Neuro: myotomes, dermatomes, reflexes Flashcards
What are the three neuro screens we have talked about so far
motor, somatosensory, and reflexes
motor
-assessed by myotomes
-observing muscle bulk (any atrophy etc)
-resistance to passive stretch (elbow and knee flexors)
Somatosensory
assessed by dermatomes
Reflexes
Assessed by deep tendon reflexes
myotomes
-muscles or muscle group innervated by a single spinal root, usually performing similar actions
Dermatome
-region of skin whose sensory information is received by a single spinal nerve root
C5 myotome
-shoulder abduction
(“arms out wide”)
(deltoid and biceps)
C6 myotome
-elbow flexion
(“flex on yo b*tch”)
(wrist extensors)
C7 myotome
-Elbow extension
(“no zombies in heaven”)
(triceps, wrist flexors, and finger extensors”)
C8 myotome
-Finger flexion (grip) or thumb abduction
(“you’re doing great”)
(finger flexors)
T1 myotome
-Finger abduction
(“high five son”)
(interossei muscles)
positive finding in myotome testing would indicate
significant weakness or diminished resistance relative to the opposite side
L2-L3 myotome
Hip flexors
(“bring up my knee”)
L3-L4 myotome
Knee extensors
(“kick down the door”)
L4 myotome
Ankle dorsiflexors
(“my foot is sore”)
L5 myotome
hallux extension
(“that’s a big toe guys”)
S1 myotome
Ankle plantar flexors
(“Put down to run”)
Somatosensory neuro screen is used for what
Dermatomes (light touch)
C5 dermatome
lateral antecubital fossa proximal to the elbow
C6 dermatome
Dorsal surface of the proximal phalanx of thumb
C7 dermatome
Dorsal surface of the proximal phalanx middle finger
C8 dermatome
Dorsal surface of the proximal phalanx little finger
T1 dermatome
Medial antecubital fossa proximal to the elbow
L2 dermatome
Anterior medial thigh
L3 dermatome
Medial femoral condyle above knee
L4 dermatome
over the medial malleolus
L5 dermatome
Dorsum of the foot at the third metatarsal phalangeal joint (just above the top of the middle toe)
S1 dermatome
Lateral aspect of the calcaneus (lateral heel)
S2 dermatome
Midpoint of the popliteal fossa (back of the knee)
Deep tenden reflexes
Biceps
brachioradialis
triceps
patellar
achilles
Biceps brachii DTR location
C5
Brachioradialis DTR location
C6
Triceps DTR location
C7
Patellar DTR location
L2-L4
Achilles DTR location
S1-S2
what is a DTR grade of 4+
very brisk response; associated with clonus
what is a DTR grade of 3+
Brisk response; possibly hyperreflexive
what is a DTR grade of 2+
Normal, average response
what is a DTR grade of 1+
Low-normal response
what is a DTR grade of 0
No response
what is a DTR grade of 1+(R)
Absent response which appears with reinforcement
what is a DTR grade of 0(R)
No response even with reinforcement
