Neuromuscular Flashcards
Mononeuropathy
involves single nerve (may have motor and sensory fibers)
Mononeuropathy Multiplex
simultaneous or sequential inflamm. of several nerves in unrelated parts of the body (noncontiguous nerve trunks)
Polyneuropathy
generalized, usually homogenous process affecting many peripheral nerves,
distal MOST affected
Does polyneuropathy affect more proximal or distal nerves?
DISTAL
Radiculopathy
irritation of nerve root: cervical, lumbar or thoracic
Plexopathy
injury to a nerve plexus: brachial, lumbosacral
Myelopathy
d/o of spinal cord
Myopathy
disease of muscle
Myotome
innervation of the muscle, functions of a spinal root
Dermatome
innervation of the sensory fans of spinal root
What is the pathophys of peripheral neuropathy?
impaired fxn of periphery nerves, sensory, motor or autonomic
In peripheral neuropathy when are the reflexes lost?
reflexes are lost EARLY!!!
peripheral early : physical exam
What causes peripheral neuropathy?
genetic traumatic infx toxins autoimmune nutritional vascular metabolic (renal/liver failure)
Are peripheral neuropathies inside or outside of the brain and spinal cord?
affects nerves OUTSIDE!
dying back/ demyelinating/ axonal
What causes neuromuscular junction d/o?
autoimmune (myasthenia gravis)
What is the pahtophy of neuromsk jxn?
hinder production, release or uptake of ACh
postsynaptic autoimmune attach doesn’t recognize the ACh
What happens the reflexes in neuromsk jxn?
reflexes are NORMAL
Where is the pathophys of myopathies and muscular dystrophy
muscle tissue is the primary site of pathology
What causes myopathies/ MD?
genetic
meds (statins)
autoimmune-inflamm.
hypothyroid
Reflexes in myopathies/MD?
Reflexes proportional to weakness!!
dec. muscle, dec. reflexes
What is motor neuron disease?
degenerative disorder
progressive weakness/wasting of muscle without sensory changes
What are the reflexes in MND?
HYPERreflexic with ATROPHY of the muscle!
counterintuitive
What labs do you run for these?
CBC & CMP HbAIc UA B12/MMA ESR, RF, ANA, SPEP Hep C, HIV TSH (no longer)
Muscular dystrophy presentation:
symmetric proximal weakness
not painful d/t dystrophy, but painful d/t posture
intact sensory function
intact bladder/bowel
What is progressive, degenerative and can be genetic?
Muscular dystrophy
What is Duchenne MD?
Affects Males the worst, don’t live long enough to reproduce
onset 3-5yo, progressive weakness
wheelchair by 12 yo
Pathophys of duchenne?
caused by mutation of the gene that makes dystrophin (GOOD and necessary serves many fxn inc. linking the contractile apparatus to the sarcomere
Concurrent conditions with Duchenne
scoliosis cardiomyopathies arrhythmias pulmo insufficiency contractures cognitive slowing cataracts high CPK > 3000, ALT enzymes elevated Calf HYPERtrophy (but WEAK)
How are the reflexes in duchennes?
proportional to the weakness
Tests for duchenne?
EMG- confirm muscular dx
Muscle bx– DNA to confirm
What is metabolic myopathy?
- error in energy metabolism d/t glycogen/lipid/mitochondria
- think metabolic w/ exercise intolerance, progressive myopathy, isolated respiratory distress
Labs for metabolic myopathy
Increase CPK resting lactate abnl urine abnl- organic acids serum ischemic exercise test EMG muscle Bx abnl serum acytcarnitine labs
Subtypes of metabolic myopathy
Types 2-4: MC Pompe’s Dz (acid maltase)
Type 5: McArdle’s Dz (myophosphorylase deficiency)
Sx of Glycogen storage dx (type 2-4)
Adults: ptosis, neck flexor weakness, pulmo weakness
bx with rimmed vacuoles
Sx of Type 5 McArdles
high intensity exercise intolerance and painful muscle ramps
Tx for glycogen storage type 2-4
enzyme replacement-
Myozyme
What are the muscle channelopathies?
Myotonia Congenita
Paramyotonia Congenita
Periodic paralysis
Which channelopathies are abnl sodium?
Paramyotonia Congenita
Periodic paralysis
P.S.
What channelopathies are abnl chloride
Myotonina Congenita
hey, it’s already MC!
Sx of myotonia congenita
myotonia present in second decade w/ improvement on myotonia w/ exercise and VERY muscular build
muscle stiff, large and do not fatigue but NOT weak
Sx of paramyotonia congenita
muscle pain, myotonia, stiffness, paralysis episodes and phenotypic types, cold intolerance
What is an attack of paralysis w/ either high or low K+ during attack?
Tx?
Periodic Paralysis
Carbonic anhydrase inhibitors