How common is Pain Associated with Neurological Conditions?

Johnson MI

doi:10.4172/2324-903X.1000e107

Editorial, Analg Resusc Curr Res Vol: 6 Issue: 1

How common is Pain Associated with Neurological Conditions?

Johnson MI^*

Centre for Pain Research, School of Clinical and Applied Sciences, Leeds Beckett University City Campus, Leeds LS1 3HE, United Kingdom

*Corresponding Author : Johnson MI
Centre for Pain Research, School of Clinical and Applied Sciences, Leeds Beckett University City Campus, Leeds LS1 3HE, United Kingdom
Tel: +44 113 2832600
E-mail: m.johnson@leedsbeckett.ac.uk

Received: January 10, 2017 Accepted: January 18, 2017 Published: January 25, 2017

Citation: Johnson MI (2017) How common is Pain Associated with Neurological Conditions? Analg Resusc: Curr Res 6:1. doi:10.4172/2324-903X.1000e107

Abstract

Neurological conditions are associated with pain, anxiety and depression which are known to diminish the quality of life. Guidelines for the treatment of specific neurological conditions often give little consideration to pain. This may be because pain is not as visible as functional impairment and treatment tends to focus on curing or slowing disease progression and improving functional outcome.

Keywords: Neurological conditions, Pain, Chronic pain, Musculoskeletal pain

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Editorial

Neurological conditions are associated with pain, anxiety and depression which are known to diminish the quality of life. Guidelines for the treatment of specific neurological conditions often give little consideration to pain. This may be because pain is not as visible as functional impairment and treatment tends to focus on curing or slowing disease progression and improving functional outcome. In 2013, Calvert et al. [1] conducted a survey of 266 people with various neurological conditions including motor neurone disease, Huntington’s disease, cerebellar ataxia and multiple system atrophy, and found that health-related quality of life and access to health and social care was substantially reduced when compared with the general population. The aim of this Editorial is to appraise epidemiological research on the point prevalence of pain associated with neurological conditions to determine the extent of the challenge.

Inadequate management of pain is financially costly. The national healthcare and socioeconomic costs of chronic pain accounts for 3-10% of gross domestic product in Europe (see [2]). In the United States the annual costs related to health care delivery and lower worker productivity due to pain was between $560 and $635 billion dollars which was greater than heart disease ($309 billion), cancer ($243 billion), and diabetes ($188 billion) [3]. In 2006, Breivik et al. [4] published a seminal paper reporting the findings of a pan-European survey of 15 European countries and Israel (46,394 participants) that estimated the point prevalence of chronic pain of > 6 months to be 19%. Approximately 40 per cent of participants with chronic pain reported inadequate pain management with 64 per cent of participants reporting that medication did not adequately control their pain at some point.

In 2012, we published a comprehensive systematic review of surveys conducted in 34 countries and estimated the prevalence of chronic pain of >3 months in the general adult population worldwide to be 30.3 ± 11.7 per cent (weighted mean ± standard deviation, 19 studies, 65 surveys, 34 countries, 182,019 participants) [5]. This figure decreased to 28.0% ± 11.8% (47 surveys, 33 countries, 139,770 participants) following the removal of a large study that may have included a sample of people with comorbidities. We provided tentative evidence that the prevalence of chronic pain in North America (35.6% ± 4.9, 6 surveys) was higher than the rest of the world, and that the prevalence in East Asia and Pacific (25.3% ± 13.7%, 9 surveys) and in South Asia (19.0%, 1 survey) was lower than the rest of the world when these regions were taken together. Interestingly, there was no correlation between the prevalence of chronic pain and a country’s Human Development Index.

A number of systematic reviews have been published since our analysis and they support our findings. In 2016, Jackson et al. [6] reported the findings of a systematic review of 119 publications in 28 low-income and middle-income countries which included 68 surveys from general adult populations, elderly general populations, or workers. They estimated the prevalence of unspecified chronic pain to be 34% (95% confidence intervals (CI), 26, 42%) in the general adult population and 62% (95% CI, 41, 81%) in the general elderly population. In elderly people, unspecified pain was 1.83 (95% CI, 1.13, 2.65%) times more prevalent than in adults and musculoskeletal pain was 1.74 (95% CI, 1.03, 2.69%) times more prevalent than in adults. A systematic review of 19 studies by Fayaz et al. [7] estimated that the prevalence of chronic pain of adult residents of the UK was between 35.0 and 51.3% (7 studies) with the prevalence of moderateseverely disabling chronic pain between 10.4 and 14.3%. In 2015, a systematic review of 19 surveys conducted in Asia and the Middle East and North Africa (MENA) found the prevalence of chronic pain to be variable across nations with estimates ranging from 7.1% in Malaysia to 61% in Cambodia and Northern Iraq [8]. We published the findings of a cross-sectional telephone survey before the onset of the Libyan Civil War (February 2011) and estimated the prevalence of chronic pain ≥ 3 months to be 19.6 % (95% CI, 14.6, 24.6 %, 1212 participants). The mean ± SD duration pain was 6.5 ± 5.7 years and only 29.8 % of respondents with chronic pain reported that their pain was being adequately controlled. Risk factors for chronic pain were female, elderly and unemployed. The prevalence of neuropathic pain was equivalent to 3.9% (95% CI, 2.8, 5.0%) of the general adult population. In 2012, a systematic review by Smith et al. [9] was unable to estimate of the worldwide prevalence of neuropathic pain with any degree of accuracy because of inter-study variability in criteria for neuropathic pain, methods of assessment, survey tools, patient selection, aetiologies, symptoms and underlying mechanisms.

The point prevalence of pain associated with neurological conditions is higher than previously believed and is underdiagnosed and inadequately managed [10,11]. Pain is reported to be the most bothersome symptom in Parkinson’s disease [12,13]. Broen et al. [14] conducted a systematic review of 8 studies and found the mean prevalence of pain associated with Parkinson’s disease to be 67.6% (range 40% to 85%). An investigation of 176 home-living patients with Parkinson’s disease found that 83% of patients reported having pain with 29% of patients having more than one type of pain [15]. Musculoskeletal pain presenting in the neck, upper back and extremities was most common, in 70% of patients, and peripheral neuropathic pain (20%) and central neuropathic pain (10%) less common. Only 34% of patients were receiving analgesic medication.

In multiple sclerosis, pain is generally due to nerve and muscle damage and/or dysfunction. A systematic review by Foley et al. [16] found the mean prevalence of any type of pain associated with multiple sclerosis was 63% (95% CI, 55, 70%; 17 studies, 5319 participants). The most prevalent types of pain were headache (95% CI, 33, 52%) and back pain (95% CI, 13, 28%) but other pains were also prevalent including L’hermitte sign (95% CI, 10%, 25%), neuropathic extremity pain (95% CI, 7, 53%), and painful spasms (95% CI, 8.5, 23%). The location of demyelinating lesions has been shown to be associated with neuropathic pain and headache and facial pain [17].

In 2016, de Tommaso et al. [11] published a review of pain associated with neurodegenerative disease and found that the prevalence of pain was high in Alzheimer’s disease (95% CI, 38, 75%) and motor neurone disease (95% CI, 19, 85%). To date, there are no systematic reviews on the prevalence of pain in Huntington’s disease or muscular dystrophies although the findings of clinical studies have been inconsistent, possibly due to small sample populations. For example, Scherder et al. [18] reported that 11 of 19 patients (58%) with Huntington’s disease who lived in nursing homes had pain, whereas De Tommaso et al. [19] found that only 3 of 28 patients with postural and musculoskeletal defects associated with Huntington’s disease reported pain (11%). People with Huntington’s disease may not complain of pain because of dampened emotional recognition for pain [18,20]. A Swedish survey by Lager et al. [21] found that 50% of adolescents with spinal muscular atrophy and Duchene and Becker muscular dystrophy reported chronic pain in the previous 3 months.

The prevalence of pain is high in acquired brain disorders resulting from trauma. Pain resulting from traumatic brain injury may be a direct consequence of injury to brain tissue or as an indirect consequence of the injury such as deep venous thrombosis. Often pain involves the musculoskeletal system presenting as spasticity and muscle spasms causing painful postural abnormalities [22]. In 2008, a systematic review of 23 studies (4206 participants) by Nampiaparampil et al. [23] estimated that 51.5% of civilians experienced chronic pain following traumatic brain injury (95% CI, 49.8, 53.2%; 20 studies, 3289 participants). The prevalence of headache was 57.8% (95% CI, 55.5, 60.2%; 12 studies, 1670 participants). Interestingly, the prevalence of chronic pain in mild traumatic brain injury was 75.3% (95% CI, 72.7, 77.9%) and higher than 32.1% seen with moderate or severe traumatic brain injury (95% CI, 29.3%-34.9%). The reviewers concluded that chronic pain was a frequent occurrence even with minor brain injury and was independent of post-traumatic stress disorder and depression.

Musculoskeletal pain and central neuropathic pain is known to develop immediately after a stroke, or several months after a stroke. A review by Harrison and Field [24] summarised population studies on the prevalence of post-stroke pain syndromes and found that approximately 50% of people experience post-stroke pain although estimates of prevalence varied due to differences in study design and sampled populations. In 2016, Paolucci et al. [25] estimated mean overall prevalence of pain from 443 stroke survivors to be 29.56% with pain most frequently reported in the sub-acute (42.73%) and chronic (31.90%) stages.

Spinal cord injury produces pain that presents in a variety of ways including spasm-related pain and neuropathic pain and also other pain such as constipation-related pain and pressure-sore pain [26,27]. In 2009, Dijkers et al. [28] published a systemic review of 42 studies that estimated the prevalence of chronic pain associated with spinal cord injury to be between 26% and 96%. In 2014, Michailidou et al. [29] estimated the prevalence of chronic musculoskeletal pain associated with spinal cord injury to be 49% (95% CI, 44, 55%), chronic back pain to be 47% (95% CI, 43, 50%) and chronic low back pain to be 49% (95% CI, 44, 55%) based on a systematic review of 8 studies. In 2016, Burke et al. [30] conducted a systematic review of 17 studies (2529 participants) that included a meta-analysis which found the pooled point prevalence of neuropathic pain post spinal cord injury to be 53% (95% CI, 38.58, 67.47%) suggesting that the prevalence of neuropathic pain following spinal cord injury to be high.

In summary, chronic pain is very common in neurological conditions. Health care professionals often focus treatment on cure and slowing disease progression, especially as functional impairments are more visible than pain. Evidence from epidemiological studies demonstrate that the prevalence of chronic pain in the general population is higher in the presence of a neurological condition such as multiple sclerosis, Parkinson’s disease, Alzheimer’s disease, motor neurone disease, traumatic brain injury, stroke, and spinal cord injury. Neurological conditions are a consequence of disease or trauma to the peripheral and/or central nervous system. However, pain associated with neurological conditions may be due to a variety of factors including direct consequence of disease or trauma on the nervous system or as an indirect consequence of the effects of the neurological condition on neural and non-neural structures. Epidemiological evidence suggests that neuropathic pain is less common than musculoskeletal pain in neurological conditions. Nevertheless, neuropathic pain can have a severe impact on functioning and quality of life and as a consequence management of neuropathic pain is often very challenging.

Pain assessment should be integral to the overall clinical assessment of people with neurological conditions and pain scales have been developed for use in specific populations such as Parkinson’s disease [12]. Pain management should form the basis of the resultant treatment plan. A working knowledge of the risk factors for the development of chronic pain, long-term disability, or work absence is necessary to aid decisions about appropriate treatment strategies. A new episode of pain that is severe, multi-site, and/or of longer duration is at risk of becoming chronic. Other factors that influence a less successful outcome include female, older age, physical inactivity, poor quality diet, low psychological status (e.g. depression, anxiety and catastrophizing cognition), and adverse family and social environment including major physical trauma during childhood [31].