Neuropathies- Peripheral Neuromuscular Conditions

Question 1

Peripheral nerve characteristics

Answer 1

the thickness of myelin determines the conduction speed

Schwann cells–> PNS

oligodendrocytes–> central nervous system

Question 2

Neurapraxia

Answer 2

temporary failure of nerve conduction
without structural changes. Usually caused by blunt trauma, pressure, or ischemia.

Axon remains intact and muscle does not atrophy. Paresis gradually resolves.

Question 3

Axonotmesis

Answer 3

Axon is damaged due to crush, stretch,
lacerating injury or disease process.

Connective tissue support for the nerve remains intact

Question 4

Neurotmesis

Answer 4

Most severe axonal loss with complete
severance of the axon and its connective tissue coverings.

If the cell body remains viable, regenerative sprouting occurs with growth approx. 3mm/day near the lesion and 1mm/day further from the lesion.

Question 5

Neuropathy

Answer 5

wide variety of causes

disease or dysfunction of one or more peripheral nerves, typically causing numbness or weakness.

Question 6

4 Acquired and idiopathic neuropathies discussed in class

Answer 6

-trigeminal neuralgia- due to vascular compression

-Bell’s palsy- typically preceded by a viral infection
–> motor part of facial nerve is affected

-ICU-acquired weakness
—linked to multi-organ failure and ventilator > 2 weeks

chemotherapy-induced neuropathy
—common side affect of cancer treatment

Question 7

Bell’s Palsy characteristics (type of neuropathy)

Answer 7

• Differentiate from a stroke
• Urgent medical care is indicated for
  treatment
• Develops overnight
• 71% have a full recovery, 13% mild
  residual weakness

STROKE
-lesion in left side of brain –> the lower face is affected but you are still able to raise eyebrows due to area of lesion in the brain and the cortex gets information about the upper face on both sides

BELL’S PALSY
-upper and lower face affected because the lesion is not in the cortex but the facial nerve is affected–> lose upper and lower face innervation on one side of the face

Question 8

Trigeminal neuralgia characteristics

Answer 8

• Brief, intense “shock-like” bursts of pain
  within a distribution of the nerve
  (typically V2- maxillary division)
  –maxillary div of the trigeminal nerve: Supplies lower eyelid, cheek, nostril, upper lip, and upper gum.
• Pain control is needed
• Could be related to herpes zoster,
  inflammatory reactions, tumors, and other
  compression of the nerve

Question 9

types of infectious neuropathies:

Answer 9

poliomyelitis

PPS - post-polio syndrome

Question 10

types of immune-mediated/inflammatory neuropathies:

Answer 10

Guillain-Barre Syndrome / AIDP
(Acute inflammatory demyelinating polyneuropathy)

Question 11

types of hereditary neuropathies:

Answer 11

Charcot-Marie tooth also known as hereditary motor sensory neuropathy

Question 12

types of metabolic neuropathies:

Answer 12

diabetic neuropathy

Question 13

CMT characteristics:

Answer 13

DISTAL limb muscle wasting and
weakness, usually with skeletal deformities, DISTAL sensory loss, and abnormalities of DTRs

-begins with a peroneal nerve disorder–> ankle DF and EV affected
-later: weakness and wasting of intrinsic hand muscles, then forearm

ETIOLOGY:
-gene mutations that affect proteins involved in peripheral nerve axon or myelin sheath
-distal greater than proximal muscles –> usually LEs first then UE
-inherited disorder

-hereditary neuropathies: 43% of undiagnosed neuropathies

COMMON PATHOLOGIES/DEFORMITEIS:
-pes cavus- clawing of toes and high arch –> bones fracture and collapse–> rocker bottom deformity–> Charcot foot
–more common in children to have pes cavus
–adults: more common progression to rocker botttom

-pes cavus or rocker bottom can happen in adults with DM (different disease process)

Question 14

Are there any specific treatments for CMT?

Answer 14

NO

-goals of therapy - minimize deformity and max function

Question 15

PT management CMT:

Answer 15

prevent contractures

UE function- may need OT rx

pain - neuropathic vs MSK, joint preservation

balance- discourage barefoot walking, supportive footwear encouraged, gait aids encouraged

exercise- moderate level safe, focus on unaffected muscles, ** strength and function CAN improve

DOSE:
-40-60% 1 RM strengthening
-aerobic: 70-90% HR max, at intervals

-periodic short episodes of PT as needed
-assess and be proactive regarding work and modifications
-long term management key

Question 16

Surgical interventions CMT

Answer 16

Surgery for residual calcaneovalgus deformities at the ankle include triple
arthrodesis

-the term “triple” arthrodesis refers to a fusion procedure of three joints of the hindfoot; the subtalar joint (talus and calcaneus), the talonavicular joint, and the calcaneocuboid joint.

-perimalleolar tendon transfers –> compensate for triceps surae insufficiency

Question 17

DPN- diabetic peripheral neuropathy characteristics

Answer 17

“a descriptive term meaning a demonstrable
disorder, either clinically evident or subclinical, that occurs in the setting of
diabetes mellitus without other causes for peripheral neuropathy.” (consensus
statement)

** MOST COMMON METABOLIC NEUROPATHY
- 50% of those with DM –> DPN

-stocking-glove pattern–> sensory and motor nerves affected in a distal to proximal symmetric pattern
-vascular compromise–> nontraumatic amputations

-with decreased 1st toe and ankle joint mobility–> leads to increased risk for development of metatarsal ulcerations

-footdrop during gait is common in this population

Question 18

pathogenesis of DPN:

Answer 18

-caused by chronic metabolic disturbances that affect neurons and schwann cells

-vascular changes also affect the peripheral nerves

CAUSES OF METABOLIC DYSREGULATION:
-hyperglycemia, obesity, dyslipidemia
-oxidative stress
-increased AGEs
-mitochondrial dysfunction
-chronic inflammation
LEADS TO
-loss of neurotrophic signals/growth factors
-direct nerve damage and microvascular complications
-nerve degeneration

Question 19

PT treatment for DPN:

Answer 19

-SYSTEMS REVIEW:
-blood glucose
-blood pressure
-physician clearance

-proper footwear
-joint mob and stretching for 1st toe and ankle–> prevent ulcerations

-FOOT CARE:
–skin inspection
–pressure relief
–footwear

-FOOTDROP DURING GAIT:
–toe up device
-orthotics prescription

Question 20

Poliomyelitis characteristics

Answer 20

-caused by a virus that is highly infectious, especially in children < 5 yo

-initial symptoms: fever, fatigue, headache, vomiting, stiffness of the neck and pain in the limbs

-transmission: person-to-person fecal-oral route or by contaminated water or food

-PATHO: paresis–>paralysis within hours to days: affects anterior horn cells of SC

-5-10% die when their respiratory muscles become immobilized
-1/3 lifelong disability
-1/3 pretty healthy life

Question 21

What part of the NS is affected in those with polio?

Answer 21

focal and asymmetric motor impairments- anterior horn cells (possible brainstem) may be affected, absent DTR

RECOVERY attributed to:
-recovery of anterior horn cells, collateral sprouting from intact peripheral nerves
-hypertrophy of spared muscle fibers

Question 22

Acute infantile paralysis

Answer 22

mimics the symptoms of polio currently

-recent years have seen a marked decrease in polio vaccinations in the US –> could this lead to a resurgence?

Question 23

PPS- postpolio syndrome characteristics

Answer 23

-refers to new neuromuscular symptoms that occur decades after recovery

-in 25-50% of those with childhood polio–> develop PPS

-the compensated reinnervation that occurred cannot maintain that muscle fiber innervation later on in life–> new onset weakness

-FAST motor unit loss (twice that) compared to healthy ppl the same age (older than 60)

-if LE deterioration occurs–> upper extremity usage for compensation

Question 24

Key considerations for PPS for rehab:

Answer 24

** KEY FOR REHAB:
-partially denervated mm. does not have the physiologic capacity to respond to a conventional strengthening program

-individuals with PPS have decreased peak workloads and decreased oxygen uptake

REHAB FOCUS:
-non-exhaustive, general conditioning
-don’t fatigue
-monitor vital signs before and after–> Monitor the client’s response
-functional exercises at submaximal intensity –> maintain and improve endurance and functional capacity

-energy conservation techniques recommended

-COMPENSATION: gait aids, orthotics, circumstantial w/c use

Question 25

Guillain Barre Syndrome - Acute Inflammatory Demyelinating Polyneuropathy characteristics

Answer 25

Most common cause of RAPIDLY EVOLVING motor paresis, paralysis and sensory deficits (mild sensory loss/more profound motor loss)

INCIDENCE: peak frequency in the 5-8th decades

CAUSE: bacterial and viral infections, surgeries, vaccines, ** likely immune-mediated/inflammatory

COMMON PREOCCURENCE: respiratory or GI illness in the 30 days preceding the onset of symptoms - up to 90% of those with GBS

SYMPTOMS:
-first: paresthesia in toes–> weakness distally in legs
-distal to proximal sensory loss (symmetric)
-spreads to arms, trunk, and facial muscles
-flaccid paralysis
-no DTRs
-may need ventilator–> respiratory failure
-2-4 weeks until max weakness due to demyelination
-recovery takes weeks to months (the body repairs myelin)

Question 26

What are the primary targets of attack in those with GBS?

Answer 26

Schwann cells

-peripheral NS myelinating cells

Question 27

MED management of GBS/AIDP:

Answer 27

DIAGNOSIS
-lumbar puncture - albumin, 10 mononuclear leukocytes
-electrophysiologic studies- NCVs slowed if myelin is damaged
-fibrillations if axonal damage
-look for tachycardia, arrhythmia, labile blood pressure

TREATMENT
-plasmapheresis - removes and filters plasms–> remove or dilute antibodies
-high dose intravenous immunoglobulin

PROGNOSIS -poor factors
-older age
-longer time before recovery begins
-need for mechanical ventilation
-reduced evoked motor potential amp–> axonal degeneration

LONGER HOSPITAL STAY
-muscle belly tenderness
- severe lower limb weakness as measured by MMT
-ventilator depedence
-axonal damage
-lower FIM scores

Question 28

In those with GBS, the shorter time it takes for recovery to begin after maximum impairment has been reached _______

Answer 28

the less likely it is that long-term disability will occur

63 days- average length in acute rehab

Question 29

GBS management- ascending weakness phase

Answer 29

-DO NOT strengthen bc active demyelination is occurring

-look at the summary slide

Question 30

GBS management- descending weakness phase

Answer 30

-start to strengthen but don’t over fatigue and prioritize function –> remyelination is occuring

-begin a gentle exercise, avoiding fatigue
-consider compensatory devices
-decrease level of assistance needed
-pain control

** LOOK AT SUMMARY SLIDE

Question 31

GBS management- outpatient phase

Answer 31

look at the summary page on slide

-may resume more normal activity and exercise; fatigue and recovery from the activity may still be a limiting factor

-return to work, independence, exercise
-wean from compensatory devices, fall prevention

Question 32

What is the recommended RPE for those with peripheral nerve and muscle disorders?

Answer 32

RPE 4-6- Moderate (exercise is generally safe with modifications and careful monitoring)

• prevent deformity, skin breakdown, and falls
• plan for next stages if the disorder is progressive