7 degenerative and demylinating Diseases Flashcards
Is demyelination or dysmyelination acquired? What does this mean about the original myelin?
- demyelination
2. originally normal myelin as opposed to abnormal myelin in dysmyelination
Are axons usually preserved in in dysmyelination?
No- they usually undergo degeneration. They are preserved in demyelination
Can remyelination occur in demyelination?
Yes
In dysmelination- myelin sheaths may not form, those that do are abnormal and often undergo degradation
T-F- diphtheria causes toxic demyelination of the CNS?
False- PNS
What is defined as an acquired autoimmune demyelinating disease typified by well defined episodes of neurological deficits separated by time and by space?
Multiple sclerosis
What does separated by time and by space mean?
multifocal with lesions of different ages and in different site.
T-F- multiple sclerosis is the 2nd most common demyelinating disease of the CNS?
False- most
In MS- more commonly progressive or relapsing and remitting ?
Relapsing and remitting in 80%
There are 4 types of MS- classic, acute, neuromyelitis optics, schilder’s– which one has spinal cord and optic nerve involvement? What is the defect in?
- Neuromyelitis Optica (Devic’s type)
2. Aquaporin 4
What type of MS- occurs in children, extensive demyelination, acute, can be remitting? does it respond to steroids?
Shilder’s disease
Yes
Is MS more common in men or women? age? is there a genetic component?
- Women 4.1 to 1
- Age- 20-40
- Yes- [risk 20x if in first degree relatives, Class II MHC, DR2, DR4, DR15 DQ6, Polygenic]
What is the etiology of MS?
Immunological- antibodies against components of myelin sheath.
There is a CD4+ Th-1 T-cell mediated attack against a number of oligodendrocyte and white matter antigens.
Normally- are B lymphocytes included in the CNS?
B-lymphocytes are excluded from the CNS
What happens to B-lymphoctes in the CSF in MS?
T-helper cell induced clonal expansion in the CSF producing IgG immunoglobulins
What is the diagnostic hallmark of MS?
oligoclonal banding seen on CSF electrophoresis due to clonal proliferation
The antibody antigen complex formed by antibodies to the myelin proteins is recognized by what?
Fc receptos on the surface of macrophages
[this with complement activation results in damage to myelin and phagocytksed by macrophages]
Does lymphocyte mediated injury take place in multiple sclerosis?
Yes- C8+ T cells are thought to target oligodendroglia
Besides ingesting myelin- how to macrophages damage myelin?
productions of ROS and nitrogen species, proteolytic enzymes, cytokines
Where are MS demyelinating plaques frequently found?
periventricular
- but can be anywhere in the white matter of the brain and at the junction of cortex and white matter, brain stem, spinal cord, optic chiasm, cerebellum
What do macrophages distinctively contain in them in MS?
myelin debris
Does and MS active or inactive plaques have long term loss of axons, loss of oligodendroglia and gliosis/cavitation?
Inactive
-[active has loss of myelin, preservation of axon, perivascular T cells]
What does the shadow plaque in MS have?
reduced myelin and remyelinating axons
What does the luxol fast blue stain?
myelin
What does the bielschowsky stain stain?
axons
What stain is best for remyelination?
luxol fast blue stain
What does the luxol fast blue stain?
myelin- Really makes macrophages with myelin bodies really stand out
What does the bielschowsky stain stain?
axons- a type of silver stain
What stain is best for remyelination?
luxol fast blue stain
Note on the luxol fast blue stain-
active plaque is nearly white and the shadow plaque is in between the dark blue and the white color. KINDA LIKE A SHADOW I GUESS
What form of MS is acute, rare, rapidly progressive with a poor outcome, severe disability and death?
marburg variant
What are some of the signs of the marburg variant?
confusion, HA, vomiting, gait unsteadiness and hemiparesis
What protein is messed up in neuromyelitis optica?
Aquaporin 4- part of the integrity system of the BBB
What are the 2 primary Poser diagnostic criteria for Schilder’s Disease? review the others
- acute/subacute with one or more roughly symmetrical bilateral plaques measuring at least 2x3cm involving the centrum semiovale
- No other lesions clinically, paraclinical, or imaging
- no PNS lesions
- normal adrenal function
- normal very long chain fatty acids
- pathology resembles MS
What is a mono phasic demyelinating disease that predominantly involves the pontine basis? What is it caused by? how does it rapidly present?
- Central pontine myelinolysis
- complication of rapidly correcting hyponatremia, or low magnesium
- confusion, limb weakness, conjugate gaze palsy, dysarthri, dysphagia- FATAL IN WEEKS.
Guillain-Barre Syndrome - also known as acute inflammatory demyelinating polyradiculoneuropathy is a rapidly ascending paralysis of spinal nerve roots. What is a key laboratory characteristic of this condition?
VERY HIGH CSF PROTEIN
Is acute disseminated encephalomyelitis (inflammatory disease) a type II or type IV hypersensitivity case? What is the outcome?
- Type IV- T-cell mediated hypersensitivity reaction
2. Resolve over weeks in most, steroids + plasmophoresis, 20% die in acute phase
Name(review) some viral, bacterial and iatrogenic causes?
viral- measles, mumps, varicella, rubella, influenza, imono
bacteria- mycoplasma, campylobacter, strepA (rare)
iatrogenic- gold, levamisole, 5FU
What causes progressive multifocal leukoencephalopathy? is it progressive?
- polyoma virus/ JC virus
2. yes- leading to death
What disease is described by the following pathology- multiple foci of demyelination, viral inclusions in oligodendroglia nuclei, atypical/bizarre astrocytes and perivascular inflammatory infiltrate?
progressive multifocal leukoencephalopathy
What are the different signs between thiamine deficiency types WErnicke’s and Korsakoff’s?
Wernicke- gaze palsy, ataxia, apathy, clouded conscious
Korsakoff- retro and anterograde amnesia and confabulation
What causes direct toxicity in cerebellar degeneration?
thiamine
What chemo drug is very prominent in neuro toxicity?
methotrexate
What toxicity leads to hypoesthesia of hands and feet, ataxia, impairment of hearing, visual constriction, dysarthria, maybe coma and death?
mercury- methyl mercury especially through consumption of contaminated fish or skin lightening creams used in pregnant women.
What does a gross brain with CO poisoning look like?
Tons of little red dots everywhere (hypoxia)- symmetrical necrosis of the globus pallidus
[movement disorders in survivors]
Can remyelination occur in demyelination?
Yes
In dysmelination- myelin sheaths may not form, those that do are abnormal and often undergo degradation
There are 4 types of MS- classic, acute, neuromyelitis optics, schilder’s– which one has spinal cord and optic nerve involvement? What is the defect in?
- Neuromyelitis Optica (Devic’s type)
2. Aquaporin 4
What type of MS- occurs in children, extensive demyelination, acute, can be remitting? does it respond to steroids?
Shilder’s disease
Yes
Is MS more common in men or women? age? is there a genetic component?
- Women 4.1 to 1
- Age- 20-40
- Yes- [risk 20x if in first degree relatives, Class II MHC, DR2, DR4, DR15 DQ6, Polygenic]
What is the etiology of MS?
Immunological- antibodies against components of myelin sheath.
There is a CD4+ Th-1 T-cell mediated attack against a number of oligodendrocyte and white matter antigens.
What is the diagnostic hallmark of MS?
oligoclonal banding seen on CSF electrophoresis due to clonal proliferation
The antibody antigen complex formed by antibodies to the myelin proteins is recognized by what?
Fc receptos on the surface of macrophages
[this with complement activation results in damage to myelin and phagocytksed by macrophages]
Besides ingesting myelin- how to macrophages damage myelin?
productions of ROS and nitrogen species, proteolytic enzymes, cytokines
What stain is best for remyelination?
luxol fast blue stain
Note on the luxol fast blue stain-
active plaque is nearly white and the shadow plaque is in between the dark blue and the white color. KINDA LIKE A SHADOW I GUESS
What are some of the signs of the marburg variant?
confusion, HA, vomiting, gait unsteadiness and hemiparesis
What protein is messed up in neuromyelitis optica?
Aquaporin 4- part of the integrity system of the BBB
What are the 2 primary Poser diagnostic criteria for Schilder’s Disease? review the others
- acute/subacute with one or more roughly symmetrical bilateral plaques measuring at least 2x3cm involving the centrum semiovale
- No other lesions clinically, paraclinical, or imaging
- no PNS lesions
- normal adrenal function
- normal very long chain fatty acids
- pathology resembles MS
What is a mono phasic demyelinating disease that predominantly involves the pontine basis? What is it caused by? how does it rapidly present?
- Central pontine myelinolysis
- complication of rapidly correcting hyponatremia, or low magnesium
- confusion, limb weakness, conjugate gaze palsy, dysarthri, dysphagia- FATAL IN WEEKS.
Guillain-Barre Syndrome - also known as acute inflammatory demyelinating polyradiculoneuropathy is a rapidly ascending paralysis of spinal nerve roots. What is a key laboratory characteristic of this condition?
VERY HIGH CSF PROTEIN
What disease is described by the following pathology- multiple foci of demyelination, viral inclusions in oligodendroglia nuclei, atypical/bizarre astrocytes and perivascular inflammatory infiltrate?
progressive multifocal leukoencephalopathy
What are the different signs between thiamine deficiency types WErnicke’s and Korsakoff’s?
Wernicke- gaze palsy, ataxia, apathy, clouded conscious
Korsakoff- retro and anterograde amnesia and confabulation
What causes direct toxicity in cerebellar degeneration?
thiamine
What chemo drug is very prominent in neuro toxicity?
methotrexate