10-21 L1 Demyelinating and Degenerative disease Flashcards
Name the 6 Demyelinating Diseases
- Remyelination
- GBS (Guillain-Barre syndrome)
- MS (Multiple Sclerosis)
- CPM (Central Pontine Myelinolysis)
- PML (Progressive multifocal Leukoencephalopathy)
- ADEM (Acute Disseminated Encephalomyelitis)
Name the 4 Degenerative Diseases?
- CMT (Charcot Marie Tooth Disease)
- FA (Freidreich’s Ataxia)
- HD (Huntington’s Disease)
- AML (Amyotrophic Lateral Sclerosis)
What primary demyelination is direct damage to what?
Direct damage to the oliodendroglia or schwann cells with relative preservation of axons.
Name the 3 causes that demyelination can cause clinical symptoms because of conduction block:
- Voltage-gated sodium channels exist only at nodes of ranvier
- Demyelinated strect of axon cannot produce action potentials (no voltage-gated Na channels)
- Demyelinated axons have terrible cable properties
Remyelination
reverses clinical symptoms by what mechanism?
- restores cable properties (sufficiently for action potentials to be triggered at nodes of Ranvies)
- Conduction velocities of remyelinated axons are slow (diagnostic nerve conduction velocites)
- time lag is clinically insignificant
Name key symptoms of GBS (guillain-Barre Syndrome)
- Demyelinating peripheral neuropathy
- Ascending paralysis
- Loss of reflexes
- Respiratory failure is most common cause of death (preventable)
What causes weakness in GBS?
What is elevated in CSF?
- weakness is caused by a conduction block
- Spinal fluid protein is elevated (otherwise CSF is normal)
What is used to treat pts w/GBS?
- Intravenous immunoglobulin (IVIG)
- plasmapheresis
Desribe the epidemiology of MS (multiple sclerosis)
- Def.
- incidince
- gender
- geneitic (hereditary)
- regional observations
- **Def.: **autoimmune disease of young adults (95% of cases are from 15-50)
- incidince: 2nd most common cause of neurological disability (1st is trauma)
- gender: 2F/1M
- geneitic (hereditary): concordance is 1/3 in identical twins, 1/15 fraternal twins)
- regional observations: latitidue (temperature zone is high, tropics low) and adolescence.
MS has a wide range of varited subacute presentations, what are they?
- Monocular loss of vision, diplopia, walking trouble, bladder dysfunction are relatively common
- Psychiatric or behavioral changes reflect frontal lobe involvement.
Describe the Intranuclear Opthalmoplegia (seen in pts w/MS)
- Lesion of MLF
- Impaired adduction of contrallateral eye
- Nystagmus in abducting eye
What are common findings on pts with MS?
Assuming that you have made sure lumbar puncture is safe
- Modest pleocytosis (increase in CSF white blood cells).
- Elevated CSF index
- Presence of oligoclonal bands
What are som imitators of MS?
- Mass lesions (CNS lymphoma)
- SLF (young women)
- Neurosyphilis
- Sarcoidosis
- HIV-related CNS disease
Which two diseases can be treated with IV methylprednisone?
- MS (Multiple sclerosis)
- ADEM (Acute disseminated Encephalomyelitis)
Name the 6 medications used for MS.
- IV methylprednisone
- Beta-interferon (30-40% reduction in relapse)
- Glatiramer acetate (30-40% reduction)
- Natalizumab
- Fingolimod (oral)
- Dimethyl fumarate & teriflunomide (other oral agents)
beta interferon (30-40% reduciton in relapse rate)
used to treat MS
- inhibits pro-inflammatory cytokines, T-cell proliferation, CNS trafficking
- myalgias chills, SQ & IM
Glatiramer acetate (30-40% reduction)
used in MS
- synthetic polypeptide SQ
- Similar efficacy and side effects beta interferons
Natalizumab
- desinger antibody (binds to integrin- cellular adhesino molecule)
- blocks lymphocytes-endothelial binding/penetrating BBB
- IV monthly, causes PML (0.2%)
Fingolimod
(oral, $$$)
- block egress of lymphocytes from lymph nodes and spleen
- heart block, oral (first case of PML reported 08-29-213)
CPM
(Central pontine myelinolysis)
- Demyelination of the ventral pons
- caused by: rapid correctino of hyponatremia (malnutrition and alcohol may increase risk)
- May present as a locked-in state or quadraplegia (more extensive lesions cause coma)
- has the tridant sign
An immunocompromised pt, informs you of initial complaints of aphasia, visual field defects, hemiparesis.
The pt family member informs you of instances of confusional states and seizures.
What’s your diagnosis?
PML (progressive multifocal leukoencephalopathy)
What are theclinical findings of PML:
on MRI?
on CT?
-
MRI is excellent
- non-enhancing
- no mass effects
-
CSF is usually normal
- PCR: JCV
- serum JC antibodies (60-80% of population)
- IRIS (immune reconstitution inflammation syndrome)
What is ADEM?
- Acute disseminated Encephalomyelitis: asymmetrical swelling of the brain
- follows viral infection or vaccination
What is used to diagnosis it?
- CT shows cerebral edem and mass effects
- MRI shows gadolinium enhacement of white matter
