A meta-analysis of treating acute traumatic brain injury with calcium channel blockers

Interventional Treatment of Symptomatic Vasospasm in the Setting of Traumatic Brain Injury: A Systematic Review of Reported Cases

Traumatic subarachnoid hemorrhage (tSAH) is frequently comorbid with traumatic brain injury (TBI) and may induce secondary injury through vascular changes such as vasospasm and subsequent delayed cerebral ischemia (DCI). While aneurysmal SAH is well studied regarding vasospasm and DCI, less is known regarding tSAH and the prevalence of vasospasm and DCI, the consequences of vasospasm in this setting, when treatment is indicated, and which management strategies should be implemented. In this article, a systematic review of the literature that was conducted for cases of symptomatic vasospasm in patients with TBI is reported, association with tSAH is reported, risk factors for vasospasm and DCI are summarized, and commonalities in diagnosis and management are discussed. Clinical characteristics and treatment outcomes of 38 cases across 20 studies were identified in which patients with TBI with vasospasm underwent medical or endovascular management. Of the patients with data available for each category, the average age was 48.7 ± 20.3 years (n = 31), the Glasgow Coma Scale score at presentation was 10.6 ± 4.5 (n = 35), and 100% had tSAH (n = 29). Symptomatic vasospasm indicative of DCI was diagnosed on average at postinjury day 8.4 ± 3.0 days (n = 30). Of the patients, 56.6% (n = 30) had a new ischemic change associated with vasospasm confirming DCI. Treatment strategies are discussed, with 11 of 12 endovascularly treated and 19 of 26 medically treated patients surviving to discharge. tSAH is associated with vasospasm and DCI in moderate and severe TBI, and patients with clinical and radiographic evidence of symptomatic vasospasm and subsequent DCI may benefit from endovascular or medical management strategies.

Outcomes following therapeutic intervention of post-traumatic vasospasm: A systematic review and meta-analysis

BACKGROUND

Vasospasm occurrence following traumatic brain injury may impact neurologic and functional recovery of patients, yet treatment of post-traumatic vasospasm (PTV) has not been well documented. This systematic review and meta-analysis aims to assess the current evidence regarding favorable outcome as measured by Glasgow Outcome Scale (GOS) scores following treatment of PTV.

METHODS

A systematic review of PubMed, Ovid MEDLINE, and Ovid EMBASE was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Included manuscripts were methodically scrutinized for quality; occurrence of PTV; rate of favorable outcome following each treatment modality; and follow-up duration. Treatments evaluated were calcium channel blockers (CCBs), endovascular intervention, and dopamine-induced hypertension. Outcomes were compared via the random-effects analysis.

RESULTS

Fourteen studies with 1885 PTV patients were quantitatively analyzed: 982 patients who received tailored therapeutic intervention and 903 patients who did not receive tailored therapy. For patients undergoing treatment, the rate of favorable outcome was 57.3 % (500/872 patients; 95 % CI 54.1 - 60.6 %) following administration of CCBs, 94.1 % (16/17 patients; 95 % CI 82.9 - 100.0 %) following endovascular intervention, and 54.8 % (51/93 patients; 95 % CI 44.7 - 65.0 %) following dopamine-induced hypertension. Of note, the endovascular group had the highest rate of favorable outcome but was also the smallest sample size (n = 17). Patients who received tailored therapeutic intervention for PTV had a higher rate of favorable outcome than patients who did not receive tailored therapy: 57.7 % (567/982 patients; 95 % CI 54.1 - 60.8 %) versus 52.0 % (470/903 patients; 95 % CI 48.8 - 55.3 %), respectively.

CONCLUSIONS

The available data suggests that tailored therapeutic intervention of PTV results in a favorable outcome. While endovascular intervention of PTV had the highest rate of favorable outcome, both CCB administration and dopamine-induced hypertension had similar lower rates of favorable outcome.

Carvacrol as a Potential Neuroprotective Agent for Neurological Diseases: A Systematic Review Article

BACKGROUND & OBJECTIVE

Neurological diseases are becoming a significant problem worldwide, with the elderly at a higher risk of being affected. Several researchers have investigated the neuroprotective effects of Carvacrol (CAR) (5-isopropyl-2-methyl phenol). This review systematically surveys the existing literature on the impact of CAR when used as a neuroprotective agent in neurological diseases.

METHOD

The systematic review involved English articles published in the last ten years obtained from PubMed, Google Scholar, and Scopus databases. The following descriptors were used to search the literature: "Carvacrol" [Title] AND "neuroprotective (neuroprotection)" [Title] OR "stroke, traumatic brain injury, Alzheimer's disease, Parkinson's disease, seizure, epilepsy [Title].

RESULTS

A total of 208 articles were retrieved during the search process, but only 20 studies met the eligibility criteria and were included for review. A total of 20 articles were identified, in which the efficacy of CAR was described in experimental models of stroke, traumatic brain injury, Parkinson's disease, Alzheimer's disease, , epilepsy, and seizure, through motor deficits improvements in neurochemical activity, especially antioxidant systems, reducing inflammation, oxidative stress and apoptosis as well as inhibition of TRPC1 and TRPM7.

CONCLUSION

The data presented in this study support the beneficial impact of CAR on behavioural and neurochemical deficits. CAR benefits accrue because of its anti-apoptotic, antioxidant, and anti-inflammatory properties. Therefore, CAR has emerged as an alternative treatment for neurological disorders based on its properties.

Rehabilitation of Concussion and Persistent Postconcussive Symptoms

Concussion and persistent postconcussive symptoms (PPCS) are encountered by clinicians in sports medicine, pediatrics, neurology, physiatry, emergency medicine, and primary care. Clinical management may require a multidisciplinary approach. This article presents a structured method for the diagnosis of concussion and PPCS in the outpatient setting, which includes a history, physical examination, and additional tests as clinically indicated to help identify underlying symptom generators. Treatment for concussion and PPCS should be individualized, based on predominant signs and symptoms, and can include subsymptom threshold aerobic exercise, cervical physical therapy, vestibulo-ocular rehabilitation, behavioral and cognitive psychotherapy, and some symptom-specific pharmacological therapies.

Prognostic Analysis of Emergency Decompressive Craniectomy for Patients with Severe Traumatic Brain Injury with Bilateral Fixed Dilated Pupils

OBJECTIVE

For patients with severe traumatic brain injury (sTBI) with bilateral fixed dilated pupils (BFDP), the value of aggressively decompressive craniectomy (DC) treatment is still controversial. The objective of this study was to analyze and validate the outcome of DC in patients with sTBI with BFDP.

METHODS

We retrospectively collected data from 44 patients with sTBI with BFDP who underwent DC treatment from July 2011 to June 2018. Outcomes used as indicators were mortality and favorable outcome. The analysis was based on the Glasgow Outcome Scale score recorded at discharge, 6, and 12 months after trauma.

RESULTS

The overall survival was 36.4% (16/44) at discharge and 25.0% (11/44) at 6 and 12 months, and the favorable outcome (Glasgow Outcome Scale score = 4-5) at discharge, 6, and 12 months after injury was 9.1% (4/44), 13.6% (6/44), and 20.5% (9/44), respectively. Sex (P = 0.046), preoperative Glasgow Coma Scale (GCS) score (P = 0.031), injury-surgery intervals (P = 0.022), and tracheotomy (P = 0.017) were independent associations to 6 and 12 months follow-up survival, whereas only preoperative GCS score (odds ratio, 6.088; confidence interval, 1.172-31.612; P = 0.032) and injury-surgery intervals (odds ratio, 0.241; confidence interval, 0.065-0.893; P = 0.033) were independent associations with 12 months follow-up favorable outcome.

CONCLUSIONS

BFDP indicates a grave prognostic sign after sTBI, but the higher preoperative GCS score and shorter injury-surgery intervals in patients who underwent DC treatment might independently predict favorable outcome for patients with sTBI with BFDP, and patients might benefit more than expected if the DC treatment were applied more aggressively and positively.

Nilvadipine suppresses inflammation via inhibition of P-SYK and restores spatial memory deficits in a mouse model of repetitive mild TBI

Repeated exposure to mild TBI (mTBI) has been linked to an increased risk of Alzheimer’s disease (AD), chronic traumatic encephalopathy (CTE) and other neurodegenerative diseases. Some pathological features typically observed in AD have been found in postmortem brains of TBI and CTE, hence treatments tested for AD have a potential to be effective against r-mTBI outcomes. Neuroinflammation may present a possible answer due to its central role both in acute brain injury and in chronic degenerative-like disorders. Our previous studies have shown that drug nilvadipine, acting as an inhibitor of spleen tyrosine kinase (SYK), is effective at reducing inflammation, tau hyperphosphorylation and amyloid production in AD mouse models. To demonstrate the effect of nilvadipine in the absence of age-related variables, we introduced the same treatment to young r-mTBI mice. We further investigate therapeutic mechanisms of nilvadipine using its racemic properties. Both enantiomers, (+)-nilvadipine and (−)-nilvadipine, can lower SYK activity, whereas (+)-nilvadipine is also a potent L-type calcium channel blocker (CCB) and shown to be anti-hypertensive. All r-mTBI mice exhibited increased neuroinflammation and impaired cognitive performance and motor functions. Treatment with racemic nilvadipine mitigated the TBI-induced inflammatory response and significantly improved spatial memory, whereas (−)-enantiomer decreased microgliosis and improved spatial memory but failed to reduce the astroglial response to as much as the racemate. These results suggest the therapeutic potential of SYK inhibition that is enhanced when combined with the CCB effect, which indicate a therapeutic advantage of multi-action drugs for r-mTBI.

Efficacy of Simultaneous Administration of Nimodipine, Progesterone, and Magnesium Sulfate in Patients with Severe Traumatic Brain Injury: A Randomized Controlled Trial

OBJECTIVE

To investigate the safety and efficacy of simultaneous administration of nimodipine, progesterone, magnesium sulfate in patients suffering from severe traumatic brain injury (TBI).

METHODS

Overall, 90 patients with blunt head trauma who were admitted to the Besat hospital, Hamadan University of Medical Sciences, Iran through the Emergency Department in 2017 to 2018 were randomly assigned to the study or control groups each containing 45 patients. In the study group, intravenous nimodipine 60 mg every 12 hours for 5 days, intramuscular progesterone 1 mg/kg daily for 5 days, and magnesium sulfate 5 grams stat followed by 2.5 grams every 4 hours for 21 days were administered. Daily GCS and jugular venous oxygen saturation (SjvO2) of the patients were measured on admission day (day 0) through hospitalization day 4 at the intensive care unit. Then, all patients were visited at three months after discharge.

RESULTS

The mean age of the patients was 31.4 ± 12.8 years including 59 (65.6%) men with no significant difference between the groups. The baseline GCS and SjvO2 of the patients were comparable in both groups, however, GCS of the patients in the study group were significantly higher in the next 4 hospitalization days compared to the controls. Whereas, the SjvO2 of the patients were not significantly different between the groups during these days. Three-month mortality rate of the patients in the study group was significantly lower than the three-month mortality rate of the patients in the control groups (22.2% vs. 42.2%, p=0.042).

CONCLUSION

Administration of combined protocol of magnesium sulfide, progesterone and nimodipine may be safe and effective in patients suffering from severe TBI.

CLINICAL TRIAL REGISTRY

IRCT201210229534N2.

Knockdown of RTN1-C attenuates traumatic neuronal injury through regulating intracellular Ca2+ homeostasis

Reticulons (RTNs) are a family of membrane-bound proteins that are dominantly localized to the endoplasmic reticulum (ER) membrane. RTN1-C is one member of RTNs abundantly expressed in the brain and has been shown to mediate neuronal injury in cerebral ischemia models. In the present study, we investigated the role of RTN1-C in an in vitro brain trauma model mimicked by traumatic neuronal injury (TNI) in primary cultured cortical neurons. TNI increased the expression of RTN1-C in cortical neurons but had no effect on RTN1-A and RTN1-B. Knockdown of RTN1-C with specific siRNA (Si-RTN1-C) significantly decreased cytotoxicity and apoptosis after TNI. The results of Ca²⁺ imaging showed that intracellular Ca²⁺ overload induced by TNI was attenuated by RTN1-C knockdown. Furthermore, the activation of metabotropic glutamate receptor 1 (mGluR1)-induced Ca²⁺ response was partially prevented by Si-RTN1-C transfection. We also evaluated the role of RTN1-C in store-operated Ca²⁺ entry (SOCE) in cortical neurons using the ER Ca²⁺ inducer thapsigargin (Tg). The results showed that knockdown of RTN1-C alleviated the SOCE-mediated Ca²⁺ influx and decreased the expression of stromal interactive molecule 1 (STIM1). In summary, the present study found that knockdown of RTN1-C protected neurons against TNI via preservation of intracellular Ca²⁺ homeostasis, which was associated with the inhibition of mGluR1-mediated ER Ca²⁺ release and suppression of STIM1-related SOCE. Thus, RTN1-C might represent a therapeutic target for traumatic brain injury (TBI) research.

Treatment With Nilvadipine Mitigates Inflammatory Pathology and Improves Spatial Memory in Aged hTau Mice After Repetitive Mild TBI

Mild traumatic brain injury (mTBI) is the most common form of brain trauma worldwide. The effects of mTBI are not well-studied within the elderly population, yet older adults constitute a significant portion of all mTBI patients. Few preclinical studies have focused on the effects of mTBI, or mTBI treatments, in the aged brain, and none have explored repetitive mTBI (r-mTBI). In this study, we have administered our well-characterized 5-injury model (5 r-mTBI) to hTau mice aged 24 months to explore the neurobehavioral and neuropathological outcomes, and the effects of treatment with the dihydropyridine, Nilvadipine. Our previous studies have shown that Nilvadipine inhibits spleen tyrosine kinase (Syk), is effective at reducing inflammation, tau hyperphosphorylation, and amyloid production, and it has recently been investigated in a European Phase III clinical trial for Alzheimer’s disease (AD). In our 24-month-old r-mTBI mice, we observed increased neuroinflammation and a trend toward impaired cognitive performance compared to sham controls. Treatment with Nilvadipine mitigated the TBI-induced inflammatory response in aged r-mTBI animals and significantly improved spatial memory. To our knowledge, this is the only preclinical study focusing on the treatment of r-mTBI in aged, and these results suggest a therapeutic potential of Nilvadipine for consequences of mTBI.

Diltiazem Promotes Regenerative Axon Growth

Axotomy results in permanent loss of function after brain and spinal cord injuries due to the minimal regenerative propensity of the adult central nervous system (CNS). To identify pharmacological enhancers of axon regeneration, 960 compounds were screened for cortical neuron axonal regrowth using an in vitro cortical scrape assay. Diltiazem, verapamil, and bromopride were discovered to facilitate axon regeneration in rat cortical cultures, in the presence of chondroitin sulfate proteoglycans (CSPGs). Diltiazem, an L-type calcium channel blocker (L-CCB), also promotes axon outgrowth in adult primary mouse dorsal root ganglion (DRG) and induced human sensory (iSensory) neurons.

Suppression of cortical TRPM7 protein attenuates oxidative damage after traumatic brain injury via Akt/endothelial nitric oxide synthase pathway

Neuronal death after traumatic brain injury (TBI) is a complex process resulting from a combination of factors, many of which are still unknown. Transient receptor potential melastatin 7 (TRPM7) is a transient receptor potential channel that has been demonstrated to mediate ischemic and traumatic neuronal injury in vitro. In the present study, TRPM7 was suppressed in the rat cerebral cortex by intracortical injections of viral vectors bearing shRNA specific for TRPM7 to investigate its potential role in an in vivo TBI model. We found that TRPM7 suppression significantly reduced brain edema, brain contusion volume and motor functional deficits, which was sustained for at least 2 weeks after the insult. These protective effects were accompanied by inhibited apoptosis in injured cortex. Also, TRPM7 suppression attenuated lipid peroxidation, decreased the expression of protein carbonyl, and preserved the endogenous antioxidant enzyme activities. The results of western blot analysis showed that TRPM7 suppression markedly increased the phosphorylation of Akt and endothelial nitric oxide synthase (eNOS). In addition, blocking Akt/eNOS pathway activation by the specific inhibitor LY294002 (LY, 10 μL, 10 mmol/L) or L-NIO (0.5 mg/kg) partially reversed the protective effects of TRPM7 suppression and its anti-oxidative activities. Taken together, these findings demonstrated that regional inhibition of TRPM7 in cerebral cortex exerts neuroprotective effects against TBI through activation of Akt/eNOS pathway. Thus, TRPM7 might represent a potential drug development target for the treatment of TBI.

Differential expression of microRNAs in the brains of mice subjected to increasing grade of mild traumatic brain injury

OBJECTIVE

To investigate the effect of heterogeneity in mTBI on miRNA expression in mouse brain and to identify molecular pathways targeted by the modulated miRNAs.

METHODS

A weight drop device was used to induce four increasing grades of mTBI. MiRNA expression was evaluated using TaqMan rodent miRNA arrays. Bioinformatics analysis was done using the DIANA miRPath tool and Ingenuity Pathway Analysis software. Histology of brain sections was evaluated using H&E staining.

RESULTS

No histologic lesions were observed in the brains of injured mice; however, significant modulation in miRNA expression profile was observed. Global miRNA profiling indicated a trend of decrease in the number of modulated miRNAs from 24 hours to day 7 post-injury, except for the most severe grade of mTBI. Canonical pathways like calcium signalling, synaptic pathways and axon guidance pathway were the major targets of the modulated miRNAs. Network correlation analyses indicated an interaction between the modulated miRNAs and putative protein biomarkers of TBI.

CONCLUSIONS

The data demonstrated that varying intensities of mTBI induced a differential miRNA expression profile in the brain post-injury. Pathways such as calcium and synaptic signalling were major targets of modulated miRNAs and may play a role in the pathophysiology of mTBI.

Antidepressant-like activity of liposomal formulation containing nimodipine treatment in the tail suspension test, forced swim test and MAOB activity in mice

Previous studies have shown that intracellular calcium ion dysfunction may be an etiological factor in affective illness. Nimodipine (NMD) is a Ca(2+) channel blocker that has been extensively investigated for therapy of central nervous system (CNS) disorders. In this work, we have evaluated the antidepressant-like activity of nimodipine encapsulated into liposomes (NMD-Lipo) in mice through tail suspension and forced swim assays, as well as MAOB activity. During the tail suspension test, the administration of NMD-Lipo at 0.1, 1 and 10mg/kg was able to promote a reduction in the immobility time of animals greater than the positive control (imipramine). In the forced swim test, the immobility time of mice treated with NMD-Lipo was reduced. This reduction was significantly greater than that found in the animals treated with imipramine and paroxetine. This may suggest that NMD-Lipo provides more antidepressant-like activity than in positive controls. The groups that received a combination of liposomal NMD and antidepressant drugs showed lower immobility time than the groups, which were treated only with imipramine or paroxetine. The mice treated with the combination of NMD-Lipo and reserpine presented an increase in the time of immobility compared with animals treated only with NMD-Lipo. There was a significant decrease in MAOB activity in animals treated with NMD-Lipo compared with untreated animals. The results of the tail suspension test, forced swim test and MAOB activity suggested that the antidepressant activity of NMD-Lipo may be related to an increase in the cerebral monoamine concentrations.