Pneumocephalus; a rare cause of coma.

We report the case of an 84-years old female patient who developed cerebral air embolism in association with the indwelling hemodialysis central venous catheter. Pneumocephalus, even though rare, should be included in the differential diagnosis of acute manifestation of neurologic deficits, especially in association with central venous access, surgical interventions or trauma, and requests prompt management. Brain computed tomography scanning remains the investigation of choice.

Tension pneumocephalus in a patient with NF1 following ventriculoperitoneal shunt-deciphering the cause and proposed management strategy.

INTRODUCTION: Spontaneous pneumocephalus following ventriculoperitoneal shunting is a very unique complication, seen in a handful of patients. Small bony defects form as a result of chronically raised intracranial pressure, which can later lead to pneumocephalus once intracranial pressure decreases following ventriculoperitoneal shunting. CASE REPORT: Here, we present a case of a 15-year-old girl with NF1 who presented to us with pneumocephalus 10 months following shunting and our management strategy along with a literature review of this condition. CONCLUSION: NF1 & hydrocephalus can lead to skull base erosion, which needs to be looked up before proceeding with VP shunting to avoid delayed onset pneumocephalus. SOKHA with the opening of LT is a minimally invasive approach suitable to tackle both problems simultaneously.

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.

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.

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.

Clinical Significance of Pneumocephalus in Pediatric Mild Traumatic Brain Injury.

OBJECTIVES: Mild traumatic brain injury (mTBI) comprises most (70%-90%) of all pediatric head trauma cases seeking emergency care. Although most mTBI cases have normal initial head computed tomography scan, a considerable portion of the cases have intracranial imaging abnormalities on computed tomography scan. Whereas other intracranial pathological findings have been extensively studied, little is known about the clinical significance of pneumocephalus in pediatric mTBI. METHODS: We retrospectively identified pediatric mTBI patients with pneumocephalus using the institutional database of a large regional trauma referral center. Outcome measures were defined as clinically important TBI (ciTBI), hospitalization, intensive care unit (ICU) admission, and neurosurgical intervention. Comparisons were made between pneumocephalus and control (isolated linear fracture) groups as well as between isolated (only linear fracture and pneumocephalus) and nonisolated pneumocephalus (pneumocephalus and TBI) groups. RESULTS: Among 3524 pediatric mTBI cases, 43 cases had pneumocephalus (1.2%). Twenty-one cases (48.8%) had isolated pneumocephalus. The pneumocephalus group had higher rates of ciTBI, hospital admission, ICU admission, and neurosurgery when compared with the isolated linear fracture (control) group. The isolated pneumocephalus group had fewer ciTBI (21.1% vs 70%, P = 0.002), fewer hospitalization (23.8% vs 81.8%, P < 0.001), but similar ICU admission rates (4.8% vs 22.7%, P = 0.089) and length of hospital stay (4.0 ± 2.7 vs 3.6 ± 2.4 days, P = 0.798) in comparison to the nonisolated pneumocephalus group. None of the patients in the isolated group had neurosurgery whereas 2 patients in the nonisolated pneumocephalus group underwent surgery. Multivariable analysis revealed pneumocephalus as an independent predictor of ciTBI and hospital admission, but not ICU admission or neurosurgical intervention. CONCLUSION: Pneumocephalus is associated with increased rates of hospitalization and ciTBI, but not ICU admission, unfavorable outcome, or neurosurgical intervention in pediatric mTBI. Although usually spontaneously resolving pathology, it may occasionally be linked with complications such as cerebrospinal fluid leakage, meningitis, and tension pneumocephalus. Therefore, careful evaluation, close observation, and early detection of complications may prevent adverse outcomes.

The Effect of Surgical Positioning on Pneumocephalus in Subthalamic Nucleus Deep Brain Stimulation Surgery for Parkinson Disease.

OBJECTIVES: This research analyzed the effect of surgical positioning on postoperative pneumocephalus and assessed additional potential risk factors of pneumocephalus in subthalamic nucleus (STN) deep brain stimulation (DBS) for Parkinson disease (PD). MATERIALS AND METHODS: In this study, 255 consecutive patients with PD who received bilateral STN DBS under general anesthesia were retrospectively included. Of these, 180 patients underwent surgery with their heads in an elevated position, and 75 patients underwent surgery in a supine position. The postoperative pneumocephalus volume was compared between the two groups. Other potential risk factors for pneumocephalus also were analyzed. RESULTS: The mean pneumocephalus volume for the group with elevated-head positioning (16.76 ± 15.23 cm3) was greater than for the supine group (3.25 ± 8.78 cm3) (p < 0.001). Multivariable analysis indicated that the pneumocephalus volume was related to surgical positioning, lateral trajectory angle, intraoperative mean arterial pressure (MAP), microelectrode recording (MER) passage number, brain atrophy degree, and the anterior trajectory angle. No correlation was found between pneumocephalus and age, sex, duration of PD, surgery length, or intracranial volume. In the subgroup analysis, the pneumocephalus volume exhibited a negative correlation with intraoperative MAP (r = -0.210, p = 0.005) and positive correlations with degree of brain atrophy (r = 0.242, p = 0.001) and MER passage number (r = 0.184, p = 0.014) in the elevated-head group. Specifically, an MER passage number > 3 was a significant risk factor for pneumocephalus in the elevated-head group. A positive correlation was observed between the pneumocephalus volume and the lateral trajectory angle in both groups (elevated-head positioning, r = 0.153, p = 0.041; supine positioning, r = 0.546, p < 0.001). CONCLUSIONS: In patients with PD who were anesthetized and receiving STN DBS, supine positioning reduced pneumocephalus volume compared with patients with PD receiving STN DBS with their heads elevated. The pneumocephalus volume was negatively correlated with intraoperative MAP and positively correlated with the degree of brain atrophy, the lateral trajectory angle, and the MER passage number.

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 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.

The Role of Endonasal Endoscopic Skull Base Repair in Posttraumatic Tension Pneumocephalus.

OBJECTIVES: Information about the endonasal endoscopic approach (EEA) for the management of posttraumatic tension pneumocephalus (PTTP) remains scarce. Concomitant rhinoliquorrhea and posttraumatic hydrocephalus (PTH) can complicate the clinical course. METHODS: The authors systematically reviewed pertinent articles published between 1961 and December 2020 and identified 6 patients with PTTP treated by EEA in 5 reports. Additionally, the authors share their institutional experience including a seventh patient, where an EEA resolved a recurrent PTTP without rhinoliquorrhea. RESULTS: Seven PTTP cases in which EEA was used as part of the treatment regime were included in this review. All cases presented with a defect in the anterior skull base, and 3 of them had concomitant rhinoliquorrhea. A transcranial approach was performed in 6/7 cases before EEA was considered to treat PTTP. In 4/7 cases, the PTTP resolved after the first intent; in 2/ 7 cases a second repair was necessary because of recurrent PTTP, 1 with and 1 without rhinoliquorrhea, and 1/7 case because of recurrent rhinoliquorrhea only. Overall, PTTP treated by EEA resolved with a mean radiological resolution time of 69 days (range 23-150 days), with no late recurrences. Only 1 patient developed a cerebrospinal fluid diversion infection probably related to a first incomplete EEA skull base defects repair. A permanent cerebrospinal fluid diversion was necessary in 3/7 cases. CONCLUSIONS: Endonasal endoscopic approach repair of air conduits is a safe and efficacious second-line approach after failed transcranial approaches for symptomatic PTTP. However, the strength of recommendation for EEA remains low until further evidence is presented.

MRI diagnosis of spontaneous intraventricular tension-pneumocephalus in a 10-month-old male Saarloos Wolfdog.

A 10-month-old male Saarloos Wolfdog was presented with a history of multiple neurologic deficits that had acutely progressed. Neurologic examination findings localized signs to the cerebrum and brainstem. Magnetic resonance imaging revealed markedly enlarged and gas-filled lateral ventricles with a mass effect leading to cerebellar herniation. A right-sided defect of the cribriform plate with a dysplastic ethmoturbinate was identified as the inlet of air and origin of the intraventricular tension pneumocephalus. Surgical findings were consistent with a ruptured, congenital, nasal meningocele.

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.

Tension pneumocephalus and bilateral orbital compartment syndrome relieved by lateral canthotomies.

Traumatic tension pneumocephalus and orbital compartment syndrome are rare, tend to be associated with severe craniofacial injuries, and can occur following both blunt and penetrating injury. Early recognition and high index of clinical suspicion are important in both cases. Emergency decompression results in improvement in vast majority of cases.

Traumatic pneumorrhachis: systematic review and an illustrative case.

Pneumorrhachis (PR) refers to free air in the spinal canal. We aim to describe a case report and conduct a systematic review focused on the clinical presentation, diagnosis, and management of traumatic PR. We conducted a language-restricted PubMed, SciELO, Scopus, and Ovid database search for traumatic PR cases published till June 2019. Categorical variables were assessed by Fisher's exact test. In addition to our reported index case, there were 82 articles (96 individual cases) eligible for meta-analysis according to our inclusion/exclusion criteria. Eighty per cent of patients had blunt trauma, while 17% had penetrating injuries. Thirty-four per cent of cases were extradural PR, 21% intradural PR, and unreported PR type in 43%. Nine per cent of patients presented with symptoms directly attributed to PR: sensory radiculopathy (2%), motor radiculopathy (1%), and myelopathy (6%). CT had a 100% sensitivity for diagnosing PR, MRI 60%, and plain radiograph 48%. Concurrent injuries reported include pneumocephalus (42%), pneumothorax (36%), spine fracture (27%), skull fracture (27%), pneumomediastinum (24%), and cerebrospinal fluid leak (14%). PR was managed conservatively in every case, with spontaneous resolution in 96% on follow-up (median = 10 days). Prophylactic antibiotics for meningitis were given in 13% PR cases, but there was no association with the incidence of meningitis (overall incidence: 3%; prophylaxis group (0%) vs non-prophylaxis group (4%) (p = 1)). Occasionally, traumatic PR may present with radiculopathy or myelopathy. Traumatic PR is almost always associated with further air distributions and/or underlying injuries. There is insufficient evidence to support the use of prophylactic antibiotic in preventing meningitis in traumatic PR patients.

How to avoid pneumocephalus in deep brain stimulation surgery? Analysis of potential risk factors in a series of 100 consecutive patients.

BACKGROUND: Accuracy of lead placement is the key to success in deep brain stimulation (DBS). Precise anatomic stereotactic planning usually is based on stable perioperative anatomy. Pneumocephalus due to intraoperative CSF loss is a common procedure-related phenomenon which could lead to brain shift and targeting inaccuracy. The aim of this study was to evaluate potential risk factors of pneumocephalus in DBS surgery. METHODS: We performed a retrospective single-center analysis in patients undergoing bilateral DBS. We quantified the amount of pneumocephalus by postoperative CT scans and corrected the data for accompanying brain atrophy by an MRI-based score. Automated computerized segmentation algorithms from a dedicated software were used. As potential risk factors, we evaluated the impact of trephination size, the number of electrode tracks, length of surgery, intraoperative blood pressure, and brain atrophy. RESULTS: We included 100 consecutive patients that underwent awake DBS with intraoperative neurophysiological testing. Systolic and mean arterial blood pressure showed a substantial impact with an inverse correlation, indicating that lower blood pressure is associated with higher volume of pneumocephalus. Furthermore, the length of surgery was clearly correlated to pneumocephalus. CONCLUSION: Our analysis identifies intraoperative systolic and mean arterial blood pressure as important risk factors for pneumocephalus in awake stereotactic surgery.

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.

Pneumorrhachis in a Pediatric Patient with an Isolated Back Injury.

BACKGROUND: Pneumorrhachis is an uncommon radiographic finding and is typically found in adult patients secondary to trauma or pneumocephalus. It is extremely rare in the pediatric population. Our case report describes a young boy who was found to have pneumorrhachis, but initially presented with an isolated back laceration. CASE REPORT: An 8-year-old boy arrived to the emergency department as a transfer from an outside hospital after initially presenting with a back laceration. After laceration repair, he developed severe headache and vomiting when sitting upright from a supine position. He was found to have T3 fractures and pneumocephalus secondary to pneumorrhachis and was managed conservatively per neurosurgery recommendations. Why Should an Emergency Physician Be Aware of This?Although extremely rare in the pediatric population, pneumorrhachis must still be considered in any pediatric patient with a penetrating injury to the abdomen, respiratory tract, or spinal column. Cases without clear etiology require further evaluation for occult spinal injuries and fractures. Conservative management is typically sufficient, although certain situations require further intervention.

Petroclival tension pneumocephalus: an unrivalled life threatening complication linked to molecular-targeted therapy.

A 73-year-old man with a petroclival tumor (metastatic renal cell carcinoma) presented with a progressive consciousness disturbance attributed to tension pneumocephalus during molecular-targeted therapy following low-dose fractionated radiotherapy for a petroclival tumor. The skull base defect was successfully reconstructed vi an endoscopic endonasal approach.

A Rare Case of Temporal Bone Pneumocephalus Tracking through the Internal Auditory Canal.

A 39-year-old male with chronic hydrocephalus requiring biventricular shunts presented with progressive pneumocephalus over several years. He showed no improvement following ventriculoperitoneal (VP) shunt revision and anterior skull base repair for a sphenoid dehiscence. Imaging continued to show worsening pneumocephalus with air tracking along the right facial nerve from the geniculate ganglion to the internal auditory canal (IAC). The patient then underwent tympanomastoidectomy and skull base reconstruction. Based on a search of published literature, this appears to be the first reported case of temporal bone pneumocephalus coursing through the IAC, unlike most cases associated with tegmen defects and middle fossa pneumocephalus.

The Complication of Tension Pneumocephalus After Septoplasty.

ABSTRACT: This paper presents a case of tension pneumocephalus with severe headache 2 days after septoplasty surgery. In such cases, endoscopic sinus surgery (ESS) or open approach can be used for repair of the defect. However, pneumocephalus, especially caused by minor defects, improves spontaneously with conservative treatment. In our case, the pneumocephalus was responsive to conservative treatment with bed rest, head elevation. His examinations in the 3rd and 8th months after discharge were uneventful and CT scan revealed no signs of pneumocephalus. In severe headaches developing after septoplasty, the possibility of intracranial complications should be evaluated. Simple conservative treatment should be tried before surgery, but then the patient should be examined at regular intervals.