Reports of nail gun injuries are rare; most unintentional injuries are non-fatal and occur in occupational settings. Patients with limited or concealed injuries and non-specific sequelae pose a challenge, with documented evidence of many initial presentations being misdiagnosed or not discovered. This case was clinically significant because the lead clinician had previously treated another patient several years earlier who had discharged multiple nails from a nail gun into his cranium. The patient was initially discharged from the emergency department with a diagnosis of cephalalgia but returned the following day to mental health services, where multiple traumatic injuries were identified. This case report was approved by the institutional review board (IRB No. NPS12022025), and the requirement for informed consent was waived.

Emergency medical services received an emergency call from a third-party reporting that an elderly patient had slurred speech, left-sided paralysis, and was unable to ambulate from his chair. A paramedic-staffed emergency ambulance was dispatched approximately 1 hour after receipt of the emergency call; the call was coded pursuant to the Advanced Medical Priority Dispatch System (AMPDS) coding as a 28C03 “Stroke/CVA with Speech Problems.” The ambulance arrived on scene within 15 minutes of dispatch, to find a male in his 70s who was sitting in his armchair with marked aphasia and a left-sided slump with inability to sit fully upright unaided. Observations were unremarkable. The patient had a Glasgow Coma Scale of 15 and was normotensive, with equal and reactive pupils. However, the Balance, Eyes, Face, Arms, Speech, Time (BEFAST) assessment was positive based on aphasia, left-sided motor weakness and an abnormal leftwards gait on ambulation. An approximate 15 mm purple hematoma with a 3 mm laceration was noted to the center of the patient’s sinciput, with no external hemorrhage present. The patient was questioned about this and as to any history of trauma, this is when he disclosed that he had attempted to commit suicide by discharging a nail gun into his forehead but reported that it had jammed and not fired. In an adjacent room was a layer of commercial plastic on a bed with small blood drops and a nail gun by the side of the bed.

The patient was extricated from the residence using a carry chair and was placed on the ambulance stretcher, basic analgesia was offered due to the patient reporting a headache, and 1 g of oral paracetamol was administered. The patient was transported to the closest hospital under emergency driving conditions. The closest hospital was also the regional major trauma center that had intensive care, neurosurgical and hyperacute stroke facilities. The patient reported that the onset time of his symptoms was over 2 and a half hours before the time of call, but he was not sure if the symptom onset time corresponded to when he attempted to discharge the nail gun. As the timeframe was over 4 and a half hours, the patient was not a candidate for hyperacute stroke treatment. The patient arrived at the major trauma center approximately 15 minutes after leaving scene. The paramedic immediately discussed the patient with the resuscitation coordinator and advised that the patient was hemodynamically stable and denied successful nail gun discharge. The paramedic however, had seen a similar incident where a patient had discharged multiple nails into his cranium with no neurological symptoms and therefore requested that the patient be triaged as an “immediate” or Manchester Triage Scale 1 patient and be seen in the resuscitation room, the medical staff were initially hesitant given the patient’s clinical presentation. An enhanced trauma call was not initiated as per local protocol, but the patient was taken immediately to computed tomography (CT) for imaging.

The patient was assessed by a Specialist Registrar in Emergency Medicine in the resuscitation bay and CT imaging was obtained and showed a 5-inch (approximately 12.7 cm) stainless steel nail, completely lodged in the center of the cerebral cortex on a sagittal plane. It is hypothesized that due to the patient’s advanced age the flange of the nail did not stop on the patient’s skull, rather, due to the force, fully penetrated into the cranium, leaving no external signs of the nail, as is commonly seen in similar cases. Neurosurgical consult was immediately sought, and the patient was discharged from the department of clinical neurosciences to his home address several days later with good prognosis and no ongoing neurological sequelae, conservative management was opted for with no surgical removal or exploration. Antibiotic therapy was used with intravenous vancomycin and metronidazole. The same paramedic who attended the initial event returned for an unrelated emergency call approximately a year later to find that the patient was still living independently in his home with no loss of neurological function or mobility.

Suicide attempt by nail gun discharge to the head is a rarely reported event in the literature that generally proves to not be fatal, unless the projectile has reached deep into the midbrain or the brainstem [1-3]. Most cases of fatal suicide by nail gun discharge are due to cardiac trauma with intraventricular penetration or penetration of large pulmonary vessels or the aorta [4]. This has been hypothesized to be due to the lack of rotational effect of the nail as it enters the human body, compared with projectiles from firearms. A nail from a nail gun generally has a diameter of 2–3 mm compared with a standard 9 mm bullet that has a diameter of 9 mm. The 9 mm bullet causes much greater destruction and also has a far more prominent rotation than the nail. The dangers of nail gun injuries are that if they are not detected in the acute phase, further pathology can develop such as infection, severe intracranial hemorrhage and further suicide attempts [3].

In conclusion, nail gun injury to the cranium will generally manifest with undifferentiated neurological sequelae and very minor external trauma with little or no hemorrhage. Some patients may even present largely asymptomatic with only a specific complaint such as a headache. Clinicians in emergency care must have a low threshold for imaging in patients who have the possibility of having nail gun trauma. Most commonly reported in the literature, including this case, is a patient with minor trauma at the site of entry and no significant neurological sequelae or deranged observations that either openly reports they have discharged the nail gun intentionally as a suicide attempt or patients reporting undifferentiated and vague symptoms such as “a bad headache.” Any patient who verbalizes an attempt to fire a nail gun into a central location of their body, with any signs of trauma or nonspecific neurological sequelae should be treated as a major trauma patient with hospital pre-notification, emergency transport to a major trauma center and request for a trauma team activation.