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Abstract
Four patients with intracranial penetrating injuries from screwdrivers are presented. Two cases were fatal; the others were left with functional deficits. In two of the patients a penetrating injury was not suspected initially because the history was limited and the significance of the small entry wounds were not appreciated. Unless these wounds are carefully examined a penetrating injury is easily overlooked.
- skull injury
- brain injury
- penetrating wound
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Screwdrivers are fortunately only rarely used as weapons. However, when used in an assault on the head the concentration of force into the small area at the tip of these rigid tools may enable penetration into the vault of the skull. Once through the bone the shaft of the screwdriver may then pivot around the entry point in the skull, causing an arc of intracranial injury. If the screwdriver is withdrawn, then clinical examination later may miss the small entry wound, and the seriousness of the injury may not be appreciated as intracranial injuries from screwdrivers have a high mortality rate.1–3
These four patients who were referred to a regional neurosurgical centre illustrate both the seriousness of this penetrating injury and how easily it can be missed.
Case reports
CASE 1
A 26 year old man presented to his local accident and emergency (A&E) department after an assault with a screwdriver. Initially he was thought to be intoxicated and the only apparent injury from the screwdriver was a small laceration of his left pinna. He was discharged home, but returned the next day with a headache, increasing confusion, vomiting and a dense right hemiplegia. Computed tomography showed intracranial haemorrhage within the left parietal lobe and extending into the lateral ventricles. This intracranial injury lay directly beneath the site of the laceration to the pinna. He was transferred to the regional neurosurgical unit, where he was managed conservatively. There was gradual resolution of his right hemiplegia and mild dysphasia. He was transferred to a rehabilitation unit 17 days after admission.
CASE 2
A 26 year old man was brought by ambulance to A&E after an assault in the street. Although he had blood over the left side of his head no wound was noticed. He smelled strongly of alcohol. He was mildly confused, with a Glasgow Coma Score of 14/15, and was reluctant to speak. He was initially observed to allow him to “sober up” and it was not until several hours later, when he had not improved, that closer examination revealed a 1 cm laceration and slight swelling in the left parietal region. No other injury was noted. Skull radiographs showed a depressed skull fracture and subsequent computed tomography showed a large intracerebral haematoma in the left frontal lobe with an overlying skull vault fracture (fig 1). He was admitted to the neurosurgical unit before transfer for rehabilitation.
(A) Computed tomography showing left frontal intracerebral haematoma and skull vault fracture with (B) corresponding plain skull radiograph showing a depressed skull fracture.
CASE 3
A 26 year old man was reported to have been assaulted with a sharpened screwdriver. At presentation he had a GCS of 4/15, a fixed dilated left pupil and was bleeding from a point just anterior to the left ear. Computed tomography demonstrated a small depressed fracture 4 mm in diameter above the floor of the left temporal fossa with an acute left sided subdural haemorrhage and a small contusion within the brainstem. He underwent craniotomy to evacuate the subdural haemorrhage but despite aggressive management died two days after surgery.
CASE 4
A 17 year old man was assaulted with a screwdriver and brought to A&E with the screwdriver still embedded in the left parietal region of his head. On arrival his GCS was 3/15, he was maintaining an adequate circulation but required mechanical ventilation. His pupils were fixed and dilated with no “dolls eyes” movement. Skull radiography and compted tomography showed the tip of the screwdriver to be within the brain stem. He subsequently underwent formal brain stem testing and was pronounced dead.
Discussion
The few penetrating intracranial injuries seen in the UK are predominately gun shot wounds. Occasionally more unusual weapons have been used to penetrate the cranium including nails, wooden objects, and drills.4–6 The commonly used weapons such as knives and broken bottles rarely penetrate the skull, and are more likely to glance off the cranial surface or break. However screwdrivers, because of their rigid structure and narrow tip, may forcefully penetrate the cranial bone.
If the screwdriver is not still embedded then the external injury may appear insignificant. Unlike cranial stab wounds when the damage is usually limited to a focal area along the tract,7 being a tool with a narrow diameter the intracranial injury can be extensive from pivoting of the tip of the screwdriver within the brain substance.
These cases are a reminder of the importance of cleaning blood from the scalp in patients with head injuries to assess any underlying wounds. The possibility of a penetrating injury can then be considered. The first two cases are also a reminder of the need for a high index of suspicion in intoxicated head injured patients in whom the diagnosis of intracranial injuries is often delayed.
In patients where there is a possibility of a penetrating intracranial injury, skull radiographs and subsequent computed tomography are indicated. As compound wounds these injuries require appropriate antibiotic cover and tetanus prophylaxis. Further neurosurgical assessment will determine whether formal debridement and removal of haematoma and devitalised tissue or depressed bony fragments is indicated.8
Acknowledgments
Contributors
Matthew Tutton initiated and coordinated the data collection, reviewed the literature, and participated in the analysis and writing of the paper. Bhupal Chitnavis initiated and participated in data collection, analysis and writing of the paper. Ian Stell initiated and participated in data collection, analysis and editing of the paper. Matthew Tutton and Bhupal Chitnavis will act as guarantors.
Footnotes
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Funding: none.
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Conflicts of interest: none.