Managing Chronic Pain in Special Populations with Emphasis on Pediatric, Geriatric, and Drug Abuser Populations

Long-lasting analgesia via targeted in situ repression of NaV1.7 in mice

Current treatments for chronic pain rely largely on opioids despite their substantial side effects and risk of addiction. Genetic studies have identified in humans key targets pivotal to nociceptive processing. In particular, a hereditary loss-of-function mutation in NaV1.7, a sodium channel protein associated with signaling in nociceptive sensory afferents, leads to insensitivity to pain without other neurodevelopmental alterations. However, the high sequence and structural similarity between NaV subtypes has frustrated efforts to develop selective inhibitors. Here, we investigated targeted epigenetic repression of NaV1.7 in primary afferents via epigenome engineering approaches based on clustered regularly interspaced short palindromic repeats (CRISPR)-dCas9 and zinc finger proteins at the spinal level as a potential treatment for chronic pain. Toward this end, we first optimized the efficiency of NaV1.7 repression in vitro in Neuro2A cells and then, by the lumbar intrathecal route, delivered both epigenome engineering platforms via adeno-associated viruses (AAVs) to assess their effects in three mouse models of pain: carrageenan-induced inflammatory pain, paclitaxel-induced neuropathic pain, and BzATP-induced pain. Our results show effective repression of NaV1.7 in lumbar dorsal root ganglia, reduced thermal hyperalgesia in the inflammatory state, decreased tactile allodynia in the neuropathic state, and no changes in normal motor function in mice. We anticipate that this long-lasting analgesia via targeted in vivo epigenetic repression of NaV1.7 methodology we dub pain LATER, might have therapeutic potential in management of persistent pain states.

The association between the supply of select nonpharmacologic providers for pain and use of nonpharmacologic pain management services and initial opioid prescribing patterns for Medicare beneficiaries with persistent musculoskeletal pain

OBJECTIVE

To test the relationship between the supply of select nonpharmacologic providers (physical therapy (PT) and mental health (MH)) and use of nonpharmacologic services among older adults with a persistent musculoskeletal pain (MSP) episode.

DATA SOURCES/STUDY SETTING

Claims data from a 5 percent random sample of Medicare beneficiaries enrolled fee-for-service (2007-2014) and the Area Health Resource File (AHRF).

STUDY DESIGN

This retrospective study used generalized estimating equations to estimate the association between the county nonpharmacologic provider supply and individual service use with opioid prescriptions filled during Phase 1 (first three months of an episode) and Phase 2 (three months following Phase 1).

DATA COLLECTION/EXTRACTION METHODS

We identified beneficiaries (>65 years) with ≥2 MSP diagnoses ≥90 days apart and no opioid prescription six months before the first pain diagnosis (N = 69 456). Beneficiaries' county characteristics were assigned using the AHRF.

PRINCIPAL FINDINGS

About 13.9 percent of beneficiaries used PT, 1.8 percent used MH services, and 10.7 percent had an opioid prescription during the first three months of a persistent MSP episode. An additional MH provider/10 000 people/county [aOR: 0.97, 95% CI: 0.96-0.98] and PT/10 000 people/county [aOR: 0.98, 95% CI: 0.97-1.00] was associated with lower odds of filling an opioid prescription in Phase 1. An additional MH provider/10 000 people/county [aOR: 0.97, 95% CI: 0.96-0.98] and PT use in Phase 1 [aOR: 0.62, 95% CI: 0.58-0.67] were associated with lower odds of filling an opioid prescription in Phase 2. The associations between the supply of providers and nonpharmacologic service use in Phase 1 and Phase 1 opioid prescriptions significantly differed by metropolitan and rural counties (P-value: .019).

CONCLUSIONS

Limited access to nonpharmacologic services is associated with opioid prescriptions at the onset of a persistent MSP episode. Initiating PT at the onset of an episode may reduce future opioid use. Strategies for engaging beneficiaries in nonpharmacologic services should be tailored for metropolitan and rural counties.

Pain in the Elderly: Identification, Evaluation, and Management of Older Adults with Pain Complaints and Pain-related Symptoms

Pain is a common and often underappreciated and undermanaged problem in older adults. This article addresses the scope of the issue of pain prevalence in older adults, types of pain and their characteristics, approach to and clinical workup of older adults with pain complaints and pain-related symptoms, nonpharmacologic and pharmacologic management strategies, and caveats with attention to medication side effects in the elderly.

Persistence of pain quality in community-dwelling older adults with chronic non-cancer pain

Longitudinal assessment of chronic geriatric pain is complicated by an age-associated plateau in pain severity and increase in widespread pain, calling for innovative measures such as pain quality descriptors that characterize how pain may feel. We characterized persistence of pain quality and its relation to severity, activity interference and distribution of sites, in a population-based sample of adults aged≥70 years with chronic pain (n = 398). Persistent pain quality was defined as reporting descriptors within the same category: sensory, cognitive/affective, or neuropathic at baseline and 18 months. A count variable indicated number of persistent categories. Pain quality was highly persistent. Adjusted for baseline covariates, individuals endorsing 3 persistent categories were 2-2.5x more likely to experience more widespread pain at 18 months compared to fewer persistent categories. No associations were noted in changes in pain severity or interference. A comprehensive pain assessment that includes diverse pain quality descriptors may improve individualized pain management.