Early and Severe Symptomatic Cerebral Vasospasm After Mild Traumatic Brain Injury

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.

Neuroendovascular Surgery Applications in Craniocervical Trauma

Cerebrovascular injuries resulting from blunt or penetrating trauma to the head and neck often lead to local hemorrhage and stroke. These injuries present with a wide range of manifestations, including carotid or vertebral artery dissection, pseudoaneurysm, occlusion, transection, arteriovenous fistula, carotid-cavernous fistula, epistaxis, venous sinus thrombosis, and subdural hematoma. A selective review of the literature from 1989 to 2023 was conducted to explore various neuroendovascular surgical techniques for craniocervical trauma. A PubMed search was performed using these terms: endovascular, trauma, dissection, blunt cerebrovascular injury, pseudoaneurysm, occlusion, transection, vasospasm, carotid-cavernous fistula, arteriovenous fistula, epistaxis, cerebral venous sinus thrombosis, subdural hematoma, and middle meningeal artery embolization. An increasing array of neuroendovascular procedures are currently available to treat these traumatic injuries. Coils, liquid embolics (onyx or n-butyl cyanoacrylate), and polyvinyl alcohol particles can be used to embolize lesions, while stents, mechanical thrombectomy employing stent-retrievers or aspiration catheters, and balloon occlusion tests and super selective angiography offer additional treatment options based on the specific case. Neuroendovascular techniques prove valuable when surgical options are limited, although comparative data with surgical techniques in trauma cases is limited. Further research is needed to assess the efficacy and outcomes associated with these interventions.

Interleukin 6 in cerebrospinal fluid is a biomarker for delayed cerebral ischemia (DCI) related infarctions after aneurysmal subarachnoid hemorrhage

Interleukin 6 (IL-6) is a prominent proinflammatory cytokine and has been discussed as a potential biomarker for delayed cerebral ischemia (DCI) following aneurysmal subarachnoid hemorrhage. In the present study we have analyzed the time course of serum and cerebrospinal fluid (CSF) IL-6 levels in 82 patients with severe aneurysmal subarachnoid hemorrhage (SAH) requiring external ventricular drains in correlation to angiographic vasospasm, delayed cerebral ischemia, secondary infarctions and other clinical parameters. We observed much higher daily mean IL-6 levels (but also large interindividual variations) in the CSF than the serum of the patients with a peak between days 4 and 14 including a maximum on day 5 after SAH. Individual CSF peak levels correlated significantly with DCI (mean day 4–14 peak, DCI: 26,291 ± 24,159 pg/ml vs. no DCI: 16,184 ± 13,163 pg/ml; P = 0.023). Importantly, CSF IL-6 levels differed significantly between cases with DCI and infarctions and patients with DCI and no infarction (mean day 4–14 peak, DCI with infarction: 37,209 ± 26,951 pg/ml vs. DCI, no infarction: 15,123 ± 11,239 pg/ml; P = 0.003), while findings in the latter patient group were similar to cases with no vasospasm (mean day 4–14 peak, DCI, no infarction: 15,123 ± 11,239 vs. no DCI: 15,840 ± 12,979; P = 0.873). Together, these data support a potential role for elevated CSF IL-6 levels as a biomarker for DCI with infarction rather than for DCI in general. This fits well with a growing body of evidence linking neuroinflammation to ischemia and infarction, but (together with the large interindividual variations observed) limits the diagnostic usefulness of CSF IL-6 levels in SAH patients.

In vivo Two-Photon Imaging Reveals Acute Cerebral Vascular Spasm and Microthrombosis After Mild Traumatic Brain Injury in Mice

Mild traumatic brain injury (mTBI), or concussion, is reported to interfere with cerebral blood flow and microcirculation in patients, but our current understanding is quite limited and the results are often controversial. Here we used longitudinal in vivo two-photon imaging to investigate dynamic changes in cerebral vessels and velocities of red blood cells (RBC) following mTBI. Closed-head mTBI induced using a controlled cortical impact device resulted in a significant reduction of dwell time in a Rotarod test but no significant change in water maze test. Cerebral blood vessels were repeatedly imaged through a thinned skull window at baseline, 0.5, 1, 6 h, and 1 day following mTBI. In both arterioles and capillaries, their diameters and RBC velocities were significantly decreased at 0.5, 1, and 6 h after injury, and recovered in 1 day post-mTBI. In contrast, decreases in the diameter and RBC velocity of venules occurred only in 0.5–1 h after mTBI. We also observed formation and clearance of transient microthrombi in capillaries within 1 h post-mTBI. We concluded that in vivo two-photon imaging is useful for studying earlier alteration of vascular dynamics after mTBI and that mTBI induced reduction of cerebral blood flow, vasospasm, and formation of microthrombi in the acute stage following injury. These changes may contribute to early brain functional deficits of mTBI.

Real-time imaging of infarction deterioration after ischemic stroke in rats using electrical impedance tomography

OBJECTIVE

This study investigated the feasibility of electrical impedance tomography (EIT) for monitoring the deterioration of ischemic lesion after the onset of stroke.

APPROACH

Fifteen rats were randomly distributed into two groups: rats operated to establish a right middle cerebral artery occlusion (MCAO) (n  =  10), and sham-operated rats (n  =  5). Then, the operated rats were kept 2 h under anesthesia for EIT monitoring. Subsequently, descriptive statistical analysis was performed on whole-brain resistivity changes, and repeated-measures analysis of variance (ANOVA) on the average resistivity variation index. Additionally, pathological examinations were performed after 6 h of infarction.

MAIN RESULTS

The results obtained showed that ischemic damage developed in the right corpus striatum of the rats with MCAO, whereas the brains of the sham group showed no anomalies. The descriptive statistical analysis revealed that the whole-brain resistivity changes after 30, 60, 90, and 120 min of infarction were 0.063  ±  0.038, 0.097  ±  0.046, 0.141  ±  0.062, and 0.204  ±  0.092 for the rats with MCAO and 0.029  ±  0.021, 0.002  ±  0.002, 0.017  ±  0.011, and  -0.001  ±  0.011 for the sham-operated rats, respectively. The repeated-measures ANOVA revealed that the right MCAO model resulted in a significant impedance increase in the right hemisphere, which continued to increase over time after infarction.

SIGNIFICANCE

The overall study results indicate that EIT facilitates monitoring of local impedance variations caused by MCAO and may be a solution for real-time monitoring of intracranial pathological changes in ischemic stroke patients.

Effect of intraoperative infusion of dexmedetomidine on postoperative recovery in patients undergoing endovascular interventional therapies: A prospective, randomized, controlled trial

BACKGROUND

Rapid emergence from general anesthesia during endovascular interventional therapies (EITs) is important. However, the solution that improved quality of both analepsia and postoperative recovery after EITs has not been specifically addressed. We conducted this prospective, randomized, controlled trial to evaluate the intraoperative infusion of dexmedetomidine on quality of analepsia and postoperative recovery in patients undergoing EITs.

METHODS

Eighty-six patients undergoing EITs were divided into three groups: RD1 (dexmedetomidine at an initial dose of 0.5 μg/kg for 10 min adjusted to 0.2 μg kg^-1  hr^-1 throughout EIT), RD2 (dexmedetomidine at an initial dose of 0.5 μg/kg for 10 min adjusted to 0.4 μg kg^-1  hr^-1 throughout EIT), and RD3 (dexmedetomidine at an initial dose of 0.5 μg/kg for 10 min adjusted to 0.6 μg kg^-1  hr^-1 throughout EIT). An analgesia system delivered sufentanil only. The primary outcome measure was the total consumption of nimodipine during the first 48 hr after surgery. The secondary outcome measures were sufentanil consumption, pain intensity, hemodynamics, functional activity score (FAS), neurologic examination, level of sedation (LOS), and Bruggrmann comfort scale (BCS). We also recorded the intraoperative hemodynamic data, requirement of narcotic and vasoactive drugs, prevalence of complications and symptomatic cerebral vasospasm, duration of postanesthesia care unit (PACU) stay, Glasgow Outcome Score (GOS) at 3 months, and prevalence of cerebral infarction 30 days after surgery.

RESULTS

Dexmedetomidine application in the regimen RD3 reduced the consumption of the total dose of nimodipine and sufentanil 48 hr after surgery, prevalence of symptomatic cerebral vasospasm, consumption of narcotic drugs and nimodipine during surgery, pain intensity during the first 8 hr after surgery, and increased both BCS during the first 4 hr after surgery and hemodynamic stability. However, the LOS was increased at the 0.5 hr after surgery and surgeon satisfaction score was lower. There were no significant differences among the groups for consumption of vasoactive drugs except urapidil, Glasgow coma scale (GCS) and FAS during the first 48 hr after surgery, GOS at 3 months, and cerebral infarction after 30 days.

CONCLUSIONS

Dexmedetomidine (an initial dose of 0.5 μg/kg for 10 min adjusted to 0.6 μg kg^-1 hr^-1 throughout EIT) could reduce the total consumption of nimodipine and opioid during the first 48 hr after surgery, the concerning adverse effects, and improve pain scores. The optimal dosage of dexmedetomidine during EITs merits further investigation.