Central Pain Syndrome

Overview

Central pain syndrome is a neurological disorder caused by damage to the sensory pathways of the central nervous system (CNS). Common symptoms include pain (but also pruritus) and loss of sensation, usually in the face, arms and/or legs. Pain is often constant (but can be intermittent) and can be mild, moderate, or severe in intensity. Affected individuals may become hypersensitive to painful stimuli. The specific type of pain experience can vary from one individual to another based, in part, upon the underlying cause of the disorder and the area of the central nervous system affected. Central pain syndrome can potentially disrupt an individual’s daily routine. In severe cases, the pain can be agonizing and unrelenting and dramatically affect a person’s quality of life. Central pain syndrome can develop following a variety of conditions including stroke, multiple sclerosis, spinal cord injury, brain tumors, or iatrogenic damage to the central nervous system.

Signs & Symptoms

The onset of central pain syndrome can vary from days to weeks to months or more than a year after injury to the central nervous system. However, the disorder can also appear immediately after an injury or within a day. In most cases, central pain syndrome remains a lifelong condition.

Central pain syndrome can be limited to a specific area of the body such as the hands or feet or may be widespread over a large portion of the body. Some areas of the body may be more intensely affected than other areas. Pain can fluctuate during the day and can be affected by several factors including touch, emotions such as stress, certain movements or overall level of activity, and temperature changes, especially cold temperatures. Rest and distraction may lessen symptoms.

Central pain syndrome can vary greatly from one individual to another, in part, based upon the underlying cause of the condition. In some cases, symptoms of central pain syndrome can be vague and difficult to characterize. Many different pain sensations including burning, stabbing, lacerating, pressing, aching, prickling or tingling (a feeling of being on “pins and needles”) may occur. A constant burning sensation is in several cases the most prominent symptom. Pain can be constant and unrelenting or it may come and go (intermittent). In most cases, pain is constant and usually moderate or severe in intensity. In some cases, pain has been described as agonizing. Some affected individuals may experience short bursts of sharp, excruciating pain, which has been compared to the pain that occurs when a dental probe strikes an exposed nerve. In some cases, the constant pain associated with central pain syndrome can be debilitating and affect an individual’s ability to perform daily tasks and significantly impair quality of life.

Pain sensations associated with central pain syndrome are generally spontaneous, which means they occur despite no apparent cause or trigger. People with this disorder may be extra-sensitive or have a heightened response to acute painful stimuli (hyperalgesia, hyperpathia), which means that pain that would normally be small or minimal is felt to a far greater degree. In addition, individuals may feel pain from stimuli that would normally not be painful (allodynia). For example, affected individuals may experience pain when touched, even when lightly touched. In severe cases, this can include pain caused by a strong breeze, the weight of a blanket, or even the clothes a person is wearing.

Causes

The disorder develops following damage to the central nervous system – the brain, brainstem or spinal cord. Such damage is most often associated with a stroke, multiple sclerosis, spinal cord (but also brain) injury or brain tumors. Central pain syndrome can also develop after neurosurgical procedures involving the brain or spine.

Central pain syndrome results from damage to the pain-transmission pathway from the level of the spinal cord up to the cortex, the grey matter that covers the cerebral hemispheres.

Central pain syndrome is due to a disturbed communication between the sensory thalamus and the sensory cortex. The thalamus is a structure deep in the brain that acts as the key hub in sensory processing, in synchrony with the cortex. When this synchrony is disturbed by neural damage that unbalances the brain’s inhibitory tone, the cortex and some thalamic nuclei are “locked” together in an altered state of activity. CPS is thus due to a dysfunctional corticothalamic loop along the sensory pain-conducting pathways.

Affected populations

Central pain syndrome is estimated to affect several million people worldwide. Approximately, 5-10% of individuals who suffer a stroke, 20-40% of spinal cord injury patients, almost 30% of patients suffering multiple sclerosis and an uncertain number with other conditions develop central pain.

Diagnosis

A diagnosis of central pain syndrome is based upon identification of characteristic symptoms, a detailed patient history, a thorough clinical evaluation and a variety of specialized tests. Central pain syndrome is suspected in individuals who complain of pain or other abnormal sensations following injury to the central nervous system. Other conditions that cause pain may need to be excluded before a diagnosis of central pain syndrome is made.

Treatment

Treatment for central pain syndrome remains unsatisfactory in that, although most patients find some relief, complete control remains infrequent. Additionally, therapies that have proven beneficial in some individuals may have no benefit in others.

Traditional pain medications (e.g. NSAIDs) generally provide little to no relief for individuals with central pain syndrome. However, drug therapy remains the first-line therapy for most affected individuals. Two drugs, amitriptyline and lamotrigine, have proven beneficial in controlled trials, especially for individuals with central pain of brain origin. Amitriptyline is an antidepressant. Lamotrigine is an anti-seizure drug (anticonvulsant). Antiarrhythmics (mexiletine) and local anesthetics such as lidocaine can be effective.

Gabapentinoids, another type of anti-seizure medication, although FDA approved for central pain, are not indicated as first line therapy for central pain: close, conflict-of-interest-free, scrutiny of the entire database (including unpublished studies) reveals that these drugs are poorly effective in the vast majority of patients, only infrequently affording meaningful benefit. Although FDA approved for chronic pain, unbiased assessment of the entire database shows that use of ziconotide has a very low therapeutic index with lack of consistent benefit in a majority of patients. Opioids such as morphine or levorphanol are not effective in the vast majority of cases and are actually contraindicated for most patients.

In several cases, the effectiveness of drug therapies are limited due to associated side effects.

Recent developments point to alternative/complementary therapies that can be added to drug therapy. Of special interest is virtual-reality-assisted hypnosis. Supportive care, rehabilitation, and psychotherapy are recommended as well.

What is the prognosis (outlook) for central pain syndrome?

Central pain syndrome is not a fatal disorder, but the syndrome causes disabling chronic pain and suffering among the majority of individuals who have it.

Does central pain syndrome ever go away?

In most cases, central pain syndrome remains a lifelong condition. Central pain syndrome can be limited to a specific area of the body such as the hands or feet or may be widespread over a large portion of the body. Some areas of the body may be more intensely affected than other areas.

What is central pain syndrome also known as?

Central pain is often referred to as neuropathic pain, which has localized to the central nervous system. [1] Historically, central pain syndrome was a psychiatric diagnosis seen following a traumatic brain injury or thought to be a diagnosis of exclusion.

How do you test for central pain syndrome?

Central pain is diagnosed by:

1.A thorough medical history.

2.Physical examination.

3.Imaging studies, such as MRI scans, to locate the region of damage to the nervous system.

Can pain syndrome be cured?

There's no known cure for complex regional pain syndrome (CRPS), but a combination of physical treatments, medicine and psychological support can help manage the symptoms. It's estimated around 85% of people with CRPS slowly experience a reduction in their pain and some of their symptoms in the first 2 years.

Does exercise help Central pain syndrome?

Individuals suffering from chronic pain can enjoy a number of benefits of physical activity and exercise. Physical activity reduces chronic pain by building muscle strength and flexibility, reducing fatigue, reducing pain sensitivity, and reducing inflammation.

Who treats central pain syndrome?

A neurologist is a doctor who specializes in disorders of the nervous system, including the brain, spinal cord, and nerves. They're usually skilled in treating chronic pain. You may have to see several neurologists before deciding which one can help you manage your pain.

1.    Types of doctor department :-neurologist is a doctor who specializes in disorders of the nervous system