Neuro 1 Flashcards
What is the pathophysiology of Wilson disease? What are the lab results?
Mutated ATP7B gene results in copper accumulation – damaged hepatocytes leak copper, w/c deposits in other tissues (basal ganglia, cornea). The copper binds to sulfhydryl groups of cellular proteins and causes damage – liver injury, Parkinsonism, ataxia, Kayser-Fleischer rings .
>Dx: inc. liver transaminases, dec. ceruloplasmin.
In Alzheimer disease, what parts of the brain show the most pronounced atrophy?
Temporo-parietal lobes, Hippocampus (greatest degree of atrophy)
Dx: atrophied Hippocampus (MRI)
What is Postherpetic Neuralgia?
Pain found in Shingles usually subsides in weeks to months, but a subset of patients may have residual pain in affected dermatomes.
How do you treat postherpetic neuralgia?
> Usually treated w/ TCA (amitryptiline) or anticonvulsants (gabapentin, pregabalin).
Capsaicin is a topical treatment – calcium buildup in nerve fibers that causes defunctionalization – loss of membrane potential in nociceptive fibers.
What type of seizures do broad-spectrum anticonvulsants treat (examples)? Narrow-spectrum anticonvulsants (examples)?
> Broad-spectrum: most generalized seizure types – lamotrigine, tipiramate, Valproic acid.
Narrow-spectrum: focal onset seizures – Carbamazepine, Gabapentin, Phenobarbital, Phenytoin.
*Avoid narrow-spectrums in generalized epilepsy syndromes – can possibly aggravate seizure
How is the radial nerve most commonly damaged and what are the ssx?
Since the radial nerve passes through the supinator canal of the forearm, it may be commonly damaged through repetitive supination and pronation of the forearm. This results in weakness in finger and thumb extension – “finger drop”, w/o sensory deficits (dorsal hand, radial half)
The Arteriovenous concentration gradient reflects the overall tissue solubility of an anesthetic. How does an anesthetic with high tissue solubility act on the body and brain?
High tissue solubility means a large amount of the anesthetic is taken up from the blood, so there is low venous concentration – need more anesthetic to saturate blood to replace what’s absorbed – blood saturation takes longer, brain saturation delayed, slower onset of action
What is the area postrema and its significance during chemotherapy?
The area postrema has the chemoreceptor trigger zone that induces vomiting during systemic chemotherapy due to it’s fenestrated vessels. It’s found on the dorsal surface of the medulla, caudal end of 4th ventricle.
How does pain during a migraine occur? What is the treatment for migraines?
Activation of CN V, w/c innervates meninges – release of vasoactive peptides (substance P) – vasodilation, plasma protein extravasation – neurogenic inflammation, neuronal sensitization.
>Tx: Triptans (sumatriptan) – 5HT1b/1d agonists – inhibit vasoactive peptide release, vasoconstriction, block pain pathways to brainstem
What are Schwannomas and how do they present histologically?
PNS tumors of schwann cells, commonly found at the cerebellopontine angle at CN8. Manifests w/ tinnitus, vertigo, hearing loss.
>(+) S-100
>Histo: Biphasic pattern – Antoni A (highly cellular w/ spindle cells), Antoni B (low cellularity)
What is the significance of Amyloid precursor protein (APP) processing in Alzheimer’s dementia?
Inappropriate processing of APP on chromosome 21 can cause formation of amyloid plaques (neurotoxic).
>Alpha and gamma-secretases: doesn’t result in amyloidogenic proteins.
>Beta and gamma-secretases: Beta-amyloid – insoluble fibrils – amyloid plaques.
What is the significance of cervical spine involvement in a patient w/ chronic rheumatoid arthritis?
Chronic RA w/ cervical spine involvement may often cause subluxation of the atlantoaxial joint (highly mobile). If the patient has endotracheal intubation, can compress spinal cord and vertebral arteries – paralysis, hypotension, sudden death.
Disease course of Alzheimer (early, late)
> Early: memory loss (recent events), executive dysfunction (planning, organizing), visuospatial impairment (getting lost).
Late: language and behavioral abnormalities
