Lesions

Question 1

Lesion of a spinal nerve results in?

Answer 1

weakness

Question 2

Lesion of a peripheral nerve results in

Answer 2

paralysis. We assume complete severance. All muscles suppled by that
peripheral nerve will be paralyzed, flaccid, and will
atrophy.

Question 3

Position of limb after injury depends on

Answer 3

antagonistic active of

intact muscles.

Question 4

Skin areas supplied by spinal nerves (dermatomes) are different from the skin areas supplied by?

Answer 4

peripheral nerves (but
correlated…). May be partial or complete loss of sensation in areas supplied
by injured nerve depending upon the extent of damage

Question 5

Sensation after injury can manifest as

Answer 5

pain, paresthesia, or anesthesia

Question 6

why do patients mainly notice sympathetic deficits?

Answer 6

because parasympathetics don’t do anything with body wall

Question 7

sympathetic deficit that are notices?

Answer 7

Vasomotion (flushing), sudomotion (anhydrosis -lack of sweating), pilomotion

Question 8

autonomic deficit visceral affects?

Answer 8

bladder, bowel, and erectile desfunction

Question 9

spinal cord injury above L2
causes?
motor?
sensory?

Answer 9

Causes: Vertebral
dislocation/traumatic injury,
tumors, penetrating wounds,
etc.
Motor: Paralysis of entire lower
limbs, bladder/bowel
dysfunction
Sensory: Complete loss of
sensation of lower limb and
perineum

Question 10

spinal cord injury at L4
motor?
sensory?

Answer 10

Quadriceps and adductors would be spared. Abnormal
gait. Bladder/bowel dysfunction.
Sensory: Preserved over lateral and anterior thigh, leg,
and foot

Question 11

spinal cord injury at S2
motor?
sensory?

Answer 11

Motor: Only intrinsic foot
muscles affected for lower limb,
and dysfunction in bladder,
bowel, and sexual functions.
Sensory: Loss of sensation down
posterior limb, external
genitalia, and area around anus

Question 12

sacral plexus injury
causes?
motor?
sensory?

Answer 12

Causes: Childbirth, pelvic operations, tumors, penetrating
wounds…
 Motor: Variable, but can affect gluteal muscles, posterior
thigh, leg, and foot. Bladder, bowel, sexual dysfunction.
 Sensory: Gluteal region, posterior thigh, leg, and foot

Question 13

Lesions of L1/L2 branches?

Answer 13

Causes: Entrapment from scar tissue (c-section, abdominal surgery, hernia repair, etc). Deficits mainly sensory – loss of sensation, tingling, pain. May radiate. May be worse when walking, bending at the waist, or to the touch

Question 14

Lesion of lateral femoral cutaneous nerve?
causes?
motor?
sensory?

Answer 14

Causes: Entrapment behind lateral end of inguinal ligament. (Tight clothing, heavy tool belt, obesity, scar tissue, pregnancy…)
Motor: None
Sensory: Pain, anesthesia, or tingling down lateral thigh

Question 15

Lesion of femoral nerve?
causes?
motor?
sensory?

Answer 15

Causes: Vascular
disease, trauma
Motor: Weakness of
thigh flexion, loss of
leg extension,
weakness of hip
rotation, weakness of
hip abduction,
weakness of leg
flexion.
Sensory: Pain,
anesthesia, or tingling
down anterior thigh,
anterior & medial leg

Question 16

Lesion of obturatorl nerve?
causes?
motor?
sensory?

Answer 16

Causes: Trauma, pelvic
fractures, ovarian
cancer, pregnancy
Motor: weakness of
hip adduction,
weakness of hip
flexion, weakness of
hip extension,
weakness of leg
flexion.
Sensory: Pain,
anesthesia, or tingling
down medial thigh

Question 17

Lesion of L2 and L4 causes loss of both?

Answer 17

obturator and femoral nerve

Question 18

lesion of superior gluteal nerve?
motor?
sensory?

Answer 18

Motor: Weakness in hip abduction, unstable pelvis (difficulty walking and
abnormal gait- positive Trendelenberg sign), weakness of medial rotation of the hip.
Sensory: None

Question 19

lesion of inferior gluteal nerve?
motor?
sensory?

Answer 19

Motor: Weakness in hip extension (especially from a flexed position), weakness in lateral rotation of the hip, difficulty climbing stairs/running.
Sensory: None

Question 20

Lesion of pudendal nerve?
causes?
motor?
sensory?

Answer 20

Cause: Trauma, tumor, childbirth, ‘cyclist syndrome’.
 Motor: Bowel dysfunction (external anal canal), erectile dysfunction…
 Sensory: Pain, anesthesia, tingling around anus and external genitalia.

Question 21

Lesion of sciatic nerve?
causes?
motor?
sensory?

Answer 21

Causes: Herniated
discs, IM injections
Motor: Weakness of thigh extension, weakness of leg flexion, loss of dorsiflexion and plantar flexion, loss of
all foot movements.
Sensory: Pain, anesthesia, or tingling down posterior thigh, posterolateral leg,
heel, and sole of foot

Question 22

Lesion of tibiall nerve?
causes?
motor?
sensory?

Answer 22

Causes: Penetrating wound, popliteal aneurysm,
Motor: Weakness of plantar flexion, loss of toe flexion & toe ab/adduction.
Sensory: Pain, anesthesia, or tingling at distal posterolateral leg, sole of foot.

Question 23

Lesion of common fibular nerve?
causes?
motor?
sensory?

Answer 23

Causes: Penetrating
wound, trauma *WRAPS AROUND HEAD OF TIBIA
Motor: Loss of foot inversion and eversion, weakness of plantar flexion,
loss of dorsiflexion (FOOT DROP- swing foot around), loss of toe extension.
Sensory: Pain, anesthesia, or tingling at distal anterolateral leg, dorsum of foot