Neuromuscular Disorders- MJ Flashcards
Which neuromuscular disorder?
•Immune-mediated (autoimmune) disorder of the CNS associated with destruction of myelin and nerve fibers.
Multiple Sclerosis
- Is MS more common in men or women?
- Age of onset?
- Women
- 15-50yrs
Is there a higher or lower incidence of MS as you move towards the equator?
lower incidence
On LP, what is seen in the CSF only in MS patients and can be used as a diagnostic marker?
(this will be on exam)
Oligoclonal bands
What are the 3 types of MS? Which one is most common?
(this will be on exam)
- Relapsing-remitting MS (RRMS)- Most common
- Secondary progressive MS (SPMS)
- Primary progressive MS (PPMSP)
The following describes which type of MS?
•Unpredictable attacks which may or may not leave permanent deficits followed by periods of remission
Relapsing-remitting MS
The following describes which type of MS?
- Initial relapsing-remitting MS followed by gradual worsening with or without occasional relapses, minor remissions, and plateaus
- Occurs 10-20 years after disease onset
Secondary Progressive MS
The following describes which type of MS?
•Steady increase in disability without attacks
Primary progressive MS
What are the 5 main signs and sxs of MS?
(will be on exam)
- Internuclear ophthalmoplegia (delayed adduction and horizontal nystagmus of abducting eye)
- Optic neuritis (painful, monocular vision loss w/ blurring/scotoma)
3. Lhermitte’s sign (electic shock when flex neck)
- Uhthoff phenomenon (heat sensitivity)
- Fatigue (sleep 22hrs/day, very difficult to wake up)
T/F: Signs and sxs of MS can be isolated or in combination. Attacks usually last days to weeks
True
What are the 2 main components of the MS work up?
- Brain and spinal cord MRI (gadolinium enhanced)
- LP- look for _oligoclonal bands in CSF ***_
What are the 3 parts of the McDonald criteria for diagnosing MS?
- Uses MRI +/- CSF to diagnose
- Dissemination in space
- Dissemination in time
How do you treat acute exacerbations/attacks of MS?
(will be on exam
IV glucocorticoids- high dose Methylprednisolone
What is one of the MC disease modifying therapies (for RRMS)
Interferon
Which neuromuscular disorder?
- Variable combo of weakness due to antibody-mediated attack against muscle receptor for acetylcholine
- fatigable weakness
Myasthenia Gravis
Epidemiology of which neuromuscular disorder?
- Bimodal distribution: F: 2-3rd decade, M: 6-8th decade
- W > M
- Thymoma common
Myasthenia Gravis
Which muscle receptor antibody is most common in MG- AChR receptor Ab or MuSK receptor Ab?
AChR receptor Ab
In MG, when does weakness increase and when does it improve?
- Increases during repetitive use and as day progresses
- Improves during rest/sleep
What are the 2 types of MG and which one is more common?
- Ocular (weakness limited to eyelids and extraocular muscles)–> MC
- Generalized (weakness of ocular mm., bulbar, limb, and resp mm.)
What 3 initial presentation symptoms are most commonly seen in MG?
(will be on exam)
1. Ptosis
2. Diplopia
3. Blurred vision
The following are the second most common sxs of which neuromuscular disorder?
- Drooling
- Fatigable chewing
- Facial weakness
- Dysarthria
- Dysphagia
MG
How is MG diagnosed? (5 things)
- Based on hx and typical exam findings
- Repetitive nerve stimulation
- Single-fiber electromyography
- Serologic testign: AChR-Ab, MuSK-Ab
(will be on exam)
In comparison to LEMS, what does Repetitive nerve stimulation (RNS) show in MG?
In MG, amplitude decreases over time with the more mm that are stimulated
What are the 4 possible treatment options for MG?
- Symptomatic tx- Anticholinesterase agents
- Chronic tx- Glucocorticoids (prednisone and other immunosuppresive drugs)
- Rapid tx- plasmapheresis and IVIG
- Thymectomy (if indicated)
What is the 1st line tx for MG?
Anticholinesterase inhibitors (Pyridostigmine)
(Slows the degradation of ACh which prolongs its effect)
What is a Myasthenic crisis in a patient with MG?
- Respiratory failure from wekness of resp muscles
- Precipitated by infection
- (will be on exam)
Myasthenia Gravis:
What treatment can be helpful in hastening recovery after a Myasthenic Crisis?
(will be on exam)
Plasmapheresis
Which neuromuscular disorder?
- Autoimmune dz where reduced ACh is released from the presynaptic nerve terminals
- Proximal muscles of lower limbs MC affected
- Ocular involvement not common
Lambert-Eaton Myasthenic Syndrome (LEMS)
(very similar to MG- differences are highlighted)
Which cancer is the most commonly associated tumor in patients with Lambert-Eaton Myasthenic Syndrome (LEMS)?
(will be on exam)
Small cell lung cancer
What is the hallmark presentation of LEMS?
Postexercise facilitation
(recovery of DTRS or improvement of muscle strength with vigorous movement)
- Which diagnostic study is important in diagnosing LEMS, especially in differentiating it from MG?
- What will this study show?
- Repetitive Nerve stimulation (RNS)
- LEMS will have increased amplitude w/ stimulation (MG would be decreased)
How do you treat LEMS if there is moderate to severe weakness? (3 options)
- Amifampridine (enhances Ca entry at the presynaptic terminal)
- Guanidine
- Pyridostigimine + above Rx
LEMS or MG?
Antibodies against the nerve where ACh is released
LEMS
LEMS or MG?
Antibodies against the muscle receptor for ACh
MG
LEMS or MG?
- _________starts at eyes and moves down
- __________ starts at extremities and moves up
- __\__MG_____starts at eyes and moves down
- ___\_LEMS___ starts at extremities and moves up
LEMS or MG?
- ________= Weakness improves upon activity
- ________= Weakness worsens upon activity
- ___LEMS___= Weakness improves upon activity
- \___MG___= Weakness worsens upon activity
LEMS vs. MG:
- _____ is associated w/ small cell lung cancer
- _______ is associated w/ thymoma
- \__LEMS___ is associated w/ small cell lung cancer
- _\_MG_____ is associated w/ thymoma
Which neuromuscular disorder?
- Acute immune-mediated polyneuropathy
- Provoked by preceding infection by 2-4 weeks (Campylobacter jejuni)
Guillain- Barre Syndrome (GBS)
The following is the pathophys behind which neuromuscular disorder?
- infection–> immune response–> antibody production–> Ab attaches to peripheral nerve cells–> molecular mimicry–> macrophages attack peripheral nerves–> acute polyneuropathy
GBS
T/F: There is only one form of GBS
False. There are several different forms of Guillain-Barre
Which GBS variant is MC?
(Variants= Acute motor axonal neuropathy, Acute inflammatory demyelinating polyneuropathy, Acute motor and sensory axonal neuropathy, Miller Fisher syndrome)
Acute inflammatory demyelinating polyneuropathy (AIDP)
- This is progressive symmetric weakness accompainied by absent or depressed DTRs and parasthesias in hands/feet
What is the hallmark presentation of GBS?
(will be on exam)
- Progressive symmetric ascending muscle weakness (starts in LE and works its way up)
- diminished DTRs
Which neuromuscular disorder should be considered in any child w/ an acute gait disturbance?
GBS
T/F: Everyone with GBS can be treated outpatient
FALSE
everyone w/ GBS requires hospitalization b/c respiratory failure can develop
Which diagnostic test is essential for diagnosis of GBS? What does this show?
(will be on exam)
- LP → CSF studies are essential for diagnosis
- If GBS, will show elevated protein with normal WBC count
What are the 2 most important treatment components for GBS?
- Supportive care in the hospital
-
Plasmapheresis
*
T/F: It is extremely important to give Corticosteroids to patients w/ GBS
False
Corticosteroids are not beneficial
- How long after symptom onset does a patient w/ GBS begin to spontaneously recover?
- Do symptoms ascend or descend as they resolve?
- Spontaneous recovery begins after 3-4 weeks
- Descends on recovery
