Quadriplegic spasms are involuntary muscle contractions that happen below the level of a spinal cord injury. These movements can range from small twitches to powerful and sometimes painful jerking of the limbs. They arise not from the muscles themselves, but from changes in the nervous system following the injury. Understanding these spasms is the first step toward managing them effectively.
The Neurological Basis of Spasms
After a spinal cord injury, the flow of information between the brain and the body is disrupted. The brain sends signals that both initiate and inhibit movement. When the spinal cord is damaged, these calming, inhibitory messages from the brain can no longer get through to regulate the spinal cord’s natural reflex pathways.
Without the brain’s regulation, the spinal cord’s reflex circuits become hyperexcitable. This means that normal sensory information, like the touch of clothing or a slight muscle stretch, can trigger an exaggerated response. The local nerves in the spinal cord react excessively, causing muscles to contract suddenly. This condition is often referred to as spasticity.
Think of it like a radio where the volume control is broken and stuck on high. The radio (the spinal cord) still receives signals from the antenna (sensory nerves), but it can’t regulate the output. As a result, even a weak station comes through as a blast of sound. Similarly, the spinal cord below the injury over-amplifies incoming sensory information, resulting in powerful spasms.
This development of spasticity is not immediate. Following a spinal cord injury, there is often a period where muscles are flaccid, or without response. Spasms begin to emerge around six weeks after the initial injury as the nervous system reorganizes itself without the brain’s top-down control. The severity and frequency of these spasms can vary greatly.
Common Triggers for Spasms
While the cause of spasms is neurological, specific events can set them off. These triggers can be internal or external and are important to identify for daily management. A frequent internal trigger originates from the urinary system, where a full bladder, a urinary tract infection (UTI), or bladder stones can provoke spasms. Similarly, issues with the bowel, such as constipation or hemorrhoids, can act as powerful irritants.
External stimuli are also common culprits. Any form of skin irritation can initiate a spastic reflex, including pressure sores, an ingrown toenail, a burn, or tight clothing. Because sensation may be altered, a sudden increase in spasms can sometimes be the first sign of such a skin issue.
Movement and changes in body position are also well-known triggers. Activities like stretching, being moved for transfers, or sudden shifts in posture can activate the stretch reflex in muscles, leading to spasms. Other factors like illness, fever, or significant changes in temperature can heighten the sensitivity of the nervous system and make spasms more frequent.
A sudden change in the pattern or severity of spasms, especially if it appears more than a year after the injury, might signal a more serious issue. One such condition could be the development of a syrinx, which is a fluid-filled cavity within the spinal cord. In these cases, it is important to seek a medical evaluation.
Potential Benefits and Drawbacks of Spasms
Spasms can be painful, disrupt sleep, and make daily activities like getting dressed or transferring from a bed to a wheelchair difficult and unsafe. Severe spasms can cause falls from a wheelchair or lead to joint contractures, where muscles become permanently shortened. The unpredictable nature of spasms can also lead to social embarrassment or anxiety.
However, not all aspects of spasticity are detrimental. For some individuals, mild to moderate spasms can offer advantages. The involuntary muscle contractions can help maintain some muscle tone and mass. This muscle activity can also improve blood circulation and may contribute to maintaining bone density.
Functionally, some people learn to use their spasms to their advantage. For instance, extensor spasms in the legs can help provide stability for standing or during transfers. A spasm that causes the fingers to bend can sometimes be used to help grip an object. A noticeable increase in spasms can also serve as a valuable indicator of an underlying health problem that might not be felt, such as an infection or a skin sore.
Management and Treatment Approaches
Managing spasms often involves daily physical strategies. Regular stretching routines help maintain muscle length and flexibility, which can reduce the frequency and severity of spasms. Proper positioning in a wheelchair or bed is also a component; ensuring the body is well-supported can prevent muscle shortening or skin irritation that triggers spasticity. Weight-bearing activities, often performed with a standing frame, can also be beneficial.
When physical strategies are not enough, medical treatments are available. Oral medications are a common first line of defense. Drugs like Baclofen and Tizanidine are frequently prescribed to reduce generalized spasticity. For spasms concentrated in specific muscle groups, targeted injections of Botulinum toxin (Botox) can be effective, providing temporary relief for several months.
In cases of severe spasticity that doesn’t respond well to other treatments, surgical options may be considered. One of the most effective is the intrathecal baclofen pump. This involves surgically implanting a small pump in the abdomen that delivers baclofen directly to the spinal fluid. This method allows for a much lower dose of the medication, minimizing side effects like drowsiness while providing more potent relief. Another, less common surgical procedure is a selective dorsal rhizotomy, which involves cutting specific nerve roots to reduce spasticity.