Understanding Chronic Pain after Stroke
Surviving a stroke often means adapting to physical and emotional changes that can last the rest of your life. Many patients develop chronic pain syndromes after suffering from a stroke. But one type of pain is often undertreated or misdiagnosed: central poststroke pain (CPSP) syndrome.
Poststroke pain can take several forms. Some patients develop peripheral neuropathic pain, a type of nerve sensitivity that causes muscle aches; painful cramps; and other symptoms. Spasticity, or stiff and rigid muscles, is common, too, and most often results in shoulder pain. Other people suffer from headaches or musculoskeletal pain.
But CPSP is differentand harder to treat. CPSP, also known as thalamic syndrome or thalamic pain syndrome, is a neurological disorder that develops when the central nervous systemthe brain and spinal cordis damaged. It can occur when a stroke injures the thalamus or parietal lobethe parts of the brain that process sensory stimuli like heat, cold and touch. As a result, sensory neurons in these areas of the brain misfire, so the brain no longer responds properly and registers all stimuli as pain. This malfunction leads to chronic, and sometimes disabling, pain.
Ischemic strokes, in which blood flow to the brain is obstructed, are a common type of stroke that can cause central pain, while strokes brought on by ruptured blood vessels in the brain (known as hemorrhagic strokes) are less common than ischemic stokes but carry a higher risk of triggering CPSP. About 8 percent of people who have a stroke develop CPSP, according to a recent review article in the March 2013 issue of Topics in Stroke Rehabilitation, which takes an in-depth look at current CPSP diagnosis and treatment practices.
A mix of sensations
People who have CPSP sometimes describe the pain as a burning or "pins-and-needles" sensation. The pain can be widespread or focused on a specific body part, such as the hands or feet. Pain can be persistent or intermittent. Some people experience spontaneous stabbing or searing sensations that can be intolerable.
Others feel a loss of sensation in the area affected. Touch, movement, stress and temperature changes can all worsen pain. Patients may also develop a condition called allodynia, which makes the body ultrasensitive to normal touch and other physical contact.
CPSP can start immediately after a stroke but usually doesn't emerge until weeks, months or sometimes years later. According to a study cited in the review article, roughly two-thirds of patients who developed CPSP first noticed the symptoms within one month; the remaining patients said their pain didn't begin until six months to a year after their strokes. In some cases, CPSP took up to 18 months to emerge.
Doctors unfamiliar with CPSP may not at first link new pain to the past stroke because of the time lag before symptoms appear. CPSP symptoms also resemble those of other pain syndromes, and sometimes patients have more than one type of poststroke pain, making it more difficult to achieve an accurate diagnosis.
CPSP is often misdiagnosed as a musculoskeletal condition. Getting CPSP under control requires an accurate diagnosis and proper treatment plan.
A Doctor's Viewpoint
Richard Leigh, MD, Assistant Professor, Neurology, Johns Hopkins Hospital
Central poststroke pain syndrome can strike a patient at a time when he or she is already struggling to adjust to new neurologic deficits. Along with poststroke depression and poststroke insomnia, CPSP can prevent a patient from getting the rehabilitation therapy they need to recover. Recognition of this condition is key because there are a variety of medical therapies that may be effective. It is important to recognize that this is a potentially chronic pain syndrome and to avoid treatment with narcotic medications, which can lead to dependence.
Source: Prepared by the Editors of The Johns Hopkins Medical Letter: Health After 50