Intraoperative neuromonitoring during resection of cranial meningiomas and its effect on the surgical workflow.

PURPOSE: Resection of meningiomas adjacent to the central sulcus entails a high rate of morbidity. Explored for intra-axial lesion resection, intraoperative neuromonitoring intraoperative neuromonitoring (IONM) has been shown to decrease neurological deficits. The use of IONM is relatively uncommon and is not considered routine practice in the removal of extra-axial lesions. We sought to characterize IONM's impact on the surgical workflow in supratentorial meningiomas. METHODS: We retrospectively analyzed a prospectively collected database, searching cases in which IONM was used for resection of meningioma between 2017 and 2020. We classified the IONM effect on surgical workflow into 5 distinct categories of workflow changes (WFC). RESULTS: Forty cases of meningiomas with IONM use were identified. In 1 case (class 1 WFC), the operation was stopped due to IONM input. In 5 cases (class 2 WFC), the tumor was incompletely resected due to input from the IONM. In 14 cases (35%), IONM leads to an alteration of the resection process (alteration of approach, class 3 WFC). In 4 cases (10%), anesthesia care was modified based on IONM input (class 4 WFC). In 16 cases, no changes were made (class 5 WFC). In all patients in whom a change was made (24 cases, WFC 1-4), only 8.3% suffered a temporary deficit, and there were no permanent deficits, whereas when no change was made, there were 18.75% temporary deficit and 6.25% permanent deficit. CONCLUSION: IONM has an impact during resection of meningiomas in eloquent areas and may guide the surgical technique, approach to tumor resection, and extent of resection.

Outcomes of pituitary apoplexy: a comparison of microadenomas and macroadenomas.

PURPOSE: We aimed to assess clinical characteristics of apoplexy of pituitary microadenomas compared to macroadenomas. METHODS: We retrieved clinical records of patients > 18 years old, hospitalized in Rambam hospital between January 2001 and October 2017, with pituitary apoplexy and follow-up of at least one year. We compared clinical course and outcomes of apoplexy between patients with microadenomas and macroadenomas, and between patients who received conservative or surgical treatment. Statistical analysis was done using Fisher's exact and Mann-Whitney tests. RESULTS: Twenty-seven patients with pituitary apoplexy were included in the final analysis: mean age was 40.7 ± 12.5 years, 13(48%) were female, 7(26%) had microadenomas, and 21(78%) harbored clinically nonfunctioning pituitary adenomas. Upon admission, hyponatremia, random cortisol level of < 200 nmol/L, and secondary hypothyroidism, were evident in 6/20, 8/18, and 4/18 patients with macroadenoma and 1/5, 2/5, and 1/6 patients with microadenoma, respectively (P = 1.0). Hypogonadotropic hypogonadism was evident in 9/12 men with macroadenoma. In 12 macroadenoma patients, the tumor abutted the optic chiasm, of whom eight had visual field defects. Fifteen patients with macroadenoma and two with microadenoma underwent transsphenoidal surgery. Median follow-up was 3 years. At last follow-up visit, patients with microadenoma had lower rates of corticotropic deficiency or secondary hypothyroidism compared to macroadenoma patients (1/7 vs. 13/20 respectively, p = 0.033). Only two patients with macroadenomas had persistent visual field defects. Outcomes were comparable between conservative and surgical treatment groups. CONCLUSIONS: Long term pituitary hormone deficiencies are more common in pituitary apoplexy patients with macroadenomas. Apoplexy of pituitary microadenoma carries a more favorable prognosis.

Management of Pediatric Orbital Fractures.

INTRODUCTION: Although uncommon in children, orbital fractures can be devastating to both vision and appearance. Due to the scarce information in the literature, the authors here present our experience and management with all pediatric orbital fracture patients. MATERIAL AND METHODS: A 6-years retrospective study was conducted on pediatric patients presented with orbital wall fracture (OFx). All patients (n = 43) were grouped for comparison based on the treatment method. The cohorts were analyzed for demographics data, location of fracture, type of material used for reconstruction, complication rate and follow up length. Data was analyzed utilizing SPSS for χ2 test. RESULTS: The majority of patients were male (86%) and the mean age of patients was 12.09 ±â€Š4 years. Mean follow-up time was 237 ±â€Š72 days. Most of Patients 31 (72%) underwent surgical intervention. A higher rate of complications was observed in the surgically treated group (32%) compared to the conservative group (8%) regardless to the defect size. Subgroup analysis of the surgery treated group revealed that large size defect had inferior outcome compared to small size defect. CONCLUSION: The consequences of treatment on long-term growth and development must be a cornerstone when choosing the optimal therapeutic method. Conservative management should be considered first in the absence of significant clinical pathologies. In addition, when surgery is indicated the least invasive procedure should be applied. The use of autogenous bone graft is preferable over alloplastic materials, however, when there is insufficient bone quantity the use of alloplastic materials is not contraindicated for reconstruction.

Intraspinal hypotension syndrome presents as transient quadriplegia.

Intracranial hypotension can be a complication of epidural anaesthesia. Pure clinical spinal hypotension manifesting as acute transient quadriplegia following epidural anaesthesia is a severe, life-threatening complication that have not been described before. This complication can be solved with an epidural blood patch; thus, it should be familiar to doctors across all specialities.

Uncal herniation in a fully conscious patient-The sliding uncus syndrome.

Uncal herniation is accompanied by a decreased level of consciousness. We describe a patient who remained fully alert despite the uncal herniation. The computed tomography (CT) scans allowed us to visualize the uncus and its spatial relation to the cerebral peduncle. We describe the sliding uncus syndrome.

Why mortality is still high with modern care of 613 evacuated mass lesions presented as severe head injuries 1999-2009.

Of 1,949 successive acute severe head injuries (SHI) over a period of 11 years 1999-2009, 613 (31.5%) underwent evacuation of mass lesions. Mortality at 3 months of evacuated mass (EM) lesions was higher over 10 years compared with that of non-EM lesions (it was overall 22%). The reduction of mortality was significantly less in EM compared with that for non-surgical cases (14.4-9.4% recently) and for the cases that were operated but not for mass evacuation (18.1-12.1%). A few explanations are: first, more SDH (60.5% of the EM recently compared with 45.9% in the first few years); second, more severe cases and older patients with co-morbidities were treated surgically; third, advances in prehospital care brought more severe patients to operative care - the rate of referrals decreased from 61.5% to 52.8% recently; fourth, part of the significant shortening of the injury to NT admission time (163-141 min) vanished owing to the parallel elongation of admission to operation time (95-100 min), thus, the threshold recommendation of 4 h to mass evacuation was achieved in only 52%; fifth, introducing decompressive craniectomy was not associated with outcome improvement.

Mechanism underlying painful radiculopathy in patients with lumbar disc herniation.

BACKGROUND: Painful lumbar radiculopathy is a neuropathic pain condition, commonly attributed to nerve root inflammation/compression by disc herniation. The present exploratory study searched for associations between pain intensity and inflammatory markers, herniated disc size, infection, psychological factors and pain modulation in patients with confirmed painful lumbar radiculopathy scheduled for spine surgery. METHODS: Prior to surgery, 53 patients underwent the following evaluation: pain intensity measured on a 0-10 numeric rating scale (NRS) and the Short-Form McGill Pain Questionnaire; sensory testing (modified DFNS protocol); pain processing including temporal summation and conditioned pain modulation (CPM); neurological examination; psychological assessment including Spielberger's Anxiety Inventory, Pain Sensitivity Questionnaire and the Pain Catastrophizing Scale. Pro-inflammatory cytokine levels (IL-1b, IL-6, IL-8, IL-17, TNFα, IFNg) and microbial infection (ELISA and rt-PCR) in blood and disc samples obtained during surgery. MRI scans assessments for disc herniation size/volume (MSU classification/ three-dimensional volumetric analysis). RESULTS: Complete data were available from 40 (75%) patients (15 female) aged 44.8 ± 16.3 years. Pain intensity (NRS) positively correlated with pain catastrophizing and CPM (r = 0.437, p = 0.006; r = 0.421, p = 0.007; respectively), but not with disc/blood cytokine levels, bacterial infection or MRI measures. CPM (p = 0.001) and gender (p = 0.029) were associated with average pain intensity (adjusted R2  = 0.443). CONCLUSIONS: This exploratory study suggests that pain catastrophizing, CPM and gender, seem to contribute to pain intensity in patients with painful lumbar radiculopathy. The role of mechanical compression and inflammation in determining the intensity of painful radiculopathy remains obscure. SIGNIFICANCE OF STUDY: Pain catastrophizing, CPM and gender rather than objective measures of inflammation and imaging seem to contribute to pain in patients with painful radiculopathy.

Spontaneous cerebellar hemorrhage carries a grim prognosis in both operated and unoperated patients.

Management of spontaneous cerebellar hemorrhage (SCH) has been scarcely reported, and controversies still exist regarding their surgical management. METHODS: We performed a retrospective review of the Rambam Medical Center registry. All cases with a SCH, operated or not, were reviewed. Basic patient parameters, clinical status on admission and imaging results, management and outcome measures were evaluated. Parameters were compared between the operated and unoperated groups, and assessed for their correlation to patient death within 12 months. When operated, patients underwent Suboccipital craniectomy (SOC), insertion of an external ventricular drain (EVD) or both. RESULTS: 57 patients were treated for SCH in the years 2005-2017. 20 patients (35.09%) died during their original admission. 16 were discharged in non-functional status. In total, 36 patients died within 12 months of their admission. Only 21 patients (36.84%) were alive one year after their bleed. The following parameters were correlated to death in the entire cohort: older age, larger hematoma size, hydrocephalus, brainstem compression by the bleed and outcome status. The unoperated patients were younger, and had a lower Glasgow Coma Scale (GCS) on admission. Death within 12 months occurred in 69.77% of the operated patients, but only 42.86% of the unoperated patients, p = 0.10. Unfavorable outcome was found in 36% of the unoperated group and 72% of the operated group, p = 0.024. CONCLUSION: SCH carries a grim prognosis in both operated and unoperated patients. Roughly one third of patients in our series died during their admission and another third were either vegetative or severely disabled on discharge.

Decreasing External Ventricular Drain-Related Infection Rates with Duration-Independent, Clinically Indicated Criteria for Drain Revision: A Retrospective Study.

OBJECTIVE: To lower external ventricular drain (EVD)-related infection rates, in April 2013, our institution enacted a major protocol change, switching from routine EVD replacement every 5 days to EVD replacement only when clinically indicated. In the present study, we evaluated the effect of this change on nosocomial EVD-related infections. METHODS: We performed a retrospective cohort study to compare the EVD-related infection rates between 2 groups (group A, elective EVD replacement; group B, clinically indicated EVD replacement). We analyzed the data from 142 patients (group A, n = 43; group B, n = 99), with a total of 227 EVDs for 5 years and 3 months (1721 catheter days). RESULTS: The overall EVD-related infection rates were elevated in group A (0.14; 32% of patients) compared with group B (0.08; 8%; P = 0.001). The median hospital stay (33 vs. 24 days; P = 0.001) and neurosurgical intensive care unit stay (30.5 vs. 17 days; P < 0.0001) were also longer for group A. The requirement for multiple EVDs was an independent risk factor (P = 0.003), with a 4.6 times greater risk in group A (odds ratio, 4.64; 95% confidence interval, 1.7-12.6). CONCLUSIONS: The findings from our study strengthen an increasing body of evidence suggesting the importance of inoculation of skin flora as a critical risk factor for EVD-related infections, underscoring the importance of drain changes only when clinically indicated and that, as soon as clinically permitted, catheters should be removed.

Long-term outcome of superficial temporal artery-middle cerebral artery bypass for patients with moyamoya disease in the US.

OBJECT: The authors report the long-term results of a series of direct superficial temporal artery-middle cerebral artery (STA-MCA) bypass procedures in patients with moyamoya disease from the western US. METHODS: All patients with moyamoya disease treated at the University of Washington from 1990 through 2004 (39 patients) were included in this study. Patients underwent pre- and postoperative evaluation of cerebral perfusion dynamics. Surgical revascularization procedures were performed in all patients with impaired cerebral blood flow (CBF) findings. RESULTS: The mean age of patients at diagnosis was 34 years (range 10-55 years). All 39 patients had impaired CBF and/or vasomotor reserve and underwent revascularization procedures: 26 patients underwent bilateral operations, 13 unilateral (65 total procedures). An STA-MCA bypass was technically possible in 56 procedures (86.2%); saphenous vein interposition grafts were required in 3 procedures (4.6%); encephaloduroarteriosynangiosis was performed in 6 procedures (9.2%). Three patients died due to postoperative complications, yielding a procedure-related mortality rate of 4.61%, and 8 experienced non-life threatening complications (for a procedure-related rate of 12.3%). Long-term follow-up appeared to indicate a reduction in further ischemic events in surviving patients compared with the natural history. Cerebral perfusion dynamics improved postoperatively in all 36 surviving patients. CONCLUSIONS: Moyamoya disease may differ in the US and Asia, and STA-MCA bypass procedures may prevent future ischemic events in patients with this condition.

Minimally Invasive Surgery for Resection of Parapharyngeal Space Tumors.

Background Surgical removal of parapharyngeal space tumors (PPST) poses challenges due to the complex anatomy of the region. PPSTs are routinely resected by a transcervical approach using blind finger dissection. Large PPSTs or those located high at the skull base, often require transmandibular or infratemporal fossa approaches, associated with considerable morbidity. Objective Here, we describe an approach for PPST removal that comprises transcervical endoscopic, with or without transoral robotic technique. Materials and Methods We retrospectively studied the demographic, clinical, surgical, and outcome data of 11 consecutive patients who underwent PPST excision between June 2013 and July 2017 at our center. Patients either underwent a transcervical endoscopic procedure ( n = 4), a transoral robotic procedure ( n = 2) or a combination of the two procedures ( n = 5). Results Complete tumor excision was achieved in all cases, with no intra-, peri-, or postoperative complications. Final histopathologic findings demonstrated pleomorphic adenoma for seven patients, cavernous hemangioma for one patient, and malignant tumors for three patients. The average tumor size was 44.22 ± 31.9 cm 3 (range: 7.5-111 cm 3 ). At follow-up (range: 3-42 months), there was no evidence of recurrence. Conclusions The approach described provides improved visualization and safe vascular control with minimum tumor stress, preventing the need for blind finger dissection, and allowing complete tumor removal while minimizing tumor spillage, nerve injury, and blood loss, maintaining excellent cosmetic and functional results. This approach could be utilized for the removal of large benign PPST, or small PPST located high.

Asymmetric dynamic cerebral autoregulatory response to cyclic stimuli.

BACKGROUND AND PURPOSE: Dynamic cerebral autoregulation has been shown to be fast and effective, but it is not well known if the mechanism is symmetric, that is to say, it acts with equal compensatory action to upward as compared with downward abrupt changes in arterial blood pressure (ABP). METHODS: Fourteen patients with head injuries and 10 normal subjects had bilateral transcranial Doppler and continuous ABP recording. Cyclic ABP stimuli were generated by large thigh cuffs, which were rapidly inflated above systolic pressure for 15 seconds alternating with 15 seconds of deflation. At least 8 such cycles were ensemble-averaged and the dynamic autoregulatory gain (AG(up) and AG(dn)) was estimated separately for upward and downward changes in ABP. The results were compared with the autoregulation index using conventional leg cuff releases. RESULTS: In normal subjects, AG(dn) was 0.74+/-0.18 and AG(up) was 0.77+/-0.17 (mean+/-SD); the difference was insignificant. The correlation between AG(dn) and AG(up), however, was weak (r=0.24). In the patients with head injury, AG(dn) was 0.30+/-0.21 and AG(up) was 1.27+/-0.76, the difference being highly significant (P<0.001). There was a negative relationship between AG(dn) and AG(up) (r=-0.33). Autoregulation index correlated well with AG(dn) (r=0.79) and weakly negatively with AG(up) (r=-0.47). CONCLUSIONS: A strongly asymmetric dynamic response of the cerebral autoregulation was seen the majority of patients with head injury. It might also have been present, albeit to a lesser degree, in the normal subjects. The findings suggest that nonlinear effects may be present in the operation of the cerebral autoregulation mechanism.

Monitoring of cerebral metabolism: non-ischemic impairment of oxidative metabolism following severe traumatic brain injury.

OBJECTIVE: To investigate and compare the respective dynamics of cerebral blood flow (CBF) and metabolism in response to changes in neurological condition and intracranial pressure (ICP) in severe traumatic brain injury (TBI). METHODS: Eight-four patients with severe TBI were prospectively enrolled in this study. CBF was measured daily and global cerebral metabolic rates of oxygen (CMRO(2)), glucose (CMRGlc) and lactate (CMRLct) were calculated using arterial jugular differences. In addition, 33 patients had a second evaluation shortly after a significant change (>5 mmHg) in their ICP. RESULTS: Eight hundred and ninety-four evaluations were collected during a period ranging between 1 and 12 days (mean: 5.1 +/- 2.6 days). CBF was moderately but significantly decreased. Oppositely, CMRO(2) was profoundly reduced with evidence for critical metabolic failure (<1.2 ml/100 g/min) in 30.5% whereas only 8.5% of CBF measurements were lower than 20 ml/100 g/min. Furthermore, in 78 instances of a dynamic assessment performed following ICP increase (n = 20) or decrease (n = 58), CMRO(2) but not CBF proved to be significantly and inversely affected by ICP fluctuations. Finally, CMRO(2) and CMRLct correlated with GCS score in contrast with CBF. Both CBF and metabolic indices, however, correlated with neurological outcome. CONCLUSION: This study shows that cerebral metabolic failure following TBI is a common finding that is not of ischemic origin in most instances. Unlike frequently assumed, cerebral metabolism is not constrained within the narrow range of a static depression sustained for weeks but rather subject to significant variations in response to changes in ICP or neurological condition.

Combined endoscopic transcervical-transoral robotic approach for resection of parapharyngeal space tumors.

BACKGROUND: Parapharyngeal space tumors (PPSTs) pose exposure challenges; they are routinely resected by the transcervical approach using blunt/blind finger dissection, increasing the risk of tumor spillage and of neurovascular injury. Large PPSTs or those located high at the skull base often require mandibulotomy or an infratemporal fossa approach, baring considerable morbidity. METHODS: The novel minimally invasive approach described, utilizes endoscopic equipment introduced transcervically for circumferential separation of the tumor from the neurovascular structures of the skull base. After the tumor is separated, it is removed en bloc, via transoral robotic surgery (TORS). RESULTS: The technique provides improved visualization and safe vascular control with minimum tumor stress, preventing the need of blunt/blind finger dissections, and allowing complete tumor removal while minimizing tumor spillage, nerve injury, and blood loss, maintaining excellent cosmetic and functional results. CONCLUSION: This approach could be utilized for the removal of large benign PPSTs, or small PPSTs located high at the skull base. © 2017 Wiley Periodicals, Inc. Head Neck 39: 786-790, 2017.

Endoscopic Endonasal Repair of Internal Carotid Artery Injury during Endoscopic Endonasal Surgery.

Background Injury to the cavernous portion of the internal carotid artery (ICA) during endoscopic skull base surgery is a well-recognized rare complication that can be associated with high rates of morbidity and mortality. Many techniques have been suggested to manage ICA injury with varying degrees of success. Objectives We provide a detailed technical description of an operative technique for endoscopic management of carotid artery injury. Methods A case of ICA injury during endoscopic skull base surgery is presented. The immediate treatment measurements include: (1) early recognition of ICA injury, (2) briefing of the team and preparations, (3) packing, (4) harvesting of temporalis muscle patch, (5) placement of the muscle patch over the defect, and (6) gentle compression for 10 minutes. Results The technique facilitates quick repair and restores normal blood flow through the damaged artery. Exsanguination or the symptoms of stroke that may occur from prolonged occlusion of the ICA are therefore prevented. Conclusion The proposed protocol is useful for the management of a potentially life-threatening ICA injury.

Impact of basilar artery vasospasm on outcome in patients with severe cerebral vasospasm after aneurysmal subarachnoid hemorrhage.

BACKGROUND AND PURPOSE: The purpose of the present study was to evaluate the impact of basilar artery (BA) vasospasm on outcome in patients with severe vasospasm after aneurysmal subarachnoid hemorrhage (aSAH). METHODS: Sixty-five patients with clinically suspect severe cerebral vasospasm after aSAH underwent cerebral angiography before endovascular treatment. Vasospasm severity was assessed for each patient by transcranial Doppler measurements, angiography, and (99m)Tc-ethylcysteinate dimer single-photon emission computed tomography (ECD-SPECT) imaging. Percentage of BA narrowing was calculated in reference to the baseline angiogram. RESULTS: BA narrowing >or=25% was found in 23 of 65 patients, and delayed brain stem (BS) hypoperfusion, as estimated by ECD-SPECT, was found in 16. Fourteen of 23 patients with BA narrowing >or=25% experienced BS hypoperfusion, whereas only 2 of 42 patients with >or=25% BA narrowing experienced BS ischemia (P<0.001). Stepwise logistic regression after adjusting for age with Hunt and Hess grade, Fisher grade, hydrocephalus, and aneurysmal location as covariables revealed BA narrowing >or=25% and delayed BS hypoperfusion to be significantly and independently associated with unfavorable 3-month outcome (P=0.0001; odds ratio, 10.1; 95% CI, 2.5 to 40.8; and P=0.007; odds ratio, 13.8, 95% CI, 2.18 to 91.9, respectively). CONCLUSIONS: These findings suggest for the first time that BA vasospasm after aSAH is an independent and significant prognostic factor associated with poor outcome in patients with severe cerebral vasospasm requiring endovascular therapy. Further study should be done to evaluate the role of interventional therapy on outcome in patients with posterior circulation vasospasm.

Dynamic perfusion computerized tomography in cerebral vasospasm following aneurysmal subarachnoid hemorrhage: a comparison with technetium-99m-labeled ethyl cysteinate dimer-single-photon emission computerized tomography.

OBJECT: The aim of this study was to correlate cerebral blood flow (CBF) and mean transient time (MTT) measured on dynamic perfusion computerized tomography (CT) with CBF using (99m)Tc ethyl cysteinate dimer-single-photon emission computerized tomography (SPECT) in patients with cerebral vasospasm following aneurysmal subarachnoid hemorrhage (SAH). METHODS: Thirty-five patients with vasospasm following aneurysmal SAH (12 men and 23 women with a mean age of 49.3 +/- 10.1 years) underwent imaging studies; thus, 35 perfusion CT scans and 35 SPECT images were available for comparison. The CBF and MTT values in 12 different brain regions were defined relative to the interhemispheric occipital cortex values using perfusion CT scans and were compared with qualitative relative (rel)CBF estimated on SPECT images. In brain regions with normal, mild (relCBF 71-85%), moderate (relCBF 50-70%), and severe (relCBF < 50%) hypoperfusion on SPECT, the mean relCBF values measured on perfusion CT were 1.01 +/- 0.08, 0.82 +/- 0.22, 0.6 +/- 0.15, and 0.32 +/- 0.08, respectively (p < 0.0001); the mean relMTT values were 1.04 +/- 0.14, 1.4 +/- 0.31, 2.16 +/- 0.46, and 3.3 +/- 0.54, respectively (p < 0.0001). All but one brain region (30 regions) with severe hypoperfusion on SPECT images demonstrated relCBF values less than 0.6 and relMTT values greater than 2.5 on perfusion CT scans. CONCLUSIONS: Relative CBF and MTT values on perfusion CT showed a high concordance rate with estimated relCBF on SPECT in patients with vasospasm following aneurysmal SAH. Given its logistical advantages, perfusion CT may be a valuable method of assessing perfusion abnormality in the acute setting of vasospasm and in patients with an unstable condition following aneurysmal SAH.

Cavernous Carotid Artery Pseudoaneurysm Following a Radical Cavernous Sinus Resection.

Iatrogenic cavernous carotid pseudoaneurysms are a special group among other intracranial aneurysms. They can occur during the dissection phase of the surgery if the tumor encases a vessel. Complications of their rupture as hemorrhage or stroke are life threatening. Early recognition and treatment is mandatory to avoid catastrophic sequelae. We present the successful diagnosis and endovascular treatment of a postoperative cavernous carotid pseudoaneurysm following radical cavernous sinus resection.

Massive cerebral swelling immediately after cranioplasty, a fatal and unpredictable complication: report of 4 cases.

Cranioplasty after decompressive craniectomy (DC) is associated with increased morbidity, but the reported mortality rate is low. Recently, some authors have reported a rare unexplained complication of sudden death in association with massive cerebral edema immediately after cranioplasty. The author reports on 4 patients who underwent cranioplasty after DC between January 2005 and August 2010 at his department and died because of massive cerebral edema immediately after uneventful surgery and anesthesia. All 4 of the new cases reported involved young male patients who underwent decompressive hemicraniectomy after traumatic brain injury. They developed massive cerebral swelling immediately after uneventful cranioplasty (3 patients) or after removal of an epidural hematoma several hours after surgery (1 patient). All 4 patients had a large skull defect and significantly sunken craniotomy site, and all were treated with a closed vacuum suction system that was placed under the scalp and kept open at the end of the cranioplasty procedure. After surgery, the patients' pupils became fixed and dilated, and brain CT scans showed massive brain edema. Despite emergency DC, the patients did not recover, and all 4 died. A MEDLINE search showed 8 similar cases that were reported previously. Fatal cerebral swelling after uneventful cranioplasty is a distinct clinical entity, although it is unpredictable. It is postulated that a negative pressure difference from the elimination of atmospheric pressure that had been chronically applied on the injured sinking brain in combination with the negative pressure applied by the closed subgaleal suction drain may lead to a massive brain shift toward the cranioplasty site and initiate a fatal vasomotor reaction.