When you think of someone who has had a stroke, you probably imagine a person with hemiplegia, language difficulties, issues with mobility and maybe difficulty swallowing, but one of the last things you probably envision is pain.
Central post-stroke pain affects between 2-14% of stroke patients. It often isn’t recognised and when it is, it is generally difficult to manage (Greenwood et al. 2013; Kumar et al. 2009). It shouldn’t be confused with other feelings of pain that the individual may experience such as the headaches, spasticity pain and musculoskeletal pain that 70% of stroke victims experience every day (Harrison 2015).
If an individual develops a chronic pain syndrome following a stroke, they generally have an increased cognitive decline and higher levels of functional dependence than those who don’t. Although pain is known to be a potential consequence following a stroke, it continues to remain under-diagnosed and under-treated. This remains so even though effective pain management is proven to improve quality of life in all individuals who experience pain (Harrison 2015; O’Donnell et al. 2013).
Central post-stroke pain is more common in those who have experienced a stroke in the left hemisphere of the brain. The pain generally develops 3 to 6 months following the stroke but has also been found to develop immediately following the stroke or even years later. It also doesn’t just occur in stroke victims – it can occur along with diseases that cause damage to the central nervous system, such as multiple sclerosis, tumours and trauma.
It is caused by damage to the central nervous system but the exact cause of the pain remains unknown. Therefore, the difficulty in treatment of central post-stroke pain lies in our inability to know the exact cause of the pain. (Greenwood 2013; Mauk 2012; Mulla et al. 2015).
Symptoms of central post-stroke pain are neuropathic in nature and therefore patients describe sensations such as burning, tingling and shooting sensations of pain. This is where diagnosis of central post-stroke pain often becomes difficult. Generally the individual will be experiencing other types of pain in addition to the neuropathic pain, which can hinder diagnosis. There is also no clear diagnostic criteria for central post-stroke pain (Mauk 2012).
Treatment involves the use of multimodal analgesia, including pharmacological and non-phamacological interventions. It also involves attempting to avoid any aggravating factors of the pain such as movement, touch, cold and emotion (Greenwood 2013). The aim of treatment isn’t to completely eradicate the pain but to control the pain to a point where the individual can maintain an acceptable quality of life.
Medication-wise, opioids are generally ineffective in the pain management of central post-stroke pain. Pharmacological treatment tends to revolve around antidepressants and anticonvulsants, and every individual will have different results from these medications (Mulla et al. 2015). Non-pharmacological treatments are often included in the treatment plan and include psychological interventions, transcutaneous nerve stimulation and desensitisation techniques (Mauk 2012; Mulla et al. 2015).
Another common cause of pain in patients following a stoke can result from hemiplegia and it’s effects on the patient’s shoulders. This type of pain occurs in 5-84% of stroke victims. Hemiplegic shoulder pain syndrome can be quite detrimental for the individual as it can negatively affect upper extremity movement and motor skill function, and hinders the person’s recovery (Mauk 2012).
It can, however, be treated and managed with rehabilitation, which involves determining the exact cause of the pain and then the use of treatments such as splinting, slinging, range of motion exercises, anti-inflammatory medications or ice and heat (Mauk 2012).
Contracture of joints can also occur and be another painful condition for the individual recovering from a stroke. Contractures happen following a stroke when the muscle of an area and its supporting tendons contract. This shortens the tissues and makes them very resistant to stretching and flexing, hence decreasing range of motion in that area (Mauk 2012).
Prevention is the key with contractures. They can be avoided by ensuring correct anatomical positions of limbs are used as well as regular range of motion exercises with the limb being performed. Once a contracture occurs, treatment involves splinting or casting to help move the joint into a more anatomical and comfortable position (Mauk 2012).
Spasticity can be common after a stroke with about 25% of patients experiencing some form of increase in muscle tone following the event. Spasticity generally develops after an upper motor neuron injury and is a velocity dependent increase in tone in resistance to muscle stretch (Francisco & McGuire 2012; Harrison 2015). Not only can it cause pain to the individual, it also affects the person’s mobility and level of function.
The relationship between pain and spasticity is not totally understood but it is thought to involve both neuropathic and nociceptive mechanisms (Harrison 2015). The goal of treatment is to reduce reflex activity that will then help to reduce muscle tone (Francisco & McGuire 2012). This can be done with oral medications such as antispastic medications, nerve blocks, botulinum neurotoxins, intrathecal baclofen therapy, or surgical interventions such as tendon lengthening (Francisco & McGuire 2012). Management should not only be based on the impact which it will have on the individuals function but also on their degree of difficulty with muscle stretch and range of motion (Francisoc & McGuire 2012).
Chronic headaches following stroke occur in approximately 10% of stroke victims. There is little literature discussing this pain syndrome so further studies are needed. However, it has been found that if a headache occurs for the individual during the stroke onset or the individual has a history of tension headaches, then they are more likely to experience post-stroke headaches (Harrison 2015).
Post-stroke headaches are often described as having a pressing quality and similar to a tension headache but are not aggravated by movement. The cause of post-stroke headaches is not known however they are thought to occur as a result of either the brain injury, alterations to blood vessels, inflammation or disruption to the pain pathway (Harrison 2015).
Not only does pain decrease the quality of life for individuals, it is also associated with depression, cognitive and functional decline, and fatigue. Effective treatment of pain improves quality of life and cognition and has also been found to reverse any pain-related cognitive impairment (Harrison 2015). This is why effective pain management is so important.
Pain occurring following a stroke can also have significant effects on the individual’s level of function and their recovery. It can decrease range of motion of limbs and joints and impair motor function. This then hinders recovery when then has more negative impacts on quality of life for the individual. Therefore, prompt identification and management of pain is essential in the individual following a stroke to ensure their successful recovery.