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Mechanisms of Disease -Myopathies


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what are the 4 main myopathies discussed?
what are the two neuromuscular junction (NMJ) diseases discussed?
Myasthenias Gravis
What Neuropathies were discussed?
median, ulnar, radial, peroneal nerve entrapment
what two forms of headaches were discussed?
(besides the one you get from class)
subaracnoid hemorrhage
what are the two inflammatory myopathies we covered?
name the myopathy:
*presents ages 5-14yo
*malar or heliotrope rash
*edema of periorbital skin
dermatomyositis- an inflammatory myopathy
Duchenne MD
Rubbery Calves - disease and cause of
Duchenne MD
from fat replacing CT
subsarcolemmal cytoskeletal protein
what disease does this pertain to:
sed rate, CPK-MM,Aldolase all increased
TX: Steroids and inmmunosuppressants
dermatomyositis and polymyositis inflammatory myopathies
most common dystrophy- especially kids and more common in bosy
Duchenne Muscular dystrophy
Stabbing, penetrating, burning, explosive pain
ONLY on one side of head
Starts at eyes and spread to same side of head
cluster headache
secondary symptoms of cluster headache
stuffy or runny nose
redness or watering eyes
droopy eyelid
constrx of pupil
facial swelling
what disease?
presents age 50-60 yo
can be viral, bacterial, idiopathic
what disease?
*axial muscle wkness
*phonation and deglutination affected*dysphonia & dysphagia
in what disease is abscence or abnormal levels of Dystrophin an issue?
Duchenne MD, dystrophinopathies
T/F? dystrophin protein is absent in all types of dystrophies?
FALSE, the "muscular dystrophies" have abnormalities with the muscle, not the protein
innervates skin of hand
flexor carpi digitorum
hypothenar muscles
ulnar nerve
results to Gower's Maneuver
Duchenne MD, when unable to walk
innervates flexor abductor digitiminimi
3rd and 4th lumbricals
interroseous muscles
ulnar nerve -
also innervates flexor carpi ulnaris
combined the lumbricals and interosseus help to
flex the MCP joint
extend the IP joints
compression of nerve and transverse carpal ligament
median nerve entrapment and carpal tunnel
foot drop
entrapment of peroneal nerve from wearing too tight boots
difficulty grabbing and opening a jar
symptom of carpal tunnel syndrome - median nerve injry
ape hand
median nerve entrapment
innervates skin of hand and most flexor muscles that flex fingers and wrist
median nerve
Claw hand
injury of ulnar nerve
CPK-MM increased to 50x Nl
fibrosis necrosis and Fat infiltration seen on biopsy
Duchenne MD
abscence of this protein causes wkness of sarcolemma and permits rupturing of muscle
Dystrophin - sarcolemmal cytoskeletal protein
walks on toes, contracture of achiles tendon, waddling gait
Duchenne MD
onset around age 4
ambulatory loss by age 8-12, death in teens or 20's
Duchenne MD
signs/symptoms of carpal tunnel
pain and paresthesia in wrist and hand
pain may radiate to forearm, elbow, shoulder
increased by flexion and/or extension of wrist
wkness of grip
weak thumb abduction and opposition
restrictive pulmonary deficit from progressive kyphoscoliosis ----disease?
Duchenne MD
the most common nerve entrapment injury
carpal tunnel syndrome
causes of carpal tunnel
repetitive stress
excessive use of wrist
CT thickening of the ligament
**arthritic tenosysnovitis
symptoms include generalized muscle cramps and early fatigue from exercise - lack of energy
McArdles metabolic myopathy- due to inability to break down glycogen to glucose for energy
pain and paresthesia in wrist and hand and first 3 1/2 fingers
carpal tunnel syndrome - median nerve entrapment
corticosteroid myopathy
complications of high dose steroids
Cushing's Syndrome
what treatments are available for carpal syndrome
splint wrist in neutral position
-steroid injection
-surgical decompression
division of carpal ligament
subsarcolemmal glycogen vacuoles seen histologically
McArdles-metabolic myopathy
treatment is limited to physical therapy and bracing
Duchenne MD
Tinsels test is diagnostic for
carpal tunnel syndrome
thenar atrophy is a late sign
carpal tunnel
caused by myophosphorylase deficiency
McArdles disease
what is Phalen's test?
carpal tunnel compression test -
an endocrine disorder in which the adrenal gland overproduces corticosteroids
Cushing's syndrome
causes muscle catabolism, atrophy of fibers, wkness in shoulder, hip and other areas
Cushing's Disease - a metabolic myopathy
symptoms can include:
dysphagia, dyspnea, nasal speech, smile degeneration to snarl
myasthenias gravis
what gland is a major player in Myasthenias Gravis?
Thymus gland - it produces the Ab that kill the Nm receptors causing rapid fatigability, and motor deficits
describe in order the affects of Myasthenias gravis on the body
1. eyelid-ptosis
2. extraocular - diplopia
3. bulbar muscles
-nasal speech
- jaw hangs open
4. dysphagia
mimetic muscle inactivity
smile degenerates to snarl
intercostal musclse and diaphragm depressed
death can be caused from respiratory muscle depression - cant take another breath in
botulism poisoning
rapid fatigability
bulbar muscles affected
Myasthenias Gravis
bacteria that cx foamy frothy food
Clostridium botulinum - an anerobic bacteria implicated in Botulism poisoning
deep tendon reflexes or sensory fx not affected but muscles of facial expression are
myasthenias gravis - a NMJ disorder
treatment includes discontinuation of steroids
Cushing's syndrome
treatment includes pyridostigmine, plasmaphoreses, IV gamma globulin and immunosuppressants
Myasthenias gravis - NMJ disease
some symptoms of this disorder include:
acute progressive wkness w/in 72 hours
-alpha motor neuron and parasympathetic terminals affected
-dilated pupils
-dry mouth
botulilsm toxin poisoning - a NMJ disorder
'index muscle' is used for diagnosis of this
ulnar nerve lesion
arthritis tenosysnovitis
implicated with carpal tunnel syndrome
bilateral damage, may be an issue related to systemic conditions, diabetes, alcoholism
this causes loss of deep tendon reflexes (DTR's)
unilateral affects
risus sardonicus is a rsult of ....
tetanus- Clostridium tetani
T/F, Tetanus is not a NMJ disease?
True, it is a result of bacillus bacteria invasion of the brain and spinal cord
destruction of cholinergic axon terminals causing a decreased release of Ach is a sign of
Botulism poisoning
what is the treatment for Botulism toxin?
IV antiserum
cardiorespiratory support may be needed
Bilateral damage
distal sensory nerves
Distal motor nerves
Bottoms of feet are 1st,
Dorsum and ankles
Calves and/or hands
affects of this include blocking of inhibitory neurons, hyperreflexia, and muscle spasms
Clostridium tetani, Tetanus
this affects the cubital tunnel
ulnar nerve
this includes entrapment of compound nerves: ulnar, median, radial, peroneal and tibial
mononeuropathies - where nerve entrapment is the key issue
this nerve is implicated in 'saturday night palsey'
Radial nerve entrapment
this can be seen and palpated on the thumb side of the 2nd metacarpal
index muscle - diagnostic for ulnar nerve lesion
symptoms include difficulty spreading fingers, 1st dorsal interooseus atrophy, wk or atrophied
ulnar nerve, cubital tunnel syndrome
prominent 1st dorsal interosseus atrophy is a sign of this
index muscle - early diagnosis of ulnar nerve paralysis
wrist drop
radial nerve entrapment
worst headache of my life
subarachnoid hemorrhage from ruptured cerebral aneurysm
innervates triceps, supinator, brachioradialis and skin of dorsum of hand
radial nerve
atrophy of lumbricals,interosseus and hypothenar eminence
ulnar nerve (mainly)
the MC cx of subaracnoid hemorrhage
rupture of a cerebral aneurysm
restlessness, agitation and nausea area result of this
cluster headache
signs are pain & paresthesia of dorsum of hand,fingers but not weak triceps, supination
injury at mid-humerus, from a blunt trauma
denervation causing muscle atrophy and tophic changes of the skin
atrophy of severe chronic denervation
this nerve innervates wrist and finger extensors and helps flex elbow and aids supination
Radial nerve
Lavisnky sign
take reflex hammer, stroked across ball of foot, and if upper motor neuron lesion in brain, the big toe flexes upward =
MC peripheral mononueropathy
proximal, middle,
which cranial nerves are ONLY sensory
olfactory, optic, vestibulochoclear
smell, vision, parasympa to eyes
olfactory, optic, occulomotor
in a cranial neuropathy that affects CN 3, what is a deficit?
medial rectus muscle - ocular convergence
levator palpebral - troubel opening the upper eyelid = hanging eyelid
what causes hanging eyelid?
damage to CN 3, affecting the levator palpebral muscle
superior oblique muscle, action and innervation
CN 4,trochlear N. moves eye down and medially
olfactory N
CN 1
CN 2, optic
parasympathetic to eye muscles
occulomotor CN 3
pupillary constrictor muscle CN 3
lens focus
CN 3, occulomotor
ciliary body
ocular convergence
medial rectus
opens upper eyelid
levator palpebral mucsle
superior oblique muscle
moves eye down and medially
oronasal mucus membranes and teeth
sensory action from CN 5, trigeminal
corneal reflex
cornea - sensory of CN 5, trigeminal
facial nerve actions
para to lacrimal gland - tears
submaxillary and
lateral movement of eye
lateral rectus , CN VI
submaxillary and sublingal glands - innervation
CN , facial
motor to jaw muscles, masseter temporal and pterygoid muscles
CN 5, trigeminal
anterior 2/3 tongue, taste, pinna of the ear
CN 7, facial - sensory fx
obicularis orus closes eye in response to
CN 7, facial nerve motor function
facial expression
facial mumetic muscles
this .....muscle elevates the pharynx and larynx and is innervated by.....nerve
stylopharyngeus muscle - CN 9 glossopharyngeal
sensory from semicircular canals, saccule and utricle for dynamic and static balance
innervated by vestibulocochlear n
pupillary constrictor, CN 3
CN 3, levator palpebrae
what two cranial nerves fx in salivation
CN 7, facial = submaxillary and sublingual
CN 9, glossopharyngeal - acts at parotid gland - salivation
? sensory from
S from: posterior 1/3 tongue=taste
*orpharynx - swallowing
eustachian tube - middle ear pain
carotid sinus & body
CN 9, motor to
stylopharyngeal muscles-elevates pharynx and larynx
CN 10 - Vagus
*para motor?
* sympa motor to
para motor to abd & thoracic organs
*sympa motor - solft palate, pharynx, larynx
CN 10 is sensory from ?
aortic bodies and arch
posterior 1/3 tongue
pharynx, larynx, ear cancal
CN 1 olfactory - cant smell
what innervates the tongue?
posterior 1/3 = CN 10
anterior 2/3 taste-CN 7
CN 12 - motor to tongue
motor action of sternocleidomastoid and upper traps
Cn 11, accessory
gag reflex
CN 10. cagus - via pharynx and layrnx
the difference b/t diplopia and blurred vision
diplopia is seeing two images from non fx EOM's and blurred vision is from failur of lens to accommodate - both CN 3
herperacusis (loudness)
stapedius muscle neuropathy - CN 7
unilatery palsy of front of neck when frowning, unilateral facial wkness
platysma muscle - and facial muscles from motor fibers of CN 7
sluggish or absent light reflex of eye
deficit to pupillary constrictor muscle of CN 3
jaw deviates to one side
CN 5 neuropathy of masticator muscles casuing wk or malaligned jaw
Tic douloureux
trigeminal neuralgia
short bouts of exruciating pain in any of the CN 5 facial divisions
what can cause Diplopia ?
EOM not fx due to
1. palysy of CN
2. entrapment of eye muscle
3. orbital fracture
from either CN 3, or CN 4
affecting medial rectus or superior oblique
Cn 6 - lacteral rectus
bilateral loss of corneal reflex , with numbness or pain
neuropathy of the facial dvision of trigeminal nerve
dry eyes, dry mouth
deficits of CN 7, facila nerve -
para to lacrimal gland, submaxillary, sublingual glands
vertigo and nystygmus
sensory fibers of CN 8 vestibular
severe pain in the ear for 2 days, vesicular rash in and external to ear
herpes zoster oticus
greatest cause of grey hair, hair loss, palsy of buttocks
this class - just checking to see if you were paying attention :-)
Bell's palsey
facial paralysis of cN 7
(w/assoc.drooling) cx by viral infx, entrapment of nerve (acoustic neuroma) lyme disease (bilateral palsy)
Meniere's Disease
recurrent episodes of low-freq hearing loss, tinnitus, vertigo, and nystygmus
cx by overproduction of endolymph in cochlear duct (CN 8)
sensoneural hearing loss
sensory from Cn 8, cochlear
causes of conductive hearing loss
-excessive cerumen
-otitis media
-congenital ankylosis of ossicles
-otosclerosis (older adults)
causes of sensorineural hearing loss
dying hair cells -neuronal fx abnormal from
2. ototoxic drugs
3. acoustic neuroma
4.Meniere's disease
what is Presbycusis
gradual dying off of cochlear hair cells with age
what are the ototoxic drugs?
aminoglycosides and diuretic
What is an acoustic neuroma?
slow-growing tumor (benign) of the Schwan cells (sometims schwannoma) surrounding CN 8, vestiublar portion
-unilateral deafness and nystagmus
what is nystagmus?
involuntary cyclic movement of the eyes
what is Meniere's Disease and how is it caused?
recurrent episodes of low-frequency hearing loss, tinnitus, vertigo and nystagmus
Cx: overproduction of endolymp in the cochlear duct
differentiate between true vertigo and vasovagal syncope
True vertigo- pt feels she is moving or her surroundings are moving, ALWAYS cx some nystagmus, vertical, rotary, or horizontal. Vasov. does not present with that
peripheral vertigo- cause
cx by abnl fx within the cochlea, semcircular canals or vestibular fibers of CN 8
peripheral vertigo - signs/symptoms
severe= pt falls; N/V, tinnitus or hearing loss and horizontal or rotary nystagmus
what are the 3 forms of peripheral vertigo?
Meniere's disease
Acoustic Neuroma
Vestibular neuronitis
Vestibular neuronitis:
viral,bacterial or idiopathic
(labrynthitis)acute onset vertigo, postural imbalance, N/V and persistent horizontal or rotary nystagmus.
NO hearing loss
abnl fx in the vestibular nuclei- brainstem, cerebellum or cerebral hemispheres
Benign Positional Vertigo
common in the elderly
acute change of head position getting into or out of bed
-due to carbonate crystals breaking off the otoliths in the utricle and clogging the posterior semicircular canal.
symptoms of central vertigo
mild, no N/V tinnitus or hearing loss;
-nystagmus can be rotary or vertical
in what diseases is central vertigo present?
*multiple sclerosis
*TIA, brainstem stroke
*cerebellar hemorrhage
what signs/symptoms often accompany central vertigo?
dysfunction of CN other than CN 8:
diplopia, dysarthria, dysphagia, facial wkness or numbness
pt's vertigo is due to stx such as cerebellum, brainstem, etc , this is .....
central vertigo
vestibular apparatus is composed of
3 semicircular canals
if pt's vertigo is due to a problem anywhere from the root of CN 8 - toward and into the labyrinth, it is..
peripheral vertigo
deficient or absent gag reflex stems from what neuropathy?
dificit in CN 9, or 10
severe pain in throat, tongue, and ear on swallowing
glossopharyngeal neuralgia
constant pain in one ear, severe pain in throat and tongue
possibly cancer of the pharynx
paralysis of soft palate, nasal speech, deviation of uvula toward normal side onn phonation - due to what nerve issue?
CN 10 vagus
hoarseness of voice results from
paralysis of larynx
weakness turning head to the right
paralysis of LEFT sternocleidomastoid muscle of CN 11 accessory nerve
weakness shrugging left shoulder
paralysis of left trapezius- CN 11, accessory
deviation of protruded tongue toward weak side, & may possibly see fasciculations and atrophy of paralyzed side of tongue
CN 12 neuropathy
unilateral, asymmetric
-distal axons are sick
-starts in feet
-symmetric,larger, fast-conducting, sensory fibers affected
-affects DC-ML and DTR
peripheral neuropathies
prototype for all peripheral neuropathies
diabetic neuropathy
2 phenomena of diabetic neuropathy
1. microangiopathy
2. direct axonal damage
happens to caps supplying distal nerves
-non-enzymatic glycosylation (caramellization)
-advanced glycosylation endproducts
-LDL trapped - atherosclerosis os small vessels
what tissues do not require insulin in order to take up glucose from the blood?
nerves, kdiney, vessel walls, lens of the eye
what happens when plasma glucose is too high for too long?
and increased amount of glucose diffuses into nerve, kidney, vessal walls and lens of eye (tissues)
negative effects of increased intracellular sorbitol and fructose?
sorbitol cx degeneration of schwann cells - demyelination
both: inc'd intracellular osmolarity>osmosis>CELL LYSIS & SCWANN CELL INJURY
signs and symptoms of diabetic neuropathy
large fiber neuropathy :
DC-ML fibers
sensory>bottoms of feet>lower leg>hand>
stocking and glove presentation
sensory:painles paresthesias, numbness, dec'd proprioception & vibration sense
motor:dec'd or absent ankle flexion, wk plantar/dorsiflexion
presents with small fiber neuropathy
A-delta, C-fibers==
distal pain and temp loss
proprioception/vibration preserved
Nl reflexes
unpleasant abnoarmal sensation produced by normal stimuli to skin
focal neuropathies
acute onset of neuropathies -
acute vascular occlusion-ischemia-pain and neuro deficient
diabetic opthalmoplegia
CN 3 cranial neuropathy
unilateral eye pain
neurological issue associated with diabetes
stocking and glove
focal neuropathies
cranial neuropathies
risk of carpal tunnel
autonomic neuropathies
hyperglycemic unawareness
hyperglycemic unawareness
unaware of early signs of low glucose:
-wkness,tremor, nervousness,tachycardia
sudden neuroglycopenia:
-visual disturbances
-confusion, bizarre behavior
T/F beta blockers are a recommended treatment?
Guillian-Barre' Syndrome
peripheral neuropathy
acute inflammatory demyelinating polyneuropathy
aka postinfectious polyneuropathy
affects of Guillian-Barre' syndrome
rapidly progressive, ascending motor wkness of:
legs,arms,resp myo, = paralysis
early & general HYPO- or areflexia
early paresthesias
NO true sensory loss
causes may include:
viral URI or GI infx, campylobacter jejuni infx, and may occur w/ SLE, or Lymphoma
Guillian-Barre' Syndrome
signs and symptoms of GB syndrome
symmetri or asymmetric ascending weakness
-legs,arms,resp. myo
-paralysis in 50%~1wk,90%1mo.
-early & genera. hypreflexia or areflexia, and paresthesias
1/3 on vent. support, most 2-4 wk, paralysis all 4 limbs
5% die
no true sensory loss,
definitive signs and labs of GBS
inc'd CSF protein w/out pleocytosis
-ALWAYS present w/early and gen. hyporeflexia or areflexia- if wk patient has NL reflexes its NOT GBS
prognosis and treatment for GBS
tx: leave it to the neuro team
prog: most recover completely w/in 3-6mo, some have residual weakness
Lou Gerhrigs disease - Amyotrophic lateral sclerosis(ALS)
cx relentless progressive deterioration upper and lower motor neuron
CN with parasympathetic motor fibers
Cn 3, occulomotor
CN 7, facial n
CN 9 glossophyrngeal
CN 10 Vagus -
primary headache
benign, no organic pathology
tention, cluster,migraine, rebound,caffeine withdrawl
secondary headache
underlying disease or pathology
-glaucoma, temporal artiritis, meningitis, intracranial hemorrage
sinusitis, influenza,severe HTN, lyme disease are what?
other secondary headaches
what are the majority of h/a classified as?
benign, primary
features of the h/p exam that indicate the h/a is secondary to serious pathology
marked change in h/a pattern
rapidly incrs. freq of h/a
sudden onset of severe
new onset after age 50
persistent h/a after trauma
what combination of other symptoms makes you suspect secondary?
h/a + fever, nuchal rigity, pailledema, clumsy, seazures, impaired mental status, focal neuro signs
T/F pain from the h/a stems from neuronal structures of brain parenchyma
FALSE, there are no pain receptors there
instead it comes from cranial structures
what cranial structures are implicated in the cause of pain of a headache?
1. head and neck muscles
2. scalp and vessels
3. meningeal & cerebral arteries
4. venous sinuses
5. pain AFFERENTS of CN 5,9,10
6 parts of dura matter at base of brain
cause of tension h/a
stress, anxiety, depression,poor posture, alcohol, various meds, osteorathritis
signs and symptoms of tension headache
from none to moderate throbbing
dull, pressing or band-like pain
treatment for tension h/a
self treat with aspirin, acetaminophen or ibuprophan

Rx: anaprox (naproxen)
antipyretic, analgesic, anti-inflammatory
NSAIDS, aspirin, but NOT acetamenophin - not anti-inflammatory
barbiturate that has potential for addiction
what happens if you use butalbital more than 2x week?
risk of progression to chronic daily h/a
= rebound h/a
define chronic daily h/a
presence of tension h/a at least 6 days/week
what Rx treatments for tension h/a?
NSAIDS, muscle relaxant
pericranial muscles
cause of tension h/a
they include the :
1. frontalis
3/ sternocleidomastoid
r. trapezius
T/F tension and cronic daily h/a's are avascular?
migraine - where
vascular h/a
cerebral cortex is hyperexcited, unilartery
head pain aka cephalalgia
mood change, blurred vision, flashing lights, photophobia, tingling, numbness
migrain headache
vasocontrictive phase
causes pts auras
vasodilatory phase
causes the headache itself
signs and symptoms of migrained
throbbing, unilateral,photophobia +/or phonophobia
wavy lines-teichopsia
weakness, clumsy

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