Neuromuscular conditions Flashcards
disorder of the motor neuron-anterior (ventral) horn cell
Motor neuron disease (LMN)
disorder of the peripheral nerve (ventral and dorsal)
Radiculopathy [one nerve affected from spine downwards]
Neuropathy [usually many nerves affected but more towards hands and feet]
disorder of the neuromuscular junction/motor end plate
where nerves meet muscles
disorder of the muscle
myopathy
Neuropathy vs. Myopathy
Neuropathy: -soma/axons involved -distal involvement (symm. > asymm) -stocking-glove pattern -longest nerves affected 1st (LE before UE) Myopathy -MEP/mm involvement -proximal involvement (symm) -difficulty arising -overhead activities
LMN vs. UMN
LMN: -flaccid or reduced stiffness -decreased tone -decreased muscle stretch reflexes -profound muscle atrophy -fasciculations seen or twitches - +/- sensory disturbances UMN: -spasticity or very stiff -increased tone -increased muscles stretch reflexes -minimal muscle atrophy -fasciculations absent - +/- sensory disturbances
Motor neuron conditions (LMN-Anterior horn cell)
Spinal muscular atrophy (progressive)
post-polio syndrome (slowly progressive after recovery from polio)
amyotrophic lateral sclerosis
Peripheral nerve conditions
Gullian-Barre (initial worsening with recovery)
Charcot Marie Tooth (initial worsening with limited recovery)
Motor end plate conditions
Myasthenia Gravis (exacerbations result in wekaness in the face, neck and hands)
muscle conditions
Muscular dystrophy (progressive)
Components of medical diagnosis
medical and family hx physical exam electrodiagnostic testing: EMG, NCV Blood labs genetic testing muscle biopsy
Components of movement system diagnosis
PIP movement observation hypothesize impairments -weakness (symm/asymm) -hypo/hypertonia -muscle flexibility -bulbar function -pain -fatigue
Keys to prognosis to inform intervention strategies
Long-term and short-term goals
Expected natural progression of condition
-onset period/age
-progression rate
-recovery potential
contextual factors that would contribute to the achievement of the goal
contextual factors that may prevent or delay the acquisition of the goal
likely time frame for achieving the goal [PROGNOSIS]
interventions for optimizing function
education encourage activities and participation strengthening (moderate intensity) aerobic training (moderate intensity) flexibility
interventions for adaption to limitation
prevent overuse
prevent respiratory dysfunction (breathing techniques/coughing)
prescribe assistive technology (orthotics, AD, w/c) to support participation
interventions for maximizing quality of life
addressing respiratory dysfunction (postural drainage and assistive coughing)
positioning
supporting and training the caregiver
Spinal muscular atrophy
- genetic disorder: 5q gene deletion
- premature death of alpha motor neurons in spinal cord and brainstem (CN V, VII, IX, XII)
- premature death of alpha-motor neurons –> weakness & wasting of voluntary muscles (more sever in legs vs arms)
- classified according to type I-IV
Type I spinal muscular atrophy
- acute infantile (Werdnig-Hoffman)
- onset birth-6 mos
- progression : rapid
- movement system: never sits, poor head control/suck/swallow/cry
- prognosis: usually fatal within 2 years
Type II spinal muscular atrophy
- chronic infantile (Dubowitz Disease)
- onset: 6 mo - 18 mo
- progression: slower
- movement system: delayed motor milestones; able to sit but not stand or walk
- prognosis: variable
Type III spinal muscular atrophy
- chronic juvenile (Kugelberg-Welander)
- onset: after 18 mo
- progression: slower
- movement system: most can stand and walk, but have trouble going up/down stairs; may lose ability to walk later; in w/c- develop scoliosis; bulbar dysfunction later in life
- prognosis: typical life expectancy
Type IV spinal muscular atrophy
- adult
- onset in 30s
- lose ability to walk
- typical life expectancy
Tools for medical diagnosis of spinal muscular atrophy
genetic testing (5q) EMG (reduced amplitude, fibrillations) muscle biopsy (muscle fiber atrophy)
common impairments associated with spinal muscular atrophy
several proximal muscles weakness
flaccidity or hypotonicity
bulbar dysfunction (difficulty swallowing and breathing) in more severe cases, as in type I or in later disease progression of type II or III
Common PT diagnoses for spinal muscular atrophy
- difficulty rolling secondary to weakness in SCM, pec major, AO, and RF
- difficulty sitting secondary to weakness of paraspinals (including cervical), and abdominals
- difficulty reaching secondary to weakness in deltoid and triceps
- difficulty lying prone secondary to poor flexibility in iliopsoas and hamstrings
- difficulty transitioning to standing secondary to poor strength in glute max and quadriceps
intervention guidelines for spinal muscular atrophy
- strength training of proximal muscle groups: shoulder flexors/extensors, elbow flexors/extensors, hip flexors, extensors, and knee extensors
- 2 sets of 15 reps for each muscle group with 5 minute rest between sets
- initial intensity should emphasize biomechanics using body weight as resistance and progressed by adding light resistance
- monitor with RPE; goal under “somewhat hard” to “hard”
Post-polio syndrome
- onset is adulthood (35 yrs)
- late manifestation of acute poliomyelitis
- degeneration of large motor neuron pools
- slowly progressive new muscle weakness in previously affected areas
- asymmetrical distribution
- distal or proximal or patchy
Keys to medical diagnosis of post-polio syndrome
prior paralytic poliomyelitis
EMG (polyphasic motor unit potentials, fibrillations)
muscle biopsy (muscle atrophy)
movement system diagnosis for post-polio syndrome
difficulty walking and standing secondary to…
fatigue
pain
weakness
Intervention guidelines for post-polio syndrome
- lifestyle modifications
- energy conservation techniques
- avoid overuse of muscle groups
- non-fatiguing muscle strengthening program can result in strength gains
- be aware of poor body mechanics and malalignment and incorporate postural exercises
- monitor fatigue and pain
Amyotrophic Lateral Sclerosis
acquired disease
degeneration of cortical spinal tract: UMN and LMN
primarily anterior horn cells and motor cranial nuclei
progressive asymmetrical weakness: distal then proximal
sensory function intact
onset: adulthood (avg. 50 yr.)
progression: rapid (fatal in 3.5 yrs)
Macro/microscopic exam findings in ALS
- anterior spinal nerve roots are shrunken/atrophied
- loss of cell bodies
- loss of corticospinal tracts
Classification of ALS
Suspected ALS: LMN signs only in 1 or more regions
Suspected ALS: UMN signs only in 1 or more regions
Probable ALS: LMN and UMN signs in 2 regions
Definite ALS: LMN and UMN signs in 3 regions
clinical presentation of ALS
LMN sxs
-bulbar–dysarthria, dysphagia, tongue atrophy & fasciculations
-Peripheral– weakness, MM atrophy, fasciculations, hypotonia, dyspnea
UMN sxs
-bulbar– dysphagia, dysarthria
peripheral– spasticity/clonus/hyperreflexia, +Babinski, spastic gait, poor balance
Components of medical diagnosis for ALS
History– progressive weakness/atrophy of mm: bulbar, cervical, thoracic & lumbosacral neurons
Genetics–most cases sporadic
clinical course– unrelenting deterioration months > years
neuro exam–UMN & LMN sxs; EMG/NCV; imaging, biopsy
prognosis for ALS
Devastating, rapidly progressive neurodegeneration of AHC, LMN, and UMN with highly predictable clinical course
patient survival: 2.5-4 yrs post-diagnosis; 50% survival 1yr after bulbar onset.
Medications: Riluzole (prolongs survival by 2-3 mo)
Intervention guidelines for ALS
- Old controversial idea: epidemiological data suggests vigorous activity is a risk factor for motor neuron loss.
- animal studies suggest lifetime of vigorous activity unrelated to onset time or progression of ALS
- positive effect of moderate exercise in individuals with ALS
- monitor post-exercise fatigue to monitor intensity
Non-pharmacological management of ALS
PT, OT, Speech T respiratory dietitians social workers nursing psychologists spiritual care
Pharmacological management for ALS
Riluzole Symptom management: -anxiety-- lorazepam -spasms--Quinine sulphate -spasticity-- Baclofen -drooling-- Atropine
Symptomatic management for ALS
dysphagia– diet modification, PEG, speech-language
Dysarthria– communication device
Thick mucous– humidifier, chest PT
dyspnea– chest PT, morphine
respiratory failure–non-invasive positive pressure ventilation, tracheotomy, ventilation
Guillain-Barre Syndrome
Acute inflammatory demyelinating polyneuropathy
Onset is adulthood and initially rapidly progressive (within 24 hours - 4 weeks) but recovery occurs
GBS variant: AIDP
- demyelinating polyneuropathy
- myelin more than axons - Sensorimotor GBS
- progressive a-reflexic weakness, mild sensory changes, autonomic dysfunction, some CN deficits
GBS variant: MFS
- Normal NCV
- Sensory changes
- opthalmoplegia, ataxia, areflexia
GBS variant: AMAN
- pure motor GBS
- Axonal polyneuropathy (motor axon involvement–not myelin)
- CN rarely affected
GBS variant: AMSAN
- Severe variant of AMAN but with sensory deficits
- axonal polyneuropathy
- sensory and motor axons (not myelin)
- primarily in Asia, Central & South America
Pathology of GBS
- Autoimmune response happens within 2 weeks of infection
- antibodies made to eliminate virus
- antigens of virus look like those on myelin nodes = molecular mimicry
- antibodies attack Schwann cells
- breaks down myelin
- some attack node-axonal degeneration (bystander effect)
- affects nerve roots and peripheral nerves
- recovery: proximal to distal (remyelination is faster than regeneration)
Phases of GBS
Acute: progressive, ascending, symmetrical weakness and sensory loss (distal to proximal)
Plateau phase
Recovery phase
“Classic” features of GBS
LE weakness UE weakness Areflexia Paresthesia Sensory loss Dysautonomial (HR, BP, etc) Oropharyngeal weakness pain respiratory failure sphincter involvement
key components for medical diagnosis of GBS
lumbar puncture (presence of elevated albumin) NCV (delays in latency suggesting demyelination) EMG (suggests axonal degeneration)
differential diagnosis for GBS
Botulism Lyme Disease Tick Paralysis Poliomyelitis other Neuropathies (diphtheria, toxins)
Medical management of GBS
admit to ICU
respiratory changes: when FVC is ~1.5 L –> tracheostomy & vent
psychoemotional support
immunomodulation (shortens disease duration)
-IVIG
-plasmapheresis/plasma exchange
- oral corticosteroids significantly slow recovery
Movement system diagnosis for GBS
difficulty rolling, transitioning to sitting & standing, standing, walking…
secondary to weakness, sensory deficit, autonomic symptom
Prognosis for GBS
return to motor/sensory takes months to years
(15% full recovery, 67% residual weakness, 10% severe weakness/sensory loss, 8% die in acute phase)
recovery occurs mainly during first year post-onset, however motor and sensory impairments are still detectable in 50% of patients at 2 years
(31% decrease grip strength, 7% unable to walk 10 m independently, 52% sensation affected)
Interventions for GBS
avoid fatigue
after plateau phase and recovery has begun:
-short periods of non-fatiguing exercise (PROM/AAROM/AROM)
-increase activity if pt improves or not deteriorating after 1 wk
-exercise to promote functional activities; gait & balance, including endurance
-equipment: ambulatory aids, AFOs
-monitor neuro signs & ANS (tachy/bradychardia, facial flushing, labile BP, abnormal sweating, paresthesia) may suggest overwork
Charcot Marie Tooth
Hereditary motor and sensory neuropathy
polyneuropathy impacting myelin or axons
distal, symmetrical “stocking glove” weakness and sensory loss
onset is childhood and initially rapidly progressive (within 24 hours- 4 months) but recovery occurs
key components for medical diagnosis of CMT
genetics NCV (delays in latency suggest demyelination)
Activity limitations in CMT
reduced walking
reduced hand function
Common impairments in CMT
Paresthesias: cutaneous and proprioceptive
Muscle weakness: symmetrical with distal involvement, weak TA, weak Peroneals
Pes Cavus: elevation of medial longitudinal arch, progressing to clawing of toes (loss of intrinsic muscle innervation)
Movement system diagnosis for CMT
difficulty running/jumping, climbing stairs, walking, standing, reaching and grasping…
…secondary to weakness, sensory loss, reduced muscle flexibility
Intervention guidlines for CMT
ROM strengthening balance training task-oriented AFOs Gait: AD adaptive home equipment for safety in tub/shower
Myasthenia Gravis
- decreased number and defective functioning of ACh receptor sites at neuromuscular junction
- autoimmune condition where antibodies bind the ACh receptor
- painless disorder of strength occurring during sustained or repetitive muscle contractions: loss of muscle power occurs in association with continuous effort
- relatively uncommon; women: men = 2:1; 20-30 years for women, but 60-70 years for men
Clinical signs of MG
ptosis diplopia facial weakness dysarthria dysphagia neck mm weakness weak grip
Lab tests used for diagnosis of MG
IV tensilontest (short acting anti-AChE) --> reverse weakness ACh receptor antibody titer
treatment for MG
Mestinon (cholinesterase inhibitor), corticocosteroids, thymectomy
Prognosis for MG
with treatment, most individuals with MG can significantly improve their muscle weakness and lead normal or nearly normal lives.
Sometimes, severe weakness of MG can cause respiratory failure, which requires immediate medical care.
Some cases of MG may go into remission–either temporarily or permanently–muscle weakness may disappear completely so that medications can be discontinued.
Stable, long-lasting complete remissions are the goal of thymectomy and may occur in about 50% of individuals who undergo the procedure.
Interventions for MG
Muscle weakness worsens as affected mm are used repeatedly, therefore sx improve with rest. PT typically not involved.
Stable patients with MG may exercise following ‘rules’:
-exercise at your best time of day
-exercise at peak dose of meds
-exercise large, proximal mm groups for short periods of time, building up to only moderate intensity
Do NOT exceed moderate intensity exercise levels
-HR should not elevate > 30 bpm form baseline
-exercise should not cause you to become SOB
-Sx should not become worse during exercise
-should not be tired 2 hours after exercise
-should not have residual soreness day(s) post exercise
Postural exercises
Breathing exercises (abdominal); inspiratory trainer
