Transcript Neuropathic Pain (excluding headache)

PAIN AND PAIN
SYNDROMES
Dayna Ryan, PT, DPT
Winter 2012
Neuropathic Pain
(excluding headache)
• What will the patients tell you?
• numbness / tingling / pins / shooting / needles /
uncomfortable / burning
• Definition of pain
• “...unpleasant sensory and emotional experience
associated with actual or potential tissue damage, or
described in terms of such damage…”
• Neuropathic pain caused by direct lesions or
disease affecting somatosensory pathways
• e.g. sensory nerves, nerve roots, thalamus, cortex
Central Post-Stroke Pain Syndrome
• Overview
• First described by Déjerine & Roussy in 1906 as
“Thalamic Pain Syndrome”
• Characterized by gradual onset of neuropathic pain
& sensory disturbances after stroke (~50% within 1
month of stroke)
• Vascular lesions in somatosensory pathways in the
brain, especially spinothalamic cortical tract
• Etiology is central sensitization
• Signs & Symptoms
• Distribution of symptoms
• Sensory disturbances
• Abnormal sensation
• Allodynia: pain evoked by stimuli that is usually not
painful (e.g. touch or brush)
• Neuropathic pain
• A variety of qualities: burning, pricking, aching,
lacerating, shooting, squeezing
• Spontaneous
• Evoked, elicited by mechanical or thermal stimuli
• Intense, 3-6 on 10 point scale
• Usually a daily pain with varying pain-free intervals
lasting a few hours at the most
• Diagnosis
• History of pain
• Imaging confirming a CNS lesion (CT, MRI)
• Comprehensive somatosensory test
• Rule out other causes
• Treatment
• Antidepressants (amitriptyline)
• Anticonvulsants (gabapentin)
• TENS is occasionally helpful
Migraine
• Overview
• Varies in intensity, frequency, duration
• Commonly unilateral
• Associated with anorexia, nausea & vomiting
• Some are preceded by neurologic & mood disturbances
• Incidence
• 6% of men / 18% of women = 1/3
• 1st attack before age 40 in 90% of patients
Lesion involves vasculatures of the brain (blood vessels
dilation cause headache)
Etiology: unknown
• Genetic factors
• Environmental factors, e.g. stress, pain
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Phases of Migraine
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Prodrome: last hours or days
Aura: last < 1 hour prior to pain
Headache: last 4 to 72 hours
Postdrome: hours or days after pain
Classification of Migraine
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Migraine with aura
Migraine without aura
Visual aura
Signs & Symptoms
• Prodrome
• Mood disturbances, loss or changes in appetite
• Aura
• Focal neurological symptoms
• #1 visual disturbances; #2 paresthesias
• Headache
• Episodic, commonly unilateral, build up gradually
• Dull, throbbing pain
• Nausea, vomiting, fatigue, pallor
• Photophobia, sonophobia, blurred vision
• Aggravated by physical activities
• Postdrome
• Fatigue, aching, tender head
• Increased urination (i.e. diuresis)
• Diagnosis
• History
• Occasionally EEG (focal slowing)
• Treatment
• Acute
• NSAID, narcotics
• analgesics (+caffeine)
• rest in dark & quiet place
• Prophylactic medication
• PT
• Biofeedback
• C-spine manipulation & modalities
• Sleep
Cluster Headache
• Overview
• Rare but most painful
• Episodic (80% of patients)
• Chronic (pain >= 12 months without remission)
• Primarily in men age 20 to 50
• Black males
• Lesion Site: vasodilation of one external carotid artery
• Etiology
• Vasodilatation ipsilateral to the pain
• ANS dysfunction (activation of trigeminal vascular & parasympathetic
systems)
• Genetic link
Signs & Symptoms
• Pain
• Sudden, excruciating, mostly unilateral
• Orbital & frontotemporal
• Boring & non-throbbing
• Short duration (15-180 min)
• Wake patient up from sleep
• Autonomic symptoms
• Ipsilateral to the headache
• Photophobia
• Tearing, nasal congestion
• Horner’s syndrome
• constricted pupils
• droopy eyelid
• Diagnosis
• History
• Treatment
• Avoid precipitating factors
• alcohol
• abrupt changes of sleeping patterns
• anger, anxiety
• altitude > 5000 feet
• laying down
• Ergotamine (vasoconstrictor)
• Biofeedback & exercise
Muscle Tension Headache
• Overview
• Most common type of headache
• “bandlike”, “tightness” head pain
• Intermittent, recurrent, or chronic
• Etiology
• Lesion site: Musculoskeletal disorders at C-
spines, TMJ, and atlanto-occipital joint
• Previous trauma to neck
• Abnormal neck & trunk posture
• Stress increases muscle tension
• More common in women
Signs & Symptoms
• Pain
• Bilateral forehead, temples, or back of head &
neck
• Radiates to neck & shoulders
• Non-Pulsating, vasoconstricting, moderate
intensity
• Last <= 7 days
• Minimum aggravation by physical activity
• Tender scalp, rigidity/spasm of neck
• Diagnosis
• History, rule out other causes, referred pain
• Treatment
• NSAID or anagelsics (+ caffeine), TCAs
• Biofeedback, massage, heat
Trigeminal Neuralgia (CN V)
• Etiology
• Unknown
• Herpes zoster, multiple sclerosis,
tumors
• Demyelination
• pain fibers become hyper-excitable in
response to mechanical stimulation (e.g.
pressure, touch)
• Incidence
• More common in women
• More common in older adults age
50-70
• Spontaneous remission in some cases
• Signs & Symptoms
• Sudden onset
• “like a lightning bolt inside my head that lasts for
seconds to minutes”
• Sharp, shooting pain
• Most common in 5th CN V2 (maxillary) & V3
(mandibular) branches
• Diagnosis
• History
• No sensory or motor impairment
• Imaging studies to rule out other causes
• Treatment
• Anticonvulsant (Tegretol)
• Neurosurgical procedure (rhizotomy)
Post-Herpetic Neuralgia: “shingles”
• Etiology
• Reactivation of varicella zoster virus (chicken pox)
causes inflammation in cranial or dorsal roots ganglia
• Demyelination & degeneration of affected nerves
secondary to inflammation
• Onset & Course
• Mostly in older adults age 50 to 70
• Immuno-compromised individuals at risk
• 1%-2% (rarely) develops motor paralysis
• Prognosis is good unless motor neurons or vision is
affected
• Early Signs & Symptoms
• Fever, malaise, GI disturbances
• Tingling and pain, followed by rash and blisters along
affected dermatomes
• Thoracic & trigeminal most commonly affected
• Skin lesions last ~ 1 month
• Later Signs & Symptoms
• Pain
• chronic
• severe
• constant
• aching, burning, cutting, stabbing
• Diagnosis
• Clinical presentation
• Treatment
• Treat symptoms. No cure.
• Corticosteroids (for itching), antiviral (Acyclovir)
• Analgesics, Lidocaine patches
• Controlled-release oxycodone
• Implications for PT
• Relaxation
• Avoid heat & ultrasound
• Get vaccinated yourself!
• Don’t touch the skin lesions! (Contagious!)
Complex Regional Pain Syndrome
• Overview
– usually affect arm or leg
– uncommon, chronic condition
– Classification
• CRPS1: Type 1 (“Reflex Sympathetic Dystrophy”)
– 90% of cases
– Occurs after an illness or injury that did not
directly damage the nerves
• CRPS2: Type 2
– Occurs after a distinct nerve injury
• Etiology: secondary to some type of trauma usually
• Lesion site: Overactive sympathetic efferent fibers
• General Signs & Symptoms
• Intense burning or aching pain
• Swelling (cycles with pain)
• Trophic skin changes
• Thinning
• Shininess
• Loss of wrinkling
• Stages
• Stage 1
• Pain increases with stress
• Changes in skin & nails
• Stage II
• Tremor, dystonia, inability to initiate movements
• Joint stiffness, swelling
• Stage III
• Muscle atrophy
• Joint contracture
• Diagnosis
• X-ray, bone scan identifies the bone affected
• Thermographic to study skin temperature
• Sympathetic ganglion block will abolish pain
• Medications
• Sympathetic nerve block
• Corticosteroids (prednisone)
• NSAIDs for pain and inflammation
• Antidepressants (amitriptyline) & anticonvulsants
(neurotin)
• Intrathecal Baclofen to control dystonia
• Implanted dorsal column stimulation to reduce pain
• PT to increase mobility, TENS, modalities
Phantom Limb Pain
• Overview
– Pain is felt distal to residual limb
– Pain varies from mild electrical shock, tingling, to
intense shooting, throbbing or burning
– Present in 75% of amputee, persistent & chronic in
~ 5% of amputees
– Prognosis is poor with pain > 6 months
• Etiology
– Overactive central pain pathways due to loss of
peripheral sensory inputs
– Maladapted cerebral cortex remapping
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Treatment
• Anesthesia to brachial plexus fibers
• Pain medications
• Surgery to remove scar entangling a nerve
• Mirror Therapy
• Virtual Reality
• Biofeedback, relaxation
• Heat & massage (PT)
• TENS (PT)