Early Treatment of Central Post-Stroke Pain Syndrome Hindered by Diagnostic Difficulty

Early Treatment of Central Post-Stroke Pain Syndrome Hindered by Diagnostic Difficulty

Early Treatment of Central Post-Stroke Pain Syndrome Hindered by Diagnostic DifficultyOf all of the challenges that face patients after a stroke, there’s one problem they don’t see coming—post-stroke pain. Post-stroke pain can be chronic and disabling beyond the effect of the stroke. It is responsible for greater cognitive and functional decline, and it’s a predictor of suicidality.

Early intervention significantly improves the odds of a better outcome, yet post-stroke pain is notorious for being unrecognized and underappreciated. When pharmacists reach out to stroke survivors, they offer hope of early diagnosis and treatment that prevents progressive deterioration.

Multiple Types of Post-Stroke Pain

The impact of post-stroke pain becomes clear when you realize that it occurs in half of all stroke patients, or about 333,000 people every year.1 In spite of being such a common problem, experts still believe post-stroke pain remains under-reported, in large part due to its complex clinical presentation.

For starters, the pain may be widespread or localized, but the time of onset is more confounding. It may appear immediately or within a few weeks, which suggests a clear connection to the stroke. Or, symptoms may not occur for many months or even years, and they’re not easily associated with stroke.

Central post-stroke pain is just one of five subtypes of post-stroke pain:2

  • CPSP – Accounts for more than one-third of all cases of post-stroke pain.
  • Spasticity-related pain – Nearly one-quarter of all stroke patients develop muscle spasticity within one week.
  • Musculoskeletal pain – Pain occurs in the shoulder due to subluxation and contractures; prevalent in 16 to 72 percent of stroke patients.
  • Complex regional pain syndrome – Estimated to occur in 2 to 49 percent of stroke patients; complex regional pain syndrome also involves edema, vasomotor changes and bone demineralization of an extremity.
  • Post-stroke headache – May occur in 10 percent of post-stroke patients; characterized as a tension-type headache.

The type of stroke often predicts the risk for developing post-stroke pain (PSP). Ischemic strokes, thalamic and brainstem strokes are more likely to cause PSP than hemorrhagic strokes.

Assessment and Early Detection of Central Post-Stroke Pain

Pharmacists are always important members of the healthcare team, but your intervention to help identify CPSP is vital because it often goes undiagnosed. You’re also positioned to catch the symptoms long before patients may think about consulting a doctor and early detection prevents decline in cognitive and behavioral functioning caused by CPSP.

A general knowledge of CPSP’s clinical characteristics can guide a quick assessment, but you should begin by evaluating the patient’s pain. Experts have stated that many post-stroke patients don’t disclose pain unless they’re specifically asked, which may be due to not associating bodily pain with a stroke.

When you ask about pain, remember that post-stroke patients are in various stages of rehabilitation—some will find it hard to express details about their symptoms. Since a pain scale specific for post-stroke pain has not been developed, you can use any of the pain assessment scales as reviewed in Pharmacy Times to facilitate communication.3

Key clinical characteristics:

  • Onset is variable but often within three to six months of stroke.
  • Pain often develops gradually.
  • Spontaneous appearance of dysesthesia is highly predictive for CPSP.

Risk factors for CPSP include:

  • Young age; young stroke patients have double the risk.
  • Previous depression.
  • Cigarette smoker.
  • Increased baseline stroke severity.
  • Thalamic stroke – represents about one-third of CPSP cases.

Types of pain found in CPSP:

  • Constant – pain is unrelenting and may be described as aching, burning, freezing and squeezing.
  • Spontaneous intermittent component – often lasts just a few hours.
  • Hyperalgesia and allodynia, especially allodynia to touch and mild temperatures and abnormal sensitivity to a pinprick.
  • Thalamic stroke may cause persistent paroxysmal pain, often on the hemiplegic side.

Treatment Options for Central Post-Stroke Pain

Don’t let a neat list of drugs fool you into thinking that treatment of CPSP is easy—it’s definitely not. Finding the best therapeutic regimen often requires trial and error because it must target varying degrees of psychological, central, peripheral and autonomic pathology. Multiple pharmacologic agents and nonpharmacologic options must be tailored to each person’s needs. The list of medications includes:

  • Tricyclic antidepressants Amitriptyline is the first-line choice for CPSP, but it may not be appropriate for older adults.4 Nortriptyline is less likely to cause adverse effects.
  • Anti-epileptics – Lamotrigine, gabapentin, pregabalin and carbamazepine are also considered for first-line treatment.
  • Analgesics – Patients should avoid NSAIDs and local anesthetics such as lidocaine, ketamine and botulinum toxin.
  • Opioids – Refractory cases may need opioids, but they’ve never been studied for their efficacy for CPSP.

Nonpharmacologic therapy. One good way to approach the topic of nonpharmacologic treatment is to create a handout that lists the options and includes professional resources in the area, such as physical therapists, rehabilitation facilities and mental health clinics. Be sure to include online resources such as the American Stroke Association, which provides several helpful articles about central pain syndrome.5 Some nonpharmacologic options include:

  • Neurostimulation – May improve pain in 50 to 77 percent of patients, but success is less likely in patients with peripheral neuropathic pain.
  • Physical activity – Encourage your patients to stay as active as possible to prevent loss of lean muscle mass. Structured physical therapy may be the best option, especially for older patients.
  • Tactile desensitization – Some patients will benefit from referral to an occupational therapist who can develop and implement a plan to alleviate tactile defensiveness.
  • Professional counseling – Be aware that patients with CPSP are at risk for anxiety and depression, and you may need to suggest consulting a social worker or psychologist, especially for patients who don’t know where to turn.

Pharmacists Provide Multiple Avenues of Support

Patients who already have a diagnosis of CPSP still need your support and expert advice. They may need a reminder about the nature of CPSP and how finding the best therapy requires trial and error. Then, they’ll need you to work with insurance providers to get their long-term and frequently changing medications approved. Though it’s a complex and difficult healing process, effective treatment must be achieved to improve their ability to live a productive life.

Pharmaceutica North America provides a variety of bulk APIs and prescription drug products that can help your patients with central post-stroke pain. Call us today to talk about how we can support all of your pharmaceutical needs.

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