention due to its pleiotropic action in the organism and its role in maintaining energy homeostasis. Ghrelin is also involved in stress responses, assuming a modulatory action on immune pathways. Previous studies have identified many other functions related to an anti-inflammatory role in ischemia reperfusion injury. Under these challenging conditions, studies described acylated and unacylated ghrelin in activation and/or inhibition processes related to ischemia-reperfusion injury. The aim of this article is to provide a minireview about ghrelin mechanisms involved in the proinflammatory response of I/R injury. However, the regulatory processes of ghrelin in this pathologic event are still very limited and warrant further investigation.

Cerebral Fat Embolism: Recognition, Complications, and Prognosis

Fat embolism syndrome (FES) is a rare syndrome caused by embolization of fat particles into multiple organs including the brain. It typically manifests with petechial rash, deteriorating mental status, and progressive respiratory insufficiency, usually occurring within 24-48 h of trauma with long-bone fractures or an orthopedic surgery. The diagnosis of FES is based on clinical and imaging findings, but requires exclusion of alternative diagnoses. Although there is no specific treatment for FES, prompt recognition is important because it can avoid unnecessary interventions and clarify prognosis. Patients with severe FES can become critically ill, but even comatose patients with respiratory failure may recover favorably. Prophylactic measures, such as early stabilization of fractures and certain intraoperative techniques, may help decrease the incidence and severity of FES.

Effect of oxidative stress in rostral ventrolateral medulla on sympathetic hyperactivity after traumatic brain injury

Sympathetic hyperactivity occurs in a subgroup of patients after traumatic brain injury (TBI). The rostral ventrolateral medulla (RVLM) is a key region for the activity of sympathetic nervous system. Oxidative stress in the RVLM is proved to be responsible for the increased level of sympathetic activity in animal models of hypertension and heart failure. In this study, we investigated whether oxidative stress in the RVLM contributed to the development of sympathetic hyperactivity after TBI in rats. Model of diffuse axonal injury was induced using Sprague-Dawley rats, and level of mean arterial pressure (MAP) and plasma Norepinephrine (NE) was measured to evaluate the sympathetic activity. For the assessment of oxidative stress, expression of reactive oxygen species (ROS), malondialdehyde (MDA), and superoxide dismutase (SOD) in the RVLM was determined. Microinjection of Tempol into the RVLM was performed to determine the effect of oxidative stress on sympathetic hyperactivity. According to the results, TBI led to elevated MAP and plasma NE in rats. It also induced a significantly increased level of ROS, MDA production and decreased level of SOD in the RVLM. The sympathetic activity, ROS, and MDA in the RVLM decreased significantly after microinjection of Tempol. Therefore, the present results suggested that oxidative stress in the RVLM was involved in the development of sympathetic hyperactivity following TBI.

Acute encephalopathy with biphasic seizures and late reduced diffusion accompanied by Takotsubo cardiomyopathy

BACKGROUND

Acute encephalopathy with biphasic seizures and late reduced diffusion (AESD) is characterized by biphasic seizures and impaired consciousness. Takotsubo cardiomyopathy (TTC), which is typically triggered by psychological or physical stress, is characterized by transient myocardial dysfunction affecting the left ventricular apex. Recent reports have suggested that seizures can also trigger TTC. However, no cases of TTC accompanied by AESD have been reported.

PATIENT

A previously healthy 4-year-old girl was brought to a hospital with first-time febrile generalized tonic-clonic convulsions, which lasted approximately 40 min. After the seizure resolved, she was intubated due to respiratory deterioration. On the next day, her cardiac function deteriorated, and echocardiography revealed systolic apical ballooning of the left ventricle accompanied by hyperkinesis of the basal wall, which are typical in patients with TTC. Her condition gradually improved, and catecholamine support was tapered. However, 6 days after admission, she experienced a cluster of brief convulsions. Ten days after admission, head MRI revealed lesions with reduced diffusion throughout the cortex, except in the occipital lobe, as well as perirolandic sparing. Follow-up MRI 35 days after onset revealed whole-brain atrophy, following which she developed severe cognitive dysfunction.

CONCLUSIONS

Our patient developed TTC accompanied by features of AESD. Our findings may thus provide insight into the development of TTC and prompt further studies regarding the relationship between prolonged seizures and TTC.

Paroxysmal sympathetic hyperactivity syndrome caused by fat embolism syndrome

Paroxysmal sympathetic hyperactivity represents an uncommon and potentially life-threatening complication of severe brain injuries, which are most commonly traumatic. This syndrome is a clinical diagnosis based on the recurrent occurrence of tachycardia, hypertension, diaphoresis, tachypnea, and occasionally high fever and dystonic postures. The episodes may be induced by stimulation or may occur spontaneously. Underdiagnosis is common, and delayed recognition may increase morbidity and long-term disability. Trigger avoidance and pharmacological therapy can be very successful in controlling this complication. Fat embolism syndrome is a rare but serious complication of long bone fractures. Neurologic signs, petechial hemorrhages and acute respiratory failure constitute the characteristic presenting triad. The term cerebral fat embolism is used when the neurological involvement predominates. The diagnosis is clinical, but specific neuroimaging findings can be supportive. The neurologic manifestations include different degrees of alteration of consciousness, focal deficits or seizures. Management is supportive, but good outcomes are possible even in cases with very severe presentation. We report two cases of paroxysmal sympathetic hyperactivity after cerebral fat embolism, which is a very uncommon association.

Development and validation of a nomogram for predicting self-propelled postpyloric placement of spiral nasoenteric tube in the critically ill: Mixed retrospective and prospective cohort study

BACKGROUND & AIMS

Equipment-aided or experience-dependent methods for postpyloric nasoenteric tube placement are not so readily accessible in the critically ill setting. Self-propelled postpyloric placement of a spiral nasoenteric tube can serve as an alternative approach. However, the success rate of this method is relatively low despite using prokinetics. This study aims to develop a user-friendly nomogram incorporating clinical markers to individually predict the probability of successful postpyloric nasoenteric tube placement and facilitate intensivists with improved decision-making before tube insertion.

METHODS

Patients consecutively recruited in the stage between May 2012 through December 2016 constituted the development cohort for retrospective analysis to internally test the nomogram, and patients in the stage between January 2017 through March 2018 constituted the validation cohort for prospective analysis to external validate the nomogram. A multivariate logistic regression analysis was firstly performed in the development cohort by a backward stepwise method to identify the best-fit model, from which a nomogram was obtained. The nomogram was validated in the independent external validation cohort concerning discrimination, calibration. A decision curve analysis was also performed to evaluate the net benefit of insertion decision with the nomogram.

RESULTS

A total of 364 and 119 patients, 52.7% and 55.5% with successful postpyloric placement, were included in the development and validation cohort, respectively. Predictors contained in the prediction nomogram included primary diagnosis, APACHE II score, AGI grade. The derived model showed good discrimination, with an area under the receiver operating characteristic curve (AUROC) of 0.809 (95%CI, 0.765-0.853) and good calibration. Application of the nomogram in the validation cohort also gave good discrimination with an AUROC of 0.776 (95%CI, 0.694-0.859) and good calibration. The decision curve analysis of the nomogram provided better net benefit than the alternate options (insert-all or insert-none).

CONCLUSIONS

A prediction nomogram that incorporates primary diagnosis, together with APACHE II score and AGI grade can be conveniently used to facilitate the pre-insertion individualized prediction of postpyloric nasoenteric tube placement in critically ill patients.

Eyeball pressure stimulation induces subtle sympathetic activation in patients with a history of moderate or severe traumatic brain injury

OBJECTIVE

After traumatic brain injury (TBI), there may be persistent central-autonomic-network (CAN) dysfunction causing cardiovascular-autonomic dysregulation. Eyeball-pressure-stimulation (EPS) normally induces cardiovagal activation. In patients with a history of moderate or severe TBI (post-moderate-severe-TBI), we determined whether EPS unveils cardiovascular-autonomic dysregulation.

METHODS

In 51 post-moderate-severe-TBI patients (32.7 ± 10.5 years old, 43.1 ± 33.4 months post-injury), and 30 controls (29.1 ± 9.8 years), we recorded respiration, RR-intervals (RRI), systolic and diastolic blood-pressure (BPsys, BPdia), before and during EPS (120 sec; 30 mmHg), using an ocular-pressure-device (Okulopressor®). We calculated spectral-powers of mainly sympathetic low (LF: 0.04-0.15 Hz) and parasympathetic high (HF: 0.15-0.5 Hz) frequency RRI-fluctuations, sympathetically mediated LF-powers of BPsys, and calculated normalized (nu) LF- and HF-powers of RRI. We compared parameters between groups before and during EPS by repeated-measurement-analysis-of-variance with post-hoc analysis (significance: p < 0.05).

RESULTS

At rest, sympathetically mediated LF-BPsys-powers were significantly lower in the patients than the controls. During EPS, only controls significantly increased RRIs and parasympathetically mediated HFnu-RRI-powers, but decreased LF-RRI-powers, LFnu-RRI-powers, and LF-BPsys-powers; in contrast, the patients slightly though significantly increased BPsys upon EPS, without changing any other parameter.

CONCLUSIONS

In post-moderate-severe-TBI patients, autonomic BP-modulation was already compromised at rest. During EPS, our patients failed to activate cardiovagal modulation but slightly increased BPsys, indicating persistent CAN dysregulation.

SIGNIFICANCE

Our findings unveil persistence of subtle cardiovascular-autonomic dysregulation even years after TBI.