Neuro/GI Wk 4 Flashcards
1
Q
How can acute hepatitis B present?
A
Like serum sickness with joint pain, lymphadenopathy and rash.
2
Q
Positive and negative predictive values is dependent on what feature?
A
The prevalence in a tested population
3
Q
MOA of triptans?
A
Triptans are serotonin agonist that inhibit trigeminal nerve activation and prevent vasoactive peptide release and induce vasoconstriction.
Abortive therapy for migraines
4
Q
HDAg is considered to be replicative defective and must be ____ before it can penetrate the hepatocyte?
A
Coated by the external coat hepatitis B surface antigen (HBsAg)
5
Q
The spleen is an embryological derivative of?
A
Mesoderm
6
Q
What meds can you treat Chronic Hepatitis C with?
A
Direct acting antivirals (DAAs). E.g Ledipasvir and sofosbuvir. These target specific HCV enzymes that inhibit viral replication and assembly.
7
Q
How does the histopathology of celiac sprue present?
A
Crypt hyperplasia, villous atrophy and intraepithelial lymphocyte infiltration.
**mostly affects distal duodenum and proximal jejunum
8
Q
Metabolism of 1g protein/carbohydrate produces __ calories of energy?
1g of fat?
A
4 calories of energy
9 calories of energy
9
Q
In alcoholic induced hepatitis, what is the ratio of AST to ALT?
A
AST>ALT
**every other cause of hepatitis has a ALT>AST.
10
Q
Elevated concentrations of ____ & ____ increase cholesterol solubility and decrease risk of gallstones
A
Bile salts and phosphatidylcholine
11
Q
Lymphatic drainage of the recum proximal to the anal dentate line occurs via these lymph nodes?
A
Inferior mesenteric and internal iliac LN
12
Q
Areas of the rectum distal to the dentate line drain to these Lymph Nodes?
A
Inguinal LNs
13
Q
This inflammatory mediator plays a central role in the pathogenesis of Crohn’s Disease?
A
TNF-Alpha
**promotes intestinal inflammation by inducing lymphocyte proliferation, enhancing migration of neutrophils and stimulating macrophage activity.
14
Q
What is the most common cause of inherited intellectual disability?
A
Fragile X
15
Q
Cytogenic studies of fragile X show ?
A
Small gap near the tip of the long arm.
**Due to expansion of CGG (trinucleotide repeats) in the FMR gene (fragile X mental retardation gene) located on long arm of X. Area of increased repeat does not stain and appears broken.
16
Q
Occlusion of the portal triad should stop bleeding except if the bleeding is in these vessels?
A
IVC or hepatic vein.
17
Q
What makes up the portal triad?
A
Hepatic artery, portal vein and common bile duct (encased in the hepatoduodenal ligament).
18
Q
What are some examples of afferent pupillary defect?
A
Optic neuritis (demyelination) and retinal detachment, ischemic optic neuropathy & trauma.
**implies ipsilateral optic defect.
19
Q
Prostaglandins are important in the GI tract for?
A
Maintenance of intestinal mucosa (decrease gastric acid formation, increase bicarb production and increase mucuosal blood flow).
20
Q
Absence of normal enteral stimulation in patients receiving total parenteral nutrition can lead to ?
A
Gallstones (via decrease in cholecystokinin release, biliary stasis)
21
Q
Diphenoxylate MOA?
A
Binds to mu receptor agonist in the gut and slows motility.
22
Q
To avoid abuse of diphenoxylate what is typically co-administered?
A
Atropine - anticholinergic effects (induces adverse effects if taken in high doses).
23
Q
Hereditary nonpolyposis colon cancer is also known as?
A
Lynch syndrome
24
Q
HNPCC leads to occurence of ___ at young age <50?
A
Colonic adenocarcinoma and increased disposition for extraintestinal malignancies (endometrial and ovarian)
** Fam Hx will be +ve for cancers.
25
Mutations in ____ are responsible for HNPCC?
DNA mismatch repair genes (MSH2 & MLH1)
*Autosomal dominant.
Inherit mutated copy, 2nd copy affected in adulthood.
26
Patients with MS often develop these symptoms?
Respiratory failure (also COD) due to inspiratory muscle weakness (Decreased vital capacity), expiratory m. weakness (ineffective cough) and bulbar dysfunction (dysphagia and chronic aspiration).
27
Pathology of abetalipoproteinemia?
Inherited inability to synthesize apolipo B. Lipid absorbed cannot be transported into blood and accumulate in intestinal epithelium -> enterocytes with foamy cytoplasm.
28
Describe the inclusions found in Hepatitis B?
Finely granular, pale eosinophilic 'ground glass' appearance.
29
What is a pseudomembrane?
Exudate on colonic mucosa consisting of fibrin and inflammatory cells.
30
What can lead to the formation of pseudemembrane?
Antibiotics -> disrupt normal flora -> overgrowth of clostridium -> watery diarrhea and colitis
**Also common in pts with recent hospitalization, PPI.
31
This is a potentially fatal neonatal bleed that occurs during delivery when emissary veins between the dural sinuses and scalp are sheared?
Subgaleal hemorrhage.
**Accumulation of blood between periosteum and galea aponeurosis. Px with fluctuant scalp and neck swelling.
**Massive blood loss -> shock and death.
32
How does IL-10 attenuate inflammatory response?
Inhibition of TH1 cytokines, reduction of major histocompatibility complex II expression and suppression of activated macrophages and DC.
33
Hepatic angiosarcoma is associate with exposure to ?
Arsenic, thorotrast (radio contrast agent), and PVC exposure.
34
What endothelial cell markers does a hepatic angiosarcoma express?
CD31
35
What are the most common causative agents in intraabdominal infections?
Normal colonic bacteria: E. coli and B. fragilis (anaerobic, favors abscess formation).
Others: enterococci and streptococci
36
Small intestinal bacterial overgrowth is characterized by increased production of?
Vitamin K and folate.
**asx with nausea, abd discomfort and malabsorption.
Decrease in B12, ADE and iron.
37
Gastric bypass can cause this in the blind-ended gastroduodenal segment?
Small intestinal bacterial overgrowth.
38
Patients with parkinson disease may benefit from high frequency deep brain stimulation suppressing activity of these brain regions?
Globus plallidus internus or Subthalamic nucleus.
39
What factors inhibit acid secretion?
Somatostatin & Prostaglandins
40
Charcot's triad for acute cholangitis?
Fever, jaundice, RUQ pain
41
Reynolds Pentad for acute cholangitis?
Fever, janudice & RUQ + hypotension and altered mental status
42
What is acute cholangitis?
Most common causes?
Ascending infection due to biliary obstruction
Gallstones, malignancy, stricture Primary scelrosing cholangitis), biliary stent blocakage.
43
These drugs are useful in treatment of visceral nausea due to GI insults, gastroenteritis, chemo and general anesthesia?
5-HT3 antagonist
**gastric irritation results in increased release of serotonin and activate 5HT receptors -> spinal afferent via vagal n. -> medullary vomiting center-> emesis
44
What type of nausea is treated by antihistamines and anticholinergics?
Vestibular nausea
45
Dopamine antagonists are useful for this types of nausea?
Nausea associated with migraine
46
Patients with these injuries are particularly susceptible to Sciatic neuropathy ?
Femoral head dislocation, hip fracture and or arthroplasty
47
Injury to the sciatic (L4-S3) nerve causes these deficits?
Knee flexion, common peroneal n (dorsiflexion, numbness of calf and dorsal foot) and tibial n (plantar flexion, ankle reflex).
48
What nerve is responsible for the ankle reflex?
Tibial n.
49
How can botulinum toxin help with achlasia?
Prevents acetylcholine release into NM synapse (prevents fusion of vesicles) -> inhibition of cholinergic neurons -> muscle weakness -> LES relaxation.
50
Treatment options for Clostridium difficile?
Oral vancomycin or fidaxomicin
51
MOA of fidaxomicin?
Macrocyclic antibodies that inhibits sigma subunit of RNA polymerase -> protein synthesis impairment and cell death.
52
Where are bile acids reabsorbed?
Terminal ileum
53
How can crohns disease affecting the terminal ileum lead to coagulation disorders?
Decreased absorption of bile acids -> fat malabsorption -> ADEK (fat soluble vitamins) ->
Vitamin K is cofactor for 1972 -> coagulation problems (easy bruising, hematoma formation).
54
Increased uptake of Tc-pertechnetate in the periumbilical/RLQ is characteristic of?
Meckel's diverticulum
**pertechnetate has an affinity for parietal cells of the gastric mucosa which is often found in a meckel's diverticulum
55
What arteries does the splenic artery give off?
Short gastric (vulnerable to ischemic injury - due to poor anastamoses), L. gastroepiploic and pancreatic.
56
In which gastric layer are parietal cells located?
Predominantly in the upper glandular layer
57
What cells does pernicious anemia destroy?
Parietal cells (secrete Hydrochloric acid and Intrinsic Factor).
58
Abusive head trauma (shaken baby syndrome) usually leads to?
Subdural (due to tearing of bridging veins) and retinal hemorrhages.
59
Single brain abscess is usually caused by?
Direct spread of a contiguous infection
Multiple brain abscesses typically indicate hematogenous dissemination
60
Temporal lobe abscess is usually as a result of?
Otitis media that has spread to the mastoid air cells.
61
Frontal lobe abscess is usually as a result of ?
Ethmoid or frontal sinusitis
62
The vomiting reflex is initiated by what part of the brain?
The chemoreceptor zone (area postrema) and nucleus tractus solitarius within the dorsal medulla.
**has a poor BBB -> so activated by emetogenic substances (drugs, toxins)
63
How do chemo agents trigger vomiting?
Chemo agents cause damage to enterocytes -> stimulate release of 5HT3 receptors on vagal afferent fibers in bowel wall -> ascend to area postrema -> vomiting reflex.
Can also be via direct activation of area postrema by NK1 receptors in area postrema by release of substance P.
64
Zollinger Ellinger Syndrome is often associated with which MEN syndrome?
MEN 1
Along with Pituitary adenoma (prolactinemia) and parathyroid hyperplasia.
65
Umbilical hernia are often seen with children with this condition?
Downs Syndrome
66
Umbilical hernia is associated with incomplete closure of?
Umbilical ring
** associated with defect in linea alba.
These protusions are reducible and soft.
67
The protein utilizes the RAS-MAPK pathway?
G protein.
RAS (GDP) -> active RAS (GTP) -> RAF -> MAPK -> gene activation.
68
How would a pt presenting with obstructive jaundice present?
Elevated bilirubin, dark urine, pale stools.
69
What should be considered in a patient presenting with painless obstructive jaundice and weight loss?
Pancreatic adenocarcinoma
70
What is Courvoisier sign?
Painless palpable gallbladder in jaundiced patient.
71
What is the most important RF for pancreatic cancer?
Smoking
72
Dystonia is often as a result of impaired function in the?
Basal ganglia
73
Vitamin B deficiency is also called?
| Symptoms are caused by demyelination of which tracts?
Subacute combined (ascending & descending pathway) degeneration
Demyelination of dorsal columns, spinocerebellar and corticospinal tract
Can be thought of as (tabes dorsalis + corticospinal tract).
74
Cholangiocarcinoma is a malignancy of?
Associated with?
Bile duct epithelium
Primary sclerosing cholangitis
75
There are two main causes of cholangiocarcinoma, what are they?
Primary sclerosing cholangitis & Clonorchis sinensis (liver fluke).
**both obstruct bile drainage
76
How would cholangiocarcinoma px? Imaging
Cholestasis: markedly increased alk phos, hyperbilirubinemia
Is an adenocarcinoma so Cuboidal/columnar cells arranged in glandular structures (mucin production).
Bile duct dilation in absence of stone.
77
Adenocarcinoma is the esophagus often drain to these LN?
SSC drain to which nodes?
Celiac and gastric nodes
Mediastinal LN
78
Diverticular disease can present with ____ bleeding?
Painless bleeding
79
In CMV reactivation, what are some of the common syndrome?
CMV retinitis, CMV colitis.
80
Colonoscopy in CMV colitis shows?
Histology?
Mucosal erythema, erosions and ulceration.
Giant cells with centralized intranuclear basophilic inclusions
81
How do protease inhibitors work?
Block viral protease from cleaving gag pol polyproteins -> formation of immature virions that are non infectious
82
Failure of neural tube closure at ___ weeks results in neural tube defects?
Week 4
83
Early onset (<60) alzheimer's is associated with these 3 protein mutations?
APP (chromosome 21), Presenilin 1 and presenilin 2.
84
What are the altered proteins involved in the sporadic form of Alzheimer's disease? Which is protective and which is not?
ApoE -2 -> Protective
| ApoE-4 -> Increased risk
85
What are the two ezymes that are deficient in PKU?
Phenylalanine hydroxylase and BH4 (tetrahydropterin).
86
What is the hallmark px for PKU?
Intellectual disability
87
What molecules need BH4 for production?
Tyrosine -> Dopa
Niacin -> Serotonin
Arginine -> NO
88
What products are converted from propionyl-CoA -> Methylmalonyl -COA
Odd chain FA, branched AA (Leucine, Isoleucine and Valine), Methionine and threonine
89
The "on" and "off" phenomenon is thought to be a consequence of ?
Progressive nigrostriatal neuodegenration leading to a decreased therapeutic window.
90
Why should you not give only glucose infusion to patient presenting with chronic alcohol dependency?
Thiamine absorption is affected in alcoholism. When you give glucose -> use up last stores of thiamine (thiamine is cofactor in many glucose pathways)-> Wernicke's Encephalopathy (nystagmus, gait ataxia).
91
What is the endrophonium test used for?
To differentiate between myasthenic (pt is undertreated) or cholinergic crisis (too high doses -> excessive AchE).
Endrophonium will improve symptoms if myasthenic crisis and since in cholinergic crisis, the NMJ becomes insensitive to excess AChE, Endrophonium will have no effect.
92
These antidepressants can treat diabetic neuropathy?
TCAs
SNRIs
Gabapentoids
93
In Ataxia telangiectasia, the function of the ATM gene is?
DNA break repair
94
The immune deficiency in Ataxia telangiestasi presents as?
IgA deficiency- infections in the upper and lower airways.
95
How does isonazid cause numbing and tingling?
Isoniazid is structurally similar to pyridoxine (B6) -> competes with B6 synthesis of many neurotransmitters e.g GABA. Also leads to increased urinary excretion of pyridoxine -> B6 deficiency -> Isoniazid induced neuropathy
96
First line treatment for trigeminal neuralgia?
Carbamazepine
97
Multiple sclerosis is an immune mediated disorder of CNS characterized by?
Focal demyelination (plaques) which contain perivenular infiltrates (made up of autoreactive T lymphocytes & macrophages).
Patchy demyelination followed by astrocyte hyperplasia.
98
In ataxia telangiectasia, what is the DNA of patients hypersensitive to?
Ionizing radiation (defect in DNA repair genes)
99
Where do vestibular schwannomas typically arise?
Cerebellopontine angle
100
Bilateral acoustic neuromas are assoicated with?
Neurofibromatosis type 2
101
What other nerves would a vestibular schwannoma affect?
CN 5&7
102
Involvement of the lower vermis and the flocculonodular lobe of the cerebellum would cause?
Vertigo and nystagmus (dysregulation of the vestibular nuclear complex).
103
Most cases of cerebellar hemorrhage are caused by?
Hypertensive vasculopathy
104
Klumpke palsy shows paralysis of?
All the intrinsic hand muscles (claw hand deformity)
105
Which animals can act as a reservoir for west nile virus reside?
Harbored in birds and transmitted to humans by mosquitoes.
Often cause self limited flu like illness with maculopapular rash. Rare cause of menningtitis, encephalitis and flaccid paralysis (neuroinvasive).
106
Traumatic vascular dissection is a relative common cause of ischemic stroke in the young and affects primarily these vessels?
Carotid and vertebral arteries
| can be easily injured by cervical spinal trauma
107
Lateral medullary syndrome is also called?
Wallenberg Syndrome
108
Gerstmann syndrome results from damage to this brain part?
Angular gyrus of the dominant parietal lobe
*Supplied by MCA
109
Gerstmann Syndrome is characterized by?
Agraphia (inability to write), acalculia (inability to carry out mathematical calculations), finger agnosia (inability to identify individual fingers on the hand) and left right disorientation.
110
Subacute sclerosing panencephalitis is a rare complication of?
Measles.
**occurs several years after initial infection.
111
What is the pathology for the development of subacute sclerosing panencephalitis?
Measle virus with mutated/absent matrix. Allows evasion by the immune system -> accumulation of the virus within neurons and oligodendrocytes -> inflammation, demyelination and gliosis.
112
The most common pineal gland tumor is a?
Germinonma.
**Px with obstructive hydrocephalaus (from aqueductal stenosis) and dorsal midbrain (Parinaud) Syndrome.
113
Wilson's disease has a mutation in what gene?
ATP7B - impaired cellular transport of copper.
114
Manifestations of wilson's disease?
Psych symptoms (depression, emotional liability, and impulsivity)
Parkisonism
Kayser Fletcher rings
**low ceruplasmin
115
Treatment for Wilsons disease?
Copper chelator (penicillamine)
116
Berry saccular aneurysm arising from PCA, would most likely affect this nerve?
Oculomotor (CN III)
117
Berry aneurysms mainly occur in these vessles?
Anterior circulation (ACA, PCA & MCA)
