Peripheral Nervous System Disorders II Flashcards
1
Q
What is Bells palsy/facial nerve paralysis
A
- Unilateral facial paralysis due to compression of CN VII caused by inflammation & swelling
2
Q
Incidence of Bells palsy/facial nerve paralysis
A
- Develops suddenly over hrs to days
- Causes one side of face to droop, become stiff over time
- Mostly temporary
- Affects 20-30 per 100,000 people/year
- Common age group 15-45 yrs
3
Q
Etiology and pathology of Bells palsy
A
- Suspected to be triggered by viral infections but lacks direct evidence, many cases lack signs of acute viral infection preceding onset
- More likely caused by re-activation of a latent virus rather than direct infection
- Most likely caused by herpes simplex/zoster, mumps, rubella
- Inflammation of the nerve causes compression that could lead to ischemia, demyelination, & axonal degeneration
4
Q
Risk factors of Bells palsy
A
- DM
- Pregnancy
- Hypothyroidism
5
Q
Describe the facial nerve course
A
- Passes through long bony canal causing increased risks for compression with inflammation & swelling
6
Q
Clinical manifestations of Bells palsy
A
- Unilateral facial paralysis, asymmetrical facial appearance
- Sx develop rapidly, often overnight
- Corner of mouth droops, nasolabial fold flattens, eyelids do not close
- CN VII also innervates stapedius muscle, receive taste sensation & provides autonomic innervation for salivation & lacrimation
- Compression proximal to chorda tympani branch can cause loss of taste
- If stapedius muscle innervation lost = sounds become louder
- Autonomic involvement causes dry/red eyes (lack. of tearing), thicker saliva
- Severe/chronic = pain, contractures, semi-facial spasms
- Bell’s reflex: rolling up of eyeball during attempts to close eye
7
Q
After severe injury axonal regrowth/rewiring could be misdirected & can cause
A
- Synkinesis: involuntary & undesirable facial movements associated with voluntary facial movements
- Voluntary activation of one muscle group can activate other muscles (blinking can activate mouth twitch & smelling can cause blink
- Autonomic misdirection can also happen: involuntary lacrimation while eating (crocodile tears)
8
Q
Describe how to diagnose Bells palsy
A
- Observation & physical exam
- Ask patient to wrinkle forehead, close eyes tightly, smile, whistle and observe for symmetry
- Electrodiagnostic tests: NVC/EMG can determine demyelination vs axonal degeneration
- NVC/EMG: Amplitude 90% drop = less than complete recovery; loss >98% = significant residual weakness & synkinesis
9
Q
Differential diagnosis between Bells palsy(facial nerve) and a stroke
A
- Observe forehead wrinkle, eye closing, & voluntary smiling
- Facial nerve/Bells palsy will effect one whole side of face while a stroke will only effect the lower half of face
10
Q
House Brackmann grading scale for Bells palsy severity categorization
A
- (1) Normal = normal facial function in all areas
- (2) Mild dysfunction = slight weakness noticeable only on close inspection; no synkinesis, contracture, or hemifacial spasm
- (3) Moderate dysfunction = pts who have obvious but no disfiguring synkinesis, contracture, and/or hemifacial spasm. are grade III. regardless of degree of motor activity
- (4) Moderately severe dysfunction = pts with synkinesis, mass action, and/or hemifacial spasm severe enough to interfere with function are grade IV regardless of motor activity
- (5) Severe dysfunction = only barely perceptible motion; synkinesis, contracture, and hemifacial spasm usually absent
- (6) Total paralysis = loss of tone, no motion
11
Q
Treatment for Bells palsy
A
- Early Tx with corticosteroids: anti-inflammatory effect can reduce the swelling of the facial nerve/compression in the facial canal
- General care includes proper eye care using artificial tears & ophthalmic ointment to prevent corneal abrasion & ulceration
12
Q
Prognosis for bells palsy
A
- Favorable that 85% show recovery within 3 wks
- 71% show. full recovery
- Degree of severity at onset is an important factor
- EMG results: A 90% drop in amplitude predicts less than complete recovery, and loss greater than 98% predicts significant residual weakness and synkinesis
- Absence of improvements at 3-4 mo should raise concerns regarding diagnosis & lead to search for alternative diagnoses
13
Q
Bells palsy implications for PT
A
- Neuromuscular re-ed using EMG biofeedback to regain motor control: helpful for synkinesis Tx
- Muscle stretches & exercises like wrinkling, puffing, closing eyes tightly, smiling, chin tuck, etc. can help maintain flexibility, decrease pain, & improve circulation in the affected muscles
- Facial E-stim lacks much evidence
14
Q
What is Charcot Marie Tooth disease
A
- Inherited motor & sensory neuropathy (HMSN)
- Slowly progressive disorder
- Characterized by distal limb weakness & wasting, skeletal deformities, distal sensory loss & reduced DTRs
- Fibular (peroneal) nerve is frequently affected 1st, aka perineal muscular atrophy (PMA)
- Progressive muscular atrophy foot.lower legs, progressing to hands/forearms
15
Q
Etiology and pathology of Charcot Marie Tooth disease
A
- Relatively common neuropathy
- Mostly autosomal dominant pattern of genetic mutation (autosomal recessive is rare)
- 2 genetic subtypes: CMT1 & 2
- Frequent de-/re- myelination causes hypertrophic ‘onion bulb’ formation around affected axon segments that contains Schwann cells & its processes (creates palpable areas along the peripheral nerves)
16
Q
Describe CMT1 and CMT2
A
- CMT1: causes mutations that are involved with segmental demyelination
- CMT2: disrupt neurofilament assembly causing axonal dysfunction/degeneration
17
Q
Clinical manifestations of Charcot Marie Tooth disease
A
- Distal symmetric muscle weakness, atrophy, diminished DTRs
- Fibula’s muscles affected causing weakness & wasting of DF/evertors, intrinsic muscles of foot
- As disease progresses: weakness/wasting of intrinsic hand muscles
- Sx. progress proximally
- Loss of proprioception/vibration followed by decrease pain/temp., parasthesia in glove & stocking distribution
- Balance and gait problems
18
Q
Foot deformities of Charcot Marie Tooth disease
A
- Inverted champagne bottle appearance of lower leg
- Pes cavus (high arch): imbalance b/w TA and peroneus longus
- Clawing of great toe
- Hammer toes
19
Q
How to diagnose Charcot Marie Tooth disease
A
- History: hereditary picture
- Lab tests: gel electrophoresis to detect genetic variations
- Physical motor & sensory exam
- NVC/EMG
- Nerve biopsy can demo demyelination or axonal degeneration
20
Q
Treatment for Charcot Marie Tooth disease
A
- No treatment to alter course of disease
- Symptomatic treatment for now
- If left unmanaged: can further deteriorate gait pattern due to increasing deformities, can increase fall risk, can also develop problems with writing & handling objects
- Progesterone therapy combined with ascorbic acid have been found to have positive effects in pre-clinical studies
- Gene therapy, stem cells, pharmacologic agents targeting mutated genes: all currently under research
21
Q
Prognosis for Charcot Marie Tooth disease
A
- Normal life expectancy, usually not life threatening and rarely affects muscles involved in vital functions like breathing
22
Q
Charcot Marie Tooth disease implications for PT
A
- Goal is to maintain functional mobility & minimize deformities
- Therapist should anticipate deformities due to muscle imbalance b/w Tim ant/per longus and Tim post/per brevis, which causes pes cavus & inversion of foot (tip posterior stays unaffected)
- Long term stretching recommended to maintain ROM: need to be more than 7 mo
- Skin care precautions to prevent sores
- Strengthening ex will have limited long term beenfit due to progressing axonal degeneration
- Balance/gait training: balance walking poles
- Orthotics for foot & hand can help in long term: AFOs w/ or a/o inserts/adjustments to protect skin & provide adequate support to deformed structures for improving gait & balance
23
Q
What is diabetic neuropathy
A
- Metabolic neuropathy occurring in the setting of DM without evidence of other causes of peripheral neuropathy
- Heterogeneous group of progressive syndromes
- Diverse clinical presentations: neuropathy can be diffuse or focal. (poly- or mono- neuropathy), may include autonomic and/or somatic PNs (peripheral nerves???)
24
Q
Incidence of diabetic neuropathy
A
- 20 million people affected by DM, expected to increase by 5% every year
- Neuropathy more in DM type 1 than type 2
25
What are the different ways hyperglycemia damages the nerves
- Chronic hyperglycemia causes metabolic disturbances that damages nerve cells, Schwann cells, and can effect both myelinated/unmyelinated axons, distal nerves affected more
- Chronic hyperglycemia also causes abnormalities in microcirculation, endometrial microvascular thickening, closed capillaries, local. ischemia/hypoxia in nerves, leading to axonal degeneration
-Elevated glucose also reduces levels of nerve growth factor causing reduced nutrition to nerves
26
Clinical manifestations of diabetic neuropathy
- Classified into various types
- Rapidly reversible
- Generalized symmetric polyneuropathies
- Focal. neuropathies
27
Describe rapidly reversible neuropathy
- In those who have been newly diagnosed
- Distally symmetric sensory changes: burning, paresthesia, tenderness in feet/legs
- Symptoms disappear when blood sugar gets controlled, although NVC abnormalities may persist
28
Types of generalized symmetric polyneuropathies
- Acute sensory neuropathy
- Chronic sensorimotor neuropathy
- Autonomic neuropathy
29
Describe acute sensory neuropathy
- Rapid onset of severe burning pain, deep aching pain, sharp ‘electric shock-like’ sensations, hypersensitivity of feet worse at night, allodynia
- Motor exam is mostly normal
- Recovery can occur within 1 year if individual can maintain good blood sugar
30
Describe chronic sensorimotor neuropathy (DPN)
- Most common type
- Onset mostly insidious, slowly progressive
- Clinical features depend on selective fiber type involvement
- Typical glove and stocking pattern
- Small fibers cause burning pain, paresthesia, more profound at night
- Large fibers cause painless paresthesia, impaired proprioception, vibration sense, may feel like walking on cotton
- Loss of ankle DTR, motor weakness mostly in feet/hands, mostly milder, but can cause hammer toe/hallux valgus/pes cavus/ankle equinous with muscle imbalance/wasting in advanced cases
- Autonomic: sweating (less or more), orthostatic hypotension (OH), resting tachycardia
- Balance/gait problems due to sensory ataxia, weakness, foot drop, foot deformities
31
Describe autonomic neuropathy
- Sympathetic and parasympathetic involvement
- With autonomic denervation: HR becomes fixed, may not feel ischemic angina, can suffer silent MI
32
Manifestations of autonomic diabetic neuropathy
- Tachycardia
- Exercise intolerance
- Orthostatic hypotension (OH)
- Dizziness
- Esophageal motility dysfunction
- Diarrhea
- Constipation
- Neurogenic bladder
- Bladder urgency, incontinence
- Erectile dysfunction
- Sweating, heat intolerance
- Dry skin
- Pupillary dysfunction, blurred vision
33
Describe focal neuropathies (mononeuropathies)
- Occurs less often than generalized symmetric patterns
- May involve nerves in limbs or CNs: median, ulnar, peroneal nerves most commonly affected, somatic division of oculomotor nerve
34
How to diagnose diabetic neuropathy
- Based on history, clinical exam, electrodiagnostic. tests, quantitative sensory tests, autonomic function testing
-Sensory testing: temp., vibration, and touch
- Autonomic tests: BP/HR at rest, OH test (STS), HR increase pattern with exercise
- NVC/EMG: slowing of NVC suggests demyelination, reduced amplitude suggests axonal degeneration
- Sensory symptoms appear before motor
- Profound motor involvement implies some other disorder instead of DN
35
Treatment for diabetic neuropathy
- Control hyperglycemia through extensive patient education, pharmacological agents, nutrition, & physical activity/exercise
- Pharm: insulin or non-insulin (metformin, glimepiride, -gliptins, -glutides) drugs dependent on type of DM/response to drug/individual needs
- Gabapentin, pregabalin to manage pain & parethesia
- Nutrition: distribute carbs throughout the day instead of restricting it, 5-6 smaller meals, regular menu is ok, fruit instead of juice, plenty of fluids
36
Diabetic neuropathy implications for PT
- Focus on overall health condition
- Regular cardio exercises per ACSM and ADA guidelines, use REP instead of HR: Precautions = impact cardio ex/high intensity ex should be done with caution with individuals having complications like abnormal HR response to ex, foot ulcerations, Charcot's joint (degeneration of WBing joints), unstable angina
- Resistance ex are beneficial for weakness & glucose metabolism
- Physical modalities for pain: TENS, infrared
- Balance & functional mobility training: Romberg, CTSIB, TUG, BBS< gait speed
- May need appropriate footwear, orthotics and/or ADs for skin protection & better gait
- >50% non-traumatic amputations occur in people with diabetes: appropriate prosthetic/prosthetic training after amputations
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