741 Lower Quarter Neurological Screen

what is included in a neurological screen

• dermatomes

• myotomes

• deep tendon reflexes

• upper motor neuron tests

dermatome

an area of skin supplied by the sensory fibers from a single spinal nerve root

sensory screen (light touch sensation) purpose

identify the presence, location, and pattern of sensory loss

dermatome for L1

inguinal region

dermatome for L2

anterior mid-thigh

dermatome for L3

medial side of the knee

dermatome for L4

medial low leg and foot

dermatome for L5

anterolateral leg to the dorsum of the foot

dermatome for S1

lateral side of foot

dermatome for S2

popliteal fossa

what does a sensory nerve root injury entail

if sensory loss coincides with a specific dermatome or spine segment

what does sensory peripheral nerve injury entail

sensory impairment coincides with the territory or location of a single cutaneous/peripheral nerve supplying that area

motor screen purpose

used to aid in determining if there is CNS or PNS involvement

what would happen if it was determined there was PNS involvement in a motor screen

additional follow up strength testing would need t be performed to determine if the PNS problem is due to damage to a nerve root or peripheral nerve

myotome

a group of skeletal muscles innervated by a single spinal cord level, on one side, by a single spinal nerve

myotome for L1/2

hip flexors

myotome for L3

knee extensors

myotome for L4

ankle dorsiflexors

myotome for L5

big toe extensor

myotome for S1

plantarflexors

myotome for S2

knee flexors

what does motor peripheral nerve injury entail

if muscle weakness is not segmental in nature, meaning other muscles in that nerve root, or spine segment, distribution or from adjacent segments are intact/strong

what does motor nerve root injury entail

if all muscles innervated by a particular nerve root or spine segment are weak

what does a normal motor screen grade mean

intact or strong and painless

what does an impaired motor screen grade mean

• weak and painless

• weak and painful

• strong and painful

deep tendon reflex purpose

looks to assess the integrity of the nervous system

patellar tendon reflex corresponding spinal levels

L3, L4

Achilles tendon reflex corresponding spinal levels

S1

Jendrassik Maneuver

ask the patient to interlock fingers and pull them apart; this causes a larger response because many motor units have been activated

deep tendon reflex grade 0

reflex is absent

deep tendon reflex grade 1+

trace response OR response elicited by reinforcement (maneuver)

deep tendon reflex grade 2+

average/normal

deep tendon reflex grade 3+

average/brisk

deep tendon reflex grade 4+

reflex is greater than normal but clonus is non-sustained

deep tendon reflex grade 5+

reflex is enhanced and clonus is sustained

hyperreflexia

herpactive or repeated movements from reflex

hyporeflexia

weak or absent muscle reflexes

upper motor neuron tests purpose

looking for any abnormal or positive findings that could implicate CNS lesion

Babinski reflex

a reflex that assess a motor response to scraping of the skin on the plantar aspect of the foot; looking for a extension of the big toe and flexion plus fanning of the little toes

Hoffman reflex

hold the middle finger and scrape the nail; looking for slight flexion of the fingers

Clonus

quickly move the ankle into dorsiflexion; looking for 3 or more beats

Inverted supinator reflex

tap over the distal radial styloid with reflex hammer to trigger a reflex of the brachioradialis; looking for finger flexion or elbow extension