Dynamics of cerebral blood flow and metabolism in patients with cranioplasty as evaluated by 133Xe CT and 31P magnetic resonance spectroscopy

Paradoxical brain herniation following decompressive craniectomy: A case series and systematic review of literature

INTRODUCTION

Paradoxical brain herniation (PBH) represents a rare and potentially life-threatening complication observed in individuals following decompressive craniectomy. Its diagnosis necessitates a high level of suspicion, combined with clinical and imaging evidence, such as midline shift, herniation, and a decreased Glasgow Coma Scale (GCS). Given the rarity and severity of this condition, we conduct a comprehensive literature review to identify all documented predisposing factors, clinical presentations, and appropriate clinical management. This review will serve as a guide for effective treatment strategies.

CASE PRESENTATION

In this report, we document three cases of post-traumatic PBH following decompressive craniectomy. The patient's predisposing factor was a lumbar puncture, with two cases resolving after Terendlenburg repositioning, hydration, and elective cranioplasty. The third case developed PBH after external ventricular drainage (EVD) insertion. Although the patient's GCS improved after clamping the EVD and hydration, the patient ultimately succumbed to meningitis.

CLINICAL DISCUSSION

The primary clinical manifestations of PBH often encompass a diminished GCS alongside radiographic evidence of midline shift and brain herniation. Various precipitating factors have been associated with PBH after decompressive craniectomy, including CSF drainage, dehydration, and upright positioning, although instances of spontaneous PBH have been documented. Reported therapeutic strategies encompass rehydration, Trendelenburg positioning, temporary cessation of CSF drainage, and cranioplasty.

CONCLUSION

Given the infrequency of PBH and the potential for misdiagnosis with brain edema, it is imperative to consider this condition in every patient who experiences a decreased level of consciousness following decompressive craniectomy.

Neurological functional outcome of early versus delayed cranioplasty following decompressive craniectomy at a tertiary care centre

Cranioplasty performed after a decompressive craniectomy (DC) for traumatic brain injury (TBI), stroke, or aneurysmal bleed has a role of restoring cerebral protection and craniofacial cosmesis as well as improving neuromotor function. There has been no consensus with regards to the ideal timing of cranioplasty (CP) after DC. A retrospective cohort study was carried out at a tertiary care hospital on patients who had undergone early (less than or equal to 12 weeks) and late (greater than 12 weeks) cranioplasty using autologous cranial bone after DC. Functional independence measure (FIM) tools were used to compare neuromotor and cognitive function outcome between the two groups. Appropriate statistical tools were used to compare neuromotor and cognitive function improvement as well as complication rates between early and late cranioplasty. A total of 31 adult patients of cranioplasty (21 male and 10 female) were evaluated. Sixteen had undergone early and 15 late cranioplasty. Comparison for neuromotor and cognitive function using FIM tools revealed statistically significant neuromotor and cognitive advantages in the early cranioplasty group. Overall complication rates between the two groups varied but were statistically insignificant. Performing an early cranioplasty provides advantages of improvement of neuromotor and cognitive function through early restoration of cerebrospinal fluid and intracerebral haemo-dynamics. It further avoids the potential problems of developing the 'Syndrome of the Trephined' (otherwise known as sinking skin flap syndrome) and resorption of the autologous bone.

Earlier cranioplasty following posttraumatic craniectomy is associated with better neurological outcomes at one-year follow-up: a two-centre retrospective cohort study

PURPOSE

Cranioplasty (CP) after decompressive craniectomy (DC) is routinely performed for reconstructive purposes and improves rehabilitation. However, the optimal timing of CP remains controversial. This study aimed to assess differences in clinical outcomes following different timings of CP in patients with traumatic brain injury.

MATERIALS AND METHODS

Patients with traumatic brain injury who underwent CP after DC in Zhongnan Hospital of Wuhan University from 1 January 2010 to 1 May 2017, and in Affiliated Hospital of Guizhou Medical University from 1 January 2015, to 1 May 2017, were retrospectively reviewed. According to the timing of CP, patients were divided into an 'early group' (3-6 months) and a 'late group' (6-12 months). The clinical characteristics of patients and postoperative complications occurred within 1-year follow-up were analysed. The neurological function was assessed with Barthel Index (BI).

RESULTS

A total of 100 patients (58 cases in early group and 42 cases in late group) were included. The median interval between DC and CP was 135 days and 225 days in the early and late CP groups, respectively. The overall complication rate after CP was 16%, and no significant difference in complication rate was observed between the early and late CP groups (17.2% vs.14.3%, p = 0.69). The neurological function was improved in early CP group (pre-CP 85.77 ± 11.61 vs. post-CP 95.34 ± 9.02, p < 0.001, but not in late CP group (pre-CP 82.74 ± 22.82 vs. post-CP 88.93 ± 22.86, p = 0.22). In addition, a significantly higher proportion of patients in the early CP group showed neurological functional improvement in comparison with the late CP group (early vs. late: 74.1% vs. 57.1%, p = 0.04). Multivariate analysis further demonstrated that the timing of CP is an independent predictor for neurological outcomes (OR = 0.32, 95% CI 0.13-0.82, p = 0.02).

CONCLUSION

Early CP (3-6 months) following posttraumatic DC was associated with better neurological outcomes than late CP (>6 months).

Towards a core outcome set for cranioplasty following traumatic brain injury and stroke 'A systematic review of reported outcomes'

Background

There is wide-ranging published literature around cranioplasty following traumatic brain injury (TBI) and stroke, but the heterogeneity of outcomes limits the ability for meta-analysis. Consensus on appropriate outcome measures has not been reached, and given the clinical and research interest, a core outcome set (COS) would be beneficial.

Objectives

To collate outcomes currently reported across the cranioplasty literature which will subsequently be used in developing a cranioplasty COS.

Methods

This systematic review adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. All full-text English studies with more than ten patients (prospective) or more than 20 patients (retrospective) published after 1990 examining outcomes in CP were eligible for inclusion.

Results

The review included 205 studies from which 202 verbatim outcomes were extracted, grouped into 52 domains, and categorised into one or more of the OMERACT 2.0 framework core area(s). The total numbers of studies that reported outcomes in the core areas are 192 (94%) pathophysiological manifestations/ 114 (56%) resource use/economic impact/ 94 (46%) life impact/mortality 20 (10%). In addition, there are 61 outcome measures used in the 205 studies across all domains.

Conclusion

This study shows considerable heterogeneity in the types of outcomes used across the cranioplasty literature, demonstrating the importance and necessity of developing a COS to help standardise reporting across the literature.

Sinking skin syndrome in a decompressive craniectomy series: Clinical and radiological features

Background:

The sinking skin syndrome (SSS) is a particular complication after a decompressive craniectomy (DC). It still remains a poorly understood and underestimated entity.

Methods:

Retrospective case series of craniectomized patients with and without SSS. Clinical and radiological features (DC diameter, shape of craniectomy flap, and midline deviation) were described and relative volumes of intracranial loss were quantified.

Results:

Twenty-seven patients (63% with SSS). The most common indication for DC was traumatic brain injury: 48.15%. The p50 diameter of DC was 12.8 cm for patients with SSS and 11.1 cm for patients without (Z score = 0.32). DC area was 81.5 cm² for patients with SSS and 71.43 cm² for patients without the syndrome (Z score = 0.61). According to the shape of the craniectomy flap, we classified our patients as: «same level» (51.8%), «sunken» (25.9%), and «extracranial herniation» (14.8%). Two patients (7.4%) had paradoxical herniation. Midline deviation was present in 12 (70.6%) patients with SSS. The 3^rd ventricle volume average was 1.2 cc for patients with SSS versus 2.35 cc for patients without (Z score = 0.04). About 94.11% of patients (16 out of 17) clearly improved after replacement of the cranial defect.

Conclusion:

In our series, low 3^rd ventricle volumes had a good relation with SSS. The presence of a sunken flap does not guarantee SSS per se and we propose the following radiologic description: A = sunken, B = same level, C = extracranial herniation, and D = paradoxical. Replacement of the skull defect is the main treatment.

Cranioplasty: A Multidisciplinary Approach

Decompressive craniectomy (DC) is an operation where a large section of the skull is removed to accommodate brain swelling. Patients who survive will usually require subsequent reconstruction of the skull using either their own bone or an artificial prosthesis, known as cranioplasty. Cranioplasty restores skull integrity but can also improve neurological function. Standard care following DC consists of the performance of cranioplasty several months later as historically, there was a concern that earlier cranioplasty may increase the risk of infection. However, recent systematic reviews have challenged this and have demonstrated that an early cranioplasty (within three months after DC) may enhance neurological recovery. However, patients are often transferred to a rehabilitation unit following their acute index admission and before their cranioplasty. A better understanding of the pathophysiological effects of cranioplasty and the relationship of timing and complications would enable more focused patient tailored rehabilitation programs, thus maximizing the benefit following cranioplasty. This may maximise recovery potential, possibly resulting in improved functional and cognitive gains, enhancement of quality of life and potentially reducing longer-term care needs. This narrative review aims to update multi-disciplinary team regarding cranioplasty, including its history, pathophysiological consequences on recovery, complications, and important clinical considerations both in the acute and rehabilitation settings.

3D printed customised external cranial plate in a patient with syndrome of trephined: 'a case report'

Background

Syndrome of the trephined is a well-recognised phenomenon that occurs in patients following a craniectomy. It is associated with several symptoms, including headaches, motor impairments, cognitive disorders and reduced consciousness. Treatment for the syndrome usually involves replacing the skull defect.

Case Study

A 71-year-old male underwent a left-sided craniectomy after being diagnosed with biopsy-confirmed invasive squamous cell carcinoma with associated skull erosion. Subsequently, he developed a severe case of syndrome of the trephined (SoT,) resulting in having to lie flat to prevent the motor component of the Glasgow Coma Score (GCS) falling from M5/6 (E3/4 Vt M5/6) to M1 (E3/4 Vt M1) on sitting to 30 degrees. Unfortunately, due to ongoing chest sepsis and physical frailty, he was unable to undergo a cranioplasty. Therefore, to aid in clinical stabilisation, the treating physicians and clinical engineering teams designed and manufactured a prosthesis on-site, allowing rapid patient treatment. The prosthesis led to the patient being able to sit up to 30 degrees without the motor component of the GCS falling from M6 to M1 (E4 VT M6).

Conclusion

Clinical improvements were demonstrated with definitive neurological improvement after applying the external cranial plate in clinical outcome measures and radiographically. Furthermore, we have shown that rapid prototyping technology provides a flexible solution to synthesise bespoke medical prostheses with the correct expertise and regulatory framework.

Clinical improvement after cranioplasty and its relation to body position and cerebral hemodynamics

Cranioplasty after decompressive craniectomy (DC) has been found to improve the neurological condition. The underlying mechanisms are still unknown. The aim of this study is to investigate the roles of the postural changes and atmospheric pressure (AP) in the brain hemodynamics and their relationship with clinical improvement. Seventy-eight patients were studied before and 72 h after cranioplasty with cervical and transcranial color Doppler ultrasound (TCCS) in the sitting and supine positions. Craniectomy size, shape, and force exerted by the AP (torque) were calculated. Neurological condition was assessed with the National Institutes of Health Stroke Scale (NIHSS) and the Barthel index. Twenty-eight patients improved after cranioplasty. Their time elapsed from the DC was shorter (214 vs 324 days), preoperative Barthel was worse (54 vs 77), internal carotid artery (ICA) mean velocity of the defect side was lower while sitting (14.4 vs 20.9 cm/s), and torque over the craniectomy was greater (2480.3 vs 1464.3 N*cm). Multivariate binary logistic regression showed the consistency of these changes. TCCS findings were no longer present postoperatively. Lower ICA (defect side) velocity in the sitting position correlates significantly with clinical improvement. Greater torque exerted by the AP might explain different susceptibilities to postural changes, corrected by cranioplasty.

Syndrome of the trephined: clinical spectrum, risk factors, and impact of cranioplasty on neurologic recovery in a prospective cohort

Syndrome of the trephined (SoT) is an underrecognized complication after decompressive craniectomy. We aimed to investigate SoT incidence, clinical spectrum, risk factors, and the impact of the cranioplasty on neurologic recovery. Patients undergoing a large craniectomy (> 80 cm²) and cranioplasty were prospectively evaluated using modified Rankin score (mRS), cognitive (attention/processing speed, executive function, language, visuospatial), motor (Motricity Index, Jamar dynamometer, postural score, gait assessment), and radiologic evaluation within four days before and after a cranioplasty. The primary outcome was SoT, diagnosed when a neurologic improvement was observed after the cranioplasty. The secondary outcome was a good neurologic outcome (mRS 0–3) 4 days and 90 days after the cranioplasty. Logistic regression models were used to evaluate the risk factors for SoT and the impact of cranioplasty timing on neurologic recovery. We enrolled 40 patients with a large craniectomy; 26 (65%) developed SoT and improved after the cranioplasty. Brain trauma, hemorrhagic lesions, and shifting of brain structures were associated with SoT. After cranioplasty, a shift towards a good outcome was observed within 4 days (p = 0.025) and persisted at 90 days (p = 0.005). Increasing delay to cranioplasty was associated with decreased odds of improvement when adjusting for age and baseline disability (odds ratio 0.96; 95% CI, 0.93–0.99, p = 0.012). In conclusion, SoT is frequent after craniectomy and interferes with neurologic recovery. High suspicion of SoT should be exercised in patients who fail to progress or have a previous trauma, hemorrhage, or shifting of brain structures. Performing the cranioplasty earlier was associated with improved and quantifiable neurologic recovery.

Effects of Cranioplasty After Decompressive Craniectomy on Neurological Function and Cerebral Hemodynamics in Traumatic Versus Nontraumatic Brain Injury

After decompressive craniectomy (DC), cranioplasty (CP) can help to normalize vascular and cerebrospinal fluid circulation besides improving the patient's neurological status. The aim of this study was to investigate the effects of CP on cerebral hemodynamics and on cognitive and functional outcomes in patients with and without a traumatic brain injury (TBI). Over a period of 3 years, 51 patients were included in the study: 37 TBI patients and 14 non-TBI patients. The TBI group was younger (28.86 ± 9.71 versus 45.64 ± 9.55 years, P = 0.0001), with a greater proportion of men than the non-TBI group (31 versus 6, P = 0.011). Both groups had improved cognitive outcomes (as assessed by the Mini-Mental State Examination) and functional outcomes (as assessed by the Barthel Index and Modified Rankin Scale) 90 days after CP. In the TBI group, the mean velocity of blood flow in the middle cerebral artery ipsilateral to the cranial defect increased between the time point before CP and 90 days after CP (34.24 ± 11.02 versus 42.14 ± 10.19 cm/s, P = 0.0001). In conclusion, CP improved the neurological status in TBI and non-TBI patients, but an increment in cerebral blood flow velocity after CP occurred only in TBI patients.

Changes in the prefronto-thalamic tract following cranioplasty: Case reports

RATIONALE

The prefrontothalamic tract (PTT) injury is associated with various neuropsychological impairments including cognitive impairment. We report on three women with hemorrhagic stroke who showed changes in the PTT following cranioplasty (C/P) using diffusion tensor tractography (DTT) images.

PATIENT CONCERNS

The 3 women with hemorrhagic stroke showed reductions of cognitive impairment following C/P. Mini-Mental State Examination scores (MMSE) were increased by 7-, 8-, and 5-point in patient 1, 2, and 3, respectively, after C/P compared with the patients' pre-C/P MMSE scores.

DIAGNOSIS

Three patients were diagnosed with spontaneous intracerebral hemorrhage. Three patients underwent C/P using auto-bone at 7 (patient 1 and 3) and 13 (patient 2) weeks after onset.

INTERVENTIONS

Diffusion tensor imaging data were acquired within 3 days before and 21 days after C/P.

OUTCOMES

The pre-C/P DTT results showed non-reconstruction of the dorsolateral prefrontal cortex (DLPFC; patient 2 and 3) on the contralateral operation (contra-OP) side and orbitofrontal cortex (OFC; patient 3) on both sides, but those were reconstructed on post-C/P DTT. Except for the contra-OP side OFC of patient 2, all fractional anisotropy values decreased on post-C/P DTT compared with pre-C/P DTT. The mean diffusivity values of the VLPFC and OFC were higher on post-C/P DTT except for the contra-OP side VLPFC of patient 1 and contra-OP side OFC of patient 2. The voxel numbers also increased except for the contra-OP side VLPFC of patient 1.

LESSONS

We demonstrated structural changes in the PTT along with concomitant reductions of cognitive impairments following C/P in 3 women with hemorrhagic stroke using DTT. The DTT changes suggest that C/P can affect the state of the PTT on both the OP and contra-OP sides. However, the limitation that DTT analysis may underestimate or overestimate fiber tract status due to regions of fiber complexity and crossing fiber should be considered.

Sinking Skin Flap Syndrome following Posttraumatic Hydrocephalus

Introduction

Complications following craniotomy are not uncommon and Sinking Skin Flap Syndrome (SSFS) constitutes a rare entity that may present after a large Decompressive Craniectomy. Although the entity is widely reported, the literature mostly consists of case reports. Authors present a case series of three patients with review of literature highlighting the various factors which can prove therapeutic and can help in avoidance of complications.

Materials and Methods

The study was conducted over a period of 3 years, from 2016 to 2019, and included 212 patients who underwent unilateral Decompressive Craniectomy (DC) for trauma in our institute. All 212 patients underwent a similar DC following a strict institutional protocol and the craniectomies were performed by the same surgical team. At total of 160 patients survived and elective cranioplasty was planned at a 3-month interval. Out of a total of 160 patients who survived, 38 developed hydrocephalus, 3 patients presented with hydrocephalus acutely and had to be shunted before cranioplasty and underwent ventriculoperitoneal (VP) shunting on the opposite side of craniectomy. All 3 of these patients developed SSFS and were the focus of this case series wherein review of literature was done with emphasis being laid on the salient features towards management of SSFS in such precranioplasty shunted patients. These 3 patients were treated via rehydration using normal saline (NS) till the Central Venous Pressure (CVP) equaled 8-10 cm of water, nursing in Trendelenburg position and shunt occlusion using silk 3-0 round bodied suture tied over a "C"-loop of VP shunt tube over clavicle. This was followed by cranioplasty within 2 days of presentation using a flattened, nonconvex artificial Polymethyl Methacrylate (PMMA) bone flap with central hitch suture taken across the bone flap and release of shunt tie in immediate postoperative period. The PMMA bone flap was made intraoperatively after measuring the defect size accurately after exposure of defect. 3D printing option was not availed by any patient considering the high cost and patients' poor socioeconomic status.

Results

Out of a total of 212 patients, thirty-eight patients (19%) developed posttraumatic hydrocephalus and out of 38, three presented with SSFS over the course of time. Two patients presented with hemiparesis of the side opposite to sunken flap while 1 other patient was brought by relatives in stuporous state. All 3 were subjected to VP shunt tie, rehydration, and cranioplasty using flattened artificial bone flap and showed gradual recovery in postoperative period without any complications.

Conclusion

Various factors like nursing in Trendelenburg position, adequate rehydration, early cranioplasty after resolution of oedema, preoperative tying of VP shunt and its subsequent release in immediate postoperative period, use of flattened PMMA bone flaps, placement of a central dural hitch suture across the bone, and a preoperative central burr hole in the bone flap may accelerate healing and, in most cases, reversal of sensory-motor deficits along with reduction in complication rates.

Does the skull Hounsfield unit predict shunt dependent hydrocephalus after decompressive craniectomy for traumatic acute subdural hematoma?

Background and purpose

Posttraumatic hydrocephalus affects 11.9%–36% of patients undergoing decompressive craniectomy (DC) after traumatic brain injury and necessitates a ventriculo-peritoneal shunt placement. As bone and arachnoid trabeculae share the same collagen type, we investigated possible connections between the skull Hounsfield unit (HU) values and shunt-dependent hydrocephalus (SDHC) in patients that received cranioplasty after DC for traumatic acute subdural hematoma (SDH).

Methods

We measured HU values in the frontal bone and internal occipital protuberance from admission brain CT. Receiver operating characteristic curve analysis was performed to identify the optimal cut-off skull HU values for predicting SDHC in patients receiving cranioplasty after DC due to traumatic acute SDH. We investigated independent predictive factors for SDHC occurrence using multivariable logistic regression analysis.

Results

A total of 162 patients (>15 years of age) were enrolled in the study over an 11-year period from two university hospitals. Multivariable logistic analysis revealed that the group with simultaneous frontal skull HU ≤797.4 and internal occipital protuberance HU ≤586.5 (odds ratio, 8.57; 95% CI, 3.05 to 24.10; P<0.001) was the only independent predictive factor for SDHC in patients who received cranioplasty after DC for traumatic acute SDH.

Conclusions

Our study reveals a potential relationship between possible low bone mineral density and development of SDHC in traumatic acute SDH patients who had undergone DC. Our findings provide deeper insight into the association between low bone mineral density and hydrocephalus after DC for traumatic acute SDH.

Sinking Skin Flap Syndrome and Paradoxical Herniation Provoked by a Malfunction of External Lumbar Drainage and CSF Leak

The sinking skin flap syndrome represents a less-frequent complication in patients after a decompressive craniectomy. It is defined as a neurological deterioration accompanied by a flat or concave deformity of the craniectomy-related skin flap. The underlying brain parenchyma is distorted correspondingly with its blood flow and metabolism being impaired and cerebrospinal fluid hydrodynamics being disturbed, thus causing cerebral dysfunction and neurological symptomatology. The most important options for reversal of this syndrome include Trendelenburg position, maintaining of the cerebrospinal fluid balance, and cranioplasty as a definite solution. We present a patient who underwent a decompressive craniectomy complicated by a cerebrospinal fluid leak in the operative wound treated by means of an external lumbar drainage. Subsequently he developed the sinking skin flap syndrome and a paradoxical cerebral herniation after the drainage system malfunction with a massive cerebrospinal fluid leak at the site of the lumbar drain insertion parallel to the drain itself. His symptoms were, however, successfully alleviated by a positional change, rehydration, and interruption of the lumbar drainage. This illustrational case suggests that clinicians should be aware that patients after decompressive craniectomy may develop a sinking skin flap syndrome as it may either represent an acute risk of a paradoxical brain herniation or complicate the further postoperative care if developed in a chronic way.

Postcranioplasty seizures following decompressive craniectomy and seizure prophylaxis: a retrospective analysis at a single institution

OBJECTIVE

Cranioplasty is a relatively simple and less invasive intervention, but it is associated with a high incidence of postoperative seizures. The incidence of, and the risk factors for, such seizures and the effect of prophylactic antiepileptic drugs (AEDs) have not been well studied. The authors' aim was to evaluate the risk factors that predispose patients to postcranioplasty seizures and to examine the role of seizure prophylaxis in cranioplasty.

METHODS

The records of patients who had undergone cranioplasty at the authors' medical center between 2009 and 2014 with at last 2 years of follow-up were retrospectively reviewed. Demographic and clinical characteristics, the occurrence of postoperative seizures, and postoperative complications were analyzed.

RESULTS

Among the 583 patients eligible for inclusion in the study, 247 had preexisting seizures or used AEDs before the cranioplasty and 336 had no seizures prior to cranioplasty. Of these 336 patients, 89 (26.5%) had new-onset seizures following cranioplasty. Prophylactic AEDs were administered to 56 patients for 1 week after cranioplasty. No early seizures occurred in these patients, and this finding was statistically significant (p = 0.012). Liver cirrhosis, intraoperative blood loss, and shunt-dependent hydrocephalus were risk factors for postcranioplasty seizures in the multivariable analysis.

CONCLUSIONS

Cranioplasty is associated with a high incidence of postoperative seizures. The prophylactic use of AEDs can reduce the occurrence of early seizures.

Sinking Skin Flap Syndrome After Decompressive Craniectomy: A Case Report

Sinking skin flap syndrome is a rare complication of decompressive craniectomy characterized by a sunken skin flap, neurological deterioration, and paradoxical herniation of the brain. An absent cranium allows for external compression via atmospheric pressure, causing alterations in cerebral blood flow, cerebral spinal fluid flow, and glucose metabolism, which ultimately leads to cortical dysfunction. This case report describes a patient with relatively early onset of variable neurological symptoms and imaging correlation, leading to a diagnosis and definitive therapeutic intervention with cranioplasty. Prompt recognition is critical to avoid potentially devastating neurological outcomes in this rare, but underreported condition.

A Novel Protocol to Reduce Early Seizures After Cranioplasty: A Single-Center Experience

BACKGROUND

Cranioplasty is a relatively simple and straightforward intervention; however, it is associated with a high incidence of postoperative seizures. Postcranioplasty seizures, especially early seizures, are common and associated with poor outcomes and longer hospital stays. Protocols for preventing and managing early seizures have not been well established.

METHODS

The medical records of 595 patients who underwent cranioplasty were retrospectively reviewed. Of these patients, 259 had preexisting seizures and 336 had no seizures before cranioplasty. Prophylactic antiepileptic drugs (AEDs) were administered to patients who had no seizures before cranioplasty for 1 week, whereas an advanced AED regimen was administered to patients with preexisting seizures. Subsequently, clinical characteristics, occurrence of recurrent seizures, early seizures, and postoperative complications were analyzed.

RESULTS

Our previous study showed positive results for prophylaxis in new-onset early seizures. In the patients with preexisting seizures, 46.7% of the patients (121/259) experienced recurrent seizures after cranioplasty and 17.4% of the patients (45/259) experienced early recurrent seizures within 1 week of their operation. In the group who received the advanced AEDs, early recurrent seizures were significantly reduced to 8.7% compared with the regular group (20.5%; P = 0.027). Younger age and preoperative hydrocephalus engendered a higher risk of recurrent seizures. The number of previous craniotomies was observed to have a trend of increasing early recurrent seizures.

CONCLUSIONS

Cranioplasty is associated with a high incidence of postoperative seizures. Our management protocol for postcranioplasty seizures includes seizure prophylaxis and advanced use of AEDs, which can reduce the occurrence of early seizures.

The "Negative" Impact of a Subgaleal Drain: Post-cranioplasty Negative Pressure Subgaleal Drain-induced Ascending Transtentorial Herniation

One commonly practiced procedural step to reduce the risk of postoperative hematoma accumulation when performing cranioplasties is to place a closed negative-pressure subgaleal drain. We present a patient with sinking skin flap syndrome that underwent such a procedure and subsequently experienced immediate postoperative ascending transtentorial herniation and intracranial hemorrhage remote from the surgical site. On determining that the subgaleal drain was the responsible cause, it was immediate removed, and the patient had neurological recovery. Fewer than 30 cases of life-threatening subgaleal drain-related complications have been documented, and this is the first reported case of ascending herniation occurring after cranioplasty. This report illustrates the potential risks of subgaleal drainage, the importance of early recognition of this rare phenomenon and that intervention can be potentially life-saving.

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.

Metabolic Abnormalities of Erythrocytes as a Risk Factor for Alzheimer's Disease

Alzheimer's disease (AD) is a slowly progressive, neurodegenerative disorder of uncertain etiology. According to the amyloid cascade hypothesis, accumulation of non-soluble amyloid β peptides (Aβ) in the Central Nervous System (CNS) is the primary cause initiating a pathogenic cascade leading to the complex multilayered pathology and clinical manifestation of the disease. It is, therefore, not surprising that the search for mechanisms underlying cognitive changes observed in AD has focused exclusively on the brain and Aβ-inducing synaptic and dendritic loss, oxidative stress, and neuronal death. However, since Aβ depositions were found in normal non-demented elderly people and in many other pathological conditions, the amyloid cascade hypothesis was modified to claim that intraneuronal accumulation of soluble Aβ oligomers, rather than monomer or insoluble amyloid fibrils, is the first step of a fatal cascade in AD. Since a characteristic reduction of cerebral perfusion and energy metabolism occurs in patients with AD it is suggested that capillary distortions commonly found in AD brain elicit hemodynamic changes that alter the delivery and transport of essential nutrients, particularly glucose and oxygen to neuronal and glial cells. Another important factor in tissue oxygenation is the ability of erythrocytes (red blood cells, RBC) to transport and deliver oxygen to tissues, which are first of all dependent on the RBC antioxidant and energy metabolism, which finally regulates the oxygen affinity of hemoglobin. In the present review, we consider the possibility that metabolic and antioxidant defense alterations in the circulating erythrocyte population can influence oxygen delivery to the brain, and that these changes might be a primary mechanism triggering the glucose metabolism disturbance resulting in neurobiological changes observed in the AD brain, possibly related to impaired cognitive function. We also discuss the possibility of using erythrocyte biochemical aberrations as potential tools that will help identify a risk factor for AD.

The effect of cranioplasty following decompressive craniectomy on cerebral blood perfusion, neurological, and cognitive outcome

OBJECTIVE

Decompressive craniectomy is an established therapy for refractory intracranial hypertension. Cranioplasty following decompressive craniectomy not only provides protection to the brain along with cosmetic benefits, but also enhances rehabilitation with meaningful functional recovery of potentially reversible cortical and subcortical damaged areas of the affected as well as the contralateral hemisphere. The aim of the study was to assess neurological and cognitive outcome as well as cerebral blood flow after cranioplasty.

METHODS

Thirty-four patients admitted for replacement cranioplasty after decompressive craniectomy for head injury were studied prospectively. Clinical, neurological, and cognitive outcomes were assessed by the Glasgow Outcome Scale (GOS), the Glasgow Coma Scale, and a battery of cognitive tests, respectively. Simultaneously, cerebral blood perfusion was assessed by technetium-99m ethyl cysteinate dimer (99mTc-ECD) brain SPECT imaging 7 days prior to and 3 months after cranioplasty.

RESULTS

Prior to cranioplasty 9 patients (26.5%) had GOS scores of 5 and 25 patients (73.5%) had GOS scores of 4, whereas postcranioplasty all 34 patients (100%) improved to GOS scores of 5. Approximately 35.3%–90.9% patients showed cognitive improvement postcranioplasty in various tests. Also, on comparison with brain SPECT, 94% of patients showed improvement in cerebral perfusion in different lobes.

CONCLUSIONS

Cranioplasty remarkably improves neurological and cognitive outcomes supported by improvement in cerebral blood perfusion.

Massive Brain Swelling and Death After Cranioplasty: A Systematic Review

BACKGROUND

Although cranioplasty is a common procedure, it may cause a variety of complications. Massive brain swelling after cranioplasty (MBSC) is an unusual complication that has been reported more frequently in recent years. Most of the existing information about this condition is speculative and the cause remains unclear.

METHODS

A PubMed and Scopus search adhering to PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines was performed to include studies reporting patients with MBSC. Different information was analyzed in these cases to describe the characteristics and identify risk factors for MBSC.

RESULTS

The search yielded 19 articles with a total of 26 patients. All studies were case reports and small case series. In most patients, preoperative intracranial hypotension and a considerable degree of sinking of skin flap were identified; this was the only constant finding observed in these cases. In addition, we propose a grading system to estimate the degree of preoperative sinking of skin flap and an algorithm with recommendations to decrease the incidence of MBSC.

CONCLUSIONS

MBSC is an unusual, highly lethal, and probably underreported condition. The information gathered in this review indicates that MBSC occurs secondary to a cascade of pathologic events triggered by the bone flap implantation. This evidence suggests that the primary pathologic change is a sudden increase in the intracranial pressure acting on a brain chronically exposed to intracranial hypotension.

Effects of Early Cranioplasty on the Restoration of Cognitive and Functional Impairments

Objective

To delineate the effect of early cranioplasty on the recovery of cognitive and functional impairments in patients who received decompressive craniectomy after traumatic brain injury or spontaneous cerebral hemorrhage.

Methods

Twenty-four patients who had received cranioplasty were selected and divided according to the period from decompressive craniectomy to cranioplasty into early (≤90 days) and late (>90 days) groups. The Korean version of the Mini-Mental State Examination (K-MMSE), Korean version of the Modified Barthel Index (K-MBI), and Functional Independence Measure (FIM) were evaluated at admission just after decompressive craniectomy and during the follow-up period after cranioplasty.

Results

Twelve patients were included in the early group, and another 13 patients were included in the late group. The age, gender, type of lesion, and initial K-MMSE, K-MBI, and FIM did not significantly differ between two groups. However, the total gain scores of the K-MMSE and FIM in the early group (4.50±7.49 and 9.42±15.96, respectively) increased more than those in the late group (−1.08±3.65 and −0.17±17.86, respectively), and some of K-MMSE subscores (orientation and language) and FIM subcategories (self-care and transfer-locomotion) in the early group increased significantly when compared to those in the late group without any serious complications. We also found that the time to perform a cranioplasty was weakly, negatively correlated with the K-MMSE gain score (r=−0.560).

Conclusion

Early cranioplasty might be helpful in restoring cognitive and functional impairments, especially orientation, language ability, self-care ability, and mobility in patients with traumatic brain injury or spontaneous cerebral hemorrhage.

Unexpected complications immediately after cranioplasty

Case

An 84-year-old man with subarachnoid hemorrhage underwent craniotomy and clipping with external decompression. Perfusion magnetic resonance imaging showed subclinical sinking skin flap syndrome, and he underwent cranioplasty on postoperative day 58. No problems occurred during the operation, but cerebral edema and hemorrhage were recognized on immediate postoperative computed tomography. Edema continued to progress, but edema and bleeding eventually improved without additional surgery.

Outcome

Neurological symptoms improved to presurgical baseline and stabilized.

Conclusion

Causes of cerebral edema and hemorrhage immediately after cranioplasty include reperfusion, reduction of automatic adjustment function, sinking skin flap syndrome, negative pressure due to s.c. drain, venous stasis, vascular damage following restoration of midline shift, and allergic reaction. Although cranioplasty itself is a relatively minor surgery, the fatality rate for this complication is high. Most complications are due to infection, convulsions, or epidural hematoma, but brain edema and hemorrhage also occur. It is necessary to elucidate the etiology before corrective surgery.

Intracerebral Hemorrhagic Infarction after Cranioplasty in a Patient with Sinking Skin Flap Syndrome

The sinking skin flap syndrome (SSFS) is a rare complication after a large craniectomy. Hemorrhage infarction after a cranioplasty is a very rare complication with only 4 cases to date. We report a case of the patient who underwent an autologous cranioplasty to treat SSFS that developed intracerebral hemorrhage infarction. A 20-year-old male was admitted to our emergency department with stuporous mentality. Emergent decompressive craniectomy (DC) have done. He had suffered from SSFS and fever of unknown origin (FUO) since DC. After 7 months of craniectomy, cranioplasty was done. After 1 day of surgery, acute infarction with hemorrhagic transformation involved left cerebral hemisphere. We controlled increased intracranial pressure by using osmotic diuretics, steroid and antiepileptic drugs. After 14 day of surgery, he improved neurological symptoms and he had not any more hyperthermia. Among several complication of large cranioplasty only 4 cases of intracerebral hemorrhagic infarction due to reperfusion injury has been reported. In this case, unstable autoregulation system made brain hypoxic damage and then reperfusion and recanalization of cerebral vessels resulted in intracerebral hemorrhagic infarction. 7 month long FUO was resolved by cranioplasty.

Sinking flap syndrome with abdominal pain: an atypical presentation

A 53-year-old man developed significant mass effect secondary to an ischaemic stroke and was treated with decompressive craniectomy. During the first few days postsurgery he developed orthostatic vertigo with nausea. After a month, with increasing mobilisation and rehabilitation, he started reporting of severe abdominal pain. No aetiology could be found despite extensive local work up and the symptoms were resistant to any symptomatic treatment. Within days postcranioplasty there was a complete resolution of all the symptoms.

CONCLUSION

the sinking flap syndrome can cause abdominal pain and orthostatic vertigo.

Early Cranioplasty in Patients With Posttraumatic Decompressive Craniectomy and Its Correlation with Changes in Cerebral Perfusion Parameters and Neurocognitive Outcome

BACKGROUND

Decompressive craniectomy is a life-saving procedure in many patients after traumatic brain injury. Delayed recovery in such patients can be attributed to various causes. Cranioplasty (CP) helps in early improvement of neurocognitive function along with better brain protection and cosmesis. The mechanism responsible for this functional improvement and the ideal time to perform cranial reconstruction is less understood.

METHODS

We studied 16 patients who underwent CP after decompressive craniectomy (DC) for traumatic brain injury. These patients were divided in 2 groups, early and late CP, depending on the interval between DC and CP. Three months was the cutoff time for early CP. Neurocognitive status was assessed by Glasgow Coma Scale, Glasgow Outcome Scale, and Mini-Mental State Examination scores prior to and after CP. Computed tomography (CT) perfusion was done to correlate the improvement in neurologic status and CT perfusion parameters.

RESULTS

We observed that there was a positive influence of CP on neurologic and psychologic function in all of the patients. The neurocognitive improvement after CP was more remarkable in the early CP group. More complications were noted in patients in the late CP group. Brain perfusion after CP showed improvement in all parameters in both of the groups, both on the operated and contralateral side.

CONCLUSIONS

Neurocognitive improvement is noted after CP in all of the patients. CP should be offered once the brain edema subsides, at the earliest. Improved cerebral perfusion may be the key factor for the improved functional outcome.

Paradoxical Herniation After Unilateral Decompressive Craniectomy Predicts Better Patient Survival: A Retrospective Analysis of 429 Cases

Paradoxical herniation (PH) is a life-threatening emergency after decompressive craniectomy. In the current study, we examined patient survival in patients who developed PH after decompressive craniectomy versus those who did not. Risk factors for, and management of, PH were also analyzed. This retrospective analysis included 429 consecutive patients receiving decompressive craniectomy during a period from January 2007 to December 2012. Mortality rate and Glasgow Outcome Scale (GOS) were compared between those who developed PH (n = 13) versus those who did not (n = 416). A stepwise multivariate logistic regression analysis was carried out to examine the risk factors for PH. The overall mortality in the entire sample was 22.8%, with a median follow-up of 6 months. Oddly enough, all 13 patients who developed PH survived beyond 6 months. Glasgow Coma Scale did not differ between the 2 groups upon admission, but GOS was significantly higher in subjects who developed PH. Both the disease type and coma degree were comparable between the 13 PH patients and the remaining 416 patients. In all PH episodes, patients responded to emergency treatments that included intravenous hydration, cerebral spinal fluid drainage discontinuation, and Trendelenburg position. A regression analysis indicated the following independent risk factors for PH: external ventriculostomy, lumbar puncture, and continuous external lumbar drainage. The rate of PH is approximately 3% after decompressive craniectomy. The most intriguing findings of the current study were the 0% mortality in those who developed PH versus 23.6% mortality in those who did not develop PH and significant difference of GOS score at 6-month follow-up between the 2 groups, suggesting that PH after decompressive craniectomy should be managed aggressively. The risk factors for PH include external ventriculostomy, ventriculoperitoneal shunt, lumbar puncture, and continuous external lumbar drainage.

The impact of cranioplasty on cerebral blood flow and its correlation with clinical outcome in patients underwent decompressive craniectomy

Context:

Decompressive craniectomy is commonly use as the treatment for medically refractory intracranial hypertension. Unexpected improvement in patient's neurological status has been observed among patients that underwent cranioplasty. Restoration of cerebral blood flow (CBF) hemodynamics is one of the contributing factors. This study was conducted to determine the impact of cranioplasty on CBF and its correlation with clinical outcome.

Aims:

This study was done to evaluate the effect of cranioplasty on CBF with computed tomography perfusion (CTP). It also aimed to determine the correlation between postcranioplasty CBF and clinical outcome.

Settings and Design:

Prospective observational study.

Subjects and Methods:

All patients had CTP done to determine precranioplasty CBF. CTP was repeated at 6 weeks postcranioplasty and clinical assessment at 6 and 24 weeks postcranioplasty.

Statistical Analysis Used:

Data analysis was done using Statistical Package for Social Sciences version 12.0.1.

Results:

The median value of the ipsilateral CBF was 48.87 and 61.10 ml/min/100 g at precranioplasty and 6 weeks postcranioplasty (P < 0.001). Contralateral CBF also showed improvement from 60.55 to 71.84 ml/min/100 g (P < 0.001). Median value for mini mental state examination showed a significant difference with value of 22, 25, and 25.5 at precranioplasty, 6 and 24 weeks postcranioplasty (P = 0.001 and P < 0.001). Median value for frontal assessment battery was 12, 14.5, and 15 (P = 0.002 and P = 0.001).

Conclusions:

Cranioplasty can remarkably improve cortical perfusion for both ipsilateral and contralateral hemisphere. Though we are unable to establish strong correlation, between CBF and clinical outcome, cranioplasty was observed to have a therapeutic role in terms of clinical outcome improvement.

Factors influencing the outcome (GOS) in reconstructive cranioplasty

After performing a decompressive craniectomy, a cranioplastic surgery is usually warranted. The complications of this reconstructive procedure may differ from the initial operation. The authors of this study report on their experience to define patient-specific and procedural risk factors for possible complications following cranioplasty influencing the outcome (Glasgow Outcome Scale (GOS)), mobility, shunt dependency, and seizures. A retrospective analysis of 263 patients of all ages and both sexes who had undergone cranioplasty after craniectomy for traumatic brain injury (including chronic subdural hematoma), subarachnoidal hemorrhage (including intracerebral hemorrhage), ischemic stroke, and tumor surgery in one single center in 12 years from January 2000 to March 2012 has been carried out. A multiple logistic regression analysis was performed to identify potential risk factors (age, gender, used cranioplasty material, initial diagnosis, clipped or coil-embolized subarachnoidal hemorrhage (SAH) patients, time interval, complications especially hydrocephalus and seizures, mobility) upon the prognosis described as a dichotomized Glasgow Outcome Scale. Two hundred forty-eight patients met the study criteria. The overall complication rate after cranioplastic surgery was 18.5% (46 patients). Complications included: surgical site infection, epidural hematoma, hydrocephalus with or without former SAH, and new-onset seizures. Logistic regression analysis identified significant correlation between a low GOS (2 or 3) and postoperative seizures (OR 2.37, CI 1.35-4.18, p < 0.05), shunt-depending hydrocephalus (OR 5.83, CI 3.06-11.11, p < 0.05), and age between 51 and 70 years (OR 2.4, 95% CI 1.09-5.29, p = 0.029). However, gender, time interval between craniectomy and cranioplasty, initial diagnosis, and used cranioplasty material had no significant influence on post-cranioplasty complications as surgical site infections, hematoma, wound healing disturbance, seizures, or hydrocephalus. Evaluation of treatment modality in aneurysmal SAH clip vs. coil showed no significant relation to postoperative complications either. Complications after cranioplastic surgery are a common problem, as prognostic factors could identify a shunt-depending hydrocephalus and epilepsia to develop a major deficit after cranioplastic surgery (GOS 2 or 3). We detected a significant extra risk of people between the age of 51 and 70 years to end up in GOS level 2 or 3.

The impact of cranioplasty on cerebral blood perfusion in patients treated with decompressive craniectomy for severe traumatic brain injury

BACKGROUND

A large cranial defect following decompressive craniectomy (DC) is a common sequela in patients with severe traumatic brain injury (TBI). Such a defect can cause severe disturbance of cerebral blood flow (CBF) regulation. This study investigated the impact of cranioplasty on CBF in these patients.

METHODS

Patients who underwent DC and secondary cranioplasty were prospectively studied for a severe TBI. CT perfusion was used to measure CBF before and after cranioplasty. The basal ganglia, parietal lobe and occipital lobe on the decompressed side were chosen as zones of interest for CBF evaluation.

RESULTS

Nine patients representing nine cranioplasty procedures were included in the study. Before cranioplasty, CBF on the decompressed side was lower than that on the contralateral side. During the early stage (10 days) after cranioplasty, CBF on the decompressed side was increased and this increase was significant in the parietal and occipital lobe. CBF was also increased on the contralateral side. In addition, the difference in CBF between the contralateral side and the decompressed side was reduced after cranioplasty. Further, the CT perfusion showed that the CBFs decreased again 3 months post-cranioplasty among four cases, but was still higher than those before cranioplasty.

CONCLUSIONS

This study indicates that cranioplasty may increase CBF and benefit the recovery in patients with DC for TBI.

Unexpected Severe Cerebral Edema after Cranioplasty : Case Report and Literature Review

This report details a case of unexpected, severe post-operative cerebral edema following cranioplasty. We discuss the possible pathological mechanisms of this complication. A 50-year-old female was admitted to our department with sudden onset of stuporous consciousness. A brain computed tomography (CT) revealed a subarachnoid hemorrhage with intracranial hemorrhage and subdural hematoma. Emergency decompressive craniectomy and aneurysmal neck clipping were performed. Following recovery, the decision was made to proceed with an autologous cranioplasty. The cranioplasty procedure was free of complications. An epidural drain was placed and connected to a suction system during skin closure to avoid epidural blood accumulation. However, following the procedure, the patient had a seizure in the recovery room. An emergency brain CT scan revealed widespread cerebral edema, and the catheter drain was clamped. The increased intracranial pressure and cerebral edema were controlled with osmotic diuretics, corticosteroids, and antiepileptic drugs. The edema slowly subsided, but new low-density areas were noted in the brain on follow-up CT 1 week later. We speculated that placing the epidural drain on active suction may have caused an acute decrease in intracranial pressure and subsequent rapid expansion of the brain, which impaired autoregulation and led to reperfusion injury.

Neurological susceptibility to a skull defect

BACKGROUND

There continues to be considerable interest in the use of decompressive craniectomy in the management of neurological emergencies. The procedure is technically straightforward; however, it is becoming increasingly apparent that it is associated with significant complications. One complication that has received relatively little attention is the neurological dysfunction that can occur due to the absence of the bone flap and the subsequent distortion of the brain under the scalp as cerebral swelling subsides. The aim of this narrative review was to examine the literature available regarding the clinical features described, outline the proposed pathophysiology for these clinical manifestations and highlight the implications that this may have for rehabilitation of patients with a large skull defect.

METHODS

A literature search was performed in the MEDLINE database (1966 to June 2012). The following keywords were used: Hemicraniectomy, decompressive craniectomy, complications, syndrome of the trephined, syndrome of the sinking scalp flap, motor trephined syndrome. The bibliographies of retrieved reports were searched for additional references.

RESULTS

Various terms have been used to describe the different neurological signs and symptoms with which patients with a skull defect can present. These include; syndrome of the trephined, posttraumatic syndrome, syndrome of the sinking scalp flap, and motor trephined syndrome. There is, however, considerable overlap between the conditions described and a patient's individual clinical presentation.

CONCLUSION

It is becoming increasingly apparent that certain patients are particularly susceptible to the presence of a large skull defect. The term "Neurological Susceptibility to a Skull Defect" (NSSD) is therefore suggested as a blanket term to describe any neurological change attributable to the absence of cranial coverage.

Temporal changes in CT perfusion values before and after cranioplasty in patients without symptoms related to external decompression: a pilot study

INTRODUCTION

Little is known about hemodynamic disturbances affecting cerebral hemispheres in traumatic brain injury (TBI) after cranioplasty.

METHODS

We prospectively investigated six stable TBI patients who underwent cranioplasty more than 90 days after effective decompressive craniectomy. Computerized tomography perfusion (CTP) studies and evaluation of clinical outcome were performed for each patient before cranioplasty and at 7 days and 3 months after surgery. Cerebral blood flow (CBF), cerebral blood volume (CBV) and mean transit time (MTT) were measured in multiple cortical circular regions positioned in cranioplasty-treated and contralateral hemispheres.

RESULTS

Neither complications associated with cranioplasty nor changes in outcome were observed. On the treated side, CBF and CBV values were higher before and 7 days after cranioplasty than at 3 months after surgery, whereas MTT values were lower at 7 days than at 3 months after surgical treatment.

CONCLUSIONS

Our results indicate that cortical perfusion progressively declines in the cranioplasty treated hemisphere but remains stable in the contralateral hemisphere after surgery and suggest that CTP can represent a promising tool for a longitudinal analysis of hemodynamic abnormalities occurring in TBI patients after cranioplasty. In addition, these data imply a possible role of cranioplasty in restoring flow to meet the prevailing metabolic demand.

Beneficial impact of early cranioplasty in patients with decompressive craniectomy: evidence from transcranial Doppler ultrasonography

BACKGROUND

A cranioplasty (CP) is often performed after decompressive craniectomy (DC) for cosmetic and protective reasons; however, the timing of CP needs to be better evaluated to maximize beneficial outcomes and neurological recovery.

OBJECTIVE

We investigated the effects and mechanisms of early CP compared to late CP on neurological recovery, from the perspective of cerebral blood flow (CBF).

METHODS

This study retrospectively reviewed 43 patients undergoing early (<12 weeks) or late (≥ 12 weeks) cranioplasty after DC. The CBF velocity was measured by transcranial Doppler ultrasonography and was analyzed prior to and after CP in every patient. Complications were recorded.

RESULTS

The CBF velocity in the middle cerebral artery (MCA) ipsilateral to the CP was increased in both groups and was statistically different between groups (p < 0.05). On the contralateral side, however, the CBF in the MCA was increased in the early CP group, but not the late CP group. Change (expressed as delta, Δ) was defined as the difference in CBF velocity between pre- and postoperative status in the early and late CP groups. A statistically significant difference was detected in the Δ of MCA on the ipsilateral side between the early and late groups. There were no differences in the incidence of complications between groups.

CONCLUSIONS

Our results show better post-DC improvements in the CBF of patients receiving CP < 12 weeks after DC, compared to those receiving CP ≥ 12 weeks after DC. Therefore, early CP has potential benefits for cerebral perfusion.

Comprehensive cognitive and cerebral hemodynamic evaluation after cranioplasty

Decompressive craniectomy is an established procedure to lower intracranial pressure and can save patients' lives. However, this procedure is associated with delayed cognitive decline and cerebral hemodynamics complications. Studies show the benefits of cranioplasty beyond cosmetic aspects, including brain protection, and functional and cerebrovascular aspects, but a detailed description of the concrete changes following this procedure are lacking. In this paper, the authors report a patient with trephine syndrome who underwent cranioplasty; comprehensive cognitive and cerebral hemodynamic evaluations were performed prior to and following the cranioplasty. The discussion was based on a critical literature review.

Brain motion in patients with skull defects: B-mode ultrasound observations on respiration-induced movements

BACKGROUND

Since ancient times, brain motion has captured the attention of human beings. However, there are no reports about morphological changes that occur below the cortex or skin flap when a patient, with an open skull breathes, coughs, or engages effort. Thus, the aim of this study was to characterize brain motion caused by breathing movements in adults with an open skull.

METHODS

Twenty-five craniectomized patients were studied using B-mode ultrasonography during early and late postoperative periods. Twelve patients were analysed during surgery. Brain movements induced by breathing activity were assessed in this prospective observational study.

RESULTS

Taking as a reference the cranial base, an increase in intrathoracic pressure was accompanied by a rise of the brain due to the expansion of the basal cisterns. Greater increases in intrathoracic pressure (resulting from the Valsalva manoeuvre and coughing) propelled the brain in a block from the foramen magnum towards the craniectomy, mainly in structures near the tentorial incisure. Prolonging the Valsalva manoeuvre also resulted in thickening of the cortical mantle attributable to vascular congestion. The magnitude of these movements was directly related to breathing effort.

CONCLUSIONS

The increase in intrathoracic pressure was immediately transmitted to the brain by the rise of cerebrospinal fluid, while brain swelling attributable to vascular congestion showed a brief delay. The Valsalva manoeuvre and coughing caused abrupt morphological changes in the tentorial hiatus neighbouring structures because of the distension of the basal cisterns. These movements could play a role in the pathophysiology of the syndrome of trephined.