Peripheral Neuropathies Flashcards
What is a peripheral neuropathy?
- When peripheral nerves are affected by pathological processes resulting in motor, sensory &/or autonomic dysfunction
- Acquired or inherited
- AKA polyneuropathy
What are the types of acquired peripheral neuropathies?
- Diabetic
- Metabolic due to renal disease, alcoholism, drugs/toxins & vitamin deficiency
- Acute & chronic inflammatory demyelinating (GBS, CIDP)
- Neuropathy associated with infection or malignancy
What are the types of inherited peripheral neuropathies?
- Motor neuron disease
- Charcot-Marie Tooth disease
- Hereditary sensory neuropathy
- Spinal muscular atrophy
What is Guillian-Barre syndrome?
- Acute inflammatory demyelinating peripheral neuropathy
- Predominantly motor, although 42-75% of patients experience altered sensation
- Autonomic dysfunction may occur in severe cases
What is the aetiology of GBS?
- Unknown
- Usually preceded by respiratory tract infection or GI infection
- Some reports of immunisation or surgery preceding symptoms
What is the pathophysiology of GBS?
- Auto-immune reaction resulting in inflammation & destruction of myelin sheath of peripheral nerves
- Loss of myelin causes slowed conduction causing weakness
- If multiple adjacent nerve fibres become demyelinated it can cause a complete nerve block causing paralysis
- In 20% of patients, axon will also be destroyed
What are the different forms of GBS?
- Ascending paralysis (most common)
- Miller Fisher syndrome
- Acute motor axonal neuropathy
- Acute motor sensory axonal neuropathy
What is Miller Fisher syndrome?
- Rare form of GBS
- Involves descending paralysis
- Presents as ophthalmoplegia, ataxia (due to significant loss of sensation) & areflexia
What is acute motor axonal neuropathy?
- Form of GBS
- Purely motor neuropathy
- Recovery can be slow or rapid
What is acute motor sensory axonal neuropathy?
- Form of GBS
- Also affected sensory nerves
- Associated with severe axonal damage
- Recovery is slow & often incomplete
How is GBS diagnosed?
- Clinically, supported by lumbar puncture or nerve conduction studies which may show conduction slowing/block and/or reduced amplitude of action potentials
- Typical CSF findings include elevated protein level
What is the required clinical criteria for GBS diagnosis?
- Progressive, relatively symmetrical weakness of 2 or more limbs
- Areflexia
- Disease course < 4 weeks
- Exclusion of other causes
What is the prognosis for GBS?
- Most often recovery commences 4 weeks from onset
- 80% of patients recover completely in 12 months
- 5-15% have severe disability due to weakness, contracture or sensory loss
- 5% fatal
- Approx 5-10% have one or more relapses (classified as having CIDP)
What does the medical management of GBS involve?
- Drug therapy including steroids & immunosuppressants
- Plasmaphoresis (plasma exchange - shown to decrease recovery time)
- Immunoglobulin therapy (injection)
What does the physio management of GBS involve?
- Restore motor performance & ADLs to previous level
- Maintain cardiorespiratory & neuromuscular system while awaiting remyelination
- Utilise principles of specificity, repetition & feedback
What are the common impairments in GBS?
- Loss of strength
- Loss of sensation
- Autonomic dysfunction
- Contracture
What should the physio assessment of GBS include?
- Strength
- Contracture
- Sensation
- Activities (bed mobility, sitting up, sitting, standing up, standing, walking, R&M)
What are the physio interventions for GBS?
- Respiratory physio
- Strength training
- Serial casting
- Sensory retraining
- Activity training (part, modified or whole task)
What did Ruhlands & Shields 1997 find regarding strengthening in CIDP?
- Home exercise program including mild strengthening, stretching & aerobic exercise over 6 weeks
- Resulted in significant increase in strength & QOL
What did Khan et al 2011 find regarding rehab in GBS?
- RCT of GBS patients
- Compared high intensity vs low intensity rehab (additional 3 hours over 3 months)
- Significant but small improvement in FIM scores & Perceived Impact Problem Profile at 12 months
What did Bussmann et al 2007 find regarding general exercise programs in GBS?
- Examined effects of exercise in severely fatigued GBS patients on physical fitness, fatigue, objectively measured actual mobility, perceived physical functioning & perceived mental functioning
- 12 week cycling program 30 mins 3 times/week
- Significant improvement in all domains
- Strong correlation between fatigue & perceived physical function
What is motor neurone disease?
- Terminal progressive degenerative disease
- Affects anterior horn cells of spinal cord, corticospinal tract & motor nuclei of brain stem
- Results in upper & lower motor neuron lesions & bulbar palsy (dysarthria, dysphagia)
What is the clinical presentation of MND?
- Insidious onset, aetiology unknown
- Up to 50% of motor neurons can be lost before weakness is evident as a consequence of neural plasticity
What are the 3 main forms of MND?
- Amyotrophic lateral sclerosis
- Progressive bulbar palsy
- Progressive muscular atrophy
(although patients can present with a mixture of signs & symptoms)
What is amyotrophic lateral sclerosis (ALS)?
- Accounts for 65% of all MND
- Involves UMN, LMN & bulbar signs
- Hands most commonly affected first (report dropping things frequently etc)
What is progressive bulbar palsy?
- Accounts for approx 25% of MND
- Initially results in dysarthria & dysphagia (often unable to communicate verbally or swallow)
- May have atrophied/spastic tongue
- Associated with emotional lability
- Upper & lower limb occurs with progression of the disease
What is progressive muscular atrophy?
- Accounts for approx 10% of MND
- Predominantly affects men < 50 years
- Only affects LMN & usually upper limbs first
- With progression there is lower limb weakness & bulbar involvement
- Progression is slower than in other forms & most patients live 5-10 years after diagnosis
What are some of the other problems associated with MND?
- Pain
- Dyspnoea (reported in approx 50%)
- Sore eyes (unable to blink enough)
- Constipation
- Insomnia (pain, orthopnoea, fear of not waking up)
- Fatigue
- Pressure areas (less common than SCI due to intact sensation)
- Urinary retention
What is the role of physio in MND?
- Maintenance of strength, length & ROM
- Promote mobility & independence with aids & adaptations
- Education & reassurance
- Pain & fatigue management
- Management of respiratory dysfunction
What did Lunetta et al 2016 find regarding exercise in patients with ALS?
- RCT of patients with ALS
- Compared supervised exercise program (cycling & strength training) for 6 months with passive exercise & stretching
- Significantly better motor score in ALS functional rating scale in experimental group
- No difference in respiratory decline or QOL
What are the guidelines for exercise in MND?
- Encourage patients to continue sports/activities if safe
- Encourage low intensity activities
- Encourage active lifestyle when sport is no longer possible
- Exercise for short bursts often to minimise fatigue
- Include stretching, strengthening & aerobic work
- Educate patients that exercise will not cure the condition or prevent deterioration but may improve QOL if they enjoy exercise
- Rigid adherence to exercise is not necessary
- Let the patient do what they want
What needs to be considered for seating in MND?
- Meeting individual needs
- Maintaining muscle length
- Preventing deformity
- Improving comfort
- Preventing pressure areas
- Maximising function & social interaction
What are some of the assistive devices used in MND?
- Orthoses: Improve mobility & protect soft tissue from trauma due to malalignment
- Neck collars for cervical weakness
- Mobile arm supports & splints for upper limb function
- Communication systems (ipad apps, pointer charts, light-writers, computers)
What does management of the terminally ill patient involve?
- Palliative care starts from diagnosis
- Incorporates psychological care, care of the family & counselling
- Problems must be anticipated so symptoms are well controlled & patient/family are well supported
- Final deterioration is usually very short (< 12 hours), most commonly from respiratory infection
How is the physio management different for a GBS patient compared to a stroke patient?
- No dexterity training
- No spasticity management
- No e stim (doesn’t work when the peripheral nerve is not intact)
