Neuro6 Flashcards
What do we see histopathologically/grossly in Huntington Disease? (3)
- -Degeneration of the GABAergic neurons of the caudate nucleus –> expansion of lateral ventricles
- -Also degenerative changes in the putamen and cortex
- -decreased levels of GABA and ACh in the brain
What are the clinical characteristics of Huntington Disease?
- -Chorea
- -writhing movement (athetoid)
- -progressive dementia
- -behavioral disorders
**sometimes Huntington disease is initially mistaken for substance abuse
60% of abscesses in the brain are caused by what primary disease process?
otitis media (middle ear infection)
cerebellar and temporal lobe abscesses are associated with otitis media
Cerebellar abscesses are specifically associated with what disease?
otitis media (middle ear infection)
What bacteria are most commonly responsible for otitis media?
Haemophilus influenzae
Streptococcus pneumoniae
What is a subdural empyema?
A collection of pus between the dura and the arachnoid. This is usually a complication of bacterial meningitis.
Where in the brain would sinusitis cause abcesses?
frontal and temporal lobe
What is a ring-enhancing lesion in the brain on CT indicative of?
a brain abscess
Unlike injury to the lateral geniculate nucleus or optic radiations, why do we observe macular sparing with a lesion to the occipital cortex?
This is because the most posterior region of the occipital cortex, which is where the macula is represented, has a bilaterally redundant blood supply. It is supplied by the PCA (posterior cerebral artery) and a branch of the middle cerebral artery.
What blood vessel pathology would lead to a bitemporal hemianopia?
The anterior communicating artery is located in the vicinity of the optic chiasm. Aneurysm of the anterior communicating artery can therefore compress the optic chiasm, producing a bitemportal hemianopia.
What artery gives rise to the ophthalmic artery?
Internal carotid artery
How would occlusion of the ophthalmic artery manifest clinically?
This artery perfuses the optic nerve and the retina. Occlusion of this artery would lead to monocular blindness in the affected eye.
What would be the ophthalmologic deficit that results from aneurysm of the posterior communicating artery?
The posterior communicating arteries overlie CN III. Aneurysm of these arteries can lead to a CN III palsy. Because the parasympathetic fibers of CN III are located peripherally, the first sign of compression of this nerve would manifest as mydriasis (pupil dilation) on the affected side. If the aneurysm grows to impinge the centrally located motor fibers, extraocular eye movement will be impaired: lateral strabismus, with the affected eye pointing down and out on primary gaze.
What blood vessel pathology would lead to a binasal hemianopia?
The internal carotid arteries also run next to the chiasm on their outside; calcification of these vessels could compress the non-decussating fibers of the chiasm, leading to a binasal hemianopia. (The nasal visual field projects to the temporal retina; the optic nerve fibers of the temporal retina do not decussate.)
What is PrP sc?
PrP sc is a prion protein that is responsible for the spongiform changes seen in Creutzfeldt-Jakob Disease (CJD)
What is mutation in zinc-copper superoxide dismutase associated with?
It is associated with some hereditary forms of Amyotrophic Lateral Sclerosis (ALS)
What are neurofibrillary tangles composed of?
Hyperphosphorylated tau proteins. Tau proteins are microtubule-associated proteins that normally bind to and stabilize microtubules.
The hyperphosphorylated tau proteins form insoluble paired helical filaments (PHF)
Where is the facial nucleus located?
The lower pons