ICL 4.5: UE Radiculopathies Flashcards
what is a radiculopathy?
commonly referred to as pinched nerve
refers to a set of conditions in which one or more nerve ROOTS are affected and do not work properly = a neuropathy
this can result in pain (radicular pain), weakness, numbness, or difficulty controlling specific muscles
how many pairs of spinal roots do you have?
31
ventral roots come from anterior horn and lateral gray matter = afferent neurons
dorsal roots come from dorsal root ganglion = efferent neurons
the roots combine to form the mixed spinal nerve which then split to form the anterior and posterior rami or divisions
T/F: all nerve roots exit the spinal cord above their corresponding vertebral level
false
C1-C7 cross above but then C8 goes below C7 and above T1 and the rest continue to do below
what is a myotome?
the muscles supplied by a specific nerve root
myotomes overlap! more than 1 nerve root can innervate a muscle
what is a dermatome?
the sensory distribution of a nerve root
what are the testing spots for the dermatomes of C5-T2?
C5 = lateral antecubital fossa (anterior shoulder to elbow)
C6 = thumb
C7 = middle finger
C8 = little finger
T1 = medial antecubital fossa (dorsal elbow to fingertips)
T2 = apex of axilla (armpit)
what is the pathophysiology of a radiculopathy?
- compression can be caused by disk herniation, osseous structures, tumors
presentation can be variable
- may have sensory or motor manifestations or both
- may have demyelination or axon loss
- reflex changes because of desynchronized slowing of the fibers that should be responding = hypo reflexive
what are the types of disc herniations?
Type 1 = bulging disc: bulging disc where disc convexity is beyond vertebral margins but annulus fibrosus and nucleus pulposus are intact though
Type 2 = prolapsed disc: fibers of annulus fibrosus rupture internally but outer fibers are intact
Type 3 = extruded disc: there is a tear of the annulus fibrous and nucleus pulposus is extruding out; nucleus pulposus is extending to the posterior longitudinal ligament
Type 4 = sequestered disc: nucleus pulposus is free in the spinal canal
does disc bulging cause radiculopathy?
not always; usually it doesn’t cause much of a compression on the spinal cord to cause a radiculopathy
but it can happen if the patient has an osteophyte and the two combined could cause a radiculopathy
so not all disc herniations will compress the nerve root
what patient population usually gets a herniated nucleus pulposus?
under 50 years old
can be spontaneous like during lifting activities, coughing, sneezing, bending, twisting
what patient population usually gets spinal stenosis?
people over 50 years old
the narrowing
what are the two common causes of radiculopathy?
- herniated nucleus pulposus = herniated disc
- spinal stenosis = narrowing of the spaces within your spine, which can put pressure on the nerves that travel through the spine
which cervical nerve root is most effected by radiculopathy?
C7
what are the uncommon causes of radiculopathy?
“Hi Madam”
H – Herpes Zoster
I – Inflammtory: TB, Lyme disease, HIV, syphillis, cryptococcus, sarcoidosis
M – Metastasis
A – Arachnoiditis: myelogram, surgery, steroids, anesthesia
D – Diabetes Mellitus
A – Abscess
M – Mass: meningioma, neurofibroma, leukemia, lipoma, cysts, hematoma
what is the clinical presentation of a radiculopathy?
- often sudden onset but can be slow onset
- exacerbated with: Sitting, coughing or sneezing, flexing neck
- radiating pain down a limb; ask a patient to trace the pain down the limb which will tell you which dermatome is being effected!
- sensory/neurologic changes along a dermatome – numbness, tingling, loss of sensation
- some complaints of only motor weakness
what would look for during a PE of a suspected radiculopathy?
- spine inspection to see if the have normal lordosis/kyphosis
- spine movement: flexion, extension, rotation and lateral side bending to see where they’re having pain
- manual muscle testing - weakness
- sensory examination to see if there’s impaired light touch or pin prick
- deep tendon reflexes; will be hyporeflexive if radiculopathy
- Provocative maneuvers aka Neural tension signs:
- Foraminal compression test or Spurling test
- Manual cervical distraction
- Lhermitte sign
what is the Spurling test?
used to test for radiculopathy
performed by positioning the patient with the neck extended and the head rotated, and then applying downward pressure on the head
test is considered positive if pain radiates into the limb ipsilateral to the side to which the head is rotated (pain on the same side that the head is turned toward)
what is the manual cervical distraction test?
used to test for radiculopathy
patient in a supine position, gentle manual distraction often greatly reduces the neck and limb symptoms in patients with radiculopathy
so by pulling their neck you are improving their symptoms
what is the Lhermitte sign?
used to test for radiculopathy
electric shock-like sensation radiating down the spine, and in some patients into the extremities, elicited by flexion of the neck
what happens to the reflexes if someone has a radiculopathy?
they become hyporeflexive
it’s essential to compare side to side because some people just have weak or strong reflexes
essential to check all reflexes!
what are the key upper extremity reflexes?
C5 – biceps (and brachioradialis)
C6 – brachioradialis
C7 – triceps
C8 – pronator quadratus (not a true reflex)
if there is a C5 nerve root radiculopathy, what will the reduced reflex, action weakness and numbness be?
reduced reflex of biceps brachii
weak elbow flexion
numbness in the lateral arm
if there is a C6 nerve root radiculopathy, what will the reduced reflex, action weakness and numbness be?
reduced reflex of brachioradialis
weak elbow flexion
numbness in the lateral arm
if there is a C7 nerve root radiculopathy, what will the reduced reflex, action weakness and numbness be?
reduced reflex of triceps brachii
weak elbow extension
numbness in the middle finger