Quadriplegia, also known as tetraplegia, is paralysis resulting from a spinal cord injury (SCI) in the neck region, affecting all four limbs and the torso. This condition involves the loss of motor function and/or sensation below the injury site. While the primary symptom is loss of movement, the answer to whether a person with quadriplegia can still feel touch is not a simple yes or no. The experience of sensation after an SCI is highly individual and depends entirely on the specific nature and severity of the spinal cord damage.
Motor vs. Sensory Pathways
The spinal cord contains distinct bundles of nerve fibers, called tracts, that carry information to and from the brain. Motor signals, which control voluntary muscle movement, travel down the spinal cord through descending tracts, primarily the corticospinal tract. Damage to this tract causes the paralysis characteristic of quadriplegia.
Sensory information, including touch, temperature, and pain, travels up the spinal cord through ascending tracts. Fine touch and proprioception (the sense of where the body is in space) are carried by the dorsal column system. Crude touch, pain, and temperature sensations travel through the spinothalamic tract, located on the side and front of the spinal cord.
Because these motor and sensory pathways are physically separated, an injury may affect one set of tracts more severely than the other. It is possible for motor tracts to be fully damaged, leading to complete paralysis, while some sensory tracts remain partially intact. This allows certain feelings to register even if the ability to move is lost.
Understanding Incomplete Injuries
The possibility of retained sensation is linked to whether the spinal cord injury is classified as complete or incomplete. A complete injury (ASIA Impairment Scale [AIS] Grade A) means there is a total loss of all motor and sensory function below the neurological level of injury, including the lowest sacral segments.
An incomplete SCI indicates that some neural connection has been spared across the injury site. Incomplete injuries are categorized as AIS Grades B, C, or D. For example, a person classified as AIS Grade B has no motor function below the injury level, yet retains some sensation, such as light touch or pinprick, extending to the sacral segments.
The preservation of sensation in the sacral segments, known as sacral sparing, indicates an incomplete injury. For individuals with incomplete quadriplegia, the retained feeling is often patchy and not uniform across the body. Even if touch is perceived, it may be weak, altered, or only present in isolated areas.
Altered Feeling and Neuropathic Pain
The sensation experienced by individuals with SCI is often not normal light touch but rather an altered or uncomfortable feeling. These abnormal sensations stem from nerve damage, where irritated nerve fibers misfire and send distorted signals to the brain.
One common altered sensation is paresthesia, described as a tingling, prickling, or “pins and needles” feeling. Another is dysesthesia, which involves unpleasant or painful feelings that occur spontaneously or are triggered by non-painful stimuli. This can manifest as burning, electric shock, or painful tightness below the level of injury.
These chronic feelings are a form of neuropathic pain, which develops in over half of all SCI patients. Neuropathic pain is a direct consequence of the damaged central nervous system misinterpreting sensory input. While some quadriplegics with incomplete injuries register normal touch, many experience these challenging, painful sensations instead.