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