Neuromusclar disorders Flashcards
(47 cards)
1
Q
Bell’s Palsy
A
- paralysis or weakness of the muscles
- supplied by the facial nerve (CN VII)
- usually unilateral
- caused by inflammation within the facial canal or stylomastoid foramen
- more common in diabetics, pregnant women
2
Q
Bell’s palsy
A
- inflammation of swelling of nerve within bony passage leads to nerve pressure and diminished function
- nerve tries to go through a hole that it doesn’t fit anymore
- idiopathic, but HSV-1 involvement is suggested
3
Q
Bell’s palsy signs, sx, and course
A
- sudden onset, or may occur over days
- unilateral, total or partial paralysis of the facial muscles
- ipsilateral dry eye, due to inadequate lid closure
- possible hyperacusis, earache, loss of taste
- numbness may be reported, but not true sensory loss (feeling tingling, but you can still feel)
- resolve spontaneously within a year w/o tx
4
Q
Bell’s palsy differetial
A
- neoplastic: parotid gland tumors, basilar skull tumors
- infections: lyme disease, chronic or acute bacterial meningitis, basal skull osteomylitis, otitis media
- misc: trauma/stroke
5
Q
Bell’s palsy dx
A
- usually no studies are necessary
- clinical dx
- consider MRI to r/o posterior fossa lesions in cases that do not follow pattern
- don’t do an LP to dx. Only due if you feel the need to r/o meningitis
6
Q
Bell’s palsy tx
A
- lubricating eye drops for affected eye (dry eye)
- oral course of corticosteroids (within 3 days of onset)
- Prednisolone 25 mg BID, 6-10 days
- surgical decompression of CN VII in non-resolving cases and progressive axonal degneration
- antivirals in Ramsey-Hunt Syndrome
- follow up monthly for 6-12 months, as needed
7
Q
Guillain-Barre Syndrome
A
- Acute inflammatory condition of peripheral nerve causing acute demyelination and progressive weakness
- usually an ascending paralysis
- starts at feet and move up
- male>female
8
Q
Guillain-Barre differential
A
- encephalitis
- stroke
- polio
- vasculitis
- polymyositis
9
Q
Guillain-Barre signs and sx
A
- dysesthesias, paresthesias of feet and hands, spreading by the hour, are usually the earliest sx
- acute symmetric and usually ascending weakness of limbs within days after onset of dysesthesias
- AREFLEXIA associated w/ weakness, decreased positional and vibratory sensation
- back and leg pain
- automonic neuropathy (labile BP, cardiac arrhythemias)
- Respiratory muscle paralysis can cause death
10
Q
Guillain-Barre pathophysiology
A
- autoimmune destruction of myelin by antiganglioside antibodies
- often preceded by upper respiratory or diarrheal illness within 1-3 weeks, usually Campylobacter jejuni, CMV, EBV, Mycoplasma pneumoniae, HIV
- anything that actives the immune system can potentially cause this to happen
11
Q
Guillian-Barre dx
A
- CSF: elevated protein w/ normal white cell count (DEFINITIVE DX - Hallmark)
- screen for thyroid, hepatic, renal, autoimmune problems
- screen for toxins (botulinum is most common)
- cxr
- consider MRI if spinal cord lesion suspected
- nerve conduction studies (conduction block is common)
12
Q
Guillian-Barre tx
A
- hospitalization w/ main concern for respiratory function and elective intubation
- pain management
- DVT prophylaxis
- reassurance
- need rehab after as it tends to cause muscle atrophy
- two effective therapies: plasma exhange, immune globulin IV (IVIG)
13
Q
Myasthenia Gravis pathohysiology
A
- variable blockage of neuromusclar transmission at nictoinic receptors
- easy fatigability of voluntary muscles
- external ocular, masticatory and facial msucles prominently affected (face)
- associated w/ other autoimmune diseases such as SLE, RA, thyrotoxicosis
- may be associated w/ thymoma(!!!!!!!)
14
Q
Myasthenia Gravis presentation
A
- any age, female > male
- usually insidious onset, sometimes preceded or exacerbated by infection/illness, menses, pregnancy
- ptosis, diplopia, chewing/swallowing difficulties, respiratory difficulty, limb weakness
- sx fluctuate during day, with fatiguing of muscles; HALLMARK is increased c/o weakness at end of day
15
Q
Myasthenia Gravis exam presnentation
A
- weakness/fatigability apparent in PE, not in a nerve root/dermatomal distribution, extraocular muscles (ocular palsies, ptosis), pupillary responses unaffected
- activity results in weakness (sustained upgaze leads to increased ptosis, muscle power improving after test)
- usually no reflex changes
16
Q
Tensilon challenge
A
- used for myasthenia gravis
- edrophonium given IV
- short (about 5 min) improvement in response of affected muscles
- positive test confirms diagnosis
- neostigmine is alternate that lasts longer
17
Q
Myasthenia Gravis tests
A
- serum anti-AChR demonstrable in 80-90% w/ generalized MG
- xray or CT oc chest may show thymoma
- single fiber EMG may be helpful, but unnecessary
18
Q
Myasthenia Gravis tx
A
- anticholinesterase drugs (pyridostigmine)
- thymectomy: always with thymoma, elective otherwise
- immunosuppressants
- plasmapheresis / IVIG
- pt education (heat and exercise may exacerbate sx)
19
Q
Myasthenia Gravis prognosis
A
- usually well managed
- fatalities from respiratory complications such as aspiration pneumonia
20
Q
Multiple Sclerosis
A
- chronic, unpredictable, neuro-immunologic disease of the CNS
- cause unknown, no cure
- random attacks of inflammation w/ destruction of myelin sheath, glial scarring
- condition defects cause sx
- eventual irreversible axonal loss in many cases
21
Q
MS etiology
A
- autoimmune
- 20% genetic
- may occur after infection or trauma
- CNS usually immunologically privileged (break in BBB allows immune cell infiltration and recognition of central myelin)
22
Q
MS epidemiology
A
- young adults (20-40yr)
- highest in Caucasian females
- highest in more northern and more southern latitudes, lower in equatorial areas
23
Q
MS presentation
A
- fatigue, weakness, numbness, tingling
- unsteadiness in limb, imbalance
- spasticity, tremor
- speech, swallowing impairments
- diplopia, retrobulbar neuritis
- sphincter dysfunction
- cognitive dysfunction, depression
- sx often fleeting
24
Q
MS differential
A
- ALS
- brain stem tumors
- CNS infections
- hereditary ataxias
- pernicious anemia
- sarcoidosis
- spinal cord tumors
- small cerebral infarcts
- syphilis
- SLE
25
Clinical types of MS
- relapsing-remitting
- primary-progressive
- secondary progressive
- progressive relapsing
26
MS imaging
- MRI
- dx is based on lesion and clinical picture (evidence of plaques in 2 distinct regions of white matter, at different times, or no alternative explanation for lesions)
- lab studies not diagnostic (increased protein, IgG in CSF, autoimmune markers)
27
Brain electrophysiology studies
- visual evoked potentials abnormal in 75-97% of MS pts
- somatosensory evoked potentials abnormal
- auditory evoked potentials abnormal
- can detect subclinical disease, useful for assessment in absence of flare
28
MS PE
- nystagmus
- visual field deficits (dipolpia)
- dysarthria
- sensorimotor defects
- cerebellar signs
- dipolpia usually what brings them in not the weakness
29
MS tx goals
- initial neurology referral, primary care f/u w/ annual neurology visit
- tx sx: individualized
- exercise and preservation of function between flares
- medicines added as needed, use disease modifying drugs early
- high dose steroids for acute flares
- plasmapheresis for relapsing forms
- monoclonal immunomodulating antibodies
- antineoplastic drugs for progressing MS
30
ALS / Lou Gehrig Disease
- degenerative disease that affects the upper and lower motor neurons
- amyotrophic lateral sclerosis: sporadic and most common form of the disease
- familial ALS: similar sx, but represents a separate disease entity
- uncommon before 40
- male > female
31
ALS signs and sx
- FOCAL wasting of muscle groups
- limb weakness w/ variable symmetry and distribution
- gait disturbance
- dysphagia
- dysphonia
- fasciculations
- SPARES COGNITIVE OCULOMOTOR, SENSORY, AND AUTONOMIC FUNCTIONS
32
ALS pathophsiology
- "amyotrophic" = msucles degenerate due to lack of trophic support from nerves
- :lateral sclerosis" = lateral horn of spinal cord becomes fibrotic as MN die
- sporadic ALS: degeneration of upper and lower motor neurons with their axons. High levels of glutamate found in serum and CSF
- familial ALS: genetically transmitted degenerative disease
33
ALS differential
- focal motor neuropathy
- cervical spondylosis
- lead intoxication
- spinal MS
34
ALS diagnostics
- elevated gluatmate in CSF and serum
- anti-GM-1 antibodies common
- electromyogrpahy may be helpful
- muscle bx reveal shrunken angulated muscle fibers (grouped atrophy)
- atrophic or absent neurons in anterior horn, ventral roots, and lateral columns of the spinal cord and motor nuclei of the pons ad medulla
35
ALS tx
- outpatient
- supportive for complications; aspiration, respiratory failure
- help w/ ambulation
36
Cerebral Palsy
- involves a motor dysfunction
- may change its manifestations, but is non-progressive
- result of CNS insult that before the first 3 years of life
- male > female
37
Cerebral Palsy risk factors
- prematurity
- hypoxia
- seizures during the prenatal period
- in utero infections
- IGR
- abuse
- breech birth
- multiple gestation
38
Cerebral palsy signs and sx
- spastic
- contractures
- mental retardation w/ quadriplegia and mixed forms
- normal intelligence w/ hemiplegia or paraplegia
- scissors gait, toe walking
- seizures
- tremors w/ hemiplegia
- aphonia w/ quadriplegia
- athetotic (chorethtoid w/ jerking motions of proximal muscle groups and slow writhing of extremities, face, neck, and trunk)
- speech difficulties
- muscular hypertrophy
- typically gets picked up by PCP when the child does not meet mile stone checks
39
Cerebral palsy earl warning signs
- toe walking
- persistent fisting
- delay in motor milestones
- seizures
- hand dominance establishment before age 2
40
Cerebral palsy differential
- CP is descriptive term based on clinical observation
- must exclude metabolic or chromosomal abnormalities
- progression excludes CP
41
Cerebral palsy tx
- Baclofen for spasiticity
- Diazepam or Clonazepam for sleep disturbances and irritability
- Tx and monitoring for UTI
- goal of therapy is to improve function
- PT / OT orthosis
- Botulinum toxin injection
- surgery: tendon release, open reduction of sublexed hips
42
Upper Motor Neuron (UMN) lesion
- weakness due to upper motor neuron lesions
- characterized by selective involvement of certain muscle groups
- associated w/ spasticity
- increased tendon reflexes and extensor plantar responses
43
Lower motor neuron (LMN) lesion
- lower motor neuron lesions lead to muscle wasting as well as weakness
- flaccidity
- loss of tendon reflexes, but not change in plantar responses
44
Tetany
condition characterized by painful muscular spasms, caused by faulty calcium metabolism
45
Clonus
as muscular spams w/ regular contrations
46
Fasciculation
involuntary muscle twitch, usually localized and tempoary
47
Flaccid paralysis
interruption between the muscles and spinal cord result in flaccid paralysis (lower motor neuron lesion)
