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Pain in patients with spinal cord injury. Naveen Kumar Specialist Registrar in Spinal injuries & Rehabilitation. Scope of the problem. 47 – 96 (avg 66) % of SCI individuals experience pain ( Ref 1979-1995- 8 studies) 50% musculoskeletal 30% neurogenic
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Pain in patients with spinal cord injury Naveen Kumar Specialist Registrar in Spinal injuries & Rehabilitation
Scope of the problem • 47 – 96 (avg 66) % of SCI individuals experience pain ( Ref 1979-1995- 8 studies) • 50% musculoskeletal • 30% neurogenic • 5 - 45% experience severe disabling pain • 94% chronic pain • Comparative Neglect: Pain 2400 ( 1977-1997), 19 pain in SCI
Incidence of pain • More common in patients with: • Injuries due to gunshot wounds and violence • Lower level of injury • Incomplete SCI ? • Spasticity
Psychosocial factors • Depression / Sadness • Adjustment disorders • Anger • Anxiety • Stress
Patient evaluation • Detailed history • Quality Of Pain • Distribution Of Pain • Relieving Factors • Aggravating Factors • Physical examination • Diagnostic tests
Pain syndrome classification • Musculoskeletal • Neuropathic • Visceral
Pain classification Neuropathic • Above the level • At the level • Below the level
At-level Neuropathic pain segmental end-zone Radicular Mechanisms – nerve root compression/trauma – spinal cord damage – generation of nerve activity
Below-level Neuropathic pain • central • dysaesthetic • remote • Phantom
Below-level Neuropathic pain Mechanisms • – Spinal cord and brain • – Loss of inhibition • – Sensitization of nerve cells • – reorganisation?
Musculoskeletal pain syndrome • Bone, joint, muscle trauma • Tendon inflammation • Muscle spasm • Overuse syndrome • Instability of spine
Vertebral column pain • Neck, middle back, low back pain • Spine deformities • Arthritis • X-rays • evaluate instrumentation placement • evaluate degenerative changes
Mechanical instability of spine • Most common after cervical spine injury • Due to injury to ligaments, fx of spine • Pain around the spine
Treatment for mechanical instability of spine • Relieved by immobilization • Rest, bracing • Medications • NSAIDs • Opiates • Surgical fusion
Muscle spasm pain • Pain with visible and palpable spasms • Anti-inflammatory medications • Anti-spasticity medications • Baclofen • Tizanidine
Secondary overuse syndromes • More common in paraplegics • Pain in intact areas • Delayed onset • Shoulder pain: arthritis, tendinitis • Pain from CTS, ulnar nerve entrapment • Other arthritis
Shoulder pain • 50-95% prevalence • Secondary to: • Weight bearing • Overuse • Muscle imbalance
Shoulder pain: Differential diagnoses • Rotator cuff tendinitis and tear • Muscle pain • Radiculopathy • Arthritis
Elbow / Hand pain • Elbow pain (32%) • Hand pain (48%) • Differential diagnosis • Epicondylitis / tendinitis • Olecranon bursitis • Arthritis • CTS, Ulnar nerve entrapment
Diagnostic tests • Physical examination • Plain x-ray • MRI • EMG
Treatment options • Rest • Therapeutic exercises • Modalities- TENS, Acupuncture • Changes in positioning, ergonomics • Changes in equipment • Splints • Weight reduction
Treatment options • Anti-inflammatory medication • Opioids • Injections • Acupuncture • Surgical release for CTS
Neuropathic pain • Nerve root entrapment • Syringomyelia • Transitional zone pain • Central dysesthesia syndrome • Nerve entrapment syndrome
Nerve root pain / radicular • Unilateral pain in the single nerve root distribution • At the level of spinal trauma • Pain since the time of injury • Lancinating, burning, stabbing, shooting, paroxysmal, allodynia, hyperesthesia
Transitional zone pain • At the border of normal sensation and numb skin • Bilateral • Burning, aching, allodynia, tingling • Pain within first few months of injury • Injury to the gray matter of dorsal horn
Central pain syndrome • Pain below the level of injury • Constant • Fluctuates with mood or activity • Responds poorly to medications or other treatment
Pathophysiology of Neuropathic pain • “Imbalance hypothesis” • Imbalance between dorsal column and spinothalamic tracts • “Pattern-generating mechanism” and “loss of spinal inhibitory mechanisms” • Loss of inhibitory control • Focal hyperactivity in the spinal cord and thalamus
Pain description • Tingling • Shooting • Stabbing • Squeezing • Pressure • Cold • Numbness • Muscle cramp
Exacerbating factors • Noxious stimuli below the level of injury • Fatigue • Lack of distraction • Smoking • Psychological stress • Overexertion • Weather changes
Nerve entrapment syndrome • Carpal tunnel syndrome • Ulnar nerve entrapment • at the wrist • across the elbow • Radial nerve entrapment
Nerve entrapment syndrome: risk factors • Use of assistive devices • Routine pressure relief • Weight shifts • Transfers • Wheelchair mobility
Syringomyelia (Syrinx) • Delayed onset, years • New neurological deficits • Constant, burning pain • Pain to touch • Diagnosed with MRI • Treatment: shunt
Syringomyelia (Syrinx) • Delayed onset, years • New neurological deficits • Constant, burning pain • Pain to touch • Diagnosed with MRI • Treatment: shunt
Treatment • Pharmacological • Nerve blocks • Physical • Surgical • Stimulation techniques • Psychological • Acupuncture
Pharmacological treatment • Anticonvulsants • Antidepressants: • Alpha-adrenergic agonists • Opioids • Anti-spasticity medication
Anti-seizure medications • Carbamazepine (Tegretol) • Initially 100 mg, bd, gradually according to response; usual 200 mg tds/qid, up to 1.6 g • Gabapentin (Neurontin) • 300 mg on d1, then 300 mg BD d2, then 300 mg TDS on d3 Increase to response in steps of 300 mg daily (in 3 divided doses) every 2–3 days to max. 3.6 g daily
Antidepressants • Tricylic antidepressants: amitriptyline (Elavil), nortriptyline (orth hypo), imi & desipramine • Effective in neuropathic pain • Increase pain inhibitory mechanisms • May be used in combination with anti-seizure medication
Anti-spasticity medication • Relief of muscle spasms • Baclofen • Clonazepam • Dantrium
Alpha adrenergic agonists • Relief of neuropathic pain • Clonidine: By mouth, 50–100 micrograms 3 times daily, increased every second or third day; usual max. dose 1.2 mg daily • Zanaflex: over 18 years, initially 2 mg daily as a single dose increased according to response at intervals of at least 3–4 days in steps of 2 mg daily (and given in divided doses) usually up to 24 mg daily in 3–4 divided doses; max. 36 mg daily
Capsacin • Topical, 0.025%, • Applied to skin overlying the painful area, a small amount 4 times daily • Deplete substance P,cause pain from nerve ending
Opioids • May be used in neuropathic pain • Side effects • Physical dependency • Severe constipation • Mild cognitive impairment • Risk for addiction ( 3/52)
Therapy • Positioning • Modify transfer techniques • Splinting • Padded gloves / elbow pads • Exercise routines
Other interventions • Acupuncture • TENS unit • Spinal cord stimulator • Dorsal rhizotomy
TENS unit • Electrical stimulation on skin • More effective at the level of injury? • Requires a therapist for set-up
Spinal cord stimulator • Not generally helpful with SCI pain • More effective with transitional zone or radicular pain • Initial improvement in 20-75% of patients • Long term efficacy in 10-40%
Surgical intervention • Spine stabilization • Removal of instrumentation • Decompression of impinged nerve roots • Decompression surgery for syrinx
Dorsal root rhizotomy • May be more effective in radicular pain or neuropathic pain at the level of injury • Risks of cerebrospinal fluid leaks, sensory or motor level changes
Psychological treatment • Psychological assessment • Cognitive behavioral therapy • Relaxation techniques • Biofeedback • Peer support
Visceral pain • Above, at or below the level of injury • Poorly localized if at or below the LOI • Non-specific symptoms: • Nausea, vomiting, anorexia • Autonomic dysreflexia • Fever