Neurology of the lower limb Flashcards
How can spinal roots be tested following lower limb nerve injuries?
Test dermatomes and myotomes
What region of skin is in the L1 dermatome?
Groin level
What region of skin is in the L4 dermatome?
Anywhere on medial aspect of leg.
What region of skin is in the S2 dermatome?
Middle/back of thigh
What region of skin is in the S3 dermatome?
Gluteal region
Which dermatome do you walk on?
S1
Which dermatome do you sit on?
S3
What symptoms would a patient with S1 lesion experience?
Can’t feel interaction with the ground.
What do the cluneal nerves supply?
Cutaneous nerves of the buttocks
Which nerve supplies the first web space?
Deep peroneal nerve (L4, L5)
If a patient has a suspected peroneal injury, which areas of the lower limb should be tested?
Test dorsum of foot and first web space (lost deep branch as well as superficial?)
What does the lateral femoral cutaneous nerve supply? (L2, L3)
Skin over lateral aspect of thigh
Which region of skin does the femoral nerve supply?
Anterior thigh
Medial aspect of leg
Which region of skin does the superficial peroneal nerve supply (L5, S1)?
Lower lateral leg
Dorsum of foot (except first web space)
Which region of skin does the tibial nerve supply?
Sole of foot and posterior part of leg
Which myotomes are involved in flexion of the hip?
L2 and L3
Which myotomes are involved in extension of the hip?
L4 and L5
Which myotomes are involved in extension of the knee?
L3 and L4
Which myotomes are involved in flexion of the knee?
L5 and S1
Which myotomes are involved in extension of the ankle?
L4 and L5
Which myotomes are involved in flexion of the ankle?
S1 and S2
Which myotomes are involved in the inversion of the foot?
L4 and L5
Which myotomes are involved in the eversion of the foot?
L5 and S1
Which nerve roots supply the intrinsic muscles of the foot?
S2 and S3
Which nerve root is responsible for dorsiflexion of the big toe?
L5
Which nerve roots are responsible for moving the toes closer together?
S2 and S3
Which of femoral and obturator is A and P?
Anterior - obturator nerve
Posterior - femoral nerve
Which nerves supply the hip joint and knee joint?
Obturator nerve
Femoral nerve
Under what conditions may the nerves of the lumbar plexus be damaged?
Inflammation of psoas major
Pus in psoas sheath (TB)
Which muscle protects the nerves of the lumbar plexus?
Psoas major
What is the position of the femoral nerve relative to psoas?
Lateral
What is the position of the obturator nerve relative to psoas?
Medial
Which muscles protect the femoral nerve?
Abdominal muscles
Where might hip joint pain be referred to?
Knees
Why is the lateral femoral cutaneous nerve easily damaged?
Becomes cutaneous almost immediately after it comes through inguinal ligament
What is meralgia paresthetica/
Compression of the lateral femoral cutaneous nerve
What are the nerve roots of the lumbar plexus?
T12-L4
What are the nerve roots of the sacral plexus?
L4-S3
Paralysis of which nerve causes a positive Trendelenburg sign?
Superior gluteal nerve
Parlalysis of which nerve causes difficulty in climbing stairs?
Inferior gluteal nerve
What are the anterior divisions of the sacral plexus?
Tibial nerve
Nerve to obturator internus
Nerve to quadratus femoris
What are the posterior divisions of the sacral plexus?
Common peroneal
Superior gluteal
Inferior gluteal
Which nerve can be damaged by sitting on a hard chair?
Posterior cutaneous nerve of thigh
Which muscles are supplied by the superior gluteal nerve?
Gluteus medius
Gluteus minimus
Tensor fasica lata
Hip joint
Which muscle is supplied by the inferior gluteal nerve?
Gluteus maximus
Which nerve supplies the hamstrings then divides into the tibial nerve and common fibular nerve?
Sciatic nerve
What condition occurs due to damage of the sciatic nerve?
Sciatica
What is piriformis syndrome?
Compression of common peroneal component of sciatic nerve
Causes loss of muscle tone in anterior leg (foot drop)
Where is the sciatic nerve prone to injury?
Where it goes through tarsal tunnel
Which nerve is it more common to damage - tibial nerve or common peroneal nerve?
Common peroneal - either as it comes up the piriformis or when it goes around the neck of fibula after going through popliteal fossa
Damage to which nerve at the level of the neck of the fibula can cause an important neurological problem?
Common peroneal nerve
Which area of skin does the obturator nerve supply sensory innervation?
Inner thigh
Which area of skin does the femoral nerve supply sensory innervation?
Anterior part of thigh and leg
Which area of skin does the tibial nerve supply sensory innervation?
Posterior part of leg and sole of foot
Which area of skin does the common peroneal nerve supply sensory innervation?
Lateral part of leg
