Preventing Shift from Pneumocephalus During Deep Brain Stimulation Surgery: Don't Give Up the 'Fork in the Brain'.

Clinical vignette: We present the case of a patient who developed intra-operative pneumocephalus during left globus pallidus internus deep brain stimulation (DBS) placement for Parkinson's disease (PD). Microelectrode recording (MER) revealed that we were anterior and lateral to the intended target. Clinical dilemma: Clinically, we suspected brain shift from pneumocephalus. Removal of the guide-tube for readjustment of the brain target would have resulted in the introduction of movement resulting from brain shift and from displacement from the planned trajectory. Clinical solution: We elected to leave the guide-tube cannula in place and to pass the final DBS lead into a channel that was located posterior-medially from the center microelectrode pass. Gap in knowledge: Surgical techniques which can be employed to minimize brain shift in the operating room setting are critical for reduction in variation of the final DBS lead placement. Pneumocephalus after dural opening is one potential cause of brain shift. The recognition that the removal of a guide-tube cannula could worsen brain shift creates an opportunity for an intraoperative team to maintain the advantage of the 'fork' in the brain provided by the initial procedure's requirement of guide-tube placement.

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.

Sudden-onset, non-traumatic large volume pneumocephalus following presentation of acute bacterial meningitis.

A man in his 30s, with sinonasal undifferentiated carcinoma status post resection 6 years prior, presented with acute onset of fever, headache and altered mentation. The patient was diagnosed with bacteremia and meningitis due to Streptococcus pneumoniae A standard antibiotic and corticosteroid regimen was started. Brain MRI showed an encephalocele abutting the superolateral nasopharynx mucosa. After several days of clinical improvement, the patient's mental status and headache acutely relapsed. A CT head venogram showed a large volume pneumocephalus originating from the region of a surgical defect. Management included external ventricular drain placement followed by right pterional craniotomy with skull base packing. Skull base defects increase the risk of life-threatening conditions such as bacterial meningitis and pneumocephalus. It is crucial for clinicians to be aware of the possibility of cranial surgical defects developing years after surgery.

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.

Laparoscopic cholecystectomy induce tension pneumocephalus in a patient with ventriculoperitoneal shunt: A case report and literature review.

INTRODUCTION AND PATIENT CONCERNS: We report on a 45-year-old woman who has a ventriculoperitoneal shunt (VPS), experienced drowsy mental status, with hypesthesia and hemiplegia on the left side. Ten days ago she underwent laparoscopic cholecystectomy (LC). Computed tomography revealed tension pneumocephalus, with severe compression on the right side of the brain. INTERVENTIONS AND DIAGNOSIS: She underwent 2 surgeries, the first surgery was to place a subdural drainage catheter, however, the pneumocephalus relapsed after withdrawing the catheter, and the later surgery was to replace the new VPS. OUTCOMES: After replacing the VPS, the patient recovers completely after 10 weeks of follow-up. CONCLUSION: To our knowledge, this is the first report of LC-induced tension pneumocephalus in a patient with VPS. The purpose of this study is to share our experience, with the hypothesized mechanism being the retrograde air through the VPS valve because of high abdominal pressurization. We recommend noting the existence of the VPS when the LC or any abdominal laparoscopy is performed. The VPS should be clamped during any laparoscopic procedure until complete depressurization. Furthermore, all patients with VPS who have neurological deterioration after abdominal laparoscopy should be treated as having the diagnosis of a tension pneumocephalus. These patients need emergency surgery to replace VPS and set the valve for high-pressure, which can result in a quick and complete recovery.

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.

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 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.

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; 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.

Neumoencéfalo, una revisión de literatura / Pneumocephalus, a literature review

El neumoencéfalo corresponde a la presencia de aire intracraneal y, en general, es asintomático y autolimitado. Puede ocurrir posterior a trauma, cirugía craneofacial, defectos congénitos, infección, neoplasia o de forma espontánea. El neumoencéfalo a tensión es una emergencia neuroquirúrgica, en la que se acumula aire intracraneal de forma continua que genera un efecto de masa. Clínicamente, se caracteriza por cefalea y un deterioro neurológico marcado. A pesar de ser poco frecuente, es relevante considerar el neumoencéfalo a tensión como una posible complicación en pacientes con antecedente de neurocirugía y/o cirugía otorrinolaringológica, debido a que es una patología potencialmente grave. El diagnóstico es clínico e imagenológico, y requiere de un alto índice de sospecha. Un manejo oportuno es relevante para prevenir la herniación y la muerte.

Pneumocephalus refers to the presence of air in the cranial cavity, and in general, is self-limited and asymptomatic. It can occur after trauma, craniofacial surgery, due to congenital defects, infection, neoplasia or spontaneously. Tension pneumocephalus is a neurosurgical emergency in which intracranial air accumulates continuously, causing a mass effect. It presents with headache and marked neurological deterioration. Despite being rare, it is relevant to consider tension pneumocephalus as a possible complication in patients with a history of neurosurgery and/or otolaryngology surgery, as it can be life-threatening. Diagnosis requires a high index of suspicion and imagenologic confirmation. Timely management is relevant to prevent herniation and death.

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.

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.