Researchers have proposed a Cerebral Palsy Pain Classification (CPPC) tool that is specific for children with CP and is based on the International Classification of Diseases, 11th Revision (ICD-11) classification of pain, as reported in Developmental Medicine & Child Neurology.
Setting, research criteria, time frame, age, CP type, and Gross Motor Function Classification System level can affect the prevalence of pain in children with CP – a range of 27% to 77% – according to researchers. Hip displacement, muscle spasms, and procedures are some of the common causes of pain in children with CP, while headaches, neuropathic pain, visceral pain, and acute versus chronic pain are less discussed. The current researchers believe that although the addition of chronic pain is important in improving the recognition of pain conditions, a pain classification tool specific to children with CP would be beneficial for recognition and pain assessment in this patient population.
The objective of the current study was to talk about pain in children with CP in regards to the new ICD-11 classification, based on previous studies, and propose a CPPC tailored specifically for pain in patients with CP using the ICD-11 classification of pain and physiological terminology.
The study authors conducted a literature search in the PubMed, Embase, and Scopus databases through January 25, 2021, for original research articles on pain in children with CP.
A total of 195 studies were included in the review and were categorized based on primary theme and cause of pain. The researchers identified 4 primary themes of pain in children with CP—acute, chronic primary, chronic secondary, and nonspecified pain.
Acute pain was reported in 39 studies (20%), with 1 study distinguishing between acute and chronic pain. Chronic secondary pain, including musculoskeletal pain, visceral pain, headache or orofacial pain, and neuropathic pain, was reported in 81 studies (41.5%), 75 of which focused on musculoskeletal pain. The other 74 studies did not specify the cause or type of pain.
Acute pain in children with CP is most frequently caused by an intervention and is likely to activate nociceptors. Children with CP who have had surgery also have an increased risk of developing chronic postoperative pain.
Common sources of nociceptive secondary pain include subluxation, dislocation, scoliosis, deformities, spasms, contractures, constipation, and skin ulcers. Neuropathic secondary pain sources include surgical nerve injury, nerve compression, early brain injury, and migraine.
Based on their review, the researchers created a CPPC that is aligned with ICD-11 classifications and physiological terminology and organized pain in patients with CP into 4 tiers. The first tier differentiates between primary and secondary pain in the ICD-11, and the second tier differentiates among the physiological origins of pain. The third tier includes pain subtypes, and the fourth tier includes potential sources of pain.
A classification system of pain specific to patients with CP is necessary for facilitating new pain research and will be useful for clinicians, according to the researchers.
“The inclusion of chronic pain in the ICD-11 is an important step forward,” they stated. “It is designed to be applicable to all painful conditions; however, this makes it less specific for a condition such as CP, which encompasses many different types of pain. The CPPC is a tool that may help those working with patients with CP, while still being translatable to the ICD-11, from the pain researcher trying to classify pain from a physiological point of view to the neuropediatrician or physiotherapist trying to assess pain in patients with CP.”
Vinkel MN, Rackauskaite G, Finnerup NB. Classification of pain in children with cerebral palsy. Dev Med Child Neurol. Published online November 2, 2021. doi: 10.1111/dmcn.15102