movement disorders Flashcards
what is an autoimmune disorder of NMJ in which anti-acetylcholine receptor antibodies at the post synaptic membrane
myasthenia gravis
what are two main associations in myasthenia gravis
thymic hyperplasia (70%)
thymoma (10%)
weakness in myasthenia gravis is in what pattern
Weakness is descending (starts from the top and moves down)
• Muscle fatigue after sustained/repetitive action : better with rest
weakness in myasthenia gravis is in what pattern
• Weakness is descending (starts from the top and moves down)
• Muscle fatigue after sustained/repetitive action: better with rest
when are symptoms the worst in myasthenia gravis
at night
what are bedside tests in myasthenia gravis
o Worse when counting to 20 quickly
o Upward gaze –> ptosis; relieved by icepacks
o Outstretched arms –>slow downward drift
o Normal reflexes
what are investigations for myasthenia gravis
• Most specific: anti-AChR antibodies
• Most sensitive: single fiber electromyography
• Nerve stimulation test : decrement in evoked potential
• Anti-MuSK antibodies
• CT : thymoma/thymic hyperplasia
• Tensilon test: giving IV anticholinesterase: temporary rapid improvement
how is thymoma related to myasthenia gravis
1) thymus gland is critical for immune system, teach t-cells to distinguish btwn self +nonself
2) in thymoma, process can become dysregulated leading to production of autoreactive T cells
3) these damaged t-cells tell B cells to produce autoantibodies against AchR + Musk which decrease release of Ach
what is affected in Lambert-Eaton myasthenic syndrome
autoantibodies against presynaptic calcium channels
what type of cancer does LEMS present with
SCLC
how do symptoms improve in LEMS
symptoms improve with repeated muscle stimulation
what symptoms do LEMS present with
Presents with proximal muscle weakness and hyporeflexia
what is the tx of myasthenia gravis
•Anticholinesterases (pyridostigmine) :↑ availability of Ach at NMJ
• Immunosuppressants (steroids, azathioprine) if no response/relapse on Tx
• Thymectomy is indicated if thymoma is seen on CT (malignant potential), or if no thymoma but <50 years old & anti AchR antibodies +ve
what is botulism
o History of consumption of contaminated food (clostridium botulinum: anaerobic spore forming bacteria –> neurotoxin production)
what does botulism affect
cleaves SNARE protein no Ach release
nuscarinic symptoms
incremental response = presynaptic disorder
what is organophosphate exposure
-accidental exposure to agricultural pesticides
-irreversible inhibition of Ache
highhhhhhh Ach stimulatiom in both nicotonic and muscarinic
what is gullian barre syndrome
• Acute inflammatory demyelinating symmetrical ascending polyneuropathy
• Preceded by URTI or diarrhea (especially campylobacter jejuni/EBV/CMV)
what does GBS present with symptoms
• Progressive ascending symmetrical distal limb weakness +/- numbness
• Loss of reflexes
• Autonomic: postural hypotension, cardiac arrhythmias, ileus, bladder atony
• May progress to respiratory muscles –>respiratory failure • May progress to facial muscles –> bilateral lower CN 7 palsy
investigations in GBS
• CSF: elevated protein, normal cells # & sugar (albumin-cytological dissociation)
• Nerve conduction studies –> slowing of motor conduction: most
• Antibodies against GQ1b seen in Miller-Fisher syndrome (rare variant affecting CN to eye muscles =ophthalmoplegia & ataxia)
tx for GBS
No role for steroids
Mainstay: IVIg or plasma exchange
ivi g med in GBS contraindicated in who
igA defecient
what is CHRONIC INFLAMMATORY DEMYELINATING POLYNEUROPATHY (CIDP)
•Chronic form of Gullian-barre syndrome (chronic relapsing course)
• Slowly progressive weakness, often involving neck flexors • Areflexia is common; may also have loss of vibration sense
• Steroids are effective & treatment is required for many years. IVIg also useful
what is meningitis
Serious infection of the meninges in the brain or spinal cord, due to sepsis or direct extension (otitis media, sinusitis, cranial injury, CSF leak)
what is classic triad of meningitis
acute bacterial meningitis:
1)fever
2)nuchal rigidity
3) altered mental status
May also present with headache, vomiting, seizures, photophobia
what is kernig sign
- Have the patient lie supine (on their back).
- Flex the hip and knee to 90 degrees.
- Try to extend the knee while keeping the hip flexed.
Positive Kernig’s Sign:
• The patient experiences pain and resistance in the hamstrings/lower back when the knee is extended.
bruzinski sign
- Have the patient lie supine (on their back).
- Passively flex their neck by lifting the head towards the chest.
Positive Brudzinski’s Sign:
• The patient involuntarily flexes their hips and knees in response to neck flexion.
what are causative agents of meningitis in infants
Group B strept (agalactie)
• E. coli
• Listeria monocytogenes
causative organisms in children with meningitis
Viruses are common (enterovirus, mumps, herpes, EBV)
• Strept pneumo
• Neisseria meningitidis
• Hemophilus influenzae
causative agent in adults with meningitis
strep pneumonia #1
Neisseria meningitidis
above 50 organism with pt of meningitis
Listeria
• Aerobic gram-negative bacilli
csf bacterial
neutrophils (high)
protein (high)
glucose (low)
appearance turbid
TB csf analysis
lymphocytes (high)
protein (vv high)
neutrophils (low)
glucose (low)
viral csf analysis
lymph (high)
glucose(normal)
protein (high)
management of meningitis
Draw blood: CBC, RFT, LFT, Coagulation profile and 2 aerobic blood cultures
• Lumbar puncture
o Immediately ASAP within 1 hour
o Don’t wait for results of LP & start IV AB prophylaxis
o If LP can’t be done within 1 hour à take blood cultures and proceed immediately to IV antibiotic prophylaxis
o No need for CT before LP except in certain situations.
Head CT is needed before LP to rule out increased ICP only if:
o Papilledema
o New onset seizure (within a week)
o Abnormal level of consciousness
o CNS dx or Hx (mass or stroke)
o Focal neurological signs
o Immunocompromised
o If CT is needed: start antibiotics prior to CT
tx of meningitis
IV antibiotics: must be started ASAP within 60 minutes (after blood cultures)
o Empirical: vancomycin + 3rd generation cephalosporin
o If old age/immunocompromised: add ampicillin to cover Listeria
o Empirical for infants: ampicillin + gentamycin
Tb meningitis tx
• Intensive therapy (2 months): Isoniazid + Rifampin + Pyrazinamide + Moxifloxacin or streptomycin or levofloxacin
• Continuation phase: isoniazid + rifampin
• Steroids: 2 weeks high dose & 6 weeks tapering
what is encephalitis
Inflammation of brain parenchyma affecting cerebral function
symptoms of encephalitis
• Fever, meningism, but clinical picture is dominated by brain parenchymal inflammation–> altered level of consciousness & coma, bizarre encephalopathic
behavior or confusion, personality changes
• Focal neurological deficits, headache, seizures
causative organisms in encephalitis
1- Viral:(most common) herpes simplex virus. Others: arbovirus, CMV, VZV
2- Non-viral: cryptococcus neoformans, gram -ve bacilli, listeria, Tb
what is a characteristic in head ct and mri in enephalitis
characteristic asymmetric temporal lobe signal abnormalities in HSV encephalitis; inflammation, swelling, ↑ICP, midline shift, coning.
encephalitis diagnosis
• Lumbar puncture for CSF gram stain, culture, cell count, protein, glucose
(characteristically high lymphocytes)
• PCR for HSV, CMV, VZV
• CSF shows lymphocytosis and proteins may be increased
tx of encephalitis
Immediate IV acyclovir in case of HSV
what is brain abscess
Focal suppurative infection of the brain parenchyma usually caused by multiple organisms (polymicrobial).
Begins as a localized area of cerebritis –> collection
of pus surrounded by a well-vascularized capsule.
symptoms of brain abscess
• Headache (most common symptom)
• Fever, focal neurological deficits, seizures, confusion
• Increased ICP signs (ex: CN 3 and CN 6 deficits)
diagnosis of brain abscess in CT
• ring enhancing lesion with low density cord
• Lumbar puncture not necessary and may precipitate brainstem herniation
• Labs: peripheral leukocytosis, High ECR, CRP
tx of brain abscess
• Initiate broad-spectrum IV antibiotics and surgical drainage.
• Antibiotics alone may be used if: ↑ risk, multiple, deep/dominant location, < 3 cm in size, co-existing meningitis or ependymitis.
headache pain sources
receptors in arteries, veins, meninges, scalp, muscles –>5th
and 9th cranial nerves and upper cervical nerve roots
