Chronic pain among children with cerebral palsy attending a Ugandan hospital: a cross-sectional study


 Background: Children with cerebral palsy (CP) frequently experience chronic pain. The burden and severity of such pain is often underestimated in relation to their other impairments.Recognition and awareness of this chronic pain among children with CP constitute the cornerstone for caretakers and clinicians to improve the quality of life of those children. This study aimed to determine the prevalence of chronic pain among children with CP, and the factors associated.Methods: A cross-sectional study of children with CP, aged 2 – 12 years, attending the CP rehabilitation clinic and Pediatric Neurology Clinic at Mulago Hospital, Uganda from November 2017 to May 2018. A detailed history and clinical examination were performed and the co-morbidities were determined. CP was classified using the Gross Motor Function Classification System (GMFCS), Manual Ability Classification System, Communication Function Classification System (CFCS), and the Eating and Drinking Ability Classification System (EDACS) and documented with the level of impairment in the different domains. Pain was assessed by using the revised Face, Legs, Activity, Consolability, Cry pain scale.Results: A total of 224 children with CP were enrolled. The prevalence of chronic pain was 64.3%. The majority had spastic bilateral CP (77.8%), moderate pain lasting over 6 months, and none of them was on long-term pain management. Epilepsy (60.9%), behavioral problem (63.2%), hearing impairment (66,7%), learning problem (67,6%), dental caries (75%), gastro-esophageal reflux (75%), sleep disorders (79.5%), vision impairment (80%), and malnutrition (90%) were comorbid conditions of chronic pain in children with CP in this study. The factors independently associated with chronic pain among children with CP were the GMFC system level 4 & 5, CFCS level 4 & 5, EDACS level 4 & 5, female children, and caretaker aged more than 30 years.Conclusion: Two-thirds of children with CP attending rehabilitation in this hospital had chronic pain. None was receiving pain management. Chronic pain was associated with the presence of multiple co-morbidities and more severe disability. Rehabilitation and care programs for children with CP should include assessment of pain in routine care and provide interventions for pain relief in children with CP even at an early age.


Background
Cerebral palsy in children and adolescents is a major social disability, and affecting their quality of life, and largely of their caretakers. There is a growing recognition that pain is a signi cant problem in children and adolescents with cerebral palsy (CP) [1]. About 65 to 78% of children with CP are reported by their caretakers to experience pain [2]. Research has shown that children with CP who have pain participate less in everyday situations, experience lower quality of life than those without pain, and interferes with sleep [2]. Moreover, CP children who experience pain are more likely to struggle with anxiety, frustration, fear, depression, and behavior disorders such as aggression [3]. Self-report is considered the gold standard for pain assessment due to pain's subjective and individual nature; this is particularly challenging for children with CP because some have a speech impairment, which makes it di cult to communicate their experience and others have such severe cognitive impairment that proxy reports are necessary [4]. Research supports this alternate approach to data collection or clinical assessment, as Engel and colleagues found the agreement between parent and child report of pain occurrence was 93% [2]. Currently, there is very little literatures about how common is chronic pain among children with CP in sub-Saharan African, especially in Uganda, where there is a high prevalence of CP among children resulting from several peri-natal causes. There is little knowledge about the factors that predispose to this pain and their associated complications. Recognition and awareness of chronic pain and the burden of associated factors of this pain among children with CP could help us to provide an accurate assessment, and plan for better interventions to improve the quality of life of those children. The study aimed to determine the prevalence of chronic pain in children with CP, to describe the severity and comorbidities of pain, and determine the factors associated with such pain.

Study design and setting
This cross-sectional study was carried out in the Cerebral Palsy Rehabilitation Clinic and the Pediatric Neurology Clinic at Mulago National Referral Hospital, Kampala, Uganda, between November 2017 and May 2018.

Study participants
Cerebral palsy is a neuro-developmental condition comprising a group of permanent disorders of movement and posture that are attributed to non-progressive injury that occurred in the developing fetal or infant brain.
Study participants were Children of 2-12 years old with a documented diagnosis of CP, attending regularly the above-mentioned clinics for their follow-up, accompanied by a caretaker. The latter was responsible for providing most of the material and emotional requirements to the child for at least 3 months.
Only patients whose parents or caregivers provide informed consent were included.
Participants who came with caregivers who were unable to provide adequate information about the child on the study or refuse to provide informed consent were excluded in the study.

Study procedure
The study team consisted of medical personnel working within the above-mentioned Paediatrics clinics with additionally trained research assistants to do the enrolment, consent, history, and physical examination.
The detailed clinical history as well as comorbidities were obtained from the parents or caretakers; the child was examined to obtain the features and complications of CP. The patient's level of physical functioning was assessed using the Gross Motor Function Classi cation system (GMFCS). The GMFCS has levels I-V with level I indicating a good level of functioning while level V is the worst depicting severe handicap. The ability of hand functioning was also assessed using the manual ability classi cation system (MACS) which has also levels I-V. This was followed by assessing the child's communication ability using the communication function classi cation system (CFCS). The eating and drinking ability classi cation system ((EADACS) was assessed as well, knowing that EADACS has levels I-V.

Measurement of pain in children with CP
Pain was assessed using the revised face, legs, activity, cry and consolability (rFLACC) scale for children aged between 2-12 years old. The rFLACC scale questionnaires for children with CP were lled to determine the pain and the severity of pain. This instrument has been recognized to be reproducible, valid, and reliable in assessing pain in children with CP not able to self-report pain. The internal consistency is excellent with a Cronbach's alpha of 0.9023 and 0.9753 (two raters). A test-retest showed excellent intrarater reliability with an intra-class correlation (ICC) of 0.97530.

Data analysis
Descriptive statistics were used to explore baseline characteristics of the participants and caretakers; they were presented as means and medians, ranges, and IQR. Variables whose p-value of the Unadjusted OR (bivariable level) was less than 0.2 were considered at multivariable logistic regression analysis to nd out factors that signi cantly determine having chronic pain among children with CP. Signi cance was set at a p-value of ≤ 0.05.      Rehabilitation Clinic or General Paediatric Neurology Clinics in Mulago Hospital and were invited to participate in the study; 4 refused consent, 2 were outside the required age range of 2-12 years, 4 were unable to participate due to other reasons and 224 were recruited. The majority of participants were male (62.5%), with an overall median age of 3.6 years ( Table 1). Most of the caretakers were literate married Christian mothers, with no formal employment, living in a family size of more than 4 people ( Table 2).
One hundred forty-four (144) of the 224 children presented with chronic pain giving a prevalence of 64.3% ( Table 3). The highest percentage of children with chronic pain was observed with children with spastic bilateral CP (77.8%). None of those children with CP in chronic pain was on long-term pain management. Participants in level 4 & 5 of GMFCS, MACS, CFCS, and EADCS had a high prevalence of chronic pain compare to participants in level 1, 2 & 3 ( Table 3). The majority of participants had moderate pain, but the duration of pain was more than 6 months (Table 4). Epilepsy, sleep disorders, impaired vision, impaired hearing, dental caries, malnutrition, gastroesophageal re ux, behavioral problem, and earing problem were comorbid conditions in this study (  (Table 6).

Discussion
This study set out to determine the prevalence of chronic pain and associated factors among children with CP. We found that 64.3 % of these patients who had chronic pain with severe gross motor function level involvement or disability were more at risk. The prevalence of chronic pain in this study is consistent with previous studies done in Malaysia in 2015 [5] and turkey in 2017 [6], where the prevalence of chronic pain in children with CP in both 2 studies was found to be 65%. Also, the prevalence of pain in children with CP in this study is similar to a previous report that indicated that around 60 % of children with CP experience recurrent pain on a daily or weekly basis that signi cantly interferes with their daily activities [7]. In this study, the most common type of CP with the highest prevalence of chronic pain was spastic bilateral CP. Knowing that children with spastic bilateral CP have more severe functional motor limitation and experiencing stiffness and contractures which usually prone them to ongoing pain. A similar pattern was found in a study done by Badia  and Barney et al in 2013 [10] discovered that pain frequency, intensity, and duration were signi cantly predicted by GMFCS level, being greater among children with a higher GMFCS level 4,5. Similarly, a study done in Turkey in 2017 [6], showed that children with GMFCS 4,5 had a high percentage of getting pain compared to patients at GMFCS levels 1, 2, and 3. In this study majority of participants had moderate pain. A similar pattern was reported in a study done in Malaysia by Subhashini et al. in 2015 where patients with moderate pain were more than those with severe pain [5]. These ndings are also similar to a previous study done in Spain that showed that persons with CP experience recurrent pain of moderate-intensity on a daily or weekly basis that signi cantly interferes with daily activities [7].
Epilepsy, sleep disorders, vision impairment, hearing impairment, dental caries, malnutrition, gastroesophageal re ux disease, behavioral problem, and learning problem were comorbid conditions in children with pain and CP in this study. These ndings are similar to a previous study done by Badia

Conclusions
Approximately two-thirds of children with CP attending rehabilitation in this tertiary hospital experience chronic pain. The majority of these children have moderate pain without long-term pain management.
Comorbid conditions such as epilepsy, sleep disorders, impairment of vision, impairment of hearing, dental caries, malnutrition, gastroesophageal re ux, behavioral problem, and learning problem are associated with chronic pain among children with CP. Severe disability in terms of GMFC, CFCS, EADACS (level 4 & 5), and female participants were associated with chronic pain among children with CP. Children with older caretakers (30 years and above) may likely experience less chronic pain. We recommend rehabilitation and care programs for children with CP to assess chronic pain in routine care and provide interventions for pain relief in children with CP even at an early age.
List Of Abbreviations CP: Cerebral palsy; CFCS: Communication function classi cation system; EADACS: Eating and drinking ability classi cation system; GMFCS: Gross-motor function classi cation system; MACS: Manual ability classi cation system; rFLACC: Revised face, legs, activity, consolability, cry pain scale Declarations Ethics approval and consent to participate, and for publication: This study was reviewed and approved by the Makerere University School of Medicine Research and Ethics Committee. Written informed consent was obtained from the parent/guardian in order to participate in the study. All study methods were performed in accordance with the relevant guidelines and regulations of Declaration of Helsinki.
Availability of dataset and material: The datasets used and/or analyzed during the current study are available from the corresponding author on reasonable request.