Chapter 29 Radiculopathy Flashcards
In a sensory radiculopathy of a single nerve root, would you expect sensory loss to be
A) severe in the discrete distribution of a dermatome or
B) vague and poorly localized paresthesias?
Because dermatomes overlap widely with adjacent dermatomes, it is very unusual for an isolated radiculopathy to present with severe or dense sensory disturbance. Paresthesias are usually poorly localizable.
- What PNS disorder is suggested by a discrete area of dense sensory loss? (459)
Well-defined dense numbness is more consistent with a peripheral nerve lesion than a radiculopathy.
Which is more consistent with a radiculopathy of exactly one root: paralysis or weakness? (459)
Because muscles receive innervation from more than one nerve root, radiculopathy at just one level should result in weakness rather than paralysis.
- Which roots contribute to the brachial plexus but don’t have reliable associated muscle stretch reflexes? (459)
C5 and C6 contribute to biceps and brachioradialis. C7 is the chief supply to the triceps. C8 and T1 don’t have reliable associated muscle stretch reflexes, although abnormalities of C8 will sometimes suppress triceps.
- Which reflex is often unobtainable but when present and asymmetric could be a clue to an L5 radiculopathy? (459)
Although the quads allow testing of L3 and L4 and the ankle jerks allow testing of S1, there is no reliable muscle stretch reflex to test for L5. When present and asymmetric, the medial hamstring reflex can contribute to a clinical picture of an L5 radiculopathy.
- Can a patient have clinically significant radiculopathy with a normal spine MRI? (460)
Yes. Many causes of radiculopathy may not be apparent on MRI including vasculitides such as diabetes; infections including Zoster, HSV, CMV and Lyme disease; and infiltration with sarcoid or by tumor.
- Your patient describes pain in the neck, shoulder and anterior arm with paresthesias in the shoulder. You find abnormal spontaneous activity on needle study of deltoid, supraspinatus, infraspinatus, rhomboids, biceps and brachioradialis. Radiculopathy of which root is most consistent with this picture? (460)
This picture is most consistent with radiculopathy at C5. Paresthesias of C6, which also supplies these muscles, would include radial forearm, thumb and index finger.
- Horner’s syndrome is most associated with radiculopathy of which root? (460)
You would be most likely to find a Horner’s syndrome with a T1 radiculopathy.
- Which 3 muscle groups could be weak in an L3 or L4 radiculopathy? (460)
(460) Both L3 and L4 supply quadriceps and thigh adductors. Illiopsoas is more L3 than L4. To recap, L3 supplies quads, adductors and illiopsoas; L4 supplies quads and adductors.
- Name 3 muscles that move the ankle that are supplied by L5. (460)
L5 supplies tibialis anterior, tibialis posterior, and the peronei.
- An L5 radiculopathy could result in weakness of tibialis anterior, tibialis posterior and the peronei. Which ASIA exam key muscle is also supplied by L5? (460)
L5 supplies extensor hallucis longus.
- An L5 radiculopathy could result in weakness of tibialis anterior, tibialis posterior and the peronei. Extensor hallucis longus could also be affected. Name 2 hip muscles that L5 supplies.
(460) L5 supplies gluteus medius and tensor fascia latae.
- Three muscle sets are key muscles for an S1 radiculopathy, 1 each in the lower leg, thigh and hips. Name these three muscle groups. (460)
For an S1 radiculopathy, in the lower leg test the plantarflexors. In the thigh test the hamstrings. In the hips test the gluteus maximus. Plantarflexors, hammies, gluts.
- In an S1radiculopathy, the sensory disturbance is in the lateral foot, posterior calf and sole of the foot. Where’s the sensory disturbance in an L3 radiculopathy? (460).
In an L3 radiculopathy, the sensory disturbance is in the anterior thigh.
- In an L3 radiculopathy, the sensory disturbance is in the anterior thigh. Where’s the sensory disturbance in an L4 radiculopathy? (460).
In an L4 radiculopathy, the sensory disturbance is in the medial calf and medial foot.
- In an L4 radiculopathy, the sensory disturbance is in the medial calf and medial foot. Where’s the sensory disturbance in an L5 radiculopathy? (460).
In an L5 radiculopathy, the sensory disturbance is in the dorsum of the foot, the great toe and the lateral calf.
- In an L5 radiculopathy, the sensory disturbance is in the dorsum of the foot, the great toe and the lateral calf. Where’s the sensory disturbance in an S1 radiculopathy? (460)
In an S1 radiculopathy, the sensory disturbance is in the lateral foot, posterior calf and sole of the foot.
- In an L3 radiculopathy, the sensory disturbance is in the anterior thigh. Where is pain? (460)
In an L3 radiculopathy, pain is also in the anterior thigh and groin.
- In an L4 radiculopathy, the sensory disturbance is in the medial calf and medial foot. Where is the pain? (460)
In an L4 radiculopathy, pain is in the anterior thigh but not in the groin.
- In an L5 radiculopathy, the sensory disturbance is in the dorsum of the foot, the great toe and the lateral calf. Where is the pain? (460)
In an L5 radiculopathy, pain is in the posterolateral thigh and calf, extending into the great toe and dorsum of the foot. In other words, the pain is in the posterolateral thigh plus the distribution of sensory disturbance.
- In an S1radiculopathy, the sensory disturbance is in the lateral foot, posterior calf and sole of the foot. Where’s the pain? (460)
In an S1 radiculopathy, the pain is in the posterolateral thigh and calf, extending into the lateral toes and heel. In other words, the pain is roughly in the posterolateral thigh plus the distribution of sensory disturbance.
- Your patient with radiculopathy has pain that radiates into the foot. Which two root levels are the most likely cause? (460)
Pain radiating into the foot is more likely to be caused by L5 and S1 radiculopathies than L3 or L4.
- Your patient with radiculopathy has pain that radiates into the anterior thigh. Which two root levels are the most likely cause? (460)
Pain radiating into the anterior thigh is more likely to be caused by L3 and L4 radiculopathies.
- Can entrapment neuropathies such as carpal tunnel syndrome and cubital tunnel syndrome cause pain proximal to the entrapment?.
(461) Although entrapment neuropathies don’t result in proximal paresthesias, they can refer their pain proximally into arm and shoulder