Inhibition of phosphodiesterase 4 attenuates aquaporin 4 expression and astrocyte swelling following cerebral ischemia/reperfusion injury

We have previously shown that phosphodiesterase 4 (PDE4) inhibition protects against neuronal injury in rats following middle cerebral artery occlusion/reperfusion (MCAO/R). However, the effects of PDE4 on brain edema and astrocyte swelling are unknown. In this study, we showed that inhibition of PDE4 by Roflumilast (Roflu) reduced brain edema and brain water content in rats subjected to MCAO/R. Roflu decreased the expression of aquaporin 4 (AQP4), while the levels of phosphorylated protein kinase B (Akt) and forkhead box O3a (FoxO3a) were increased. In addition, Roflu reduced cell volume and the expression of AQP4 in primary astrocytes undergoing oxygen and glucose deprivation/reoxygenation (OGD/R). Consistently, PDE4B knockdown showed similar effects as PDE4 inhibition; and PDE4B overexpression rescued the inhibitory role of PDE4B knockdown on AQP4 expression. We then found that the effects of Roflu on the expression of AQP4 and cell volume were blocked by the Akt inhibitor MK2206. Since neuroinflammation and astrocyte activation are the common events that are observed in stroke, we treated primary astrocytes with interleukin-1β (IL-1β). Astrocytes treated with IL-1β showed decreased AQP4 and phosphorylated Akt and FoxO3a. Roflu significantly reduced AQP4 expression, which was accompanied by increased phosphorylation of Akt and FoxO3a. Furthermore, overexpression of FoxO3a partly reversed the effect of Roflu on AQP4 expression. Our findings suggest that PDE4 inhibition limits ischemia-induced brain edema and astrocyte swelling via the Akt/FoxO3a/AQP4 pathway. PDE4 is a promising target for the intervention of brain edema after cerebral ischemia.

Reduction in wound healing complications and infection rate by lumbar CSF drainage after decompressive hemicraniectomy

OBJECTIVE

Wound healing disorders and surgical site infections are the most frequently encountered complications after decompressive hemicraniectomy (DHC). Subgaleal CSF accumulation causes additional tension of the scalp flap and increases the risk of wound dehiscence, CSF fistula, and infection. Lumbar CSF drainage might relieve subgaleal CSF accumulation and is often used when a CSF fistula through the surgical wound appears. The aim of this study was to investigate if early prophylactic lumbar drainage might reduce the rate of postoperative wound revisions and infections after DHC.

METHODS

The authors retrospectively analyzed 104 consecutive patients who underwent DHC from January 2019 to May 2021. Before January 2020, patients did not receive lumbar drainage, whereas after January 2020, patients received lumbar drainage within 3 days after DHC for a median total of 4 (IQR 2-5) days if the first postoperative CT scan confirmed open basal cisterns. The primary endpoint was the rate of severe wound healing complications requiring surgical revision. Secondary endpoints were the rate of subgaleal CSF accumulations and hygromas as well as the rate of purulent wound infections and subdural empyema.

RESULTS

A total of 31 patients died during the acute phase; 34 patients with and 39 patients without lumbar drainage were included for the analysis of endpoints. The predominant underlying pathology was malignant hemispheric stroke (58.8% vs 66.7%) followed by traumatic brain injury (20.6% vs 23.1%). The rate of surgical wound revisions was significantly lower in the lumbar drainage group (5 [14.7%] vs 14 [35.9%], p = 0.04). A stepwise linear regression analysis was used to identify potential covariates associated with wound healing disorder and reduced them to lumbar drainage and BMI. One patient was subject to paradoxical herniation. However, the patient's symptoms rapidly resolved after lumbar drainage was discontinued, and he survived with only moderate deficits related to the primary disease. There was no significant difference in the rate of radiological herniation signs. The median lengths of stay in the ICU were similar, with 12 (IQR 9-23) days in the drainage group compared with 13 (IQR 11-23) days in the control group (p = 0.21).

CONCLUSIONS

In patients after DHC and open basal cisterns on postoperative CT, lumbar drainage appears to be safe and reduces the rate of surgical wound revisions and intracranial infection after DHC while the risk for provoking paradoxical herniation is low early after surgery.

Craniectomy size and decompression of the temporal base using the altered posterior question-mark incision for decompressive hemicraniectomy

The altered posterior question-mark incision for decompressive hemicraniectomy (DHC) was proposed to reduce the risk of intraoperative injury of the superficial temporal artery (STA) and demonstrated a reduced rate of wound-healing disorders after cranioplasty. However, decompression size during DHC is essential and it remains unclear if the new incision type allows for an equally effective decompression. Therefore, this study evaluated the efficacy of the altered posterior question-mark incision for craniectomy size and decompression of the temporal base and assessed intraoperative complications compared to a modified standard reversed question-mark incision. The authors retrospectively identified 69 patients who underwent DHC from 2019 to 2022. Decompression and preservation of the STA was assessed on postoperative CT scans and CT or MR angiography. Forty-two patients underwent DHC with the standard reversed and 27 patients with the altered posterior question-mark incision. The distance of the margin of the craniectomy to the temporal base was 6.9 mm in the modified standard reversed and 7.2 mm in the altered posterior question-mark group (p = 0.77). There was no difference between the craniectomy sizes of 158.8 mm and 158.2 mm, respectively (p = 0.45), and there was no difference in the rate of accidental opening of the mastoid air cells. In both groups, no transverse/sigmoid sinus was injured. Twenty-four out of 42 patients in the modified standard and 22/27 patients in the altered posterior question-mark group had a postoperative angiography, and the STA was preserved in all cases in both groups. Twelve (29%) and 5 (19%) patients underwent revision due to wound-healing disorders after DHC, respectively (p = 0.34). There was no difference in duration of surgery. Thus, the altered posterior question-mark incision demonstrated technically equivalent and allows for an equally effective craniectomy size and decompression of the temporal base without increasing risks of intraoperative complications. Previously described reduction in wound-healing complications and cranioplasty failures needs to be confirmed in prospective studies to demonstrate the superiority of the altered posterior question-mark incision.

Surgery for Malignant Acute Ischemic Stroke: A Narrative Review of the Knowns and Unknowns

Malignant acute ischemic stroke (AIS) is characterized by acute neurological deterioration caused by progressive space-occupying brain edema, often occurring in the first hours to days after symptom onset. Without any treatment, the result is often fatal. Despite advances in treatment for AIS, up to 80% of patients with a large hemispheric stroke or cerebellar stroke are at risk of poor outcome. Decompressive surgery can be life-saving in a subgroup of patients with malignant AIS, but uncertainties exist on patient selection, predictors of malignant infarction, perioperative management, and timing of intervention. Although survivors are left disabled, most agree with the original decision to undergo surgery and would make the same decision again. In this narrative review, we focus on the clinical and radiological predictors of malignant infarction in AIS and outline the technical aspects of decompressive surgery as well as duraplasty and cranioplasty. We discuss the current evidence and recommendations for surgery in AIS, highlighting gaps in knowledge, and suggest directions for future studies. KEY POINTS: · Acute ischemic stroke from occlusion of a proximal intracranial artery can progress quickly to malignant edema, which can be fatal in 80% of patients despite medical management.. · Decompression surgery is life-saving within 48 hours of stroke onset, but the benefits beyond this time and in the elderly are unknown.. · Decompressive surgery is associated with high morbidity, particularly in the elderly. The decision to operate must be made after considering the individual's preference and expectations of quality of life in the context of the clinical condition.. · Further studies are needed to refine surgical technique including value of duraplasty and understand the role monitoring intracranial pressure during and after decompressive surgery.. · More studies are needed on the pathophysiology of malignant cerebral edema, prediction models including imaging and biomarkers to identify which subgroup of patients will benefit from decompressive surgery.. · More research is needed on factors associated with morbidity and mortality after cranioplasty, safety and efficacy of implants, and comparisons between them.. · Further studies are needed to assess the long-term effects of physical disability and quality of life of survivors after surgery, particularly those with severe neurological deficits..

Modifying skin flaps for achieving very large decompressive craniectomies in malignant middle cerebral artery territory infarcts: A technical note

INTRODUCTION

Decompressive craniectomy is a well described treatment to salvage life in large middle cerebral artery (MCA) territory infarcts. The size of the craniectomy is limited by the size of the skin incision and very large craniectomies need large skin flaps that are prone to necrosis at the wound margins.

MATERIAL AND METHODS

We describe two modifications in the skin flap that we have used in 7 patients to achieve very large bony decompressions in malignant MCA infarctions without compromising on flap vascularity. One consists of a linear extension posteriorly from the question mark or reverse question mark incision while the other is an "n" shaped incision.

RESULTS

With these modifications we achieved craniectomies of size 15.6-17.8 cm in the anteroposterior and 10.7-12 cm in vertical axis of the bone flap removed in our patients. There were no additional procedural or wound related complications in a 6-month follow up.

CONCLUSIONS

Removal of a standard size bone flap may achieve suboptimal decompression in cases of large MCA territory infarctions. Imaginative tailoring of skin flaps helps to remove larger volumes of skull with no added procedural morbidity.

Machine learning prediction of malignant middle cerebral artery infarction after mechanical thrombectomy for anterior circulation large vessel occlusion

OBJECTIVE

Prediction of malignant middle cerebral artery infarction (MMI) could identify patients for early intervention. We trained and internally validated a ML model that predicts MMI following mechanical thrombectomy (MT) for ACLVO.

METHODS

All patients who underwent MT for ACLVO between 2015 - 2021 at a single institution were reviewed. Data was divided into 80% training and 20% test sets. 10 models were evaluated on the training set. The top 3 models underwent hyperparameter tuning using grid search with nested 5-fold CV to optimize the area under the receiver operating curve (AUROC). Tuned models were evaluated on the test set and compared to logistic regression.

RESULTS

A total of 381 patients met the inclusion criteria. There were 50 (13.1%) patients who developed MMI. Out of the 10 ML models screened on the training set, the top 3 performing were neural network (median AUROC 0.78, IQR 0.72 - 0.83), support vector machine ([SVM] median AUROC 0.77, IQR 0.72 - 0.83), and random forest (median AUROC 0.75, IQR 0.68 - 0.81). On the test set, random forest (median AUROC 0.78, IQR 0.73 - 0.83) and neural network (median AUROC 0.78, IQR 0.73 - 0.83) were the top performing models, followed by SVM (median AUROC 0.77, IQR 0.70 - 0.83). These scores were significantly better than those for logistic regression (AUROC 0.72, IQR 0.66 - 0.78), individual risk factors, and the Malignant Brain Edema score (p < 0.001 for all).

CONCLUSION

ML models predicted MMI with good discriminative ability. They outperformed standard statistical techniques and individual risk factors.

Intracranial Pressure as an Objective Biomarker of Decompression Adequacy in Large Territory Infarction: A Multicenter Observational Study

Background

Decompressive craniectomy (DC) improves the survival and functional outcomes in patients with malignant cerebral infarction. Currently, there are no objective intraoperative markers that indicates adequate decompression. We hypothesise that closure intracranial pressure (ICP) correlates with postoperative outcomes.

Methods

This is a multicentre retrospective review of all 75 DCs performed for malignant cerebral infarction. The patients were divided into inadequate ICP (iICP) and good ICP (gICP) groups based on a suitable ICP threshold determined with tiered receiver operating characteristic and association analysis. Multivariable logistic regression was performed for various postoperative outcomes.

Results

An ICP threshold of 7 mmHg was determined, with 36 patients (48.0%) and 39 patients (52.0%) in the iICP and gICP group, respectively. After adjustment, postoperative osmotherapy usage was more likely in the iICP group (OR 6.32, p = 0.003), and when given, was given for a longer median duration (iICP, 4 days; gICP, 1 day, p = 0.003). There was no difference in complications amongst both groups. When an ICP threshold of 11 mmHg was applied, there was significant difference in the duration on ventilator (ICP ≥11 mmHg, 3–9 days, ICP <11 mmHg, 3–5 days, p = 0.023).

Conclusion

Surgical decompression works complementarily with postoperative medical therapy to manage progressive cerebral edema in malignant cerebral infarctions. This is a retrospective study which showed that closure ICP, a novel objective intraoperative biomarker, is able to guide the adequacy of DC in this condition. Various surgical manoeuvres can be performed to ensure that this surgical aim is accomplished.

Predicting Functional Outcome After Decompressive Craniectomy for Malignant Hemispheric Infarction: Clinical and Novel Imaging Factors

OBJECTIVE

Decompressive craniectomy (DC) is an established optional treatment for malignant hemispheric infarction (MHI). We analyzed relevant clinical factors and computed tomography (CT) measurements in patients with DC for MHI to identify predictors of functional outcome 3-6 months after stroke.

METHODS

This study was performed at 2 comprehensive stroke centers. The inclusion criteria required DC for MHI, no additional intraoperative procedures (strokectomy or cerebral ventricular drain placement), and documented functional status 3-6 months after the stroke. We classified functional outcome as acceptable if the modified Rankin Scale score was <5, or as unacceptable if it was 5 or 6 (bedbound and totally dependent on others or death). Multiple logistic regression analyzed relevant clinical factors and multiple perioperative CT measurements to identify predictors of acceptable functional outcome.

RESULTS

Of 87 identified consecutive patients, 66 met the inclusion criteria. Acceptable functional outcome occurred in 35 of 66 (53%) patients. Likelihood of acceptable functional outcome decreased significantly with increasing age (OR 0.92, 95% CI 0.82-0.97, P = 0.004) and with increasing post-DC midline brain shift (OR 0.78, 95% CI 0.64-0.96, P = 0.016), and decreased non-significantly with left-sided stroke (OR 0.30, 95% CI 0.08-1.10, P = 0.069) and with increasing craniectomy barrier thickness (OR 0.92, 95% CI 0.85-1.01, P = 0.076).

CONCLUSIONS

Patient age and the post-DC midline shift may be useful in prognosticating functional outcome after DC for MHI. Stroke side and craniectomy barrier thickness merit further ideally prospective outcome prediction testing.

Extensive Convexity Flattening of a Synthetic Skull Implant the Overcome Major Scalp Deficiency After Multiple Craniotomies

Multiple craniofacial surgeries and postoperative recalcitrant infections frequently can lead to secondary scalp tissue scarring and skin retraction. Although there are different methods of reducing and optimizing scalp skin tension, the authors describe a last resort treatment method of cranioplastic procedure, which despite of its unfavorable cosmetic outcome, relieves the skin tension through extensive flattening of the polyetheretherketone curvature. Thereby, a custom-made cranioplastic bone flap was extensively flattened in the curvature of the fronto-parietal area with consideration of the related brain hemisphere extension. The extent of bone curvature flatting reduced the skin tension significantly and allowed for plain and simple tension-free wound closure in a chronic smoker patient with poor skin quality and brain atrophy. Although brain extension was sufficient, the cosmetic outcome was unfavorable with regard to skull symmetry, but well accepted and satisfactory for the patient due to preoperative discussion outcome expectation from surgery. Thus, extensive polyetheretherketone curvature flattening is a straightforward and simple last resort treatment option for tension-free skin closure in high-risk patients with extensive skin scarring and retraction and previous reconstructive plastic skin relief procedures. However, this method is limited in patients with normal brain hemisphere extension.

Limiting Brain Shift in Malignant Hemispheric Infarction by Decompressive Craniectomy

OBJECTIVE

Decompressive craniectomy (DC) improves functional outcomes in selected patients with malignant hemispheric infarction (MHI), but variability in the surgical technique and occasional complications may be limiting the effectiveness of this procedure. Our aim was to evaluate predefined perioperative CT measurements for association with post-DC midline brain shift in patients with MHI.

METHODS

At two medical centers we identified 87 consecutive patients with MHI and DC between January 2007 and December 2019. We used our previously tested methods to measure the craniectomy surface area, extent of transcalvarial brain herniation, thickness of tissues overlying the craniectomy, diameter of the cerebral ventricle atrium contralateral to the stroke, extension of infarction beyond the craniectomy edges, and the pre and post-DC midline brain shifts. To avoid potential confounding from medical treatments and additional surgical procedures, we excluded patients with the first CT delayed >30 hours post-DC, resection of infarcted brain, or insertion of an external ventricular drain during DC. The primary outcome in multiple linear regression analysis was the postoperative midline brain shift.

RESULTS

We analyzed 72 qualified patients. The average midline brain shift decreased from 8.7 mm pre-DC to 5.4 post-DC. The only factors significantly associated with post-DC midline brain shift at the p<0.01 level were preoperative midline shift (coefficient 0.32, standard error 0.10, p=0.002) and extent of transcalvarial brain herniation (coefficient -0.20, standard error 0.05, p <0.001).

CONCLUSIONS

In patients with MHI and DC, smaller post-DC midline shift is associated with smaller pre-DC midline brain shift and greater transcalvarial brain herniation. This knowledge may prove helpful in assessing DC candidacy and surgical success. Additional studies to enhance the surgical success of DC are warranted.

Resection of swollen temporal muscles in patients with intractable intracranial hypertension after decompressive craniectomy

BACKGROUND

Decompressive craniectomy is employed as treatment for traumatic brain swelling in selected patients. We discussed the effect of temporal muscle resection in patients with intractable intracranial hypertension and temporal muscle swelling after craniectomy.

METHODS

Records of 280 craniectomies performed on 258 patients who were admitted with severe head injury were retrospectively reviewed. Eight patients developed intractable increased intracranial pressure with temporal muscle swelling within 24 h after craniectomy and were treated by muscle resection.

RESULTS

The initial Glasgow Coma Scale score was 7 ± 1. The mean intracranial pressure was 41.7 ± 8.59 mmHg before muscle resection and 14.81 ± 8.07 mmHg immediately after surgery. Five patients had skull fracture and epidural hematoma at the craniectomy site. The mean intensive care unit stay was 11.25 ± 5.99 days. Glasgow Outcome Scale-Extended scoring performed during the 12-month follow-up visit showed that 6 patients (75%) had a favorable outcome.

CONCLUSIONS

Our study findings indicate that a direct impact on the temporal region during trauma may lead to subsequent temporal muscle swelling. Under certain circumstances, muscle resection can effectively control intracranial pressure.

Perfusion-Dependent Cerebral Autoregulation Impairment in Hemispheric Stroke

OBJECTIVE

Loss of cerebral autoregulation (CA) plays a key role in secondary neurologic injury. However, the regional distribution of CA impairment after acute cerebral injury remains unclear because, in clinical practice, CA is only assessed within a limited compartment. Here, we performed large-scale regional mapping of cortical perfusion and CA in patients undergoing decompressive surgery for malignant hemispheric stroke.

METHODS

In 24 patients, autoregulation over the affected hemisphere was calculated based on direct, 15 to 20-minute cortical perfusion measurement with intraoperative laser speckle imaging and mean arterial blood pressure (MAP) recording. Cortical perfusion was normalized against noninfarcted tissue and 6 perfusion categories from 0% to >100% were defined. The interaction between cortical perfusion and MAP was estimated using a linear random slope model and Pearson correlation.

RESULTS

Cortical perfusion and CA impairment were heterogeneously distributed across the entire hemisphere. The degree of CA impairment was significantly greater in areas with critical hypoperfusion (40-60%: 0.42% per mmHg and 60-80%: 0.46% per mmHg) than in noninfarcted (> 100%: 0.22% per mmHg) or infarcted (0-20%: 0.29% per mmHg) areas (*p < 0.001). Pearson correlation confirmed greater CA impairment at critically reduced perfusion (20-40%: r = 0.67; 40-60%: r = 0.68; and 60-80%: r = 0.68) compared to perfusion > 100% (r = 0.36; *p < 0.05). Tissue integrity had no impact on the degree of CA impairment.

INTERPRETATION

In hemispheric stroke, CA is impaired across the entire hemisphere to a variable extent. Autoregulation impairment was greatest in hypoperfused and potentially viable tissue, suggesting that precise localization of such regions is essential for effective tailoring of perfusion pressure-based treatment strategies. ANN NEUROL 2021;89:358-368.

Decompressive craniectomy versus conservative treatment: limits and possibilities in malignant stroke

BACKGROUND

Malignant infarction of the middle cerebral artery (MCA) occurs in a subgroup of patients with ischemic stroke and early decompressive craniectomy (DC) is one of its treatments.

OBJECTIVE

To investigate the functional outcome of patients with malignant ischemic stroke treated with decompressive craniectomy at a neurological emergency center in Northeastern Brazil.

METHODS

Prospective cohort study, in which 25 patients were divided into two groups: those undergoing surgical treatment with DC and those who continued to receive standard conservative treatment (CT). Functionality was assessed using the modified Rankin Scale (mRS), at follow-up after six months.

RESULTS

A favorable outcome (mRS≤3) was observed in 37.5% of the DC patients and 29.4% of CT patients (p=0.42). Fewer patients who underwent surgical treatment died (25%), compared to those treated conservatively (52.8%); however, with no statistical significance. Nonetheless, the proportion of patients with moderate to severe disability (mRS 4‒5) was higher in the surgical group (37.5%) than in the non-surgical group (17.7%).

CONCLUSION

In absolute values, superiority in the effectiveness of DC over CT was perceived, showing that the reduction in mortality was at the expense of increased disability.

Management of the Patient with Malignant Hemispheric Stroke

Malignant hemispheric stroke occurs in 10% of ischemic strokes and has one of the highest mortality and morbidity rates. This stroke, also known as malignant middle cerebral artery stroke, may cause ischemia to an entire hemisphere causing edema, herniation, and death. A collaborative interdisciplinary team approach is needed to manage these complex stroke patients. The nurse plays a vital role in bedside management and support of the patient and family through this complex course of care. This article discusses malignant middle cerebral artery stroke pathophysiology, techniques to predict patients at risk for herniation, collaborative care strategies, and nursing care.

Decompressive craniectomy in malignant middle cerebral artery infarction: family perception, outcome and prognostic factors

OBJECTIVE

The prognosis of one hemisphere malignant infarction creates doubt among neurosurgeons about decompressive hemicraniectomy indication. What results are achieved in the short to medium term? Are families satisfied with the surgery once the patient is at home? In the present study, we analyze our experience in this matter during the last thirteen years.

MATERIAL AND METHODS

In our review, twenty-one patients were included from 2004 to 2017, according to the protocol for the management of ischaemic stroke that is implemented in our institution. The relatives were interviewed by telephone. The functional outcome at discharge, 3 months, 1 year, and at present was measured using the modified Rankin scale (mRS).

RESULTS

Patient age was shown to be directly related to the mRS (r=0.56; p=0.035) and 37.5% achieved a good outcome (mRS≤3); 78.9% of the interviewed relatives would repeat the surgical decision.

CONCLUSIONS

We present a 21 patients group where the best outcome was achieved in patients ≤60 years old. The severe neurological sequelae in patients with malignant infarction subjected to decompressive hemicraniectomy are tolerated and accepted by most families to the benefit of survival. We must not let this family satisfaction hide the prognosis, having to contextualize it within the real ambulatory situation of the patients.

Infarct volume predicts outcome after decompressive hemicraniectomy for malignant hemispheric stroke

The decision to perform decompressive hemicraniectomy (DHC) by default in malignant hemispheric stroke (MHS) remains controversial. Even under ideal conditions, DHC usually results in moderate to severe disability. The present study for the first time uses neuroimaging to identify independent outcome predictors in a prospective cohort of 96 MHS patients undergoing DHC. The primary outcome was functional status according to the modified Rankin Scale (mRS) at 12 months and categorized as favorable (mRS 0-3) or unfavorable (mRS 4-6). At 12 months, 19 patients (20%) reached favorable and 77 patients (80%) unfavorable outcome. The overall mean infarct volume was 328 ± 114 ml. Multivariable logistic regression identified age per year (OR 1.14, 95% CI 1.04-1.24; p = 0.005), infarct volume per cm³ (OR 1.012, 95% CI 1.003-1.022; p = 0.013), thalamic involvement (OR 8.65, 95% CI 1.04-72.15; p = 0.046) and postoperative pneumonia (OR 5.52, 95% CI 1.03-29.57; p = 0.046) as independent outcome predictors, which was confirmed by multivariable ordinal regression for age ( p = 0.004) and infarct volume ( p = 0.015). The infarct volume threshold for reasonable prediction of unfavorable outcome in our patients was 270 cm³, which in the future may help prognostication and development of clinical trials on DHC and outcome in MHS.

Effects of Cranioplasty on Cerebral Blood Flow Following Decompressive Craniectomy: A Systematic Review of the Literature

BACKGROUND

Cranioplasty after decompressive craniectomy (DC) is routinely performed for reconstructive purposes and has been recently linked to improved cerebral blood flow (CBF) and neurological function.

OBJECTIVE

To systematically review all available literature to evaluate the effect of cranioplasty on CBF and neurocognitive recovery.

METHODS

A PubMed, Google Scholar, and MEDLINE search adhering to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines included studies reporting patients who underwent DC and subsequent cranioplasty in whom cerebral hemodynamics were measured before and after cranioplasty.

RESULTS

The search yielded 21 articles with a total of 205 patients (range 3-76 years) who underwent DC and subsequent cranioplasty. Two studies enrolled 29 control subjects for a total of 234 subjects. Studies used different imaging modalities, including CT perfusion (n = 10), Xenon-CT (n = 3), single-photon emission CT (n = 2), transcranial Doppler (n = 6), MR perfusion (n = 1), and positron emission tomography (n = 2). Precranioplasty CBF evaluation ranged from 2 days to 6 months; postcranioplasty CBF evaluation ranged from 7 days to 6 months. All studies demonstrated an increase in CBF ipsilateral to the side of the cranioplasty. Nine of 21 studies also reported an increase in CBF on the contralateral side. Neurological function improved in an overwhelming majority of patients after cranioplasty.

CONCLUSION

This systematic review suggests that cranioplasty improves CBF following DC with a concurrent improvement in neurological function. The causative impact of CBF on neurological function, however, requires further study.

Validation of an International Classification of Disease, Ninth Revision coding algorithm to identify decompressive craniectomy for stroke

Background

Although International Classification of Disease, Ninth Revision, Clinical Modification (ICD9-CM) coding is the basis of administrative claims data, no study has validated an ICD9-CM algorithm to identify patients undergoing decompressive craniectomy for space-occupying supratentorial infarction.

Methods

Patients who underwent decompressive craniectomy for stroke at our institution were retrospectively identified and their associated ICD9-CM codes were extracted from billing data. An ICD9-CM algorithm was generated and its accuracy compared against physician review.

Results

A total of 10,925 neurosurgical operations were performed from December 2008 to March 2015, of which 46 (0.4%) were decompressive craniectomy for space-occupying stroke. The ICD9-CM procedure code for craniectomy (01.25) was only encoded in 67.4% of patients, while craniotomy (01.24) was used in 19.6% and lobectomy (01.39, 01.53, 01.59) in 13.1%. The ICD-9-CM algorithm included patients with a diagnosis codes for cerebral infarction (433.11, 434.01, 434.11, and 434.91) and a procedure code for craniotomy, craniectomy, or lobectomy. Patients were excluded with an ICD9-CM diagnosis code for brain tumor, intracranial abscess, subarachnoid hemorrhage, vertebrobasilar infarction, intracranial aneurysm, Moyamoya disease, intracranial venous sinus thrombosis, vertebral artery dissection, congenital cerebrovascular anomaly, head trauma or an ICD9-CM procedure code for laminectomy. This algorithm had a sensitivity of 97.8%, specificity of 99.9%, positive predictive value of 88.2%, and negative predictive value of 99.9%. The majority of false-positive results were patients who underwent evacuation of a primary intracerebral hematoma.

Conclusion

An ICD-9-CM algorithm based on diagnosis and procedure codes can effectively identify patients undergoing decompressive craniectomy for supratentorial stroke.

Epileptiform activity and spreading depolarization in the blood-brain barrier-disrupted peri-infarct hippocampus are associated with impaired GABAergic inhibition and synaptic plasticity

Peri-infarct opening of the blood-brain barrier may be associated with spreading depolarizations, seizures, and epileptogenesis as well as cognitive dysfunction. We aimed to investigate the mechanisms underlying neural network pathophysiology in the blood-brain barrier-dysfunctional hippocampus. Photothrombotic stroke within the rat neocortex was associated with increased intracranial pressure, vasogenic edema, and peri-ischemic blood-brain barrier dysfunction that included the ipsilateral hippocampus. Intrahippocampal recordings revealed electrographic seizures within the first week in two-thirds of animals, accompanied by a reduction in gamma and increase in theta frequency bands. Synaptic interactions were studied in parasagittal hippocampal slices at 24 h and seven days post-stroke. Field potential recordings in CA1 and CA3 uncovered multiple population spikes, epileptiform episodes, and spreading depolarizations at 24 h. Input-output analysis revealed that fEPSP-spike coupling was significantly enhanced at seven days. In addition, CA1 feedback and feedforward inhibition were diminished. Slices generating epileptiform activity at seven days revealed impaired bidirectional long-term plasticity following high and low-frequency stimulation protocols. Microarray and PCR data confirmed changes in expression of astrocyte-related genes and suggested downregulation in expression of GABA_A-receptor subunits. We conclude that blood-brain barrier dysfunction in the peri-infarct hippocampus is associated with early disinhibition, hyperexcitability, and abnormal synaptic plasticity.

High Risk of Seizures and Epilepsy after Decompressive Hemicraniectomy for Malignant Middle Cerebral Artery Stroke

Background

Decompressive hemicraniectomy (DHC) is a life-saving procedure for treatment of large malignant middle cerebral artery (MCA) strokes. Post-stroke epilepsy is an additional burden for these patients, but its incidence and the risk factors for its development have been poorly investigated.

Objective

To report the prevalence and risk factors for post-stroke seizures and post-stroke epilepsy after DHC for treatment of large malignant MCA strokes in a cohort of 36 patients.

Methods

In a retrospective cohort study of 36 patients we report the timing and incidence of post-stroke epilepsy. We analyzed if age, sex, vascular risk factors, side of ischemia, reperfusion therapy, stroke etiology, extension of stroke, hemorrhagic transformation, ECASS scores, National Institutes of Health Stroke Scale (NIHSS) scores, or modified Rankin scores were risk factors for seizure or epilepsy after DHC for treatment of large MCA strokes.

Results

The mean patient follow-up time was 1,086 days (SD = 1,172). Out of 36 patients, 9 (25.0%) died before being discharged. After 1 year, a total of 11 patients (30.6%) had died, but 22 (61.1%) of them had a modified Rankin score ≤4. Thirteen patients (36.1%) developed seizures within the first week after stroke. Seizures occurred in 22 (61.1%) of 36 patients (95% CI = 45.17–77.03%). Out of 34 patients who survived the acute period, 19 (55.9%) developed epilepsy after MCA infarcts and DHC (95% CI = 39.21–72.59%). In this study, no significant differences were observed between the patients who developed seizures or epilepsy and those who remained free of seizures or epilepsy regarding age, sex, side of stroke, presence of the clinical risk factors studied, hemorrhagic transformation, time of craniectomy, and Rankin score after 1 year of stroke.

Conclusion

The incidence of seizures and epilepsy after malignant MCA infarcts submitted to DHC might be very high. Seizure might occur precociously in patients who are not submitted to anticonvulsant prophylaxis. The large stroke volume and the large cortical ischemic area seem to be the main risk factors for seizure or epilepsy development in this subtype of stroke.

A simple prediction score system for malignant brain edema progression in large hemispheric infarction

Malignant brain edema (MBE) due to hemispheric infarction can result in brain herniation, poor outcomes, and death; outcome may be improved if certain interventions, such as decompressive craniectomy, are performed early. We sought to generate a prediction score to easily identify those patients at high risk for MBE. 121 patients with large hemispheric infarction (LHI) (2011 to 2014) were included. Patients were divided into two groups: those who developed MBE and those who did not. Independent predictors of MBE were identified by logistic regression and a score was developed. Four factors were independently associated with MBE: baseline National Institutes of Health Stroke Scale (NIHSS) score (p = 0.048), Alberta Stroke Program Early Computed Tomography Score (ASPECTS) (p = 0.007), collateral score (CS) (p<0.001) and revascularization failure (p = 0.013). Points were assigned for each factor as follows: NIHSS ≤ 8 (= 0), 9–17 (= 1), ≥ 18 (= 2); ASPECTS≤ 7 (= 1), >8 (= 0); CS<2 (= 1), ≥2 (= 0); revascularization failure (= 1),success (= 0). The MBE Score (MBES) represents the sum of these individual points. Of 26 patients with a MBES of 0 to 1, none developed MBE. All patients with a MBES of 6 developed MBE. Both MBE development and functional outcomes were strongly associated with the MBES (p = 0.007 and 0.002, respectively). The MBE score is a simple reliable tool for the prediction of MBE.

Neurologic Emergencies in the Elderly

Neurologic diseases are a major cause of death and disability in elderly patients. Due to the physiologic changes and increased comorbidities that occur as people age, neurologic diseases are more common in geriatric patients and a major cause of death and disability in this population. This article discusses the elderly patient presenting to the emergency department with acute ischemic stroke, transient ischemic attack, intracerebral hemorrhage, subarachnoid hemorrhage, chronic subdural hematoma, traumatic brain injury, seizures, and central nervous system infections. This article reviews the subtle presentations, difficult workups, and complicated treatment decisions as they pertain to our older patients."

Cranioplasty using custom-made hydroxyapatite versus titanium: a randomized clinical trial

OBJECTIVE

Cranioplasty is routinely performed in neurosurgery. One of its underestimated problems is the high postoperative complication rate of up to 40%. Due to the lack of good prospective studies and the small number of patients (5–20 each year) who receive alloplastic materials, decisions in favor or against a certain material are based on subjective empirical or economic reasons. The main goal of this study—the first prospective, randomized multicenter study in Germany—of custom-made titanium and hydroxyapatite (HA) implants was to compare local and systemic infections related to the implant within the first 6 months after implantation. Secondary objectives included comparing the reoperation rate, the complication rate, clinical and neurological outcomes, and health-related quality of life.

METHODS

The study included patient screening and randomization at 6 to 8 weeks before operation; pre-, intra-, and postoperative documentation until discharge; and postoperative follow-ups after 1 and 6 months. Approval for the study was obtained from the local ethics committee.

RESULTS

A total of 52 patients were included in the study. The rate of local implant–associated wound infection in the HA group was 2 of 26 (7.7%) patients and 5 of 24 (20.8%) patients in the titanium group (p = 0.407). Systemic inflammation within 6 months after operation affected none of the patients in the HA group and 4 of 24 (37.5%) patients in the titanium group (p = 0.107). In both groups, 7 patients required reoperation after the 6-month follow-up (26.9% of the HA group and 29.2% of the titanium group; not significant). Reoperation with an explantation was necessary in 3 patients in each group (11.5% of the HA group and 12.5% of the titanium group; not significant). The results demonstrated a significantly higher number of epidural hematomas in the HA group in comparison with none in the titanium group. Altogether, 46 adverse events were found in 27 patients (54%). An improvement in the neurological outcome after 6 months was experienced by 43% of the patients in the HA group and 26.3% of the patients in the titanium group (p = 0.709).

CONCLUSIONS

The study emphasizes that cranioplasty is a high-risk intervention. In comparison with titanium, HA shows benefits in terms of the infection rate and the neurological outcome, but at the same time has a higher postoperative risk for epidural hematoma. Depending on the individual conditions, both materials have their place in future cranioplasty therapies.

Clinical trial registration no.: NCT00923793 (clinicaltrials.gov).

Today's Approach to Treating Brain Swelling in the Neuro Intensive Care Unit

Brain swelling is an urgent clinical problem that frequently accompanies ischemic stroke, brain hemorrhage, and traumatic brain injury; it increases morbidity and mortality associated with them. It occurs due to failure of membrane transporters and leakage of the blood-brain barrier (BBB), resulting in combination of cytotoxic, ionic, and vasogenic edema. Currently, decompressive craniectomy and osmotherapy are the mainstays of management, but these therapies do not halt the underlying molecular cascade leading to brain swelling. Recent advances in the molecular underpinnings of cerebral edema have opened up possibilities of newer targeted therapeutic options. Here the authors outline the current approach for rapid diagnosis and intervention to reduce mortality and morbidity associated with brain swelling.

Management of Hemispheric Infarction and Ischemic Swelling

PURPOSE OF REVIEW

This article provides an overview of large territory hemispheric infarction, with an emphasis on recent developments and practical issues related to its evaluation, diagnosis, monitoring, and treatment. Swelling after large infarction results in severe morbidity and often death. Early vigilance for the development of swelling is critical to optimize patient outcome. Comprehensive management is highly dependent on a strong multidisciplinary, collaborative approach.

RECENT FINDINGS

Several advances in the last decade have led to an increasingly standardized approach to the patient with significant brain swelling after stroke. In particular, early identification of patients with large stroke at high risk for deterioration, and decompressive craniectomy as an important treatment option, are two significant advances.

SUMMARY

Effective management of hemispheric ischemic stroke and swelling requires a team skilled in the neurologic examination of critically ill patients and a broad understanding of the natural history of brain swelling after stroke.

[Intensive care therapy of space-occupying large hemispheric infarction. Summary of the NCS/DGNI guidelines]

Large hemispheric infarction (LHI), synonymously called malignant middle cerebral artery (MCA) infarction, is a severe neurological disease with a high mortality and morbidity. Treating physicians as well as relatives are often faced with few and low quality data when attempting to apply optimal treatment to these patients and make decisions. While current stroke treatment guidelines focus on risk factors, prevention and acute management, they include only limited recommendations concerning intensive care management of LHI. The Neurocritical Care Society (NCS) and the German Society for Neurocritical and Emergency Medicine (DGNI) organized an interdisciplinary consensus conference on intensive care management of LHI to meet this demand. European and American experts in neurology, neurocritical care, neurosurgery, neuroradiology and neuroanesthesiology were selected based on their expertise and research focus. Subgroups for several main topics elaborated a number of central clinical questions concerning this topic and evaluated the quality of the currently available data according to the grading of recommendation assessment, development and evaluation (GRADE) guideline system. Subsequently, evidence-based recommendations were compiled after weighing the advantages against the disadvantages of certain management options. This is a commented abridged version of the results of the consensus conference.

Analysis of Decompressive Craniectomies with Subsequent Cranioplasties in the Presence of Collagen Matrix Dural Substitute and Polytetrafluoroethylene as an Adhesion Preventative Material

OBJECTIVE

Decompressive craniectomy is an established treatment for malignant intracranial hypertension. Cranioplasty is performed once cerebral swelling has resolved. Complications include infection, postoperative fluid collections, hematoma, reoperation, and seizures. Our experience using a double layer technique during craniectomy with a collagen matrix onlay dural substitute and expanded polytetrafluoroethylene for antiadhesive properties during cranioplasty was reviewed.

METHODS

This is a retrospective chart review of 39 consecutive patients who underwent craniectomy with placement of collagen matrix dural onlay and expanded polytetrafluoroethylene and subsequent cranioplasty. Demographic data, size of craniectomy defect, estimated blood loss, operative time, time between operations, presence of dural tackups, and postoperative complications were analyzed.

RESULTS

Mean operative time was 132 minutes and estimated blood loss was 112 mL. Overall complication rate was 25.6% and no mortality was encountered. Nine patients had postoperative fluid collections measuring ≥ 10 mm in thickness and/or 5 mm of midline shift. Two patients required reoperation for these collections. Two patients developed infections requiring bone flap removal. Three patients developed seizures after cranioplasty. Five patients required shunt placement for hydrocephalus.

CONCLUSIONS

Our dual layer closure technique at time of decompressive craniectomy carries a similar reduction in operative time and estimated blood loss when compared with cranioplasty series with other antiadhesives present. The technique described enables easy dissection of the musculocutaneous flap from the dural plane during cranioplasty and increases the safety of the operation.

German Cranial Reconstruction Registry (GCRR): protocol for a prospective, multicentre, open registry

INTRODUCTION

Owing to increasing numbers of decompressive craniectomies in patients with malignant middle cerebral artery infarction, cranioplastic surgery becomes more relevant. However, the current literature mainly consists of retrospective single-centre (evidence class III) studies. This leads to a wide variability of technical approaches and clinical outcomes. To improve our knowledge about the key elements of cranioplasty, which may help optimising clinical treatment and long-term outcome, a prospective multicentre registry across Germany, Austria and Switzerland will be established.

METHODS

All patients undergoing cranioplastic surgery in participating centres will be invited to join the registry. Technical methods, materials, medical history, adverse events and clinical outcome measures, including modified Rankin scale and EQ-5D, will be assessed at several time points. Patients will be accessible to inclusion either at initial decompressive surgery or when cranioplasty is planned. Scheduled monitoring will be carried out at time of inclusion and subsequently at time of discharge, if any readmission is necessary, and at follow-up presentation. Cosmetic results and patient satisfaction will also be assessed. Collected data will be managed and statistically analysed by an independent biometric institute. The primary endpoint will be mortality, need for operative revision and neurological status at 3 months following cranioplasty.

ETHICS AND DISSEMINATION

Ethics approval was obtained at all participating centres. The registry will provide reliable prospective evidence on surgical techniques, used materials, adverse events and functional outcome, to optimise patient treatment. We expect this study to give new insights in the treatment of skull defects and to provide a basis for future evidence-based therapy regarding cranioplastic surgery.

TRIAL REGISTRATION NUMBER

This trial is indexed in the German Clinical Trials Register (DRKS-ID: DRKS00007931). The Universal Trial Number (UTN) is U1111-1168-7425.

Study on the behavioral changes of a post-stroke depression rat model

The aim of this study was to observe the changes in the levels of learning and memory in a post-stroke depression (PSD) rat model. Forty-eight Wistar rats were randomly divided into three groups: Group A (normal group), group B (stroke group) and group C (PSD group). Each group comprised 16 rats. Three and 7 days after successful modeling, the open-field, sucrose solution consumption and forced swimming tests were performed, so as to evaluate behavioral changes in the three groups of rats. The sucrose solution consumption of the rats in group B was lower than that in group A in the tests at the two time-points, but only the difference after 7 days was statistically significant (P<0.05). The sucrose solution consumption of the rats in group C was lower than the consumption of those in groups A and B, and the differences were statistically significant (P<0.05). The open-field test results showed that the horizontal and vertical activity scores of the rats in group B were significantly lower than those of the rats in group A (P<0.05). Furthermore, the two test levels and the vertical activity scores of the rats in group C were significantly lower than those of the rats in groups A and B (P<0.05). The immobility time of the rats in the forced swimming test was higher in group B than that in group A at the two time-points, but the difference was only statistically significant after 7 days (P<0.05). The immobility time of the rats in group C was significantly higher than that in groups A and B (P<0.01). In conclusion, rats with PSD exhibited a significantly reduced memory capacity and altered behavior. The changes in the PSD rats were more severe than those in the rats in the stroke group.