Muscle Disorders and Treatment Flashcards
what are the musculoskeletal disorders
- myofascial pain syndrome (MFPS) - centrally maintained pain
- myalgia
- fibromyalgia- centrally maintained pain
- spasm
- myositis
what are the mechanisms that produce pain for masticatory skeletal muscles
- overuse or ischemia (bruxism)
- psychological or emotional states can alter muscle tone (anxiety)
- endogenous substances can sensitize nociceptive nerve endings
- masticatory muscle pain
myofascial pain syndrome characterized by:
presence of trigger points in any voluntary muscle which cause referred pain and referred tenderness and may be active or latent
trigger points evoke:
referred pain which usually originates from a distant site rather than the site of the pain complaint
what are active trigger points
painful to palpation or spontaneously produce local pain or refer pain and autonomic symptoms to remote areas in reproducible patterns characteristic of each muscle
what are latent trigger points
exhibit local tenderness but do not currently cause spontaneous clinical pain or symptoms
what is the definition of a myofascial trigger point
- an irritable locus within a taut band of skeletal muscle or fascia which when stimulated elicits referred pain and tenderness (secondary hyperalgesia)
what is secondary hyperalgesia
referred pain from myofascial trigger points is dull and aching, usually deep and can range from discomfort to incapacitating pain
what are the considerations during the muscle palpation exam
- remember that the pain location may not be the source of pain
- palpate the masseter and temporalis muscles with mouth open
where can myofascial pain be found
in any voluntary muscle
MFPS is a ____ pain
centrally mediated
describe the pain on MFPS
chronic, continuous muscle pain (myalgia) that is aggravated by function and refers pain beyong the boundary of the masticatory muscle being palpated
what is nociception
- stimulation of specialized nerve endings designed to transmit information to the central nervous system concerning potential or actual tissue damage
- a specialized nerve ending that senses painful or harmful sensations
why is myofascial pain the most elusive and difficult to dx
it refers pain to other locations in the mouth and in the face and head and does not always follow cranial nerve distributions
what are the diagnostic criteria that must be present to dx myofascial pain
- regional dull, aching pain aggravated by mandibular function when muscles of mastication are involved
- trigger points have a characteristic pattern of pain referral and alters the pain complaint on palpation or spontaneously
- more than 50% pain reduction occurs with vapocoolant spray or local anesthetic injection (trigger point infection) using 1% procaine without vasoconstrictor
myofascial pain may be accompanies by:
muscle stiffness
- sensation of acute malocclusion not verified clinically
- ear symptoms, tinnitus, vertigo, toothache, tension type headache
- decreased mouth opening (if masticatory muscles involved)
- hyperalgesia in region of referred pain
what is hyperalgesia
an increased response to a stimulus that is normally painful
what is the pathophysiology of masticatory myofascial pain
- not fully understood
- suspect lower pain thresholds in these individuals
- estrogen and nerve growth factor may cause increased nociception which causes pain sensitivity
- hyperexcitability in CNS and upregulation of nociceptive processing (decreased inhibition of pain)
what are the parts of the central synapse
- thalamus
- locus ceruleus
- calcitonin gene related peptide
- glutamate
what does the thalamus do
relays sensory information to the cerebral cortex - pain, temperature, touch
what does locus ceruleus do
part of a major NE route of CNS
what does calcitonin gene related peptide do
contributes to pain transmissions and inflammation in migraine and neurogenic inflammation and is released from the primary terminals of primary sensory neurons. cell bodies of these neurons in the dorsal root and trigeminal ganglia give origin to unmyelinated and myelianted fibers conducting in the slow C or A- alpha range
what does glutamate do
major mediatory of excitatory signals in CNS, glutamate receptors are contained in most of the nerve cells and glial cells. NMDA receptor is a subtype of a glutamate receptor
what are the pain referral patterns for TMJ and ear pain
- masseter (deep)
- lateral ptyergoid
- medial pterygoid
- sternocleodomastoid
what are the pain referral patterns for a toothache
- temporalis
- masseter (superficial)
- digastric (anterior)
myofascial pain may be _____ and ____, resolving without serious long term effects
transient and self limiting
with myofascial pain avoid:
irreversible treatments such as occlusal adjustments
what are the diagnostic criteria that must be present to dx myalgia
- muscle pain reported by the patient in the jaw, temple, ear or pre auricular area in the last 30 days
- pain is aggravated by jaw movement or parafunction
- muscle palpation exam causes report of localized muscle pain at palpation site
- limited range of mouth opening MAY be present
myalgia is secondary to:
- ischemia
- bruxism
- fatigue
- metabolic alterations
- delayed onset muscle soreness from overuse
- protective splinting
what are the diagnostic criteria that must be present in myositis
- local muscle pain following injury (non infective) or infection
- edema, erythema and/or increased temperature over the muscle
what may be present in myositis
- serologic tests may reveal elevated enzyme levels (creatine kinase), markers of inflammation and the presence of an autoimmune disease
- diffuse tenderness over the entire muscle
- increased pain with jaw use if masticatory muscles involved
- limited range of motion of unassisted mandibular movements secondary to pain
what are the diagnostic criteria that must be present for myospasm
- acute onset of pain at rest and with function
- immediate report of limited range of jaw motion <40mm for vertical opening
- continuous involuntary muscle contraction
- EMG will confirm elevated elctromyographic activity compared to the contralateral unaffected muscle
- acute malocclusion MAY be preseent
myospasm is also known as:
trismus or cramp
myospasm occurs ______ in orofacial pain population and is typically caused by:
relatively infrequently; truama
difficult to differentiate myospasm between disc displacement without reduction clinically when:
limited unassisted vertical range of mouth opening is <40mm
what is contracture and what causes it
- shortening of a muscle due to fibrosis of tendons, ligaments, or muscle fibers
- usually not painful unless muscle is overextended
- history of radiation therapy, trauma, or infection is present
what diagnostic criteria must be present to dx contracture
progressive loss of range of motion with unassisted and assisted opening <40mm causing a “hard end feel”
what is the pathophysiology of fibromyalgia
- poorly understood but believed to involve a central sensitivity syndrome
- little evidence of peripheral tissue abnormalities
- may involve dysfunction of autonomic nervous system
what are the associated co-morbid medical disorders with fibromyalgia
- TMD (10% of population)
- inflammatory and neuroendocrine disorders
- IBS and functional chest pain from esophageal origin
- chronic pelvic pain
- headaches especially migraines
what is the dx for fibromyalgia
- widespread pain with bilateral diffuse musculoskeletal aches and stiffness both above and below the waist for more than 3 months
- associated with exaggerated tenderness in at least 11 of 18 specific anatomic sites
- commonly shows up as masticatory muscle pain
- tingling, numbness, tightness, stiffness and swelling may affect the jaw. dizziness is common
- toothache and gingival pain occur commonly in fibromyalgia patients
- may be associated with sleep deprivation and depression
- refer to rheumatologist
what diagnostic criteria must be present to dx fibromyalgia
- tenderness on palpation of at least 11 of 18 specified sites
- presence of widespread pain with concurrent masticatory muscle pain
- pain is bilateral and present above and below the waist
what are the effective fibromyalgia medications
- lyrica
- antidepressants (amitriptyline)
- savelle (SNRI)
what are the minimally effective fibromyalgia medications
- NSAIDs
- opiods
- benzos
what are the fibromyalgia conservative treatments
- sleep hygiene - keep bedtime and awakening time the same each day; only sleep while in bed- no TV or computers, rule out obstructive sleep apnea
- cognitive behavioral therapy to cope with pain
- light impact aerobic activity
- strength training with light weights
describe orofacial dyskinesia
- involves involuntary, choreatic movements
- may involve the face, lips and/or jaw disappearing during sleep
- may cause traumatic injury to the tongue or oral mucosa
- more common with advancing age, use of neuroleptic medications and/or traumatic brain injury, psychiatric or certain neurologic disorders
- patient must provide a history of dyskinesia involving the orofacial region, history and exam is positive for myalgia and arthralgia that worsens with episodes of dyskinesia
- cranial nerve exam is positive for sensory and/or motor nerve conduction deficit
how does orofacial dystonia affect pain and the mouth
painful and can make opneing/closing of mouth difficult, can impair speech, swallowing and chewing
what can cause orofacial dystonia
trauamtic injury to the brain/head/neck can trigger transient or permanent dystonia involving the masticatory muscles
orofacial dystonia is more common with what neurologic disorders
parkinsons disease or adverse reaction to medications espeically neuroleptic medications
what are the dx for orofacial dystonia
- pt must provide a history of dystonia involving the orofacial region, history and exam is positive for myalgia and arthralgia that worsens with episodes of dystonia
- cranial nerve exam is positive for sensory and/or motor nerve conduction deficit
- intramusclular EMG confirms the dystonia dx
what are the goals of treatment for masticatory muscle pain
- decrease pain
- increase ROM
- resumption of normal daily activities
- onabotulinim A injections for oromandibular dyskinesia and dystonias
what are the managment techniques for masticatory muscle pain
- PT
- splint therapy
- trigger point injection
- muscle relaxants
- NSAIDs
- rest (soft liquid diet for 2 weeks)
- heat/ice therapy (10 mins 2x a day)
- eliminate parafunctional habits
what are the treatments for muscle pain
- PT (stretching exercises, ultrasound, topical steroids with iontonphoresis, deep tissue release, vapocoolant)
- stabilization splint
- medications (NSAIDs, medrol dose pack, muscle relaxants, sleep medications, TCAs, local anesthetic injections)
- behavioral modifications (stress management, congitive therapy, elimination of parafunctional habits)
what is vapocoolant therapy made of
ethyl chloride
how is vapocoolant used
- spray and stretch
- apply 5 sprays to face 3x per day
- masseter/temporalis muscle stretch
- hold tongue on roof of mouth and open for 6 seconds, repeat 6 times. repeat 6 sets per day
how are trigger point injections done
use 1% lidocaine without vasoconstrictor - may require repeat injections 2-3x to inactivate trigger points
what is the dosing for acetominophen and the max dose
- dose: 325 Q4-6 hours or 500mg (ES) Q4-6 hours or 650 (ER) q8 hr
- max dose: 3g/day chronic pain
why is there a max dose for tylenol
hepatic failure/toxicity
what is the dose and max dose for IBU
- dose: 400-800 mg TID - QID
- max dose: 3.2g/day
what is the dose and max dose for aspirin
- 325-650mg q4h
- max dose: 4g/day
what is the dose for naproxen sodium
- 275-550mg BID
- 270-500mg BID
what is the dose for indomethacin PO
- 25-50mg BID-TID
what is the dose for indomethacin SR
75mg QD-BID
what is the dose for IBU
600-800mg BID-TID
what is the dose for ketorolac PO
10mg QID
what is the dose for ketorolac IM
30mg QD-BID
when do you prescribe an H2 blocker
- prescribe with the NSAIDs if use will exceed 2 weeks or if GI symptoms develop
- this will inhibit gastric secretion and serve to protect from GI side effects
what are examples of H2 blocker prescriptins
- prilosec 20mg QD
- nexium 40mg QD
what is the anti-inflammatory COX-2 inhibitor and dosage
celecoxib (celebrex) 100mg or 200mg QD-BID
what are the names of the muscle relaxants and when do you take them
- lioresal (baclofen)
- cyclobenzaprine (flexeril)
- carisprodal (soma)
- metaxalone (skelaxin)
- tizanidine hydrochloride (zanaflex)
- methocarbamol (robaxin)
what is the dose for lioresal (baclofen)
10mg 1 tab qd x 2d then BID-TID PRN may 80mg
what is the dose for cyclobenzaprine (flexeril)
5mg or 10mg TID PRN
what is the dose for carisprodal (Soma)
350mg 1 tab TID-QID PRN
what is the dose for metaxalone (skelaxin)
800mg TID QID PRN
what is the dose for tizanidine hydrochloride (zanaflex)
4 to 8mg q8H PRN
what is the dose for methocarbamol (robaxin)
1000mg QID PRN
what are the adverse effects of muscle relaxants
- dizziness
- drowsiness
- lightheadedness
- paradoxical stimulation
- abdominal pain
- nausea
- vomiting
- headahces
- nervousness
- urticaria
- hypotension
- blurred vision
- fatigue
- dry mouth
- constipation
