Trauma and Demyelination Disorders Flashcards
What is the usual cause of an epidural hematoma?
Fracture of the temporal bone with rupture of the middle meningeal artery
Lens shaped lesion on CT = ?
epidural hematoma
Why are epidural hematoma called the “talk and die” syndrome?
Patients can be asymptomatic for a few hours, before suddenly collapsing
What is the classic presentation of a epidural hematoma
Lucid interval, followed by quick death
What is the major lethal consequence of an epidural hematoma?
Herniation of the brain
What usually causes a subdural hematoma?
Rupture of a bridging vein 2/2 trauma
What are the usual s/sx of a subdural hematoma?
Slow progression of neurological signs, with potential herniation of the brain
What is a tonsillar herniation?
Herniation of the cerebellar tonsils through the foramen magnum, compressing the brainstem
What is a subfalcine herniation? What is the major consequence of this?
- Cingulate gyrus herniates underneath the falx cerebri
- Compression of the anterior cerebral artery leads to infarction
What is an uncal herniation?
Herniation of the uncus of the temporal lobe, into the tentorium cerebelli
What are the three structures that are compressed with an uncal herniation?
- CN III
- Posterior cerebral artery
- Paramedian artery
Where is the paramedian artery located?
arteries which supply part of the thalamus and other structures in the region
What is a Duret hemorrhage?
small lineal areas of bleeding in the midbrain and upper pons of the brainstem. They are caused by a traumatic downward displacement of the brainstem
What are the two basic etiologies of demyelinating disease?
Attack against myelin or schwann/oligodendrocytes
True or false: with demyelinating disease, the axons are destroyed
False–axons are preserved, but the myelin, and thus the conduction of impulses are impaired
What, generally, are leukodystrophies?
Inherited mutations in enzymes necessary for production or maintenance of myelin
What is metachromatic leukodystrophy?
Deficiency in arylsulfatase, causing an inability to degrade myelin. Thus it accumulates within lysosomes
What is the most common leukodystrophy?
Metachromatic leukodystrophy
What is Krabbe disease?
Deficiency of galactocerebroside beta-galactosidase, causing a buildup of galactocerebroside in macrophages
What is adrenoleukodystrophy?
Impaired addition of coenzyme A to long chain fatty acids, causing FAs to accumulate and damage adrenal glands and white matter
What is the pathogenesis of MS?
Autoimmune destruction of CNS myelin and oligodendrocytes
What is the haplotype that is associated with MS?
HLA-DR2
MS is more commonly seen where (geographically)?
Higher latitudes
Which gender more commonly gets MS?
Women
What is Charcot’s pentad of MS?
- Scanning speech
- Internuclear ophthalmoplegia
- Intention tremor
- Incontinence
- Nystagmus
What causes the intranuclear ophthalmoplegia with MS?
Involvement of the Medial longitudinal fasciculus
What is the medial longitudinal fasciculus?
Connection between CN VI on one side, and the contralateral CN III. This allows gaze to move in the same direction
What causes the hemiparesis seen in MS?
Cerebral white matter loss
What causes the lower extremity loss of sensation with MS?
Spinal cord involvement
What will an MRI of a MS patient show?
Plaques
What are the CSF findings of MS? (2)
- Ig with oligoclonal IgG bands
- Myelin basic protein
What are the gross characteristics of MS?
Graying of the white matter in the brain
What is the treatment for an acute attack of MS? Chronic?
- Acute = high dose steroids
- Chronic = IFN-beta
True or false: IFN-beta has been shown to slow the progression of MS
True
What is subacute sclerosing panencephalitis?
Progressive, debilitating encephalitis leading to death d/t slowly progressing infection of measles virus
What is the virus that causes subacute sclerosing panencephalitis (SSPE)?
Measles virus
What is the general course of SSPE?
Infection occurs in infancy, with neurological signs arising years later
What are histological characteristics of SSPE?
Viral inclusions within neurons and oligodendrocytes
Why is it called subacute, sclerosing PANencephalitis?
Both white and gray matter tracts are affected
What is progressive multifocal leukoencephalopathy? S/sx?
Latent Infection of oligodendrocytes with JC virus is reactivated by immunosuppression.
-Presents with rapidly progressive neurological signs, leading to death
What is central pontine myelinolysis, and what causes it?
Focal demyelination of the pons, 2/2 rapid IV correction of hyponatremia
What is the usual presentation of central pontine myelinolysis?
Locked in syndrome (only eyes are spared)
