peripheral nerves

3 nerves of the UE + neuropathy

issues can happen at any point, but typically where the nerves travel through tight spaces— these problems with the peripheral nerves are called neuropathy

• trauma (cut, tear) and also prolonged pressure can result in nerve damage

• a common occurrence with nerve damage is also demyelination (degeneration of the protective coating of nerves)

• 3 nerves

  • radial

  • ulnar

  • median

paresthesia

weird sensations when sensory input returning (burning, tingling, etc.)

• normal

protective sensation

minimal acceptable level of sensation to be able to protect yourself (e.g., from heat, sharp/dangerous objects); sensitivity to touch as well as temperature

• monofilaments

• 2-point discrimination

• hot/cold testing

nerves are responsible for autonomic responses as well, i.e.,

problems include

• loss of sweating,

• loss of wrinkle response in water,

• abnormal nail/hair growth, and

• sensitivity to temperatures (e.g., cold sensitivity)

tests: Semmes Weinstein monofilament

a set of thin plastic filaments of different widths gets pressed against someone’s skin— testing light touch

• if you cannot feel a certain width (a thicker one), you may have lost your protective sensation in a specific area

tests: two-point discrimination

touch with 1 or 2 points (that can come in varying distances)— testing light touch and possible loss of sensation

tests: O’Riain wrinkle test

keep hand submerged and observe lack of wrinkles

radial nerve

+ names for radial nerve injuries at different levels:

• drop wrist

• crutch palsy

• saturday night palsy

• Posterior Interosseous Nerve Syndrome

• radial tunnel syndrome

mostly posterior + radial parts of the arm + hand, allows extension at the…2/2 innervation of the extensor-supinator group of muscles of the forearm

• elbow

• wrist

• MP

names for radial nerve injuries at different levels

• “you’re gonna need a DR AND CRUTCHES AFTER SATURDAY NIGHT am I right?”

  • “DR CUMA == Drop wrist 2/2 Radial nerve” at low lesion

    • or “can’t keep the radiant bracelet on 2/2 radial nerve injury (it keeps falling off 2/2 wrist drop!)”

  • crutch palsy at high lesion (radial nerve injury at the axilla)

    • loss of triceps, leading to difficulty with elbow extension

    • e.g., when you use crutches for too long

  • saturday night palsy

    • e.g., after falling asleep with your arm over the back of your chair— your mid-humerus getting compressed

• Posterior Interosseous Nerve Syndrome— PINS

  • where nerve gets pinches/compressed in your posterior interosseous area

• radial tunnel syndrome

  • pain at lateral forearm 2/2 radial nerve compression

  • —> long arm splint

most common splint for radial nerve

1. wrist cock-up splint (supports wrist, but leaves fingers free), though an elbow flexion orthosis might be needed for a high-level injury

   1. limit tension on the area of repair/injury (i.e., give some slack during positioning for the nerve to heal)

2. or dynamic extension splint (also positions wrist in extension, like ^, to…)

   1. protect extensor tendons from being over-stretched during healing

   2. position in functional use

ulnar nerve

+ names for ulnar nerve injuries:

• claw hand

• cubital tunnel syndrome

• Guyon’s Canal Compression

+ common functional issues

travels down the ulnar half of the ring and little fingers + 1 branch innervating the thumb; needed for (1) *power grip, (2) strong wrist flexion, and (3) key pinch

• names for ulnar nerve injuries…”CU, CU, GU— CUma, CUbital, GUyon”

  • Claw hand, Ulnar == “DR CUMA”

    • hyperextension of MCP + flexion of IP joints on 4th and 5th digits

  • CUbital tunnel syndrome

    • pain at your elbow

    • numbness/tingling on the ulnar side of the forearm and hand

    • positive tinel’s sign

    • treatment: elbow splint, often used at night, to prevent elbow flexion

  • GUyon’s Canal Compression— asks Ulnar Canal

    • ulnar nerve compression in the anterior, ulnar side of your wrist

    • positive tinel’s sign

    • treatment: neutral wrist splint

• common functional issues…”The CLAW is the KEY”

  • loss of grip strength

    • especially power grip 2/2 heavy assist by your 4th and 5th digits

  • loss of key pinch

  • unable to hold objects in hand

Froment’s sign/Jeanne’s sign

ulnar nerve test

• have person hold onto a piece of paper as you pull away

  • positive sign ==> indicative of ulnar nerve injury

    • if they are unable to hold onto the piece of paper; it slips out

    • if they display compensatory movmenets, i.e., bending their finger (image)

• “I’m Jeanne Froment, key pinch specialist” *hands you business card*

• “Froment == “meant for me”

Wartenberg’s sign

ulnar nerve test showing involuntary abduction of the 5th digit

• fingers make a “W”— wants to get away from the “warty” 4th digit

common treatments for ulnar nerve

1. to address MCPs in hyperextension, you’d want an MCP dorsal flexion-block splint to counteract and keep MCPs in a more flexed position

2. to address cubital tunnel— which is at the elbow— use a nighttime splint to limit elbow flexion

   1. e.g., towel duct-taped around the elbow

median nerve

+ names for ulnar nerve injuries:

• ape hand

• sign of benediction

• pronator teres syndrome

• anterior interosseous syndrome

+ common functional loss

mostly anterior part of the arm, innervating 1st 3 digits and half of the 4th digit; important for *fine motor and sensation of 1-3 digits, basically the lumbricals and opposition of the thumb

• Median, Ape Hand == “DR CUMA” at low lesion

  • flattening of the thenar eminence + thumb adduction

  • also slight flexion of index and middle fingers

• sign of benediction at high lesion— or the “high almighty God”

  • problems with flexing 1st 3 digits, when trying to make a fist, 2/2 issues with the proximal median nerve innervating finger flexors)

• names for median nerve injuries…“straight shot up into the carpal tunnel”

  • pronator syndrome (anterior forearm)

    • like carpal tunnel (same symptoms) but occurs at the elbow

    • —> splint would be elbow splint

      • 90 degrees flexion

      • forearm neutral

  • anterior interosseous syndrome (anterior forearm)

• common functional loss

  • loss of thumb opposition and palmar abduction impedes grip formation for tasks that require pinch or grasp

*fine motor is mostly done with 1-3 digits

carpal tunnel syndrome (CTS) + signs and symptoms

compression of the median nerve at the wrist

• cause: increased pressure in the carpal tunnel

  • edema

  • trauma

  • repetitive movement

  • vibration

  • poor/awkward posture (e.g., side-sleeping with flexed wrists)

  • conditions that cause fluid retention or inflammation

    • obesity

    • diabetes

    • rheumatoid arthritis

    • hypothyroidism

    • pregnancy

signs and symptoms

• paresthesia: numbness & tingling, often described as pins and needles

• muscle weakness

  • —> clumsiness

  • —> difficulty with fine motor difficulties

• advanced CTS— muscle wasting or atrophy of thenar eminence

tinel’s sign

median nerve test involving percussion along the median nerve (on the volar wrist) to elicit a response

• if it causes uncomfortable sensations (e.g., shooting pain and paresthesia), it could be positive sign of carpal tunnel

• “rain on a TIN roof”— ~tap, tap tap

Moberg Pickup Test

median nerve test involving picking up objects from the table (e.g., coins, screws, etc.) with first 3 digits

• Moberg Pickup = Median Pickup

Phalen’s

median nerve test, testing for carpal tunnel— “FAILING” to pray

• flexed position puts pressure on the median nerve

• if you start to feel symptoms after being in that ^ position for a few mins

  • ==> positive test

Durkan’s test

median nerve test, involving holding and pressing the carpal tunnel for ~30 secs

• pain or paresthesia —> positive sign of carpal tunnel

conservative treatment for mild carpal tunnel syndrome (CTS)

• icing

• activity modifications

  • resting and avoiding painful activities (e.g., repetitive movements, forceful gripping)

• splinting

  • splint the wrist in neutral; extreme flexion or extension could increase pressure in the carpal tunnel

  • also mostly worn at night

    • semi-flexible and soft > hard, rigid splint

• may be paired with corticosteroids/cortisone injection

  • to help reduce inflammation and relieve pain

• iontophoresis and phonophoresis

  • enhanced delivery and absorption of topically applied anti-inflammatory medication (e.g., hydrocortisone, dexamethasone, NSAIDs)

  • difference

    • iontophoresis= transmission via electrical current

    • phonophoresis= transmission via ultrasound

  • safety considerations

    • medication allergies

    • contraindications (e.g., pregnancy)

• once CTS is more controlled (less pain and inflammation), you can do some exercises; introduce slowly!

  • always start with stretching

  • nerve and tendon gliding

  • strengthening

  • resistance

surgical option for advanced mild carpal tunnel syndrome (CTS)

+ post-operative care

carpal tunnel release

• cut the ligament that goes over the carpal tunnel (transverse carpal ligament) to make more space for the tendons of the median nerve to pass + release pressure on the median nerve

• *common complaint post carpal tunnel release

  • = pain on either side of surgery site for several weeks, making grasping objects difficult during recovery

post-operative care

• edema control

• AROM

• nerve/tendon gliding

• sensory re-education (protective sensory re-education is essential for peripheral nerve damage)

• strengthening exercises, particularly for thenar muscles

• activity modification

most common splint for median nerve

1. wrist cock-up splint with wrist in neutral (good to wear at night too for carpal tunnel syndrome); MP, thumb, or elbow support might also be necessary

   1. e.g., c-bar to maintain web space and prevent thumb adduction contracture— splint thumb in palmar abduction and slight opposition

   2. e.g., opponens splint to maintain thumb in a functional position, in which the thumb opposes the index and middle fingers

   3. e.g., elbow in 90-degree flexion for a high-level injury

***splinting may be combined with cortisone injection to reduce inflammation

concepts: proximal vs distal

peripheral nerve injuries will vary based on the location + severity of the injury, but proximal is worse than distal

• e.g., a radial nerve could have a lesion or impingement in the…

  • axilla,

  • mid humerus

  • elbow

  • or any 1 of several forearm locations, with impairments ranging from

    • limited sensory loss to

    • complete motor/sensory loss of muscles innervated by the radial nerve

OT role

• manage/prevent complications including pain and further injury

• maintain function— ROM and nerve gliding

• facilitate regaining function

non-surgical treatments

• nerve gliding

  • to prevent adhesions and contractures

  • a moving nerve is a healthy nerve!

• sensory re-ed

  • continue to make sensory connections + organize input

• pain management

  • education

  • desensitization

  • modalities

nerve gliding

goal: maximize movement, minimize strain— don’t apply force at the end of the movement; it increases strain

• keep proximal part relaxed/on slack for the ideal ~gliding motion (floss example)!

• “motion is lotion”

sensory re-ed

help healing sensory system to reorganize correctly

• 1st: emphasize protection (compensate for loss of hot, cold, pain)

  • use vision or protective clothing/orthoses— compensatory techniques for safety!

• then discriminatory sensation:

  • QoL > safety

  • stereognosis— what’s in my pocket? (using just sensation/touch alone to use the hand functionally)

pain management

• body ramps up pain sensitivity following injury

  • can lead to CRPS (chronic regional pain syndrome)

    • == a rare and severe chronic pain condition that usually affects an arm, leg, hand, or foot; it causes intense pain that is much stronger and lasts longer than what would normally be expected after an injury, surgery, stroke, or heart attack

• education on the source and minimizing fear is important

  • pain is an experience in the mind— is heightened by fear

  • educate patient on this process; help them decrease fear

desensitization

sensory system is oversensitive; one can become permanently fixated on all stimuli being noxious (beginning stages of CRPS)

• having client touch around or on the sensitive areas with a cloth or toothbrush while relaxing to train sensation as non-noxious

  • grade up with more and more sensation

modalities

will depend on whatever is effective and safe for the client

• CAUTION: if the protective sensation is compromised do not use superficial heat or cold

post-surgical treatments

orthosis to limit tension/stretch on nerve (why a lot of the splints have the wrist at neutral); follow up with surgeon regarding progression of therapy

brachial plexus

position of the injury in the brachial plexus corresponds fairly well with the location of the deficits

• upper and lateral == upper arm

  • upper brachial plexus injury —> will affect the upper part of the arm

• lower and medial == lower arm

  • lower brachial plexus injury —> will affect the lower, distal part of the arm/hand

• posterior is radial

  • posterior brachial plexus injury —> posterior nerve/radial type of injury

nerve injuries of the hand, call…

“DR. CUMA”

• Drop Wrist— Radial nerve

  • palm side down, your wrist is unable to hold against gravity

• (ulnar) Claw— Ulnar nerve

  • your 4th and 5th digits at rest will have

    • MCPs in hyperextension

    • PIPs/DIPs in flexion, which is what creates the ~hooked look

• Ape hand (and *sign of benediction)— Median nerve

  • problem with the muscles that pull your thumb forward (i.e., loss of palmar abduction and opposition), resulting in a cranked-back thumb at rest that is in line with all the rest of your fingers

  • *when making a fist, only the 4th and 5th digits will flex down and your 1st 3 digits stay up

    • happens when your median nerve injury is more proximal, resulting in an affected forearm + flexors

claw hand vs hand of benediction

claw hand

• injury to ulnar nerve

  • low level ulnar nerve injury: loss of innervation to

    • —> interossei muscles

    • —> ulnar lumbricals (which allow our MCP to flex and IPs to extend; without lumbricals, long extensor muscles hyperextend the MCPs)

      • ==> clinical sign: at rest, MCP hyperextension + PIP/DIP hyperflexion on 4th/5th digits

• splinting:

  • MCP flexion block splint or

  • dynamic ulnar nerve splint

hand of benediction

• injury to median nerve

  • high level median nerve injury: loss of innervation to

    • —> many flexor muscles

      • ==> clinical sign: when actively attempting to make a fist, flexion of only the 4th and 5th digits