A Taser, a brand name for a conducted energy weapon (CEW), temporarily incapacitates a person through a high-voltage, low-amperage electrical current. It functions by overriding the body’s voluntary muscle control, allowing law enforcement personnel to subdue a subject from a distance. The application of this force to the head region introduces severe risks, given the brain’s delicate structure and its function as the body’s central control system. Understanding the biological and medical consequences of a CEW discharge to the head involves analyzing both the direct electrical effects and the resulting physical trauma. This requires a detailed look at the complex cascade of events that occur when the electrical current is applied near or directly to the skull.
The Mechanism of Electroshock Injury
A conducted energy weapon primarily achieves its effect through neuromuscular incapacitation (NMI), which is the involuntary contraction of skeletal muscles. The device delivers a series of electrical pulses that mimic the signals normally sent from the central nervous system to the muscles, effectively scrambling the body’s communication system. These pulses typically involve a high peak voltage, sometimes reaching 50,000 volts, delivered at a low average current, often around 2 milliamperes. The current’s ability to cause damage is directly related to its density and the duration of contact with the tissue.
The electrical discharge overrides the motor nervous system, causing uncontrollable muscle spasms that render the person unable to perform coordinated movement. This temporary loss of control happens because the current stimulates the peripheral motor nerves, leading to massive, involuntary muscle contraction. The danger is amplified when the current’s path involves critical structures, as the current density can be extremely high at the point of dart penetration. Proximity to the skull introduces an immediate threat to the central nervous system itself.
Immediate Neurological Response and Incapacitation
When a CEW is discharged with probes impacting the head or neck, the electrical current is introduced close to the brain, which operates on its own precise electrical signaling system. This direct electrical interference can cause a disruption of normal brain activity, sometimes manifesting as a generalized tonic-clonic seizure. Such a seizure, involving loss of consciousness and full-body convulsions, has been documented in case reports following a Taser shot to the occiput. The mechanism is similar to that of electroconvulsive therapy, where a calculated electrical charge is used to induce a seizure.
Taser exposure has been shown to cause transient, short-term cognitive impairment, even when applied to the body. Studies have indicated that the electrical shock can lead to a measurable decline in verbal learning, memory, and processing speed. While these effects often resolve within an hour, the severity of the temporary disruption can place a person within the range of mild cognitive impairment. The massive neural interference from a head application may also lead to an immediate loss of consciousness.
The flow of electrical current through the head carries the potential for massive functional disruption, particularly if the current path involves the brainstem. The brainstem controls basic, non-voluntary functions, including breathing and heart rate, making it vulnerable to electrical interference. The current path is unpredictable, and high current density near the central nervous system presents an immediate threat to these vital functions.
Direct Physical Trauma and Secondary Injuries
The application of a conducted energy weapon to the head creates two categories of physical injury: direct injuries from the device components and secondary injuries from the resulting fall. Direct probe injuries occur when the weapon’s barbed darts penetrate the skin, which can be particularly sensitive around the face, eyes, and thin bone structures of the skull. In severe cases, a dart can penetrate the skull, leading to intracranial penetration and requiring emergency procedures. Injury to the eyes is a significant risk, potentially resulting in loss of vision.
Electrical burns can also occur at the entry points of the probes, especially if they are placed close together or if the electrical contact is prolonged. These are typically localized, superficial burns, but the resulting skin damage requires medical attention.
The most dangerous physical injury associated with a CEW shot to the head is the secondary trauma resulting from an uncontrolled fall. Neuromuscular incapacitation causes the body to collapse suddenly and violently from a standing height without the ability to brace or protect the head. This uncontrolled impact with a hard surface presents a high risk of severe blunt force trauma to the head. Secondary injuries can include concussions, skull fractures, and intracranial hemorrhages (brain bleeds), some of which have proven fatal. The inability to dampen the fall transforms the initial electrical event into a high-impact mechanical trauma.
Potential for Permanent Neurological Damage
The long-term consequences of a Taser shot to the head stem from both the direct electrical insult and the profound secondary impact trauma. Traumatic brain injury (TBI) is a major concern, often manifesting as a post-concussion syndrome. Individuals may experience persistent symptoms such as chronic headaches, dizziness, irritability, and difficulties with concentration and memory long after the initial event. Neurological assessments in some cases have led to a diagnosis of mild TBI, linking the lasting symptoms to the impact of the dart or the fall.
The direct electrical stimulation of the brain, or the resulting TBI, can also create a risk for developing post-traumatic epilepsy. While the immediate seizure may be provoked and non-recurrent, any significant trauma to the brain tissue raises the possibility of seizure disorders emerging months or years later. Penetrating injuries, such as a dart causing intracranial penetration, carry a particularly high risk for subsequent neurological deficits. In addition to seizures, there is a risk of permanent cognitive impairment or functional deficits, such as long-term motor control issues, depending on the severity of the damage to specific brain regions.
Determining the precise long-term effects of a CEW applied to the head is complicated by the high-risk nature of the event, which limits ethical scientific study. However, the potential for lasting damage is clear, arising from the possibility of direct tissue destruction or stroke due to the electrical current, or the profound and lasting effects of a severe blunt force head injury. The cascade of injury—from electrical shock to uncontrolled fall to TBI—underscores the potential for chronic and debilitating conditions.