Pain Management a Consultant Perspective Karen H Simpson Pain Physician Leeds

Overview Pathophysiology of chronic pain? What is a ‘chronic pain syndrome’ (CPS)? Assessment of pain Psychological vs physical pain – does this dichotomy exist? Pain management Practical advice for lawyers and experts

Chronic Pain Can be caused by minor or major injury Adults and children Defined as pain lasting for 6 months or more No evidence for ‘pain prone personality’ Evidence for organic basis for chronic pain Basic science research - animal and human Functional imaging Systematic reviews

Functional imaging PET scans of patients with LBP showing glial cell activation in thalamus (Brain 2015)

Chronic Pain Activation of nerves called “Nociceptors” Continued nociceptor activation changes in Central Nervous System (CNS) spinal cord peripheral nerves Emotional effects Functional effects Social effects family occupation litigation Financial effects

Chronic Pain Syndrome (CPS)? Persistent pain Usually no identifiable source Normal investigations Associated with abnormal illness behaviours hypervigilance catastrophization fear avoidance mood disorders effects on function withdrawal from occupation

Chronic Pain Syndrome (CPS)? Does this differ from chronic pain? Does it exist clinically? Is CPS useful terminology? Somatic symptom disorder CPS and CRPS confusion?

Psychological Component? Dualistic view pain is either physical or psychogenic Are these mutually exclusive? Current view pain is affected by multiple biopsychosocial factors it is physical and psychological DSM 5 (SSD) Exaggeration unconscious conscious

Vulnerability to chronicity? Consulted GP/HCPs more than average in past Past complaints but no cause found for symptoms More prevalent in females History of problem drug use History of abuse physical emotional sexual Social deprivation Family history of chronic pain – learned behaviours

Early indications of chronicity Pain or functional impairment out of proportion to original injury and examination findings Objective measures e.g. ODI, NDI, Behaviours and beliefs Patient and carer distress Usual therapies not effective or give transient relief Multiple consultations with different HCPs in different settings Social and work issues Litigation issues

Continuum

Factors that maintain chronicity Sleep disorders Problem drug use Social isolation and loss of status Loss of sense of self Lack of acceptance of situation Pre-accident vulnerability Anger about the accident Financial anxiety An adversarial legal system!

Neuropathic Pain Pain as a direct consequence of a lesion/disease affecting the somatosensory system Pain generated by damage and abnormal function in the nervous system shingles post-amputation CRPS

Features of Neuropathic Pain (NeP) Prickling, tingling, pins and needles (dysaesthesia) Electric shocks or shooting pain Hotness or burning sensations Ice cold sensations Numbness Pain evoked by light touch Altered appearance Altered perception about limb

Neuropathic Pain NeP poorer physical and mental health than nociceptive pain NeP commoner in elderly NeP resists normal analgesic drugs NeP associated with poor function NeP causes abnormal body perception cortical processing brain re-mapping NeP carries a poor prognosis NeP present >2 years is incurable

Treatment and Rehabilitation Medication / topicals opioid and anti-NeP drug abuse Physical therapies acupuncture/TENS Nerve blocks/Botox Surgery Neuromodulation new technology Psychological therapies PMP/rehabilitation group individual

Practical advice for lawyers Be aware of and identify potential chronic pain early Do not allow the person to exaggerate Obtain complete GP, hospital, OH and DWP records Discuss surveillance Deal with Claimant confusion about care/legal process Facilitate investigation/treatments where appropriate

Practical advice for experts Make sure the case within you area and no COI Examine complete GP, hospital, OH and DWP records Read the records before you see the Claimant Do not allow the person to exaggerate Discuss surveillance –need to record function carefully Deal with Claimant confusion about care/legal process Reply to queries in a timely manner Tell the instructing solicitor if you view changes