Denied Suicide Attempt: Penetrating Cranial Cerebral Injury with a Nail Gun

Abstract

Penetrating craniocerebral injuries with a nail gun are uncommon. In this article, we describe a highly unusual delayed presentation of a 49-year-old man after an initially unnoticed penetrating head injury with an air-powered nail gun. The nail was successfully surgically removed, and the postoperative course was uneventful. Further evaluation revealed that the penetrating craniocerebral nail gun injury was a suicide attempt and not an accident. Possible reasons for the initial unrecognition of the injury and denial of the suicide attempt were discussed.

Keywords

nail gun - head trauma - penetrating head injury

Introduction

Nail gun injuries have become more common over the past decades, but nail gun–related craniocerebral trauma occurs infrequently.[1] [2] Depending on the mechanism of how the nail is fired, the impact on the injury will differ significantly.[3] Although most nail gun–related head injuries are accidental, there have been occasional reports on suicide attempts.[1] [2]

Delayed recognition of a craniocerebral nail gun injury is most unusual.[4] There is no account on denial of a suicide attempt exerted with a nail gun to the head. Here we report on a nail gun–related craniocerebral trauma subsequent to an attempt of suicide diagnosed only with a delay, and analysis of the possible reasons for the initial denial of both the suicide attempt and the injury.

Case Report

A 49-year-old man presented with pain in the right jaw in the department of oral and maxillofacial surgery. An X-ray of the skull surprisingly showed a nail penetrating the right calvaria ([Fig. 1]). Consequently the patient was sent to us for further evaluation. Examination revealed a small scab in the right frontotemporal region ([Fig. 2]). Neurological examination revealed a barely noticeable central facial palsy on the left side. The self-employed roofer reported that he had worked on a roof 2 days earlier, using an air-powered nail gun while he suddenly slipped. He did not notice an injury. His history was remarkable for chronic alcohol abuse. He affirmed that the injury was not a result of an attempted suicide.

Fig. 1 X-ray of the scull and cranial computed tomography (coronal and axial projections) demonstrate the intracerebral trajectory of the nail penetrating the right calvaria. Computed tomography angiography reveals no vascular injury.

Fig. 2 The entry site at the right temple is shown. The 60-mm-long nail was removed via a small osteoplastic craniotomy.

Cranial computed tomography (CCT) and computed tomography angiography (CTA) showed a traumatic subarachnoid hemorrhage and a small right frontal lateral intracerebral hemorrhage at the entry site of the 60-mm-long nail with its tip lodged just below the anterior horn of right ventricle. No vascular injury was detected ([Fig. 1]).

The nail was removed surgically. Under general anesthesia the scalp and temporal muscle was incised above the nail entry site. Because the nail stuck firmly in the calvaria, a small concentric osteoplastic craniotomy was made. The bone flap was removed together with the embedded nail without any complications. Under hemostatic conditions the dural gap was closed with sutures. The nail was separated from the bone flap, which was reinserted and fixed with clamps ([Fig. 2]). Finally, the wound was closed in layers.

A postoperative CCT revealed no complication. The small intracerebral hemorrhage at the entry site was unchanged. Prophylactic treatment with antibiotics (cefazolin and clindamycin) was administered for 7 days. The postoperative course was complicated by focal motor seizures, and antiepileptic treatment with phenytoin was started. One week after surgery, upon psychiatric evaluation the patient indicated that the nail gun injury was not an accident but a suicide attempt because of family problems related to his chronic alcohol abuse.

The used nail gun was powered by a pneumatic mechanism (Paslode, Befestigungssysteme, Hemmingen, Germany) ([Fig. 3]). Recommended alcohol withdrawal therapy was refused. The further course during 3-year follow-up was unremarkable.

Fig. 3 Model of the pneumatic nail gun used by our patient.

Discussion

Nail gun–related traumas are increasingly registered along with the spread of nail guns. The number of consumer nail gun injuries nearly tripled between 1991 and 2005 in the United States.[2] According to estimates of the U.S. Centers for Disease Control and Prevention (CDC), nearly 37,000 people were treated in emergency departments in the United States from 2001 to 2005 for nail gun–related injuries.[5] Patients with nail gun injuries were mostly male and young.[5] Injuries to the upper extremities, primarily the fingers or hands, and to the lower extremities were the most common sites, but also injuries that involved other body areas such as the head or internal organs were reported. Serious injuries with fatalities occurred occasionally.[1] [2] [5]

Intracranial nail gun injuries represent less than 0.1% of nail gun injuries.[2] Penetrating head trauma secondary to nail gun injury may result in consecutive meningitis, cerebrospinal fluid leakage, seizures, pituitary insufficiency, and vascular injury.[1] [2] Despite crucial CT scans, intracranial nail gun injuries were often associated with good outcomes.[1] [2] More recently, however, catastrophic outcomes after nail gun injury with neurologic impairment or death were reported.[1] [2]

A recent comprehensive review summarized the findings of 40 craniocerebral injuries secondary to nail gun trauma.[2] The patient population was predominantly male (97.5%). Thirty-eight patients were adults and two were children. At the time of presentation, 20 (50%) patients had no focal deficit, 16 (40%) had a focal neurologic deficit, and 4 (10%) were comatose. At discharge or follow-up, 27 (67.5%) patients had no focal deficit, 10 (25%) had a focal neurologic deficit, and 3 (7.5%) died. In 17 (42.5%) patients, the injury resulted from intentional self-harm. Cranial nail gun injuries in the form of suicide attempts or associated with mental health problems have been seen also by other authors.[1] Winder et al[1] presented a series of 12 patients with nail gun head trauma over a period of 40 years in New Zealand.

The injury resulted from a suicide attempt in 75%, a psychiatric history was existent in 67%, and suicide was successful in 33%. Two of three patients who died after nail gun head trauma reviewed by Woodall et al[2] were using cartridge-activated nail guns. These nail guns produce higher velocities than pneumatic nail guns and are typically used for driving fasteners into concrete or metal. Air-powered nail guns are commonly used for woodworks. Cartridge-activated guns have a tissue injury mechanism, which is similar to that of conventional firearms.[3] Buchalter et al[3] reported that the kinetic energy (KE) of the projectile is proportional to the velocity of the projectile (KE = 1/2 mv[2]). Air-powered nail guns generate velocities approximately 105 ft/s. Conventional handguns and rifles generate velocities ranging between 300 and 2,200 ft/s. High-velocity projectiles have a different mechanism for damaging neural tissue. Because of the higher KE, they produce a cavity as they pass through the tissue, which can damage adjacent structures additionally to the pathway of the projectile. The lower kinetic energy explains why our patient with an air-powered nail gun injury did so well.

It is most unusual that our patient presented only 2 days after injury, and that initially he denied any injury at all. Only Lee and Oh[4] reported on a patient with a nail gun head injury and a delayed presentation 2 weeks after an initially incorrect diagnosed injury. The denial of the injury in our patient may have been associated with his chronic alcohol abuse. Another explanation could be that he would not have wanted to admit the failed suicide attempt to himself and to his family. Less likely, the injury might have caused neglect for the act of shooting the nail gun. The most possible feasible explanation, however, would be that the injury caused a retrograde amnesia for the event.

Conclusion

Craniocerebral penetrating nail gun injuries are seldom presented as suicide attempts. In our case the mixture of alcohol abuse, self-shame for failed suicide attempt, retrograde amnesia, and neglect led to a denied suicide attempt. It demonstrates that behind a craniocerebral nail gun injury, a hidden suicide attempt could exist. The brain damage depends on the mechanism of how the nail is fired and which brain structures are affected. Additionally, this influences prognosis and the spectrum of neurologic deficits.

Conflict of Interest

The authors declare that they have no conflict of interest.

Informed Patient Consent

The patient has consented for submission of this case report to the journal.

• References

• 1 Winder MJ, Monteith SJ, Lightfoot N, Mee E. Penetrating head injury from nailguns: a case series from New Zealand. J Clin Neurosci 2008; 15 (01) 18-25
• 2 Woodall MN, Alleyne Jr CH. Nail-gun head trauma: a comprehensive review of the literature. J Trauma Acute Care Surg 2012; 73 (04) 993-996
• 3 Buchalter GM, Johnson LP, Reichman MV, Jacobs J. Penetrating trauma to the head and neck from a nail gun: a unique mechanism of injury. Ear Nose Throat J 2002; 81 (11) 779-783
• 4 Lee AD, Oh YS. Unusual delayed presentation of a nail gun injury through the skull base. Laryngoscope 2007; 117 (06) 977-980
• 5 Centers for Disease Control and Prevention (CDC). Nail-gun injuries treated in emergency departments—United States, 2001–2005. MMWR Morb Mortal Wkly Rep 2007; 56 (14) 329-332