Lecture 6 - Neurological Scan Exam Flashcards
Neurological scan exam purpose:
Rule out serious pathology
Determine if a neural component is involved
Clears neurological structures
When to do neurological exam:
Referred pain
Muscle weakness without pain
Tingling, numbness
Spinal pain
neurological scan exam helps to determine:
whether the pathology is caused by
- nerve root
- peripheral nerve
with neurological scan exams you must be able to differentiate:
A dermatome (nerve root) from the sensory distribution of a peripheral nerve
A myotome (nerve root) from muscles supplied by a specific peripheral nerve
How many nerve root pairs are there? Where are they located?
31 nerve root pairs
8 cervical
12 thoracic
5 lumbar
5 sacral
1 coccygeal
Define dermatome
Area of skin supplied by a single nerve root
define myotome
Groups of muscles supplied by a single nerve root
- Isometric contraction for at least 5 seconds
- Repeat at least 6 times
define sclerotome
Area of bone or fascia supplied by a single nerve root
A segmental nerve has what components
Segmental nerve has a motor, sensory, and autonomic component
A facilitated segment is an area of increased irritation produced by skin, muscle, nerve, periosteum, ligament or tendon which produces an ___ response
afferent
An efferent reaction may be:
Sensory
-pins and needles
Motor
- muscle spasm
- trigger points
- weakness
ANS
-circulatory, perspiration, reflex, goose bumps, increased skin drag, skin pitting
Neurological deficits are not all or none
The first neurological change is fading of the response
Test myotomes and reflexes _ times in a row to see if the response fades
Hold for _ seconds
Fatigue indicates a facilitated segment at that _____ level
The first neurological change is fading of the response
Test myotomes and reflexes 6 times in a row to see if the response fades
Hold for 5 seconds
Fatigue indicates a facilitated segment at that vertebral level
The individual nerve roots are examined by testing;
Dermatome
Myotome
Reflexes
Nerve root compression is involved when all three are positive and may be involved if one or two tests are positive
Nerve root testing dermatome:
Segmental innervation of the skin supplied by one spinal root
Testing for altered sensation
Dermatomes vary
Positive dermatome test
-Patient does not feel the sharpness of the pin or pinwheel in one dermatome
C4 – S2 key test sites
- Above or below these areas provide a challenge
- C4 important cause phrenic nerve which innervates diaphram to stimulate breathing
Nerve root testing dermatomes upper quadrant:
C4 – lateral neck C5 – shoulder cap C6 – thumb or thumb to 2nd finger interspace C7 – middle finger C8 – lateral edge of little finger T1 – inner forearm T2 – arm pit
Nerve root testing dermatomes lower quadrant:
L3 – over knee L4 – below medial malleolus L5 – in web between 1st and 2nd toe S1 – below lateral malleolus S2 – sole and heel of the foot
Nerve root testing myotomes:
Segmental innervation of the muscle
Test key muscles for weakness or pain
Isometric test repeated 6 times, hold for 5 seconds
Pain and weakness on contraction
Nerve root testing myotomes upper quadrant:
C1 -head nodding of occiput on atlas (test tucking in chin) C2 -neck rotation of C1-C2 C3 -lateral flexion of the neck C4 -shoulder shrug -diaphragm and its ability to lower C5 shoulder abduction, elbow flexion C6 elbow flexion, wrist extension, elbow supination C7 elbow extension, wrist flexion C8 thumb extension T1 finger abduction
nerve root testing myotomes lower quadrant:
L2 – hip flexion
L3 – knee extension
L4 – dorsiflexion
L5 – great toe extension, ankle eversion, extension of all four toes
S1 – ankle plantar flexors, up and down on toes, great toe flexion
S2 – resisted knee flexion
reflexes upper quadrant:
C5-C6 – biceps jerk
C6 – brachioradialis jerk
C6-C7 – triceps jerk
reflexes lower quadrant:
L3-L4 – knee jerk
L5-S1 – achilles jerk
L5 – extensor digitorum brevis jerk
Tap on bulge on lateral side of foot
Minimal movement expected not very strong reflex
nerve root testing scleratome:
Areas of bone that are supplied by one nerve root
Not tested but be aware of bone tenderness
Describe visceral and somatic convergence
Each spinal root has autonomic fibres which innervate visceral organs and smooth muscle of the blood vessels
Nerve root compression can cause visceral and vascular changes
Facilitated segments
*Remember nerve roots have a somatic and visceral innervations
What is a nerve root?
A nerve root is a portion of the peripheral nerve that connects the nerve to the spinal cord
- Single nerve root may serve more than 1 peripheral nerve e.g. median nerve c6, c7, c8 ,t1
