Underwater versus Closed Drainage System for Surgical Treatment of Chronic Subdural Hematoma

OBJECTIVES

Chronic subdural hematoma (CDH) is a prevalent condition in neurosurgery. Standard care includes surgical evacuation with drainage of residual subdural cavity. We hypothesized that effective and timely drainage of subdural space may improve clinical and radiological outcomes. This study was conducted to compare the effectiveness of standard closed drainage and underwater drainage.

METHODS

Medical data of 300 surgically treated chronic subdural hematoma CDH patients were retrospectively collected and analyzed. The patients were divided into two 2 groups: Group I with underwater drainage, and Group II with closed drainage. Groups were compared in terms of gender, age, complication rates, recurrence rates, seizure rates, and length of hospital stay.

RESULTS

Underwater drainage was found superior to closed system by all clinical and radiographic parameters. The recurrence rate was significantly lower in Group I (2%) compared to with Group II (10%). Subdural empyema was observed in 10 patients in Group II and none in Group I. The seizure rate was higher in Group II (18%) compared to with Group I (5%). Postoperative pneumocephalus rates was were 20% in Group I and 54% in Group II. The length of hospital stay was 6±2.6 days in Group I and 8.9±6.1 days in Group II. The length of intensive care unit (ICU) stay was 0.6±1.12 days in Group I and 2.7±5 days in Group II. A minority (5%) of the patients in Group II required reoperation due to recurrence.

CONCLUSIONS

The use of underwater system significantly the reduces the rates of pneumocephalus, seizures, infection, and recurrence. Additional benefits are shorter intensive care unit ICU and total hospital stays.

Simultaneous gas embolism and pneumocephalus after paravertebral irrigation with hydrogen peroxide: A rare case report

INTRODUCTION

Gas embolism is a rare but fatal clinical emergency. Hydrogen peroxide (H2O2) can cause gas embolism when improperly used in closed cavities or for deep and large wound irrigation.

PRESENTATION OF CASE

A 31-year-old woman was diagnosed with lumbar-3 tuberculosis and paravertebral abscess and underwent emergency spinal surgery in a prone position. After removing the tuberculous pus, 200 mL of H2O2 (3 % v/w) was used to repeatedly irrigate the abscess cavity. Immediately after irrigation, the patient suffered cardiac arrest. During cardiopulmonary resuscitation, transesophageal echocardiography revealed that the right cardiac cavity was filled with a diffuse "Snowflake-Like" gas embolus, and cranial computed tomography showed a multi-point pneumocephalus in the frontal lobes. The patient eventually suffered brain death despite the return of spontaneous circulation after active resuscitation.

DISCUSSION

H2O2 can quickly release abundant oxygen and water upon contact with catalase. Oxygen bubbles enter the vascular lumen and cause mechanical obstruction of the right cardiac circulation. In addition, H2O2 and oxygen bubbles may migrate upwards and enter the intracranial tissue through the epidural space or subdural space, resulting in intracranial pneumatosis. Diagnosis and treatment of gas embolism are extremely difficult. Some suggestions are that H2O2 should not be used in closed cavities or on deep and large wounds due to the potential risk of fatal gas embolism.

CONCLUSION

The fatal complications of gas embolism and pneumocephalus rarely occur simultaneously in one patient, and we aim to highlight this potential risk of intraoperative H2O2 use in spinal surgery.

Minimizing pneumocephalus during deep brain stimulation surgery

BACKGROUND

Deep brain stimulation (DBS) surgery is an effective treatment for movement disorders. Introduction of intracranial air following dura opening in DBS surgery can result in targeting inaccuracy and suboptimal outcomes. We develop and evaluate a simple method to minimize pneumocephalus during DBS surgery.

METHODS

A retrospective analysis of prospectively collected data was performed on patients undergoing DBS surgery at our institution from 2014 to 2022. A total of 172 leads placed in 89 patients undergoing awake or asleep DBS surgery were analyzed. Pneumocephalus volume was compared between leads placed with PMT and leads placed with standard dural opening. (112 PMT vs. 60 OPEN). Immediate post-operative high-resolution CT scans were obtained for all leads placed, from which pneumocephalus volume was determined through a semi-automated protocol with ITK-SNAP software. Awake surgery was conducted with the head positioned at 15-30°, asleep surgery was conducted at 0°.

RESULTS

PMT reduced pneumocephalus from 11.2 cm3±9.2 to 0.8 cm3±1.8 (P<0.0001) in the first hemisphere and from 7.6 cm3 ± 8.4 to 0.43 cm3 ± 0.9 (P<0.0001) in the second hemisphere. No differences in adverse events were noted between PMT and control cases. Lower rates of post-operative headache were observed in PMT group.

CONCLUSION

We present and validate a simple yet efficacious technique to reduce pneumocephalus during DBS surgery.

Pneumocephalus and empyema in the subarachnoid space: An unusual imaging feature secondary to spinal-epidural anesthesia

Pneumocephalus and empyema in the subarachnoid space secondary to spinal-epidural anesthesia are very rare and have not previously been reported, to our knowledge. Here, we describe the imaging features of an older woman presenting with pneumocephalus plus subarachnoid and intraventricular empyema due to Staphylococcus epidermidis infection after spinal-epidural anesthesia, with the aim of raising awareness regarding this serious complication.

Spinal procedures, pneumocephalus, and cranial nerve palsies: A review of the literature

Purpose: Minimally invasive and surgical spine procedures are commonplace with various risks and complications. Cranial nerve palsies, however, are infrequently encountered, particularly after procedures such as lumbar punctures, epidural anesthesia, or intrathecal injections, and are understandably worrisome for clinicians and patients as they may be interpreted as secondary to a sinister etiology. However, a less commonly considered source is a pneumocephalus which may, in rare cases, abut cranial nerves and cause a palsy as a benign and often self-resolving complication. Here, we present the case of a patient who underwent an intrathecal methotrexate infusion for newly diagnosed non-Hodgkin's T-cell lymphoma and subsequently developed an abducens nerve palsy due to pneumocephalus. We highlight the utility of various imaging modalities, treatment options, and review current literature on spinal procedures resulting in cranial nerve palsies attributable to pneumocephalus presenting as malignant etiologies.

Brain Shift during Staged Deep Brain Stimulation for Movement Disorders

INTRODUCTION

Deep brain stimulation (DBS) is a routine neurosurgical procedure utilized to treat various movement disorders including Parkinson's disease (PD), essential tremor (ET), and dystonia. Treatment efficacy is dependent on stereotactic accuracy of lead placement into the deep brain target of interest. However, brain shift attributed to pneumocephalus can introduce unpredictable inaccuracies during DBS lead placement. This study aimed to determine whether intracranial air is associated with brain shift in patients undergoing staged DBS surgery.

METHODS

We retrospectively evaluated 46 patients who underwent staged DBS surgery for PD, ET, and dystonia. Due to the staged nature of DBS surgery at our institution, the first electrode placement is used as a concrete fiducial marker for movement in the target location. Postoperative computed tomography (CT) images after the first electrode implantation, as well as preoperative, and postoperative CT images after the second electrode implantation were collected. Images were analyzed in stereotactic targeting software (BrainLab); intracranial air was manually segmented, and electrode shift was measured in the x, y, and z plane, as well as a Euclidian distance on each set of merged CT scans. A Pearson correlation analysis was used to determine the relationship between intracranial air and brain shift, and student's t test was used to compare means between patients with and without radiographic evidence of intracranial air.

RESULTS

Thirty-six patients had pneumocephalus after the first electrode implantation, while 35 had pneumocephalus after the second electrode implantation. Accumulation of intracranial air following the first electrode implantation (4.49 ± 6.05 cm3) was significantly correlated with brain shift along the y axis (0.04 ± 0.35 mm; r (34) = 0.36; p = 0.03), as well as the Euclidean distance of deviation (0.57 ± 0.33 mm; r (34) = 0.33; p = 0.05) indicating statistically significant shift on the ipsilateral side. However, there was no significant correlation between intracranial air and brain shift following the second electrode implantation, suggesting contralateral shift is minimal. Furthermore, there was no significant difference in brain shift between patients with and without radiographic evidence of intracranial air following both electrode implantation surgeries.

CONCLUSION

Despite observing volumes as high as 22.0 cm3 in patients with radiographic evidence of pneumocephalus, there was no significant difference in brain shift when compared to patients without pneumocephalus. Furthermore, the mean magnitude of brain shift was <1.0 mm regardless of whether pneumocephalus was presenting, suggesting that intracranial air accumulation may not produce clinical significant brain shift in our patients.

Use of oxygen therapy for pneumocephalus: a systematic review

Pneumocephalus is the pathologic collection of air in the intracranial cavity. In sufficient volumes, it can contribute to symptoms ranging from headaches to death. For conservative treatment, oxygen use is commonplace. Although this is an accepted tenet of clinical practice, it is not necessarily founded on robust trials. An electronic search of databases EMBASE and MEDLINE and the Cochrane Library was undertaken as per the 2020 Preferred Reporting Items of Systematic Reviews and Meta-Analyses (PRISMA) statement. Three articles were included. Although the modes of oxygen delivery were heterogenous (non-rebreather versus endotracheal versus hyperbaric chamber), all studies concluded favorably on the use of oxygen therapy for increased reabsorption of pneumocephalus.

Semisitting position for cerebello-pontine angle surgery: Analysis of complications and how to avoid it

OBJECTIVE

To analyze the primary complications related to semisitting position in patients undergoing cerebelo-pontine angle surgery.

METHODS

Retrospective data analysis from patients undergoing elective tumoral cerebelo-pontine angle surgery in a semisitting position. The incidence, severity, occurrence moment, treatment, duration, and outcomes of venous air embolism (VAE), pneumocephalus, postural hypotension, and other complications were recorded. Neurointensive care unit (NICU), length of stay (LOS), hospital LOS, and modified Rankin scale scores were calculated six months after surgery.

RESULTS

Fifty patients were operated on. Eleven (22%) presented VAE (mean duration 8±4.5min): five (10%) during tumor resection, and four (8%) during dural opening. Ten (20%) were resolved by covering the surgical bed, air bubbles aspiration, jugular compression, and one (2%) tilted to a steep Trendelenburg position. One (2%) had intraoperative hemodynamic instability. The only variable associated with VAE was meningioma at histopathology OR=4.58, p=0.001. NICU was higher in patients with VAE (5.5±1.06 vs. 1.9±0.20 days, p=0.01). There were no differences in the Rankin scale. All patients presented postoperative pneumocephalus with a good level of consciousness, except one (2%) who required evacuation. Seven patients (14%) showed postural hypotension, three (6%) after positioning, and one (2%) after developing a VAE; all were reversed with usual vasoactive drugs. No other position-related complications or mortality were registered in this series.

CONCLUSIONS

The semisitting position is a safe option with the knowledge, prevention, detection, and early solution of all the possible complications. The development of VAE rarely implies hemodynamic instability or greater disability after surgery. Postoperative pneumocephalus is very common and rarely requires evacuation. Excellent cooperation between anesthesia, nursing, neurophysiology, and neurosurgery teams is essential to manage complications.

Traumatic pneumocephalus as a possible early sign of acute spinal cord injury: Case report

Background

Traumatic pneumocephalus (TPC) following craniofacial injuries is common, but isolated TPC secondary to pneumorrhachis (PR) is the rare result of upward gas migration from the spinal canal. In the absence of craniofacial and grossly unstable spinal fractures, the etiology of TPC in polytrauma can be elusive and an underlying diagnosis of acute spinal cord injury (SCI) can be easily missed. We report the first polytrauma case where TPC was the most reliable early sign of SCI.

Case Description

A 34-year-old polytrauma female with imaging findings of TPC, which was later found to be secondary to an underlying SCI. As a focused exam could not be performed at admission, the TPC was first attributed to undiagnosed craniofacial injuries. Tertiary survey revealed the patient being paraplegic and MRI workup demonstrated an acute SCI at the T3-T4 level. PR was the most likely cause of TPC in the absence of other craniofacial injuries.

Outcome

The patient did not have a meaningful recovery given the extensive hemispheric infarcts, spinal cord injury, and respiratory failure.

Conclusions

Although uncommon, TPC may be an important radiographic sign suggesting the possibility of an underlying SCI in polytrauma patients. especially when focused neurologic assessment is limited at admission. Polytrauma patients with TPC and PR in the absence of coexisting craniofacial fractures require an urgent spine consultation by the ER physician, with possible early spine MRI workup. We suggest a diagnostic algorithm for the early identification of SCI in polytrauma patients presenting with TPC and propose considering 3 groups which may have different risks for SCI based on their clinical presentation and the presence of PR.

Modified Puerto Rico Recurrence Scale for chronic subdural hematomas: augmenting the grading scale with postoperative pneumocephalus volume

BACKGROUND

Chronic subdural hematomas (CSDHs) are common in the elderly, with a relatively high rate of recurrence after initial surgical intervention. Our research team previously created a predictive grading system, the Puerto Rico Recurrence Scale (PRRS), to identify patients at high risk of CSDH recurrence. In this study, we introduce a modification of the (mPRRS) that includes pneumocephalus volume, which has been independently associated with recurrence.

METHODS

A single-center Puerto Rican population-based retrospective study was performed to analyze data for patients treated for CSDH at 1 institution between July 1, 2017, and December 31, 2019. Univariate and multivariate analyses were used to create a grading scale predictive of recurrence. Retrospective validation was conducted for the cohort.

RESULTS

Of 108 patients included in the study, 42 had recurrence, and 66 had nonrecurrence. Postoperative subdural space, postoperative midline shift, and pneumocephalus volume were all higher with recurrence (P = 0.002, P = 0.009, and P < 0.001, respectively). Multivariate analysis was used to create a 6-point grading scale comprising 3 variables (pneumocephalus volume [< 10, 10-20, 21-30, and > 30 cm3], postoperative midline shift [< 0.4, 0.41-1.0, and > 1.0 cm], and laterality [unilateral and bilateral]). Recurrence rates progressively increased in low-risk to high-risk groups (2/18 [11%] vs 21/34 [62%]; P < 0.003).

CONCLUSION

The mPRRS incorporating pneumocephalus measurement improves CSDH recurrence prediction. The mPRRS indicated that patients with higher scores have a greater risk of recurrence and emphasized the importance of measuring postoperative variables for prediction. The mPRRS grading scale for CSDHs may be applicable not only to the Puerto Rican population but also to the general population.

Tension pneumocephalus following bariatric surgery: case report

Bariatric surgery is an effective treatment for patients with idiopathic intracranial hypertension (IIH), a condition that is associated with skull base defects. A 55-year-old woman presented with symptoms of intractable nausea and vomiting, followed by headache and confusion two weeks after an elective laparoscopic vertical sleeve gastrectomy procedure. She had a presumed diagnosis of IIH and a remote history of CSF oto/rhinorrhea treated with a lumbar peritoneal (LP) shunt. Computed tomography (CT) scan of the head revealed tension pneumocephalus with midline shift and dehiscence of the tegmen. The patient underwent emergent craniotomy for decompression of the air-filled temporal lobe, clamping of the LP shunt, and repair of the skull base defect. Caution should be exercised in obese patients with a history of CSF leak secondary to a middle fossa skull base defect when being evaluated for bariatric surgery.

Otogenic Enterobacter cloacae meningitis complicated with pneumocephalus

Pneumocephalus refers to a pathologic collection of gas within the cranial cavity and is mostly caused by head trauma and neurosurgical procedures. Spontaneous nontraumatic pneumocephalus is a very rare condition. We herein report an unusual case of community-acquired bacterial meningitis with a combination of acute otitis media, Enterobacter cloacae, and nontraumatic pneumocephalus. A 75-year-old woman presented with fever, mental change, and neck stiffness. Brain imaging demonstrated pneumocephalus and fluid collection in the left mastoid air cells. E. cloacae was isolated from both blood and otorrhea cultures, and the patient was successfully treated with intravenous ceftazidime for 3 weeks. Although E. cloacae is a very rare cause of community-acquired bacterial meningitis in adults, it should be considered as a possible pathogen in otogenic meningitis complicated with pneumocephalus.

Tension Pneumocephalus: A Potentially Fatal Complication of Expanded Endoscopic Endonasal Approach

While some volume of pneumocephalus occurs following any surgery entailing dural breach, tension pneumocephalus (TP) is a rare complication of endoscopic endonasal surgery described in less than 1% cases including expanded endoscopic endonasal approaches (EEEA). It is a neurosurgical emergency warranting urgent decompression. Two cases, who developed TP following EEEA are presented. One had sinonasal malignancy (adenoid cystic carcinoma) eroding the anterior skull-base (T4N0M0) and the other was a large olfactory groove meningioma. TP was heralded in both by sudden deterioration in neurological status. Both cases underwent bifrontal craniotomy for decompression with simultaneous skull-base repair incorporating a vascularised pericranial flap. Brief literature review regarding the pathophysiology, contributing factors, diagnosis, management, and prevention of TP following EEEA is presented. TP, a life-threatening neurosurgical emergency, warrants meticulous precautions for its prevention, and vigilant postoperative monitoring for early detection. Urgent decompression with thorough skull-base repair is imperative to prevent complications.

Post-dural puncture headache combined with pneumocephalus secondary to vaginal delivery following epidural anesthesia: a case report

BACKGROUND

Pneumocephalus is rare in vaginal deliveries. Pneumocephalus may be asymptomatic or present with signs of increased intracranial pressure. However, parturients who received epidural anesthesia with air in their brains may experience low intracranial pressure headaches after giving birth, causing the diagnosis of pneumocephalus to be delayed. We report a case of a parturient who developed post-dural puncture headache combined with pneumocephalus secondary to vaginal delivery following epidural anesthesia.

CASE PRESENTATION

A 24-year-old G1P0 Chinese woman at 38 weeks gestation was in labor and received epidural anesthesia using the loss of resistance to air technique and had a negative prior medical history. She presented with postural headache, neck stiffness and auditory changes 2 h after vaginal delivery. The head non-contrast computed tomography revealed distributed gas density shadows in the brain, indicating pneumocephalus. Her headache was relieved by bed rest, rehydration, analgesia, and oxygen therapy and completely disappeared after 2 weeks of postpartum bed rest.

CONCLUSIONS

This is the first report that positional headaches after epidural anesthesia may not indicate low intracranial pressure alone; it may combine with pneumocephalus, particularly when using the loss of resistance to air technique. At this moment, head computed tomography is essential to discover other conditions like pneumocephalus.

Pneumocephalus secondary to epidural analgesia: a case report

INTRODUCTION

Epidural anesthesia is commonly used for analgesia during labor, and headache is a common complaint following this procedure. Pneumocephalus, on the other hand, is a rare and potentially serious complication of epidural anesthesia, which is most often caused by accidental puncture of the dura with the introduction of air into intrathecal space.

CASE PRESENTATION

We present the case of a 19-year-old Hispanic female who developed a severe frontal headache and neck pain eight hours following epidural catheter placement to deliver analgesia during labor. Physical examination was within normal limits without any neurological deficits. Computed tomography of the head and neck would later demonstrate small to moderate amounts of pneumocephalus, predominantly within the frontal horn of the lateral ventricles, and a moderate amount of air within the spinal canal. She was treated conservatively with analgesia. Though headache recurred after discharge, repeat imaging showed improvement in the volume of pneumocephalus and conservative management was continued.

CONCLUSIONS

Although a rare complication and an uncommon cause of headache following epidural anesthesia, a high index of suspicion must remain for pneumocephalus as it may cause significant morbidity and, in some cases, be potentially life-threatening.

Pneumocephalus, coma and seizures following lumbar decompression surgery

We describe a patient with pneumocephalus following lumbar decompression surgery who presented altered mental status at time to awake of anaesthesia and the patient was admitted in intesive care unit in mechanical ventilation. The patient has not eye-opening response, no verbal response and motor response only withdraw in response to pain (7 points on Glasgow coma scale). Then, the patient experienced a generalized tonic-clonic seizure. Immediate cranial computed tomography (CT) images were performed. Cerebral pneumocephalus was present in CT, imaging revealed a voluminous pneumocephalus responsible for a significantspace-occupying effect on the frontal and parietal lobes, lateral ventricles and quadrigeminal plate cistern. Anti-epileptic therapy (Diazepam and levetiracetam) and neurological monitoring were initiated. At 12 postoperative hours repeat CT scanning showed pneumocephalus were completely improved to minimal quantity and only limited to frontal lobe. The consciousness is impaired, and a generalized tonic-clonic seizure was present. Electroencephalogram showed continuous epileptiform activity and phenytoin IV was administered in continuous infusión. Four hours later the level of consciousness gradually improved, and the patient was right in eye opening, verbal and motor responses. A few hours later the patient was extubated, and no neurological deficits were present. Pneumocephalus should be considered in the differential diagnosis when evaluating a patient with altered mental status following lumbar surgery.

Pneumocephalus following sneeze suppression

Pneumocephalus is defined as air in the intracranial space. It is commonly caused by traumatic skull fractures and is diagnosed by head plain computer tomography. Treatment involves initial stabilization of vital signs and surgical intervention if symptoms do not resolve. We report a unique case of pneumocephalus following sneeze suppression.

Early Postoperative Computed Tomography Scan Air Distribution Predicts Postoperative CSF Leak in Endoscopic Skull Base Surgery

BACKGROUND

Cerebrospinal fluid (CSF) leak remains the primary concern of endoscopic skull base surgery (ESBS). Pneumocephalus seen in postoperative images has been linked to CSF leak in some reports; however, few studies have looked at the extent to which it is indicative of CSF leak. In the current study, we aim to examine the size and location of post-ESBS pneumocephalus in the early postoperative period and determine their association with postoperative CSF leak.

METHODS

Patients undergoing ESBS in a 5-year period were included. All patients underwent brain computed tomography scan within the first 24 postoperative hours. Computed tomography scans were reviewed by a neurosurgeon and a radiologist and have been classified based on the size and location of pneumocephalus. Patients were followed in the postoperative period for clinical signs of CSF leak and managed accordingly.

RESULTS

Out of 120 patients, 86 patients met the inclusion criteria. Thirty-five patients (41%) had no pneumocephalus on day one postoperative imaging, while 51 patients (59%) had pneumocephalus with different sizes and distributions. Eleven of 86 patients developed CSF leak. Of the 11 patients, 5 patients (45%) had grade 4 pneumocephalus (P value = 0.02). Patients with multiple locations of pneumocephalus were more likely to develop CSF leak (P value = 0.01).

CONCLUSIONS

In post-ESBS patients, both the volume and location of the pneumocephalus are potentially predictive of CSF leak. In patients with a larger volume of intra-axial air and/or multiple air locations, an impending CSF leak should be anticipated.

Pituitary Adenoma "Pneumo-Apoplexy"

Tension pneumosella has been recognized as a very rare complication of pituitary transsphenoidal surgery. To the best of our knowledge, we report the second case of a pituitary adenoma "pneumo-apoplexy", which is characterized by findings consistent with tension pneumosella in the context of apoplexy of a pituitary adenoma; although it is an extremely rare diagnosis, it should be considered in patients with compatible clinical and radiological findings, particularly with a previous history of transsphenoidal pituitary surgery.

The semi-sitting position in patients with indwelling CSF shunts: perioperative management and avoidance of complications

OBJECTIVE

Posterior fossa or midline tumors are often associated with hydrocephalus and primary tumor removal with or without perioperative placement of an external ventricular drain (EVD) is commonly accepted as first-line treatment. Shunting prior to posterior fossa surgery (PFS) is mostly reserved for symptomatic cases or special circumstances. There are limited data regarding the anticipated risk for symptomatic pneumocephalus and the perioperative management using the semi-sitting position (SSP) in such a scenario. Here, we therefore assessed the safety of performing PFS in a consecutive series of patients over a period of 15 years to allow the elaboration of recommendations for perioperative management.

METHODS

According to specific inclusion and exclusion criteria a total of 13 patients who underwent 17 operations was identified. Supratentorial pneumocephalus was evaluated with semiautomatic-volumetric segmentation. The volume of pneumocephalus was evaluated according to age and ventricular size.

RESULTS

Ten of the 13 patients had a programmable valve (preoperative valve setting range 6-14 cmH20; mean 7.5 cmH20) while 3 patients had non programmable valves. A variable amount of supratentorial air collection was evident in all patients postoperatively (range 3.2-331 ml; mean 122.32 ml). Positive predictors for the volume of postoperative pneumocephalus were higher age and a preoperative Evans ratio > 0.3. In our series, we encountered no cases of tension pneumocephalus necessitating an air replacement procedure as well as no obstruction, disconnection, infection or hardware malfunction of the shunt system.

CONCLUSIONS

Our findings indicate that a CSF shunt in situ is not a contraindication for performing PFS in the semi-sitting position and it does not increase the pre-existing risk for postoperative tension pneumocephalus. In cases of primary shunting for hydrocephalus associated with posterior fossa tumors a programmable valve set at a medium opening pressure with a gravitational device is a valid option when PFS in the semi-sitting position is opted. In patients with an indwelling shunt diversion system special caution is indicated in order to prevent and detect overdrainage especially in not adjustable valves or shunts without antisiphon devices.

Different Approaches in Skull Base Surgery Carry Risks for Different Types of Complications

Complications are not uncommon in the complex field of skull base surgery. The intrinsic relationship of lesions in this region to important neurovascular structures, dura mater, and bone may lead to significant morbidity and mortality. The evolution of endoscopic endonasal surgery has had a significant impact on this field as a less invasive option for treatment of selected lesions, but major morbidity may still occur; moreover, endoscopic approaches have been associated with higher rates of some specific complications, such as cerebrospinal fluid leaks. Based on a presented case report, the authors discuss the management of various complications associated with different approaches for resection of skull base malignancies, including epidural and intradural pneumocephalus, subdural hematoma, and subdural empyema. Important lessons learned by the senior author throughout more than 30 years of his skull base surgery practice are highlighted. The inherent risk of complications in skull base surgery emphasizes the importance of their avoidance, prevention, and learning from one's unfavorable experience so as not to repeat them.

Postoperative pneumocephalus and recurrence and outcome of chronic subdural hematoma: a systematic review and meta-analysis

We conducted a meta-analysis to analyze the effects of pneumocephalus after chronic subdural hematoma (CSDH) surgery on hematoma recurrence, mortality, and functional outcomes. In this meta-analysis, following PRISMA guidelines, PubMed, Embase, Cochrane Library, and Web of Science online databases were queried using the keywords "pneumocephalus," "pneumoencephalos," "intracranial pneumatocele," "pneumo encephalon," "subdural air," and "chronic subdural hematoma." The results were limited to English-language articles. Through the online database, we identified a total of 276 articles and finally included 14 articles for meta-analysis. The results showed that the recurrence rate in the pneumocephalus group was higher than that in the control group, with a pooled OR of 3.35 (CI: 2.51-4.46, P < 0.001). There was no difference in recurrence rate between the no/few and moderate pneumocephalus groups (OR: 1.27, CI: 0.68-2.37, P = 0.46), but the recurrence rate of the large pneumocephalus group was significantly higher than that of the moderate group, with a pooled OR of 3.29 (CI: 1.71-6.32, P < 0.001). This study failed to show higher mortality and worse outcomes in the pneumocephalus group than in the control. Pneumocephalus after surgical evacuation of CSDH was associated with the recurrence rate of hematoma. Pneumocephalus affecting recurrence was correlated with gas volume, and moderate pneumocephalus may have less impact, while patients with large pneumocephalus are more likely to recur than those with moderate pneumocephalus. More prospective cohort studies are needed for further investigation and verification. This meta-analysis was registered (PROSPERO CRD42022321800).

Extensive tension pneumocephalus presented in the setting of a challenging etiology

Background

Pneumocephalus (PNC) is a well-described consequence in postoperative settings and skull fractures that is usually self-limiting. It can get complicated into tension PNC on some rare occasions, leading to an intracranial mass effect. PNC was also reported after unintentional dural puncture throughout the epidural anesthesia process. However, tension PNC resulting from epidural anesthesia procedures is an extremely rare outcome that implies urgent intervention to relieve the tension within the brain. Here, we report a case of an extensive tension intraventricular PNC 2 days following an epidural anesthesia procedure for a femur fixation surgery.

Case Description

A 23-year-old male presented to the emergency department with basal skull fractures and a femur fracture due to a motorcycle accident. His skull base fracture was managed conservatively then he underwent a femur fixation procedure under epidural anesthesia. Two days after, he developed a severe headache with a disturbed level of consciousness. Computed tomography of the brain revealed an extensive PNC that involved all the subarachnoid spaces down to the cervical region and compressing the cerebellum, which was not found in the initial imaging. The patient's status improved after the twist-drill burr-hole evacuation of air under the water seal.

Conclusion

Extensive tension PNC can occur after traumatic brain injury, especially after epidural anesthesia. Such cases should gain high focus because they may differ from simple PNC regarding diagnosis, treatment, and follow-up.

Tension Pneumocephalus Associated with Negative Pressure Wound Therapy with Instillation and Dwell Time for Methicillin-resistant Staphylococcus aureus Infection After Spinal Deformity Surgery

PURPOSE

Surgical site infection (SSI) is a serious complication after spine surgery. Recently, it has become possible to perform negative pressure wound therapy with instillation and dwell time (NPWTi-d) for postoperative infected wounds. We report the first rare case of symptomatic pneumoencephalopathy following NPWTi-d for methicillin-resistant Staphylococcus aureus (MRSA) infection after spinal deformity surgery.

METHODS

Retrospective review of a patient's medical record and imaging.

RESULTS

A 77-year-old female patient underwent posterior corrective fixation with no intraoperative complications. On the 10th postoperative day, SSI was diagnosed, and debridement was performed. Since MRSA was detected in the wound culture, and a prolonged inflammatory reaction was observed, NPWTi-d was started to preserve the instrumentation. Gradually, good granulation was observed, and the extensive soft tissue defect decreased. On the 29th day after the start of NPWTi-d, the patient experienced sudden headache and neck pain while standing, and head computed tomography led to the diagnosis of symptomatic pneumoencephalopathy. NPWTi-d was discontinued, and when surgery was performed to close the wound, dural injury was found, which was not present at the time of the initial surgery, and dural repair was performed. After 2 weeks of bed rest, the patient's pneumoencephalopathy improved. Three years have passed since the surgery, and no recurrence of cerebrospinal fluid leakage or infection has been observed.

CONCLUSIONS

Although NPWTi-d is a useful treatment for SSI, it is always necessary to pay attention to the development of pneumoencephalopathy and promptly diagnose and treat it because of the risk of life-threatening complications.

Valve-controlled chronic subdural hematoma drainage: A feasibility study

INTRODUCTION

Pneumocephalus after chronic subdural hematoma (CSDH) evacuation is a potential predictor of hematoma recurrence.

RESEARCH QUESTION

To study the feasibility and safety of a novel CSDH evacuation technique using a valve-controlled method to avoid pneumocephalus.

MATERIAL AND METHODS

In a retrospective case series, we evacuated CSDH using very low-pressure valve-controlled drains and recorded the neurological, radiological, and functional outcomes. Patients with primary CSDH, without previous neurosurgical intervention, and who did not receive antiplatelet or anticoagulant therapy the week prior to the index surgery, were included in the study. Exclusion criteria were the evacuation with other treatment techniques and incomplete data files. Patients were assessed according to the Bender grading system to record the neurological status. The hematoma volume was estimated using the formula for ellipsoid volumes.

RESULTS

Thirty-six patients with a mean age of 73 years (±9 years) fulfilled our eligibility criteria. Our technique was effective since it decreased the CSDH volume from 141 ​ml (IQR 97 ​ml) to 20.6 ​ml (IQR 26.59 ​ml; p ​< ​0.001) and improved the neurological status according to the Bender grading system from two (IQR 0.25) to 1 (IQR 0). However, pneumocephalus and hematoma recurrence occurred in one case each (2.8%). At six months, all patients returned to their previous status, except for two patients (5.6%) who died due to irrelevant pathologies.

CONCLUSIONS

Valve-controlled CSDH evacuation aiming to decrease the postoperative pneumocephalus and hematoma recurrence constitutes an effective and safe alternative. However, larger randomized controlled studies are required to establish its role in CSDH management.

Traumatic Subarachnoid-Pleural Fistula with Pneumocephalus

Traumatic subarachnoid-pleural fistula is an uncommon occurrence. We present a case of a patient sustaining a subarachnoid-pleural fistula after a gunshot wound to the neck, which ultimately resulted in substantial pneumocephalus. The patient underwent successful operative repair of the fistula with notable improvement and resolution of pneumocephalus.

Tension pneumocephalus: case report and review

Tension pneumocephalus is a rare complication of frontal sinus fracture or neurosurgical intervention resulting from compression of the brain by entrapped air, leading to seizure, altered mental status, brain herniation, and death. This report presents a case of traumatic tension pneumocephalus associated with an anterior and posterior table frontal sinus fracture in a patient with pneumosinus dilatans and osteogenesis imperfecta.

Pneumocephalus and headache following craniotomy during the immediate postoperative period

Background

Pneumocephalus may be responsible for post-craniotomy headache but is easily overlooked in the clinical situation. In the present study, the relationship between the amount of intracranial air and post-craniotomy headache was investigated.

Methods

A retrospective observational study was performed on 79 patients who underwent minimal invasive craniotomy for unruptured cerebral aneurysms. Those who had undergone previous neurosurgery, neurological deficit before and after surgery were excluded The amount of air in the cranial cavity was measured using brain computed tomography (CT) taken within 6 h after surgery. To measure the degree of pain due to intracranial air, daily and total analgesic administration amount were used as a pain index. Correlation between intracranial air volume and total consumption of analgesic during hospitalization was tested using Spearman rank correlation coefficients. Receiver operating characteristics (ROC) analysis was used to determine the amount of air associated with increased analgesic consumption over 72 h postoperatively.

Results

The mean amount of intracranial air was 15.6 ± 9.1 mL. Total administration of parenteral and oral analgesics frequency were 6.5 ± 4.5, 13.2 ± 7.9 respectively. A statically significant correlation was observed between daily and total parenteral analgesic consumption after surgery and the amount of intracranial air at followed-up brain CT postoperatively within 24 h (r = 0.69, p < 0.001), within 48 h (r = 0.68, p < 0.001), and total duration after surgery (r = 0.84, p < 0.001). The optimal cut-off value of 12.14 mL of intracranial air predicts the use of parenteral analgesics over 72 h after surgery.

Conclusions

Pneumocephalus may be a causative factor for post-craniotomy pain and headache with surgical injuries.

Air travel with pneumocephalus: a systematic review

INTRODUCTION

Concerns arise when patients with pneumocephalus engage in air travel. How hypobaric cabin pressure affects intracranial air is largely unclear. A widespread concern is that the intracranial volume could relevantly expand during flight and lead to elevated intracranial pressure. The aim of this systematic review was to identify and summarise models and case reports with confirmed pre-flight pneumocephalus.

METHODS

The terms (pneumocephalus OR intracranial air) AND (flying OR fly OR travel OR air transport OR aircraft) were used to search the database PubMed on 30 November 2021. This search returned 144 results. To be included, a paper needed to fulfil each of the following criteria: (i) peer-reviewed publication of case reports, surveys, simulations or laboratory experiments that focussed on air travel with pre-existing pneumocephalus; (ii) available in full text.

RESULTS

Thirteen studies met the inclusion criteria after title or abstract screening. We additionally identified five more articles when reviewing the references. A notion that repeatedly surfaced is that any air contained within the neurocranium increases in volume at higher altitude, much like any extracranial gas, potentially resulting in tension pneumocephalus or increased intracranial pressure.

DISCUSSION

Relatively conservative thresholds for patients flying with pneumocephalus are suggested based on models where the intracranial air equilibrates with cabin pressure, although intracranial air in a confined space would be surrounded by the intracranial pressure. There is a discrepancy between the models and case presentations in that we found no reports of permanent or transient decompensation secondary to a pre-existing pneumocephalus during air travel. Nevertheless, the quality of examination varies and clinicians might tend to refrain from reporting adverse events. We identified a persistent extracranial to intracranial fistulous process in multiple cases with newly diagnosed pneumocephalus after flight. Finally, we summarised management principles to avoid complications from pneumocephalus during air travel and argue that a patient-specific understanding of the pathophysiology and time course of the pneumocephalus are potentially more important than its volume.

Pneumocephalus after posterior fossa surgery in prone position: Is that any clinical effect?

Introduction

The term pneumocephalus refers to the existence of air in any intracranial compartment. Its presence in the follows of a supratentorial craniotomy is very common, and it usually represents a benign complication as it is very rarely responsible for clinical manifestations.

Case presentation

We report the case of a 24 years-old man, who underwent posterior fossa surgery in prone position for resection of a vermian tumor. Postoperative, the patient presented a tonic-clonic generalized seizure associated to high levels of arterial pressure and decerebration. Control CT scan showed an important pneumocephalus. On the posterior fossa, the air was responsible for a compression of the brainstem, without any other postoperative complications. Following 12 h of conservative management, a brain MRI showed a total regression of the pneumocephalus. 3 days later, the patient presented a favorable outcome as he was extubated without any major impairments.

Discussion

Transformation of pneumocephalus into tension pneumocephalus responsible for clinical inadvertance is rare. This complication is mainly related to surgeries performed in sitting position. The occurrence of compressive pneumocephalus after a posterior fossa craniotomy performed in a prone position is seldom.

Conclusions

Through this case, we discuss pathophysiology and therapeutic approaches for tension pneumocephalus following posterior fossa performed in prone position.

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Pneumocephalus may be source for major postoperative inadvertance

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Tension pneumocephalus was reported in supratentorial surgeries. Posterior fossa craniotomies may also lead to this inadvertence.

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Rigorous peroperative prevention of pneumocephalus should be considered in order to minimize complications.

The pressure differential efflux technique - A novel approach for troubleshooting air-locked external ventricular drainage systems: A technical note and review of literature

External ventricular drainage (EVD) is carried out in many neurosurgical conditions for the diversion of cerebrospinal fluid. These EVD systems can, however, malfunction with potentially lethal consequences. Air bubbles within the EVD can result in air locking of the system with subsequent blockage of drainage, with blood clots and debris being the other causes. There are both non-invasive and invasive methods of rectifying such blockages, with invasive procedures having its associated risks. This is especially so for EVD revisions, with each surgery increasing the risk of ventriculitis. We describe a case of bilateral air locked EVD managed successfully with a novel non-invasive 'pressure differential efflux technique'. This method exploits the pressure gradient established by adjusting each EVD to a different height to evacuate the pneumoventricle. In addition, we present a sequential approach to the management of EVD malfunction, based on the current literature and our institutional protocol.

Iatrogenic pneumocephalus following a cervical epidural steroid injection: A case report

Pneumocephalus is a condition defined by air present in the intracranial space. There are several causes of pneumocephalus, however this is a case of a patient who developed pneumocephalus following a cervical epidural steroid injection. Uniquely, this patient's chief complaint was sudden onset of syncope, and respiratory arrest following the injection. The diagnosis was made by CT, and conservative treatment was used for resolution of the condition. Patients with pneumocephalus can present with a wide range of neurologic symptoms, and prompt recognition and treatment are key to preventing irreversible neurologic damage.

Clinical Outcomes and Prognostic Determinants of Surgically Treated Depressed Skull Fracture in Addis Ababa University Neurosurgical Teaching Hospitals: A Prospective Multicenter Observational Study

BACKGROUND

Depressed skull fracture is one of the most common neurosurgical emergencies in Ethiopia. The clinical outcome after surgical management and what factors predict the outcome are not well studied. Our study aimed to assess the outcome and identify predictors of the outcome in surgically treated adult patients.

METHODS

A prospective, multicenter, observational study was undertaken on 197 cases, at 4 selected neurosurgical teaching hospitals in Ethiopia. Relevant data were collected and analyzed using Statistical Package for the Social Sciences software (IBM, Armonk, New York, USA). The outcome was assessed by the extended Glasgow Outcome Scale. Multivariate analysis was done to identify independent predictors of the outcome.

RESULTS

The outcome was favorable in 81.2%. The mean age was 27. The mode of injury was violence in 79.7%. Motor deficit witnessed in 24.4%. Based on the Glasgow Coma Scale, 92.2% of patients had mild traumatic brain injury. Associated intracranial lesions were identified in 87.3%. The median hospital stay was 4.7 days. Reoperation and mortality rates were 4.1% and 0.5%, respectively. Five factors were statistically significant independent predictors of unfavorable outcome in multivariate analysis: motor deficit (adjusted odds ratio [AOR] 13.8, 95% confidence interval [CI]: 4.13-46.17, P = 0.000), Glasgow Coma Scale ≤13 (AOR 10.36, 95% CI: 1.93-55.56, P = 0.006), pneumocephalus (AOR 12.93, 95% CI: 3.12-53.52, P = 0.000), hospital stay for ≥3 days (AOR 4.39, 95% CI: 1.18-16.3, P = 0.027), and reoperation (AOR 6.92, 95% CI: 1.09-43.97, P = 0.04).

CONCLUSIONS

The overall outcome was favorable. The presence of motor deficit, postresuscitation Glasgow Coma Scale ≤13, pneumocephalus, reoperation, and hospital stays for ≥3 days were independent predictors of an unfavorable outcome.

Delayed brain reexpansion in schizophrenic patient affected by trabecular type chronic subdural hematoma

Background:

Chronic subdural hematoma (cSDH) represents a complex and unpredictable disease, characterized by high morbidity and mortality, especially in elderly patients. Factors affecting the postoperative brain reexpansion along to cSDH recurrence have not been yet adequately investigated. The authors presented the case of a schizophrenic patient affected by trabecular type cSDH that presented a delayed brain reexpansion despite a craniotomy and membranotomy.

Case Description:

A 51-year-old female patient with diagnosis of schizophrenia was admitted to the emergency department with GCS score of 5/15 and right anisocoria. An urgent brain CT revealed a trabecular right cSDH (35 mm in maximum diameter) with recent bleeding. After surgery, a brain CT scan showed a markedly reduced brain reexpansion and pneumocephalus. Nevertheless, postoperative 7-day brain CT documented a progressive brain reexpansion with reduced midline shift.

Conclusion:

According to our opinion, anatomopathological alterations in schizophrenia reduce normal brain compliance and increasing elastance, thus modifying the normal timing of reexpansion after cSDH drainage, also after craniotomy and membranotomy. Although postoperative pneumocephalus is a well-known cause of hindered reexpansion, this could be due to anatomical alterations in schizophrenia. Such factors must be considered in the preoperative planning but mostly in the postoperative management.

Hidden intra-meatal CSF fistula related to VP shunt as a cause for fatal tension pneumocephalus after vestibular schwannoma resection

BACKGROUND

Cerebrospinal fluid (CSF) leak through petrosal air cells is a known complication after drilling the posterior wall of the internal acoustic canal (IAC) for resection of vestibular schwannoma (VS). Whereas mild pneumocephalus is common after retrosigmoid craniotomy, tension pneumocephalus has been rarely documented.

OBJECTIVE

To testify a case of fatal tension pneumocephalus after VS resection in a patient with ventriculo-peritoneal (VP) shunt and to propose possible recommendations to limit the risk of this dramatic complication.

METHODS

A case of fatal tension pneumocephalus after VS resection in presence of hidden CSF fistula is illustrated with pre- and post-operative images.

RESULTS

In the uneventful situation of concomitant post-operative CSF fistula in presence of VP shunt, tension pneumocephalus may occur. The negative pressure created by the shunt system and the presence of osteo-dural defect allow the air to enter and, at the same time, prevent the outflow.

CONCLUSION

After VS resection, tension pneumocephalus can occur as a consequence of CSF fistula from petrosal air cells in the presence of functioning VP shunt. Precautions as pre-operative increase to 'virtual-off' the pressure of the valve, subsequences CT scans after surgery and sealing of the petrous air cells are recommended to avoid such as fatal complication.

Leptomeningeal pneumocephalus and pneumorrhachis: Signs of pneumothorax in case of syringopleural shunting

In this article, we present a case of leptomeningeal pneumocephalus and pneumorrhachis secondary to pneumothorax that occurred six years after syringopleural shunting.

Pneumocephalus secondary to a spinal surgery: A literature review and a case report

Introduction

We report a case of pneumocephalus, which is identified as the presence of air in the cranial cavity and is a rare complication after spinal surgeries, in addition to a literature review of similarly reported cases.

Case presentation

The patient is a 63-year-old male who developed pneumocephalus after undergoing a minimally invasive left side decompression at L3-L4 with left L4 foraminotomy even though there were no signs of dural tears or Cerebrospinal Fluid (CSF) leaks. After the diagnosis of pneumocephalus using brain Magnetic Resonance Imaging (MRI), the patient was treated conservatively and was discharged after 3 weeks without developing further complications.

Discussion

Pneumocephalus is defined as an abnormal accumulation of air within the cranial cavity. It can occur due to a variety of causes but rarely due to gas forming bacteria. Many theories are suggested concerning the pathophysiology of pneumocephalus, the inverted bottle theory, the ball valve theory, the Nitrous Oxide (N₂O) theory, and as we outweigh in our case, gas forming bacteria theory. Pneumocephalus can be treated surgically, nevertheless, conservative management methods of such cases are usually followed.

Conclusion

The aim of this study is to draw further attention to the management and diagnosis of such surgical complication. A more extended research is needed to provide a full comprehensive approach to deal with this problem if faced in the future. To the best of our knowledge, this study reports the first pneumocephalus case induced by a postoperative bacterial infection in the global English based medical literature.

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Pneumocephalus caused by gas forming infection in the spine is a rare complication after spinal surgery.

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Unexplained headache spinal surgeries should raise suspicion toward pneumocephalus.

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There are many theories regarding the development of pneumocephalus, each one need specific attention.

Expanding pneumocephalus due to craniofacial fractures: A case report

Introduction

Pneumocephalus (PNC) is the presence of air in the intracranial cavity. The most frequent cause is craniofacial trauma, though there are many etiologies, including surgical procedures. PNC with compression of the frontal lobes and widening of the interhemispheric space between the tips of the frontal lobes results in the characteristic radiological finding of the “Mount Fuji sign”.

Presentation of case

A 57-year-old man presented to the A&E with loss of consciousness due to a motorcycle collision 9 h prior. He had a GCS of E4M6V5, and a head CT scan revealed minimal PNC forming in both hemispheres. After discharge, severe headaches and rhinorrhea developed. A second CT scan revealed a massive PNC. An operation was then performed via a bicoronal incision to drain the PNC and seal the cranial defect. A burr hole in the calvarium was created, and the cranial defect was closed using a pericranial rotational flap. Post-operation, the patient's headache and rhinorrhea decreased; neither symptom was present at 1-month post-operation. The wounds healed with minimal scarring, and the cosmetic outcome for the craniofacial fracture was acceptable.

Discussion

Although the patient may at first present with a mild head injury, this can progress into something much more serious. PNC is difficult to diagnose clinically. Rarely, patients describe a splashing sound upon moving the head (termed bruit hydro-aerique), which can also be auscultated. A head CT scan is the gold standard in the diagnosis of PNC. Pericranial flaps are widely used for dural repair because they are easily accessible and have a lower rate of infection than artificial grafts on expanding PNC.

Conclusion

Tension PNC may be slow-growing and increase intracranial pressure to high levels before clinical signs are present. The pericranial rotational flap technique is the best way to close a dura mater defect in cranial base fractures with tension PNC.

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Pneumocephalus (PNC) is the presence of air in the intracranial cavity.

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Craniofacial trauma is the most frequent cause of PNC.

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We report a male with expanding PNC who required a pericranial rotational flap.

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Tension PNC may be slow-growing and increase intracranial pressure to high levels before clinical signs are present.

Diagnosis, treatment and postsurgical complications in a dog with epileptic seizures and a naso-ethmoidal meningoencephalocele

BACKGROUND

Naso-ethmoidal meningoencephalocele is usually a congenital anomaly consisting of a protrusion of cerebral tissue and meninges into the ethmoidal labyrinth. The condition is a rare cause of structural epilepsy in dogs. We report the clinical presentation, surgical intervention, postoperative complications and outcome in a dog with drug resistant epilepsy secondary to a meningoencephalocele.

CASE PRESENTATION

A 3.3-year-old male neutered Tamaskan Dog was referred for assessment of epileptic seizures secondary to a previously diagnosed left-sided naso-ethmoidal meningoencephalocele. The dog was drug resistant to medical management with phenobarbital, potassium bromide and levetiracetam. Surgical intervention was performed by a transfrontal craniotomy with resection of the meningoencephalocele and closure of the dural defect. Twenty-four hours after surgery the dog demonstrated progressive cervical hyperaesthesia caused by tension pneumocephalus and pneumorrhachis. Replacement of the fascial graft resulted in immediate resolution of the dog's neurological signs. Within 5 months after surgery the dog progressively developed sneezing and haemorrhagic nasal discharge, caused by sinonasal aspergillosis. Systemic medical management with oral itraconazole (7 mg/kg orally q12h) was well-tolerated and resulted in resolution of the clinical signs. The itraconazole was tapered with no relapsing upper airway signs. The dog's frequency of epileptic seizures was not affected by surgical resection of the meningoencephalocele. No treatment adjustments of the anti-epileptic medication have been necessary during the follow-up period of 15 months.

CONCLUSIONS

Surgical resection of the meningoencephalocele did not affect the seizure frequency of the dog. Further research on prognostic factors associated with surgical treatment of meningoencephaloceles in dogs is necessary. Careful monitoring for postsurgical complications allows prompt initiation of appropriate treatment.

The importance of imaging in diagnosis of infected otogenic pneumatoceles

OBJECTIVE

Spontaneous otogenic pneumatocele is a rare entity resulting from a pressure gradient between a dehiscent temporal bone and the intracranial space. Secondary infection can ensue in patients with concurrent otomastoiditis. The current study discusses the clinical presentation and imaging characteristics of two cases of secondarily infected otogenic pneumatoceles.

STUDY DESIGN

Case series.

RESULTS

Two patients were diagnosed with a temporal lobe abscess in the setting of otogenic pneumatocele. Diagnosis was aided by both CT and MRI demonstrating a diffusion restricting lesion within brain parenchyma in association with free air in close proximity to an underlying tegmen defect.

CONCLUSION

Prompt diagnosis of a secondarily infected otogenic pneumatocele with CT and MRI allows for surgical drainage with closure of the tegmen defect to prevent further complications and recurrence.

Rare incidence of tension pneumocephalus 2 months after repeat microvascular decompression

Background:

Tension pneumocephalus is a rare complication after intracranial procedures and craniotomy. We report a rare case of intraventricular and subdural tension pneumocephalus occurring 2 months after repeat right-sided microvascular decompression (MVD) for recurrent trigeminal neuralgia.

Case Description:

The patient in this case was a 79-year-old woman who presented with acute-onset confusion, headaches, nausea, and vomiting. On computed tomography, substantial volumes of pneumocephalus in the fourth ventricle and subdural space at the site of the retrosigmoid exposure for the previous MVD were seen. She underwent emergent wound exploration, and no obvious dural defect or exposed mastoid air cells were identified. The dura was reopened, and the surgical site was copiously irrigated. Mastoid air cells were covered with ample amounts of bone wax, and the wound was closed. The patient recovered well postoperatively with complete resolution of the pneumocephalus by her 3-month follow-up evaluation.

Conclusion:

It is important to assess for cerebrospinal fluid leakage and that air cells are sealed off before wound closure to prevent a pathway for air to egress into the surgical cavity and corridor.

Pneumocephalus in thoracoabdominal aortic aneurysm repair after lumbar drain removal and blood patch

Lumbar spinal drain use during thoracic and thoracoabdominal aortic aneurysm repair has reduced the incidence of ischemic spinal cord injury with relatively low risk. We report a case of pneumocephalus in a 55-year-old woman who had undergone open repair of a 6.7-cm type IV thoracoabdominal aortic aneurysm. After lumbar spinal drain removal, she developed a postdural headache, which was subsequently treated with blood patch placement. After discharge, she had presented with transient headaches, perioral numbness, and left-hand weakness. Computed tomography revealed intraventricular gas within the lateral ventricles. Pneumocephalus is an exceedingly rare and potentially dangerous complication of lumbar spinal drains and blood patch placement.

Hyperbaric oxygen therapy in the treatment of pneumocephalus associated with epidural block: case report

Introduction

Pneumocephalus is a rare neuraxial blockade complication, which can be associated with severe neurologic changes.

Clinical case

A 51-year-old patient was submitted to left total knee arthroplasty. Postoperatively, a pneumocephalus associated with decreased consciousness was diagnosed as a complication of the epidural analgesia. The treatment used was Hyperbaric Oxygen Therapy (HBOT) due to the severity of symptoms. Just after one session of HBOT, there was nearly full pneumocephalus resorption and significant clinical recovery.

Conclusion

This case report enables anesthesiologists to recognize HBOT as a therapeutic option to be considered when treating severe cases of pneumocephalus.

Unilateral Tension Pneumocephalus of the Sylvian Fissure: A Rare Neurosurgical Complication

Tension pneumocephalus is an uncommon complication of neurosurgical procedures. We report a patient who presented with headache, vomiting, left hemiparesis and rhinorrhea 30 days after correction of a recurrent nasal cerebrospinal fluid fistula and shunt placement. A computed tomography scan revealed a massive collection of air with air-fluid level in the right sylvian fissure and midline shift. A right pterional craniotomy was performed and a small corticectomy resulted in evacuation of air from the sylvian fissure. A dural graft from the previous surgery was recognized to be acting as a ball-valve mechanism, trapping air from the nasal cavity. It was removed and the cranial defect was corrected with a split calvarial bone graft. Follow-up brain computed tomography revealed complete resolution of pneumocephalus. After surgery there was progressive improvement of neurological symptoms over 10 days, and the patient was asymptomatic after 1 month of follow-up.

The trajectory of a low-velocity bullet from the chest to the pituitary gland

The diagnosis and treatment of gunshot injuries requires an understanding of the trajectory of the bullet in each individual case. The majority of gunshot wounds present with easily understandable trajectories resulting in a concise, stream-lined work-up. Occasionally, the initial work-up may reveal a trajectory that is atypical. This can be due to internal bullet deflection, bullet embolism, or bullets that traverse multiple body cavities. Here we present the case of a gentleman who was shot in the left posterior chest, with the bullet ultimately lying-in profile with the patient's pituitary gland. The patient suffered injuries to his left lung, left internal jugular vein, and right optic nerve. On hospital day 1, he required neurosurgical operative intervention for increased somnolence and computed tomography findings which revealed tension pneumocephalus. On hospital day 15, he was discharged home after making a full recovery with the exception of continued blindness in the right eye. Gunshot wounds involving multiple body cavities can increase the complexity of a patient's injury pattern and require increased vigilance and complete history, physical examination, and imaging to ensure optimal outcomes.

A rare case of spontaneous otogenic pneumocephalus with pictorial illustration of temporal evolution

Pneumocephalus is commonly seen on imaging in the setting of craniofacial trauma, skull base tumours, intracranial infection and after neurological intervention. Spontaneous pneumocephalus in the absence of these conditions is exceedingly rare, with only approximately 30 cases reported in the literature to date. Spontaneous otogenic pneumocephalus (SOP) is believed to occur as a result of anomalous communication between the intracranial space and a hyper-pneumatised temporal bone, with either positive extra-to-intracranial pressure or negative intracranial pressure gradient. These anomalous communicating channels may only become clinically apparent when triggered by episodes of acute increase in middle ear pressure during coughing, sneezing, Valsalva manoeuvre or significant change in atmospheric pressure. Patients may exhibit a wide range of neurological symptoms and the aim of treatment is to reduce the risk of complications such as infection and intracranial hypertension. Both conservative and neurosurgical approaches have been described. We report a case of SOP in which the patient was conservatively managed, and spontaneous resolution of pneumocephalus was documented on serial computed tomography (CT) scans. This unique case clearly demonstrates the natural history and temporal evolution of SOP without surgical intervention. This knowledge may potentially obviate the need for surgery, thus reducing morbidity and mortality in patients who are poor surgical candidates.

An unusual case of spontaneous nontraumatic pneumocephalus in the setting of remote craniofacial surgery

BACKGROUND

Pneumocephalus is an uncommon pathology that typically follows head trauma, neurosurgery, or skull base tumors. Rarely, cases of spontaneous pneumocephalus can occur, most often in the setting of barotrauma.

CASE DESCRIPTION

We describe a rare case of spontaneous pneumocephalus in the absence of barotrauma in a 31-year-old male who presented with a headache and a normal neurologic exam. Imaging revealed subarachnoid and subdural pneumocephalus. The patient underwent surgical exploration, revealing an ethmoid bone defect caused by encroachment of material from a remote reconstructive surgery of the left orbit, which was subsequently repaired.

CONCLUSION

Although rare, spontaneous pneumocephalus should be considered even in the absence of clinical neurologic findings or barotrauma, in patients with previous cranial surgery and unexplained headaches.

Delayed post-traumatic Tension Hydropneumocephalus; a Case Report of Conservative Treatment

Pneumocephalus refers to the presence of air in the cranial cavity. Trauma is the most common cause of acquired pneumocephalus. Tension pneumocephalus occurs when intracranial accumulation of air causes high pressure on the brain as compared to extracranial pressure. Tension pneumocephalus is usually acute, and causes neurological symptoms, and its delayed form rarely occurs. A 12-year-old girl presented with a headache, lethargy, mild fever, and nausea from two days before admission to emergency department of Shahid Rajaei Hospital, Qazvin, Iran. The patient had a history of head trauma in a driving accident six weeks before and had undergone brain computed tomography (CT) scan in another centre, which had revealed no sign of pneumocephalus. The patient had been treated for one week and had been discharged in good general condition.

Considering her reduced consciousness, the patient underwent brain CT scan again in our centre. CT scan revealed tension hydropneumocephalus. The patient was transferred to the intensive care unit (ICU) for treatment. Considering the trend of her recovery, the patient was a candidate for conservative non-surgical therapy based on the in-charge neurosurgery specialist’s decision. The patient reported no complications during the six-month follow-up. Delayed tension pneumocephalus is among neurosurgery emergencies usually treated with early surgical intervention and dura defect restoration, but this patient received non-surgical treatment without any serious problem during the six-month follow-up.

Anesthetic Management of Patients Undergoing Open Suboccipital Surgery

The posterior cranial fossa with its complex anatomy houses key pathways regulating consciousness, autonomic functions, motor and sensory pathways, and cerebellar centers regulating balance and gait. The most common posterior fossa pathologies for which neurosurgical intervention may be necessary include cerebellopontine angle tumors, aneurysms, and metastatic lesions. The posterior cranial fossa can be accessed from variations of the supine, lateral, park-bench, prone, and sitting positions. Notable complications from positioning include venous air embolism, paradoxic air embolism, tension pneumocephalus, nerve injuries, quadriplegia, and macroglossia. An interdisciplinary approach with careful planning, discussion, and clinical management contributes to improved outcomes and reduced complications.

Citrobacter koseri meningitis with cerebral edema and pneumocephalus in a neonate

Sometimes the only indicator of a serious infection in a neonate is a fever. Citrobacter koseri (C. koseri) has been reported to cause neonatal brain abscesses in the setting of meningitis. Although rare, pneumocephalus, secondary to C. koseri, carries a very high mortality. A 17-day-old male presented to the emergency department with a fever, decreased oral intake, and lethargy. The patient developed pneumocephalus and cerebral edema and was diagnosed with C. koseri meningitis, leading to death. This case demonstrates the presentation of C. koseri meningitis with pneumocephalus and cerebral edema in a neonate presenting with fever.