* Neuro Disorders (GBS + MS + PD) Flashcards
What is the pathophysiology of Guillain-Barre syndrome (GBS)?
- Most common cause of acute generalized weakness, with motor, sensory and autonomic dysfunction
- Cell-mediated and humoral immune attack (Auto-immune)
~ Attacks peripheral nerve myelin proteins
~ Causes inflammatory demyelination
What are the risk factors for Guillain-Barre syndrome?
- 30-50 y/o
- Male gender
- Precedence of viral infections at least 2 weeks before onset
~ Cytomegalovirus, Epstein-Barr virus
~ Campylobacter jejuni, mycoplasma
~ Influenza
~ HIV - Systemic illnesses
~ Hodgkin’s disease
~ SLE
What are the clinical features of Guillain-Barre syndrome?
- Progressive + symmetric + ascending muscle weakness/paralysis
- Usually proximal lower extremity weakness first
- May progress to respiratory failure
- Reduced/absent deep tendon reflexes
- Paresthesia + pain on hands/feet
- Dysautonomia
~ BP lability
~ Brady/tachycardia
~ Cardiac arrhythmias - Affected cranial nerves
~ Diplopia (double vision)
~ Dysarthria (slurred speech)
~ Dysphagia
~ Opthalmoplegia
~ Facial droop
What are the variant types of Guillain-Barre syndrome?
1) Acute inflammatory demyelinating polyneuropathy (AIDP)
- Most common
- Myelin sheath affected
2) Acute motor axonal neuropathy (AMAN)
- Acute paralysis and loss of reflexes
- Without sensory loss
3) Acute motor-sensory axonal neuropathy (AMSAN)
- Degeneration of both sensory and motor fibers
- Affects axons
4) Miller-Fisher syndrome
- Affects nerves in your face and can cause eye, facial and balance problems
- Opthalmoplegia, ataxia, areflexia (muscles do not respond to stimulus)
5) Chronic inflammatory demyelinating polyneuropathy (CIDP)
- When progression is over 2 months
Diagnosis of Guillain-Barre syndrome?
No single test (various supportive evidence)
- Assessment
~ Neuromuscular chart (with muscle power)
~ Forced vital capacity
~ Vital signs - Tests for infectious disorders
~ FBC
~ Antibody titres (for EBV, CMV, C. jejuni, hepatitis, HIV) - Electrodiagnostic test
~ Signs of demyelination
~ Absent F waves
~ Slow nerve conduction velocities - CSF analysis
~ Increased protein
~ Normal WBC - Anti-CQ1b Antibodies (IgG)
~ To diagnose Miller-Fisher syndrome - MRI
~ To exclude other diagnoses
What is the treatment for Guillain-Barre syndrome?
- Mechanical ventilation
- Close monitoring of vital signs and CVS function
- IV immunoglobulin
~ 0.4g/Kg once/day for 5 days
~ Healthy IgA
~ Note may cause anaphylaxis in allergic px - Plasmapheresis
~ Plasma exchange to remove damaging antibodies
~ Less favourable to IV Ig - GABAPENTIN/CARBAMAZEPINE
~ For neuropathic pain
What are the signs of impending respiratory failure?
- Dyspnea
- Tachypnea
- Orthopnea
- Accessory muscle use
- Abdominal paradox (inward motion of abdomen with inspiration)
Brief of Multiple Sclerosis?
- Chronic
- Relapsing + remitting + progressive neurological deficits
- Due to recurrent episodes of demyelination in brain and spinal cord
What are the risk factors for Multiple Sclerosis?
- Female gender
- Often begins in young adults (20-40 y/o)
~ Earlier age of onset is usually associated with benign or relapsing-remitting forms of MS - Genetic factors
- Infiltration of oligoclonal CD4 lymphocytes
What is the pathophysiology of Multiple Sclerosis?
Normal:
- Electrical impulses travel along the axon, which is covered by myelin sheath
MS:
- Damaged myelin sheath interrupts the flow of nerve impulses -> slowed
- Demyelination is scattered irregularly across the nervous system -> usually affects optics, cerebellum, brain stem and spinal cord
What are the clinical features suggestive of Multiple Sclerosis?
Depends on location and varies from mild to severe
No unique clinical manifestations
- Affected sensation in limbs
- Motor problems, limb ataxia, stiffness, weakness
- Gait and balance disturbances, vertigo
- Visual loss, optic neuritis, diplopia, ophthalmoplegia, painful eye movements
- Lhermitte sign (shock-like sensation running down back or limbs upon back flexion)
- Fatigue
- Heat sensitivity
~ Symptoms worsen with fever
What are the types of disease progression in Multiple Sclerosis?
1) Relapsing-remitting .-..-._
- Most common
2) Secondary-progressive .-./
- Has a relapse before progressing
3) Primary progressive /
- May result in quadriplegias, cognitive impairment, vision loss and brain stem syndrome
4) Progressive-relapsing _.-/
- Relapses with continuous disabling progression between exacerbation
Need to know slide 8 McDonald criteria for diagnosis of MS ???
How do you diagnose Multiple Sclerosis?
- MRI of brain and spine
~ Kurtzke Expanded Disability Status Scale to analyse
~ White patches indicate MS
~ Lesions on brain without associated clinical complaints dircetly related to lesions - Oligoclonal IgG bands in CSF
~ Note: May also be found in SLE, SAH - Serum Aquaporin 4
~ Anti-Aquaporin 4 Ab is found in px with spinal MS - Evoked potentials (EP)
~ Measures the electrical activity in the brain in response to specific sensory stimuli
What are the neurologic findings in Multiple Sclerosis?
1) on Cranial Nerves
- Optic atrophy
- Ophthalmoplegia
- Nystagmus
- Dysarthria
2) on Motor
- Spastic hemi/para/quadriparesis
3) on Reflexes and Coordination
- Hyperflexia
- Clonus
- Babinski phenomenon
- Intention tremor
- Dysdiadochokinesia (inability to perform fast alternating movements)
4) on Sensory
- Hemihyperaesthesia (less sensation on one side of body)
What is the treatment for Multiple Sclerosis?
1) Interferon beta-1a + 1b (REBIF + BETASERON)
- Cytokines that modulates immune responsiveness
- Protects against intruders/viruses
2) Steroids
- PREDNISOLONE / MTHYLPREDNISOLONE
- Decreases severity of attacks
3) Autologous stem cell transplant
- Eliminates and replaces px’s pathogenic immune system to achieve long-term remission of MS
4) Symptomatic treatment of depression, spasticity, pain
What are the risk factors of Parkinson’s Disease?
- Age
- Genetics
- Herbicides, pesticides, heavy metals
- Rural residence, well water, proximity to industrial area
- Repeated head trauma
IMPT:
What is the etiology of Parkinson’s Disease?
- Imbalance of acetylcholine (excitatory) and dopamine (inhibiting) neurotransmitters in brain
~ Extrapyramidal tract impairment - Marked striatial dopamine depletion
~ Found in susbtantia nigra
IMPT:
What is the pathophysiology of Parkinson’s Disease?
1) Ubiquitin-proteasomal system impaired
- Abnormal, toxic intracellular proteins accumulate -> apoptosis
2) Dopaminergic neurons w/ Lewy body inclusions at substantia nigra has the most metabolic burden
- Unable to keep up with repairs -> Degenerates more quickly, especially at basal ganglia
IMPT:
What are the clinical features of Parkinson’s Disease?
- Insidious onset
- Unilateral -> bilateral
Requires at least 2 out of 3 of the cardinal signs:
1) Bradykinesia
2) Rigidity / cogwheel mvmt of arms
3) Tremor at rest
Others
- Masked face
- Dysphagia
- Micrographia (very small, cramped handwriting)
- Shuffling gait
- Loss of smell
- Cognitive impairment
- Mood disorders
- Sialorrhea (saliva dripping)
- Autonomic symptoms
What is the Modified Hoehn & Yahr Staging for Parkinson’s Disease?
0: No disease
1: Unilateral disease
1.5: Unilateral + axial involvement
2: Bilateral disease
- No imbalance
2.5: Mild bilateral + recovery on pull test
3: Postural instability but independent ADL
4: Severe disability but able to walk
5: Wheelchair / bed bound
IMPT:
What are the types of Parkinson’s Syndromes?
1) Idiopathic PD
- Most common
2) Neuroleptic-induced parkinsonism
- Drug-induced
3) Multiple system atrophy
4) Progressive supranuclear palsy
- Abnormal accumulation of a protein called tau in brain cells -> cell damage
5) Vascular Parkinson syndrome
- Reduced blood flow or damage to specific areas of the brain
IMPT:
How is Parkinson’s Disease diagnosed?
- MRI brain and spine
~ To exclude other brain conditions - Positron emission topography (PET)
- Single photon emission computed tomography (SPECT)
~ Can rapidly distinguish PD from potential tremors but not classify them
IMPT:
What is the treatment of Parkinson’s Disease?
- Goal is to control symptoms
- Deep brain surgery
- LEVODOPA
- AMANTADINE
- Dopamine antagonists
- Monoamine oxidase (MAO) B inhibitors
~ SELEGILINE - Anticholinergic agents
- Catechol-O-Methyl transferase (COMT) inhibitors
