Gunshot injuries of the temporal bone

Gun shot injuries to the temporal bone: Anatomic predictors of mortality

PURPOSE

To explore anatomic predictors of mortality from gunshot wounds involving the temporal bone.

METHODS

A retrospective search of radiology reports was performed for all patients with CT reports suggestive of gunshot wounds (GSW) to the TB (2000-2020). All cases were reviewed by the senior author to confirm injury to the temporal bone. Detailed demographic and radiographic data were collected.

MAIN FINDINGS

A total of 120 patients met inclusion criteria. The majority of patients were male (n = 101) and the average age was 32.9. The squamosa was the most commonly involved subsite (n = 90), followed by the mastoid (n = 43). Squamosal entry site had the highest associated mortality (89.7 %). For those with known disposition, 65.8 % (79 of 120) expired on the same hospital admission. Inpatient otolaryngology consultation was noted in 18.3 % (n = 22) of patients, with poor outpatient follow-up.

CONCLUSIONS

This series represents the largest survey of GSW to the temporal bone to date. Although associated mortality is high and outpatient follow-up poor, otolaryngologists should be aware of associated morbidities to facilitate both inpatient and subsequent outpatient management.

Audiologic Consequences of Gunshot Wounds to the Temporal Bone Show No Relation to Concomitant Neurologic or Vascular Injuries

OBJECTIVES

To evaluate audiologic consequences of gunshot wounds (GSWs) to the temporal bone (TB), and to correlate hearing outcomes with neurologic and vascular injuries adjacent to the temporal bone.

STUDY DESIGN

Retrospective case series.

SETTING

University-based level-one trauma center.

METHODS

Retrospective review of 35 patients surviving TB ballistic injury, 2012 to 2021. Main outcomes were audiologic results. Demographics, concomitant injuries, CT, and interventions were reviewed.

RESULTS

Mean age was 30.7 years; 80% male. Seventeen patients (48.6%) underwent audiologic testing. Mean pure tone average (PTA) was 75 ± 35 dB, bone line average 41 ± 26 dB, and speech discrimination score (SDS) 60 ± 43%. Nineteen (54.3%) demonstrated facial nerve injury (FNI), who were more likely to show SNHL especially anacusis, though their mean PTA and SDS were not statistically different from those without (P = .30 and .47, respectively). Radiographic review of those with sensorineural loss (SNHL, 6/17) revealed otic capsule-disrupting fracture (n = 2), pneumolabyrinth (n = 2), intracranial hemorrhage (n = 3). Those with mixed loss (6/17) showed otic capsule-sparing fracture (n = 6), EAC injury (n = 5), ossicular discontinuity (n = 2), and intracranial hemorrhage (n = 4). Two with mastoid tip fractures alone had normal audiograms. Audiometric outcomes were not predicted by concomitant CSF leak, spinal injuries, vascular injuries, cranial neuropathies, or traumatic brain injury.

CONCLUSIONS

All patterns of hearing loss-conductive, sensorineural, mixed and normal-may be seen following TB ballistic injuries. Trauma severe enough to disrupt the facial nerve is more likely to cause anacusis. However, all should be formally evaluated, since ballistic injuries complicated by neurologic or vascular damage do not necessarily correlate with worse audiologic outcomes, while patients with minimal fractures may demonstrate losses.

Temporal Bone Trauma

Temporal bone trauma represents a potentially underrecognized condition during head injuries and remains an important consideration during the evaluation of these patients. The temporal bone contains many critical neurovascular structures in addition to the primary organs of the auditory and vestibular systems that may be violated during these injuries. Despite the lack of consensus guidelines on the management of these injuries, this review highlights the current literature regarding the diagnosis and management of temporal bone trauma and its potential complications.

A Nationwide Analysis of Gunshot Wounds of the Head and Neck: Morbidity, Mortality, and Cost

BACKGROUND

Gun violence in the United States rose continuously from 2010 to 2022, spiking during the pandemic, and peaking in 2021 at 48,830 deaths (14.8 per 100,000). Previous reports investigated health and financial burden associated with gunshot wounds (GSWs) during 2004 to 2013; however estimates related specifically to head and neck (H&N) injuries have been lacking. This population-based study aims to examine incidence, morbidity, mortality, and health resource utilization of H&N injuries utilizing the Nationwide Inpatient Sample database.

METHODS

A population-based study was undertaken using the National (Nationwide) Inpatient Sample (NIS) database (2015Q4-2017Q4). The International Classification of Diseases, Tenth Revision (ICD-10) codes were used to create a composite variable (inclusive of brain, eye, facial nerve, and facial fractures) resulting from GSW to the H&N. Incidence per 100,000 hospitalizations and case fatality rates were calculated to determine the health burden of H&N injuries. Length of hospital stay, and inflation- adjusted hospital charges were compared among H&N and non-H&N injuries. Χ 2 (classical and bootstrapped) and Mann-Whitney tests were used to compare groups.

RESULTS

Of 101,300 injuries caused by firearms, 16,140 injuries (15.9%) involved H&N region. The average incidence of H&N injuries was 20.1 cases per 100,000 hospitalizations, with intentional injuries having the highest case fatality rates of 32.4%. Patients with H&N injuries had extreme loss of function (33.4% versus 18.3%, P <0.001) and extreme likelihood of mortality (27.0% versus 11.3%, P <0.001) than non-H&N injuries. Statistically significant differences in the median length of stay (4.8 d versus 3.7 d; P <0.001) and median inflation-adjusted hospital charges ($80,743 versus $58,946, P <0.001) were found among H&N and non-H&N injuries.

CONCLUSIONS

Injuries due to GSW remain an inordinate health care and financial burden, with trauma to the H&N carrying an especially high cost in dollars, morbidity, and mortality.

Bulletproof Temporal Bone: A Case of Self-Inflicted Ballistic Injury

Temporal bone injuries due to gunshot wounds are uncommon but devastating, with a high risk of damage to critical neurovascular structures. The high resistance of the temporal bone, the densest bone in the human body, can sometimes avoid a fatal outcome. However, the complications are in many cases devastating and include hearing loss, facial paralysis, cerebrospinal fluid leakage, intracranial damage, and vascular injuries. Our goal was to report a case of ballistic injury to the temporal bone and describe the surgical approach taken for treatment. A 74-year-old man was transferred to the emergency room of our tertiary hospital, intubated and sedated, after an attempted suicide with a firearm. The CT scan showed the metal projectile lodged within the temporal bone on the right side, with the destruction of the ossicular chain and bony labyrinth. After stabilization, sedation was reversed, and the otolaryngology team was called. On examination, the entry wound was located in the cavum concha, with no active bleeding but presenting active otorrhea of cerebrospinal fluid. The patient had complete peripheral facial paralysis on the right side and spontaneous horizontal nystagmus toward the left side. Empirical antibiotic therapy was initiated. A subtotal petrosectomy was performed, with the removal of the foreign body, repair of the cerebrospinal fluid fistula, obliteration of the cavity with abdominal fat, and closure of the external auditory canal. He was discharged on the 11th-day post-surgery, maintaining complete facial paralysis and right-side anacusis, but was able to walk with assistance. In conclusion, penetrating trauma of the temporal bone is a potentially life-threatening situation, and patients that survive have a guarded prognosis, as it often leads to permanent sequelae even when managed promptly.

Management of the facial nerve following temporal bone ballistic injury

Objective

To understand the patterns of temporal bone fracture and facial nerve injury from ballistic trauma.

Study Design

Retrospective case series.

Methods

Retrospective review of 42 patients evaluated following temporal bone ballistic injury at a single institution, university‐based level‐one trauma center between 2012 and 2021. Demographics, facial nerve status, CT images, interventions, complications, and outcomes were reviewed.

Results

Mean age 30.3 years (range 5–58 years); 79% male. Racial demographics reflected the surrounding community. Seven mortalities occurred. Nineteen patients (54%) demonstrated facial nerve injury. Of those, 13/19 displayed immediate paralysis, 1 delayed, 5 unknown (due to altered mental status). On consultation, House‐Brackmann grade 6 paralysis was common (13/19). Fracture was otic capsule‐sparing in 17/19 (90%), universally comminuted, with significant disruption along the mastoid tip (16/19), external auditory canal (EAC) (15/19), and periauricular soft tissues (13/19). Nine patients underwent surgical intervention: Transmastoid facial nerve decompression to remove compressive bony spicules (n = 5); eye protection surgery (n = 3); and peripheral facial nerve exploration (n = 1), noting transection at the pes. One required middle cranial fossa and transmastoid repair of cerebrospinal fistulae in setting of severe meningitis. House‐Brackmann scores improved in 80% following transmastoid nerve decompression despite CT evidence of likely additional injury in its extratemporal course.

Conclusions

Common patterns of temporal bone fracture seen in blunt trauma (longitudinal/transverse, otic capsule‐sparing/disrupting) were not found in patients with ballistic facial nerve injury. Rather, injury was commonly apparent in the EAC, mastoid tip, and periauricular soft tissues. Clinicians should have high suspicion for extratemporal facial nerve injury following ballistic trauma.

Temporal Bone Fractures Caused by Ballistic Projectiles: A Systematic Review

OBJECTIVE

Ballistic injuries to the temporal bone are uncommon but devastating injuries that damage critical neurovascular structures. This review describes outcomes after ballistic injuries to the temporal bone and offers initiatives for standardized high-quality future research.

DATA SOURCES

A systematic search of PubMed, Embase, and Cochrane.

REVIEW METHODS

Studies in the review included adults who experienced temporal bone fractures due to gunshot wounds and survived longer than 48 hours. Individual case reports were excluded. The various searches returned 139 results, of which 6 met inclusion criteria.

RESULTS

Most of the included studies are case series with low-level evidence that report a wide range of outcomes and follow-up. Outcomes include demographic patient information, audiologic outcomes, vascular injuries, intracranial complications, facial nerve function, and surgical indications.

CONCLUSION

This review is the first to characterize the nature and progression of patients who experienced gunshot wounds to the temporal bone. Although all patients share an etiology of injury, they often have vastly different hospital courses and outcomes. This review provides a basis for future studies to guide care for these injuries, as most of the existing literature includes small dated case series.

Gunshot Wounds to the Facial Nerve

OBJECTIVE

This paper presents our experience with gunshot wounds to the temporal bone and discusses facial nerve lesions, surgical indication, surgical timing, and other findings.

STUDY DESIGN

We performed a retrospective review of patients treated for facial nerve lesion after gunshot injury to the temporal bone.

SETTING

The study was performed in the Otolaryngology Department of the University of Sao Paulo Medical School, Sao Paulo, Brazil.

PATIENTS

Ninety-eight patients treated between 1988 and 1999 were analyzed.

INTERVENTION

Facial nerve lesions, bullet locations, and surgical techniques were analyzed. Patients were monitored for 2 years.

RESULTS

Gunshot trauma to the temporal bone presented considerable tissue loss resulting from the abrasion effect and severity of the impact. The third segment of the facial nerve was most affected, and the bullet was typically found lodged in the mastoid tip. Postoperative infection was common. Such cases required revision surgery, resulting in worse cosmetic outcomes than in cases of closed trauma.

CONCLUSIONS

Surgical exploration of the facial nerve should be performed as soon as possible, since long delays increase the chance of traumatic neuroma and more pronounced scarring around the facial nerve. Open mastoidectomy with meatoplasty is the surgical technique recommended for repairing the mastoid and the facial nerve. In the majority of cases, a cable graft is necessary. Since nerve lesion in proximity to the stylomastoid foramen and extratemporal facial nerve is common, these areas must be explored carefully.

Craniofacial and skull base trauma

BACKGROUND

Traumatic craniofacial and skull base injuries require a multidisciplinary team approach. Trauma physicians must evaluate carefully, triage properly, and maintain a high index of suspicion to improve survival and enhance functional recovery. Frequently, craniofacial and skull base injuries are overlooked while treating more life-threatening injuries. Unnoticed complex craniofacial and skull base fractures, cerebrospinal fluid fistulae, and cranial nerve injuries can result in blindness, diplopia, deafness, facial paralysis, or meningitis. Early recognition of specific craniofacial and skull base injury patterns can lead to identification of associated injuries and allow for more rapid and appropriate management.

CONCLUSION

Early detection and treatment of craniofacial and skull base traumatic injuries should lead to decreased morbidity and mortality. This review discusses the most common of these injuries, their possible complications, and treatment.

Neurotologic Evaluation of Facial Nerve Paralysis Caused by Gunshot Wounds

Facial nerve injury is one of the most common neurotologic sequelae of a gunshot wound (GSW) to the head or neck. However, few neurotologic studies have been performed on the nature and time course of such facial nerve impairments. This study was designed to characterize the neurotologic manifestations and time course of facial nerve paralysis caused by GSWs to the head and neck.

We conducted a battery of electrodiagnostic tests on 10 patients who had experienced traumatic facial paralysis due to a GSW to the head or neck. The etiologies of facial nerve paralysis—including direct injury, compression, fracture, and concussion of the temporal bone—were demonstrated by audiologic, radiologic, and surgical findings. Hearing loss and other cranial nerve injuries were also seen. Six of the 10 patients experienced a complete paralysis of the facial nerve and a poor recovery of its function. We also present a comprehensive case report on 1 patient as a means of discussing the evaluation of facial nerve function during the course of management.

Acute intracranial complications of temporal bone trauma

Temporal bone trauma can be disastrous for the individual and his or her family. With the increase in violent crime throughout our society, the number of intracranial complications associated with temporal bone injury has increased significantly. Although multiple reports concerning the diagnosis and management of temporal bone trauma have been published, few studies on its intracranial complications have been addressed. In this study, we assessed the cases of 43 patients treated for temporal bone fractures between January 1992 and December 1994. The number of temporal bone fractures increased from 6 in 1992 to 21 in 1994. Twenty-one patients (49%) presented with decreased mental status. Significant alcohol and drug use was documented in 28% and 58% of patients, respectively. The most common radiologic finding was skull and intracranial injury. Thirty-six patients (84%) had at least one abnormal intracranial finding; of these patients, 14 (39%) had more than one abnormal finding on computed tomography. Cerebral midline shift, subarachnoid hemorrhage, subdural hemorrhage, and cerebral edema were the most common radiologic findings. Nineteen patients (44%) required an open neurosurgical procedure, and almost all patients with more than one abnormal radiologic finding underwent neurosurgery (86%). Seven patients required further institutional care after discharge. Four patients died (9% mortality); all the deaths were neurologically related. Mean hospital charges increased from $30,900 in 1992 to $63,000 in 1994.

Low velocity gunshot injuries to the temporal bone

OBJECTIVE

To review the presentation, symptoms and management associated with low velocity gunshot injuries to the temporal bone.

METHODS

A retrospective analysis of 26 patients treated for low velocity gunshot injuries to the temporal bone.

RESULTS

Initial presentation included otorrhoea (69 per cent), facial nerve injury (27 per cent), hearing loss (65 per cent), intracranial injuries (50 per cent), and cranial neuropathies (58 per cent). Nine patients (35 per cent) underwent angiography, which showed vascular injury in five of them. Four patients died.

CONCLUSIONS

Low velocity gunshot injuries can be devastating and may result in functional sequelae. Low velocity missiles crush and lacerate surrounding structures, while high velocity missiles cause extensive wound cavity formation. Early aggressive management for intracranial, vascular and facial nerve injury can improve outcome.