Pain Phenotypes in Adults Living With Cerebral Palsy

Pain in adults with cerebral palsy: A systematic review

AIM

To describe the prevalence and incidence of pain, identify prognostic factors for pain, determine psychometric properties of tools to assess pain, and evaluate effectiveness of interventions for reducing pain among adults with cerebral palsy (CP).

METHOD

Six databases were searched to identify studies published since 1990 in any language that met eligibility criteria defined for each objective. Titles, abstracts, and full texts were screened by two independent reviewers.

RESULTS

Sixty-three studies were identified; 47 reporting prevalence, 28 reporting prognostic factors, four reporting psychometric properties, five evaluating intervention effectiveness. Pain prevalence ranged from 24% to 89%. Prevalence was higher among adults with CP than in adults without it. Communication function, sex, and age were prognostic factors for pain prevalence. Numerical, verbal, and pictorial rating scales were valid for assessing pain intensity in adults with CP. Pharmacological and surgical interventions had no effect on pain. An active lifestyle and sports intervention reduced pain in adults with CP compared with usual care.

INTERPRETATION

Many adults with CP experience pain, although prevalence estimates vary considerably. The quality of evidence for prognostic factors and interventions is very low to low. There is a lack of evidence about effective pain management among adults with CP.

A second dimension of somatosensory system injury? Thalamic volume loss and neuropathic pain in adults with cerebral palsy and periventricular white matter injury

Objectives

Lemniscal (motor-related) and spinothalamic (neuropathic pain-related) somatosensory abnormalities affect different subsets of adults with cerebral palsy (CP). Lemniscal/motor abnormalities are associated with posterior thalamic radiation white matter disruption in individuals with CP and white matter injury. We tested the hypothesis that neuropathic pain symptoms in this population are rather associated with injury of the somatosensory (posterior group nuclei) thalamus.

Methods

In this cross-sectional study, communicative adults with CP and bilateral white matter injury and neurotypical control participants volunteered to self-report pain symptoms and undergo research MRI. Posterior group thalamic nuclei volume was computed and correlated against neuropathic pain scores.

Results

Participants with CP (n=6) had, on average, 24% smaller posterior group thalamic volumes (95% CI [10-39%]; corrected p=0.01) than control participants. More severe volume loss was correlated with more severe neuropathic pain scores (ρ=-0.87 [-0.99,-0.20]; p=0.02).

Discussion

Association with thalamic volume loss suggests that neuropathic pain in adults with CP may frequently be central neuropathic pain. Complementing assessments of white matter microstructure, regional brain volumes hold promise as diagnostic biomarkers for central neuropathic pain in individuals with structural brain disorders.

Population- and individual-level trajectories of opioid prescription patterns among adults with cerebral palsy: a retrospective cohort study

BACKGROUND

There is little epidemiologic evidence on opioid prescription among adults with cerebral palsy (CP).

AIM

To describe the population- and individual-level opioid prescription patterns for adults with versus without CP.

METHOD

This retrospective cohort study used commercial claims (Optum's de-identified Clinformatics® Data Mart Database) from the USA from 01/01/2011-12/31/2017 from adults ≥ 18 years old with CP and matched adults without CP. For the population-level analysis, monthly estimates of opioid exposure were described for adults ≥ 18 years old with CP and matched adults without CP. For the individual-level analysis, group based trajectory modelling (GBTM) was used to identify groups of similar individual-level monthly opioid exposure patterns for adults with CP and matched adults without CP for 1-year starting from their first opioid exposure month.

RESULTS

For the population-level, adults with (n = 13,929) versus without (n = 278,538) CP had a higher prevalence of opioid exposure (~ 12%, ~ 8%) and days supplied (median, ~ 23, ~17) monthly over 7 years. For the individual-level, there were 6 trajectory groups for CP (n = 2099) and 5 for non-CP (n = 10,361). Notably, 14% of CP (comprising 4 distinct trajectory groups) and 8% (comprising 3 distinct groups) of non-CP had variably high monthly opioid volume for extended periods; exposure was higher for CP. The remaining had low/absent opioid exposure trajectories; for CP (non-CP), 55.7% (63.3%) had nearly absent exposure and 30.4% (28.9%) had consistently low exposure to opioids.

CONCLUSION

Adults with versus without CP were more likely to be exposed to opioids and for a longer duration, which may alter the risk-benefit balance of opioids.

Opioid prescription patterns among adults with cerebral palsy and spina bifida

Background

Pain is the most common symptom of cerebral palsy and spina bifida (CP/SB). The objective of this study was to compare the opioid prescription patterns for differing pain types and overlapping pain among adults living with and without CP/SB.

Methods

Privately-insured beneficiaries were included if they had CP/SB (n = 22,647). Adults without CP/SB were also included as controls (n = 931,528). Oral morphine equivalents (OMEs) were calculated. A multivariable logistic regression was used to analyze the association between CP/SB and OMEs, across the three pain categories: (1) no pain, (2) isolated pain, and (3) pain multimorbidity.

Results

Adults living with CP/SB had a higher OME prescription pattern per year than adults without CP or SB (8,981.0 ± 5,183.0 vs. 4,549.1 ± 2,988.0), and for no pain (4,010.8 ± 828.1 vs. 1,623.53 ± 47.5), isolated pain (7,179.9 ± 378.8 vs. 3,531.0 ± 131.0), and pain multimorbidity (15,752.4 ± 1,395.5 vs. 8,492.9 ± 398.0) (all p < 0.001), and differences were to a clinically meaningful extent. Adjusted odds ratios (OR) for prescribed OMEs were higher for adults with CP/SB vs. control and (1) no pain (OR: 1.51; 95%CI: 1.46, 1.56), (2) isolated pain (OR: 1.48; 95%CI: 1.44, 1.52), and (3) pain multimorbidity (OR: 1.79; 95%CI: 1.72, 1.86).

Conclusions

Adults with CP/SB obtain significantly higher prescription of OMEs than adults without CP/SB.