Prognosis, incidence and management of acute traumatic intracranial pneumocephalus. A retrospective analysis of 49 cases

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.

Delayed Postoperative Tension Pneumocephalus Treated With a Subdural Evacuating Port System: A Case Report and Review of the Literature

Tension pneumocephalus (TP) is a rare neurosurgical emergency due to the rise of intracranial pressure from air in the cranial cavity. Tension pneumocephalus' clinical presentation ranges from headache, visual alterations, altered mental status, and death. Given its nonspecific clinical presentation, tension pneumocephalus is usually diagnosed via computed tomography (CT) imaging. Open burr hole craniotomy is the preferred treatment method for tension pneumocephalus. Subdural evacuating port system (SEPS) drains have, however, seen increased utilization in neurosurgery due to decreased possibilities for infections, reduced seizure probability, and better outcomes post-surgery, especially for elderly patients. In this article, we present the case of a 67-year-old female with postoperative tension pneumocephalus after the evacuation of an acute subdural hematoma. The patient became symptomatic from tension pneumocephalus, which was evacuated using a subdural evacuating port system drain. Post-drain placement, the patient had a radiographic and clinical resolution of her tension pneumocephalus. Thesubdural evacuating port system is a useful adjunctive tool for treating tension pneumocephalus.Given the favorable characteristic profile of subdural evacuating port system drains compared to open surgical modalities, further inquiry should be pursued to analyze the feasibility of establishing subdural evacuating port systems as a less invasive treatment alternative.

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.

CT of Skull Base Fractures: Classification Systems, Complications, and Management

As advances in prehospital and early hospital care improve survival of the head-injured patient, radiologists are increasingly charged with understanding the myriad skull base fracture management implications conferred by CT. Successfully parlaying knowledge of skull base anatomy and fracture patterns into precise actionable clinical recommendations is a challenging task. The authors aim to provide a pragmatic overview of CT for skull base fractures within the broader context of diagnostic and treatment planning algorithms. Laterobasal, frontobasal, and posterior basal fracture patterns are emphasized. CT often plays a complementary, supportive, or confirmatory role in management of skull base fractures in conjunction with results of physical examination, laboratory testing, and neurosensory evaluation. CT provides prognostic information about short- and long-term risk of cerebrospinal fluid (CSF) leak, encephalocele, meningitis, facial nerve paralysis, hearing and vision loss, cholesteatoma, vascular injuries, and various cranial nerve palsies and syndromes. The radiologist should leverage understanding of specific strengths and limitations of CT to anticipate next steps in the skull base fracture management plan. Additional imaging is warranted to clarify ambiguity (particularly for potential sources of CSF leak); in other cases, clinical and CT criteria alone are sufficient to determine the need for intervention and the choice of surgical approach. The radiologist should be able to envision stepping into a multidisciplinary planning discussion and engaging neurotologists, neuro-ophthalmologists, neurosurgeons, neurointerventionalists, and facial reconstructive surgeons to help synthesize an optimal management plan after reviewing the skull base CT findings at hand. Online supplemental material is available for this article. ^©RSNA, 2021.

Traumatic skull fractures in dogs and cats: A comparative analysis of neurological and computed tomographic features

BACKGROUND

Traumatic skull fractures (TSF) are relatively frequent in dogs and cats, but little information is available regarding their clinical and imaging features.

HYPOTHESIS/OBJECTIVES

To describe the neurological and computed tomographic (CT) features of a large cohort of dogs and cats with TSF.

ANIMALS

Ninety-one dogs and 95 cats with TSF identified on CT.

METHODS

Multicenter retrospective comparative study. Signalment, cause of trauma, fracture locations and characteristics, presence of neurological deficits, and 1-week survival were recorded. Fractures were classified according to the extent of fragmentation and displacement.

RESULTS

The cranial vault was affected more frequently in dogs (P = .003), whereas the face and base of the cranium more often was affected in cats (P < .001). Cats presented with multiple fractures more frequently (P < .001). All animals with TSF in the cranial vault were more likely to develop neurological signs (P = .02), especially when depressed fractures were present (95% confidence interval [CI], 1.7-8.2; P = .001). Animals with TSF located only in the facial region were less likely to have neurological signs (odds ratio with Mantel-Haenszel's method [ORMH ], 0.2; 95% CI, 0.1-0.6; P = .004). Most affected animals (84.9%) survived the first week post-trauma. Death was more likely with fractures of the cranial vault (P = .003), especially when fragmented (P = .007) and displaced (P = .004).

CONCLUSIONS AND CLINICAL IMPORTANCE

Traumatic skull fracture distribution and patterns are different between dogs and cats. Cranial vault fractures were associated with neurological deficits and worse survival. The presence of TSF alone should not be considered a negative prognostic factor because most affected animals survived the first week.

Clinical and Radiological Characteristics of Traumatic Pneumocephalus after Traumatic Brain Injury

Objective

Traumatic pneumocephalus (TP) is a common complication of traumatic brain injury (TBI), which is characterized by the abnormal entrapment of air in the intracranial cavity after TBI to the meninges. The purpose of this study was to investigate the clinical and radiological characteristics related to TP associated with TBI.

Methods

From January 2013 to March 2018, the data from 71 patients with TP after TBI were collected. Demographic and clinical characteristics were investigated and the distribution of TP was investigated as radiological characteristics. The author compared the demographic characteristics of TP to the data from the Korean Neurotrauma Data Bank System (KNTDBS).

Results

There was a higher ratio of males in patients with TP compared with KNTDBS. The mean age was 48.4±20.5 years and the incidence was highest in those 41-60 years of age (42.3%). Surgical treatment was performed in 23.9% patients. The mortality associated with the TP was 4.2%. The most common cause of injury was a traffic accident (52.1%). TP was mainly located in the epidural space (53.5%) and showed a scatter pattern (60.6%). It was mostly located in the frontal and temporal area (81.7%). Skull fractures were observed in 40.8% in the temporal bone and 25.4% in the frontal bone.

Conclusion

The author identified epidemiology, clinical, and radiological characteristics of TP associated with TBI. Although this study has many limitations, the author believes it is worthwhile as it examines various characteristics of TP, which previously had relatively little clinical interest.

Significance of cerebrospinal fluid inflammatory markers for diagnosing external ventricular drain–associated ventriculitis in patients with severe traumatic brain injury

Objective

The aim of this study was to investigate the diagnostic potential of the inflammatory markers interleukin-6 (IL-6), total leukocyte count (TLC), and protein in the CSF and IL-6, C-reactive protein, and white blood cell count in the serum for the early diagnosis of ventriculitis in patients with traumatic brain injury (TBI) and an external ventricular drain compared with patients without ventriculitis.

Methods

Retrospective data from 40 consecutive patients with TBI and an external ventricular drain treated in the authors’ intensive care unit between 2013 and 2017 were analyzed. For all markers, arithmetical means and standard deviations, area under the curve (AUC), cutoff values, sensitivity, specificity, positive likelihood ratio (LR), and negative LR were calculated and correlated with presence or absence of ventriculitis.

Results

There were 35 patients without ventriculitis and 5 patients with ventriculitis. The mean ± SD IL-6 concentration in CSF was significantly increased, with 6519 ± 4268 pg/mL at onset of ventriculitis compared with 1065 ± 1705 pg/mL in patients without ventriculitis (p = 0.04). Regarding inflammatory markers in CSF, IL-6 showed the highest diagnostic potential for differentiation between the presence and absence of ventriculitis (AUC 0.938, cutoff 4064 pg/mL, sensitivity 100%, specificity 92.3%, positive LR 13, and negative LR 0), followed by TLC (AUC 0.900, cutoff 64.5 /µL, sensitivity 100%, specificity 80%, positive LR 5.0, and negative LR 0) and protein (AUC 0.876, cutoff 31.5 mg/dL, sensitivity 100%, specificity 62.5%, positive LR 2.7, and negative LR 0).

Conclusions

The level of IL-6 in CSF has the highest diagnostic value of all investigated inflammatory markers for detecting ventriculitis in TBI patients at an early stage. In particular, CSF IL-6 levels higher than the threshold of 4064 pg/mL were significantly associated with the probability of ventriculitis.

Isolated intraparenchymal tension pneumocephalus

Pneumocephalus after trauma is not uncommon but rarely develops into tension pneumocephalus. Delayed-onset spontaneous tension pneumocephalus is rare, and delayed-onset isolated intraparenchymal/intracerebral tension pneumocephalus is even more so. We describe a 35-year-old man who presented with urinary incontinence, left eye vision loss, and nasal discharge/cerebrospinal fluid rhinorrhea 2 months after recovering from bifrontal hemorrhagic contusions following a road traffic accident. Intraparenchymal/intracerebral tension pneumocephalus was diagnosed with computed tomography and the patient was taken for an urgent decompressive surgery along with repair of the skull base defect.

Acute Outcomes of Isolated Pneumocephali in Children After Minor Blunt Head Trauma

OBJECTIVES

We aimed to determine the prevalence of and adverse outcomes caused by pneumocephali in children with minor blunt head trauma who had no other intracranial injuries (ie, isolated pneumocephali).

METHODS

We conducted a secondary analysis of a public use dataset from a multicenter prospective study of pediatric minor head trauma. We included children younger than 18 years with Glasgow Coma Scale (GCS) scores of 14 or 15 and non-trivial mechanisms of injury who had cranial computed tomographies obtained. Patients with isolated pneumocephali were those without other traumatic brain injuries (TBIs) but could have non-depressed or basilar skull fractures (BSFs). We defined adverse outcomes as death, need for neurosurgery, or intubation more than 24 hours for TBI.

RESULTS

Pneumocephali occurred in 148 (1.0%; 95% confidence interval, 0.8%-1.2%) of 14,983 patients; 54 (36.5%) of 148 were isolated. Of these 54 patients, 42 (77.8%) had associated BSFs (7 of whom also had linear skull fractures) and 8 (14.8%) had associated linear skull fractures without BSFs; 4 patients (7.4%) had no fractures. Thirty-three patients (61.1%) had both GCS scores of 15 and no other signs of altered mental status. All patients with isolated pneumocephali and available descriptive data (n = 26) had small-sized pneumocephali. There were no deaths, neurosurgical interventions, or intubations for more than 24 hours for TBI (95% confidence interval for any of the outcomes, 0%-7.9%) in the 54 patients with isolated pneumocephali.

CONCLUSIONS

Children with isolated pneumocephali and GCS scores of 14 or 15 after minor blunt head trauma are unlikely to have adverse clinical outcomes.

Traumatic pneumocephaly: trapped air from where?

Traumatic pneumocephaly is literally defined as 'air in the head' after trauma. While this phenomenon has been well described in the literature, our case report is unique in describing diffuse pneumocephalus in the subaponeurotic space, subdural space, subarachnoid space, brain and ventricles without a break in the cranial vault: a 26-year-old man fell from a =9 meter scaffolding in a water tower. Following an arduous and delayed extrication, the patient was unresponsive with loss of pulse requiring intubation, cardiopulmonary resuscitation and release of tension pneumothorax with bilateral thoracostomy tubes. Examination remained poor with a Glasgow Coma Scale of 3. Immediate exploratory laparotomy was performed for a small right retroperitoneal haematoma on Focused Assessment with Sonography for Trauma. Postoperative imaging revealed diffuse pneumocephaly without facial fractures. This case presentation explores unusual causes of fistulous connections with the atmosphere that may lead to air trapped in and around the cranial vault.

A Case of Intracranial Wooden Foreign Body: Mimicking Pneumocephalus

Intracranial wooden foreign bodies are rare. In addition, such objects are difficult to identify with conventional radiographic techniques, such as X-ray radiography or brain computed tomography. A 48-year-old man presented to our emergency room with a headache. Even though he had a history of trauma, he had no external wounds and showed no neurological deficits at the initial examination. He was initially diagnosed with trauma-related pneumocephalus. He developed a delayed intracranial infection and underwent surgery to remove the wooden foreign body. The present case illustrates the necessity for special attention to patients suspected of having pneumocephalus with a rare presentation during the initial examination. Early surgical removal of the intracranial foreign body is necessary to prevent complications.

Giant Spontaneous Epidural Pneumatocele: Case Report and Review of the Literature

BACKGROUND

Pneumocephalus is a commonly encountered finding in neurosurgery in which air displaces intracranial cerebrospinal fluid after cranial surgery or a cerebrospinal fluid leak into paranasal or mastoid sinuses. When an intracranial air collection becomes chronically established in a fixed loculation causing mass effect, pneumatocele is a more appropriate term. We present an unusual case of a spontaneous giant frontotemporal epidural pneumatocele that persisted for more than 1 year before the patient presented for neurological treatment.

CASE DESCRIPTION

A 40-year-old man with a remote history of minor head trauma presented with symptoms of headaches, dizziness, and vertigo. Imaging revealed a right giant epidural pneumocephalus secondary to bony dehiscence of the intracranial wall of the mastoid bone. A subtemporal middle fossa approach was performed to repair the mastoid defect with hydroxyapatite, fat graft, and temporalis fascia. The patient was discharged on postoperative day 2 with improvement in his headaches. One month after discharge operative imaging demonstrated complete resolution of his epidural pneumatocele and improvement in his headaches.

CONCLUSIONS

This unique case represents the first reported case in the neurosurgical literature of a giant spontaneous epidural pneumatocele occurring in an adult treated with a middle fossa approach with resolution on follow-up imaging.

Role of neuroimaging in management of traumatic brain injury

Traumatic brain injury is a significant cause of morbidity and mortality in the UK with substantial associated economic costs to the healthcare system. This article explores the role of neuroimaging in both acute and long-term management of traumatic brain injury patients. We discuss the indications for urgent cross-section imaging as well as radiological features of both primary insults and secondary injuries. The role of neuroimaging in guiding surgical therapy and monitoring post-operative traumatic brain injury patients has also been described. Following initial injury, traumatic brain injury patients can suffer from a wide variety of physical, social and psychological difficulties. New techniques such as diffusion tensor imaging in combination with conventional magnetic resonance imaging sequences may provide useful information in predicting long-term prognosis and guiding rehabilitation.

Pneumocephalus patterns following endonasal endoscopic skull base surgery as predictors of postoperative CSF leaks

OBJECTIVES

Postoperative pneumocephalus is a common occurrence after endoscopic endonasal skull base surgery (ESBS). The risk of cerebrospinal fluid (CSF) leaks can be high and the presence of postoperative pneumocephalus associated with serosanguineous nasal drainage may raise suspicion for a CSF leak. The authors hypothesized that specific patterns of pneumocephalus on postoperative imaging could be predictive of CSF leaks. Identification of these patterns could guide the postoperative management of patients undergoing ESBS.

METHODS

The authors queried a prospectively acquired database of 526 consecutive ESBS cases at a single center between December 1, 2003, and May 31, 2012, and identified 258 patients with an intraoperative CSF leak documented using intrathecal fluorescein. Postoperative CT and MRI scans obtained within 1-10 days were examined and pneumocephalus was graded based on location and amount. A discrete 0-4 scale was used to classify pneumocephalus patterns based on size and morphology. Pneumocephalus was correlated with the surgical approach, histopathological diagnosis, and presence of a postoperative CSF leak.

RESULTS

The mean follow-up duration was 56.7 months. Of the 258 patients, 102 (39.5%) demonstrated pneumocephalus on postoperative imaging. The most frequent location of pneumocephalus was frontal (73 [71.5%] of 102), intraventricular (34 [33.3%]), and convexity (22 [21.6%]). Patients with craniopharyngioma (27 [87%] of 31) and meningioma (23 [68%] of 34) had the highest incidence of postoperative pneumocephalus compared with patients with pituitary adenomas (29 [20.6%] of 141) (p < 0.0001). The incidence of pneumocephalus was higher with transcribriform and transethmoidal approaches (8 of [73%] 11) than with a transsellar approach (9 of [7%] 131). There were 15 (5.8%) of 258 cases of postoperative CSF leak, of which 10 (66.7%) had pneumocephalus, compared with 92 (38%) of 243 patients without a postoperative CSF leak (OR 3.3, p = 0.027). Pneumocephalus located in the convexity, interhemispheric fissure, sellar region, parasellar region, and perimesencephalic region was significantly correlated with a postoperative CSF leak (OR 4.9, p = 0.006) and was therefore termed "suspicious" pneumocephalus. In contrast, frontal or intraventricular pneumocephalus was not correlated with postoperative CSF leak (not significant) and was defined as "benign" pneumocephalus. The amount of convexity pneumocephalus (p = 0.002), interhemispheric pneumocephalus (p = 0.005), and parasellar pneumocephalus (p = 0.007) (determined using a scale score of 0-4) was also significantly related to postoperative CSF leaks. Using a series of permutation-based multivariate analyses, the authors established that a model containing the learning curve, the transclival/transcavernous approach, and the presence of "suspicious" pneumocephalus provides the best overall prediction for postoperative CSF leaks.

CONCLUSIONS

Postoperative pneumocephalus is much more common following extended approaches than following transsellar surgery. Merely the presence of pneumocephalus, particularly in the frontal or intraventricular locations, is not necessarily associated with a postoperative CSF leak. A "suspicious" pattern of air, namely pneumocephalus in the convexity, interhemispheric fissure, sella, parasellar, or perimesencephalic locations, is significantly associated with a postoperative CSF leak. The presence and the score of "suspicious" pneumocephalus on postoperative imaging, in conjunction with the learning curve and the type of endoscopic approach, provide the best predictive model for postoperative CSF leaks.

Chronic, otogenic, epidural pneumatocoele with delayed mass effect: case report

Introduction: Mastoid hyperpneumatisation predisposes to intracranial pneumatocoele development, due to the risk of rupture of the thin, bony walls. Intracranial pneumatocoele may be precipitated by even minor head trauma or an abrupt change in middle-ear pressure, with the potential risk of infectious or compressive intracranial complications.

Case report: A 19-year-old man with mastoid hyperpneumatisation developed a chronic intracranial–epidural pneumatocoele of traumatic origin in the right parieto-occipital area, in contiguity with the posterior mastoid cells. Eighteen months later, after a common cold, the patient developed signs of intracranial hypertension, due to the pneumatocoele spreading to the right epidural anterior fossa. A large right mastoidectomy extended to the retrosigmoid cells was performed, and a watertight seal applied over a large retrosigmoid cell using bovine pericardium and a mixture of bone powder and fibrin glue.

Results: The patient was discharged on post-operative day three with no symptoms. Ten days after surgery, computed tomography monitoring showed complete reabsorption of the pneumatocoele.

Conclusion: In cases of chronic, otogenic, epidural pneumatocoele, the possibility of the sudden onset of serious complications suggests the need for early repair of the communication between the temporal bone and the intracranial compartments. Closure of the fistula using autogenic and/or allogenic materials is usually adequate to resolve the pneumatocoele.

Pneumocephalus Following Severe Head Trauma

It is important to be alert to the possibility of pneumocephalus in patients with head injury. Pneumocephalus is a potentially lethal complication in patients with craniofacial fractures following severe head trauma. A patient presented with intracranial air after he fell down from a height of 4 m. The patient recovered without any neurological deficits after conservative treatment. A time sequence of cerebral CT scans shows how the pneumocephalus developed and finally resolved without surgical intervention. The etiology, diagnosis, treatment and possible complications of this injury are discussed briefly.

Prophylactic administration of ceftriaxone for the prevention of meningitis after traumatic pneumocephalus: results of a clinical trial

OBJECT

The purpose of this study was to compare the efficacy of the prophylactic use of ceftriaxone for the prevention of meningitis in patients with acute traumatic pneumocephalus.

METHODS

In this prospective, single-institution, randomized clinical trial, 109 patients with mild head injury and traumatic pneumocephalus were randomly assigned to receive or not receive an antibiotic medication (ceftriaxone, 1 g given twice a day) until occurrence of meningitis or at least 5 days after trauma. The patients were followed up for 1 month posttrauma. The 109 patients were divided into two groups: 53 were assigned to the prophylactic antibiotics therapy group and 56 to the control group. The overall rate of meningitis was 20.1% and the rates of meningitis in the two groups were not significantly different. The results were the same when adjusted for the patient's Glasgow Coma Scale score, sex, and age, as well as for an intradural location of air, air volume, presence of cerebrospinal fluid (CSF) rhinorrhea or CSF otorrhea, radiological sign of a skull base fracture, or intracranial hemorrhage.

CONCLUSIONS

The results of this study do not substantiate the efficacy of ceftriaxone used in the prevention of meningitis in patients with traumatic pneumocephalus after mild head injury or in any specific subgroup of these patients. Cerebrospinal fluid rhinorrhea and intracranial hemorrhage may be considered primary risk factors for the development of meningitis in patients with posttraumatic pneumocephalus and, in the absence of these symptoms, intradural location of air and air volume greater than 10 ml may be considered secondary risk factors. Further studies in this area are warranted.

Intracerebral pneumatocele presenting after air travel

In this report the authors discuss a patient who experienced symptoms of an acute right frontal, intraparenchymal pneumatocele while on an airplane descending to an international airport. This rare complication of an ethmoid sinus osteoma that eroded upward through the dura mater is described along with a literature review. A persistent headache and inappropriate behavior consistent with a frontal lobe syndrome brought the patient to clinical and imaging evaluation, which revealed a large right frontal lobe pneumatocele and an associated ethmoid sinus osteoma extending upward into the frontal lobe. Through a right frontal craniotomy, the air cavity was evacuated, the osteoma partially excised, and the dural defect closed using a vascularized pericranial flap. Postoperatively, the patient made an unremarkable recovery. For patients with air sinus osteomas extending into the cranial cavity, air travel or other barotrauma may result in a life-threatening tension pneumatocele.

Bitemporal head crush injuries: clinical and radiological features of a distinctive type of head injury

OBJECT

Most craniocerebral injuries are caused by mechanisms of acceleration and/or deceleration. Traumatic injuries following progressive compression to the head are certainly unusual. The authors reviewed clinical and radiological features in a series of patients who had sustained a special type of cranial crush injury produced by the bilateral application of rather static forces to the temporal region. Their aim was to define the characteristic clinical features in this group of patients and to assess the mechanisms involved in the production of the cranial injuries and those of the associated cerebral and endocrine lesions found in this peculiar type of head injury.

METHODS

Clinical records of 11 patients were analyzed with regard to the state of consciousness, cranial nerve involvement, findings on neuroimaging studies, endocrine symptoms, and outcome. Furthermore, an experimental model of bitemporal crush injury was developed by compressing a dried skull with a carpenter's vice. Seven of the 11 patients were 16 years old or younger. All patients presented with a characteristic clinical picture consisting of no loss of consciousness (six patients), epistaxis (nine patients), otorrhagia (11 patients), peripheral paralysis of the sixth and/or seventh cranial nerves (10 patients), hearing loss (five patients), skull base fractures (11 patients), pneumocephalus (11 patients), and diabetes insipidus (seven patients). Ten patients survived the injury and most recovered neurological function.

CONCLUSIONS

Static forces applied to the head in a transverse axis produce fractures in the skull base that cross the midline structures without producing significant cerebral damage. Stretching of cranial nerves at the skull base explains the nearly universal finding of paralysis of these structures, whereas an increase in the vertical diameter of the skull accounts for the occurrence of diabetes insipidus in the presence of an intact function of the anterior pituitary lobe. The association of clinical, endocrine, and neuroimaging findings encountered in this peculiar type of head injury supports the idea that this subset of injured patients has a distinctive clinical condition, namely the syndrome of bitemporal crush injury to the head.

Tension pneumocephalus after craniotomy in supine position

Tension pneumocephalus has been reported frequently after posterior fossa surgery, mostly in procedures done in the sitting position. Though uncommon, tension pneumocephalus is a life-threatening complication that requires urgent diagnosis and treatment. It is rare for this complication to occur after neurosurgical procedures done in the supine position. The authors report a case of an adult patient diagnosed with craniopharyngioma who developed tension pneumocephalus following craniotomy in the supine position.

Severe tension pneumocephalus caused by opening of the frontal sinus by head injury 7 years after initial craniotomy--case report

A 46-year-old man presented with severe tension pneumocephalus triggered by mild head injury 7 years after craniotomy. He had a history of subarachnoid hemorrhage due to ruptured anterior communicating artery aneurysm, coating of the aneurysm performed via a craniotomy, and a ventriculoperitoneal (VP) shunt inserted. He fell from bed in a rehabilitation hospital. Eight hours after the injury, he became comatose and suffered general convulsion. He was then transferred to our hospital. Radiography and computed tomography (CT) revealed a large amount of intracranial air and a widely opened frontal sinus. On the day of admission, the shunt tube was ligated. Surgery was performed to repair the dura mater and close the frontal sinus. Postoperative CT revealed reduction in the amount of air and frontal sinus obstruction. The patient had a good postoperative course without meningitis. Tension pneumocephalus may occur as a complication several years after a craniotomy because of the chronic lowering of intracranial pressure induced by a VP shunt. Complete frontal sinus repair is important during the initial craniotomy.

An unusual fatal complication of low basilar trunk aneurysm surgery: isolated prepontine tension pneumocephalus

OBJECTIVE

A case of postoperative tension pneumocephalus after low basilar trunk aneurysm clipping is presented. To our knowledge, this is the first case of isolated prepontine tension pneumocephalus.

BACKGROUND

A 63-year-old woman was admitted for repair of a basilar aneurysm that had caused a subarachnoid hemorrhage. She was cooperative and partially oriented. According to Hunt & Hess classification, she was considered Grade III.

METHOD

The aneurysm was clipped, using a right lateral suboccipital craniectomy with the patient in the sitting position. In the early postoperative period, she had no new neurological deficit. However, 2 hours later the patient became lethargic and unresponsive to verbal commands. Emergency CT scan revealed an isolated prepontine tension pneumocephalus with prominent posterior displacement of the pons. She was immediately taken back to surgery. Upon incision of the dura mater, air could be heard escaping under pressure from the posterior fossa cavity. The clip was in its proper position and all arteries were patent. Spontaneous respiration and pupil reflexes returned soon after surgery, but she remained unconscious and died 3 days later.

CONCLUSION

We believe that this death was directly attributable to the tension pneumocephalus and the distortion of the pons. Postoperative prepontine tension pneumocephalus, although this is an extremely rare condition, should be considered if a patient deteriorates after basilar aneurysm surgery in the sitting position.

Posttraumatic tension pneumocephalus

This case presentation will review tension pneumocephalus as a rare etiology of delayed posttraumatic headache (PTHA). It demonstrates that clinicians must be aware of even the uncommon causes of PTHA if appropriate diagnostic assessment and treatment are to be rendered. The case involves a 26-year-old right-handed white male who was 4 years post severe traumatic brain injury with facial fractures and an initial Glasgow Coma Scale score of 5. The patient's main postinjury functional impairments were cognitive-behavioral dysfunction, dysmetria, left hemiparesis, and posttraumatic epilepsy. Approximately 3 years post injury, the patient started to have complaints of right unilateral frontal headache. This complaint was addressed conservatively by several treating physicians. Due to the progressive nature of the patient's complaints, a second opinion was obtained with the author. On assessment, the patient complained of unilateral right headache and described the pain as making him feel as if his head was going to "bust open." A computed tomography (CT) scan showed findings consistent with a tension pneumocephalus. The patient was referred to neurosurgery, at which time the tension pneumocephalus was evacuated and a dural leak, felt to be responsible for the condition, patched. The patient's headache complaints resolved postoperatively. Clinicians should be aware of uncommon conditions that may be present in patients presenting with late PTHA, particularly conditions such as tension pneumocephalus which may have a significant clinical morbidity.

Clinical significance of acute traumatic intracranial pneumocephalus

Among 1142 patients with head injuries hospitalized in the Neurosurgery Department of Gazi University Medical School during the period between 1979 and 1992, 583 had initial CT scans. A retrospective analysis of these initial CT images revealed intracranial air on admission in only 21 cases. These were classified as acute traumatic intracranial pneumocephalus: a potentially serious complication of head injury. CT scans were re-evaluated so as to reveal whether air was situated in the epidural, subdural, or subarachnoid spaces or intracerebrally; whether associated space-occupying lesions were present and whether the air bubbles were single or multiple. Clinical data such as the presence of persistent rhinorrhea and/or otorrhea, tension pneumocephalus, severity and type of trauma, and outcome were were also assessed to determine the significance of this rare finding.

Traumatic pneumomyelogram. Implications for the anaesthetist

A 70-year-old man sustained a severe head injury following a fall downstairs, which resulted in him being found in a head down position. In the accident and emergency department he was noted to have subarachnoid air on a lateral cervical spine radiograph. This drew attention to the presence of fractures in the middle cranial fossa and nitrous oxide was immediately discontinued. The presence of a traumatic pneumomylogram implies a base of skull or middle cranial fossa fracture, and is almost certainly associated with intracranial subarachnoid air. Early recognition of the condition, and cessation of nitrous oxide, is essential to prevent dangerous increases in intracranial pressure secondary to the diffusion of gas into the air filled cavity.

Neurosurgical Approaches to Cerebrospinal Fluid Rhinorrhea

The evolutionary concepts of pinpointing and treating cerebrospinal fluid (CSF) fistulas over the past few decades are reviewed taking into consideration the dynamic character of CSF circulation. The localization of the site of leakage is greatly facilitated by the judicious use of a variety of radioisotope and radiological techniques. The most recent are Metrizamide CT Cisternography and Magnetic Resonance Imaging. It is asserted that still the most challenging cases are those with intermittent liquorrheas, and those patients in which the site of the fistula is not easily defined. The authors will describe their personal experience with intracranial surgical repair of fistulas located in the anterior fossa.

Tension pneumocephalus: treatment with controlled decompression via a closed water-seal drainage system. Case report

The successful treatment of a patient with tension pneumocephalus by controlled decompression via external drainage is described. The advantage of the technique includes the immediate release of high pressure and the capability of maintaining constant low pressure to enable and facilitate sealing of dural tears. The method has been used in three other patients, leading to resolution of the tension pneumocephalus without recurrence or other complications.

The traumatic air myelogram

A case of a pneumomyelogram of the cervical spine resulting from blunt trauma to the head is presented. The patient had pneumocephalus and skull fractures. On presentation the patient had no neurological deficits and remained neurologically stable throughout the hospital course. This is the first report of a traumatic pneumomyelogram and pneumocephalus with multiple skull fractures where the patient sustained no neurological sequelae.

Neurosurgical treatment of traumatic frontobasal CSF fistulae in 300 patients (1967-1989)

300 patients with traumatic fronto-basal CSF fistulae were treated neurosurgically from 1967 to 1989, i.e. via a transcranial approach. An additional intracranial space occupying lesion, a direct open endocranium and/or a large basal brain hernia was found in 68%. The following aspects were discussed: progress in establishing the exact anatomical diagnosis, especially neuroradiological advances; questions of the indication for surgery; the problem of the optimal surgical approach. Both the cranial and the rhinological approach have advantages and disadvantages. Their indications only partly coincide, so that the choice of method depends especially on the individual pathology. Advances were made in recent years in terms of neurosurgery as well as of rhinology. The neurosurgical results could be improved, and postoperative complications have become rare after the cranial approach. Besides the optimal choice of the time of operation, the following factors are important: an adequate intracranial debridement; a microsurgical technique entailing as little damage to surrounding tissue as possible and various specially mentioned brain-protective measures. An optimal collaboration between the specialties involved is the basis for further progress. More attention must be paid to endocrinological problems in the future.

"Spontaneous" pneumocephalus associated with aerobic bacteremia

Three cases of "spontaneous" pneumocephalus suspected to have resulted from aerobic bacteremia caused by Enterobacter cloacae, Escherichia coli, and Klebsiella aerogenes are reported. In two cases, the E. cloacae and K. aerogenes were isolated from the cerebrospinal fluid. These cases were characterized by a rapid accumulation of air, without niveau, in the subarachnoid space and ventricles.

Chronic spontaneous tension pneumocephalus due to benign frontal sinus osteoma

Spontaneous pneumocephalus secondary to neoplasia is a rare condition. It may present with headaches, rhinorrhoea, otorrhoea, or meningitis in various combinations. A case of unusual presentation, with several months delay in diagnosis, with remarkable postoperative improvement is reported and the literature reviewed.