MRCP Facts Flashcards
Which antibody is implicated in VITT?
Antibody against platelet factor 4 (PF4)
These activate platelets via their Fcy11a receptors to cause thrombosis in a similar mechanism to HITT
What translocation occurs in acute promyelocytic leukaemia?
t(15:17)
Retinoic acid receptor- alpha (RARA) gene on chromosome 17 is involved in a reciprocal translocation with the promyelocytic leukaemia gene (PML) on chromosome 15.
Treatment is with all-trans-retinoic acid
What causes tear drop poikilocytes?
myelofibrosis
What is the thrombolysis window for stroke?
4.5 hours from symptom onset to rule out of haemorrhage
1mg of prednisolone is equivalent to how many mg of hydrocortisone?
4mg
What is the first line antihypertensive drug in diabetic patients?
ACEi regardless of age
What is the key differential for a loss of the corneal reflex?
Vestibular schwannoma - benign tumour of the myeslin-forming cells of the vestibulocochlear nerve (CN8). It can compress CN 5 which results in a loss of the corneal reflex
Bilateral vestibular schwannomas are seen in neurofibromatosis type 2.
At what PaO2 should steroids be started in PJP?
Less than 9.3kPa
What 3 hereditary syndromes are associated with phaeochromocytomas?
Von Hipple-Lindau syndrome
MEN-2
Succinate Dehydrogenase
What is the valve area and mean gradient across the valve in severe aortic stenosis?
Valve area: <1cm^2
Mean Gradient: >40 mmHg
What is the hallmark feature of postural orthostatic tachycardia syndrome (POTS)?
An increase in HR >30 in standing without a drop in BP
What is the most likely diagnosis if someone has symptoms of asthma that do not resolve with inhalers, proximal bronchiectasis on HRCT, Increased eosinophils and IgE?
Allergic bronchopulmonary aspergillosis (ABPA)
Diagnosis confirmed with positive skin prick test to aspergillus fumigatus (Positive RAST test)
In some patients there will also be positive IgG precipitins to aspergillus.
Oral steroids are the mainstay of initial treatment. Itraconazole is sometimes used 2ns line
What are the components of the GRACE score?
Age Systolic BP Heart rate Killip class (features of CCF) Creatinine ST segment deviation Elevated Troponin Cardiac arrest on admission
What HLA is expressed in the majority of people with coeliac disease?
HLA-DQ2 in 95%
HLA-DQ8 in the remainder
What are the 3 features of Wernicke’s encephalopathy?
Confusion
Ataxia
Opthalmoplegia
Which 2 conditions commonly cause lymphocyte predominant pleural effusions?
Malignancy and Tuberculosis
What are the 3 commonest causes of viral meningitis?
Enterovirus
Echovirus
Coxsackie A and B
Viral aetiology is most likely if someone has:
- Increased CSF opening pressure
- Slightly increases CSF protein
- CSF lymphocytosis
Which artery is most commonly implicated in lateral medullary syndrome?
Vertebral artery followed by the posterior inferior cerebellar artery
Features include:
- Ipsilateral horners, ataxia and sensory loss (face)
- Contralateral spinothalamic sensory loss from the neck down
How can you diagnose upper airway obstruction from pulmonary function testing? e.g. a goitre
Empey index
FEV1 divided by PEFR
Normal value <10. >10 indicates obstruction
What is the mechanism by which metformin exacerbates lactic acidosis?
Decreased activity of pyruvate dehydrogenase
In what conditions are oral bisphosphonates contraindicated?
Oesophageal disorders: achalasia, scleroderma, strictures and varices
(IV alternatives are advised)
After suspected anaphylaxis, when should a mass cell tryptase level be sent?
ASAP. A second sample should be sent within 1-2 hours (but no later than 4 hours) from the onset of symptoms
What is the mechanism of hypercalaemia in sarcoidosis?
Increased synthesis of 1, 25- dihydroxyvitamin-D3 by macrophages
What is thyrotoxic periodic paralysis?
Who does it occur in?
What triggers it?
How is it treated?
Presents similarly to hypokalaemic periodic paralysis but with the presence of thyrotoxicosis
Under conditions of thyrotoxicosis, a genetic mutation in potassium transport is activated causes hypokalaemia and subsequent muscle weakness.
It occurs in predominantly Chinese, Japanese, Vietnamese, Filipino, and Korean Males
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Triggers include exertion, alcohol and certain foods (high carbohydrate load, high salt)
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Because the total body potassium level is not low, cautious replacement of potassium is important.
Which is the single most important test to measure in patients with pituitary incidentalomas?
Increased Prolactin can indicate either:
- Direct tumour secretion
- –Normal levels <600
- –Microprolactinoma 800-2000
- –Macroprolactinoma >2000
-Disconnection of the hypothalamus and normal pituitary gland by a large non-functioning pituitary mass. Prolactin levels are usually <2000 in these cases
What is the diagnostic criteria for SIADH?
The following triad must be present:
- Hyponatraemia <130
- Dilute serum - Plasma osmo <270
- Concentrated Urine - Urine osmo >100
Hypovolaemia must be excluded by showing that the Na in the urine is >20-30 and there is absence of hypotension
You must also exclude other endocrine causes of hyponatraemia (e.g. Adrenal failure and Hypothyroidism)
How do patients with malignancy develop hypercalcaemia?
Solid Tumours
- Increased PTHrP e.g. adeno- and squamous cell cancers
- Bone lysis e.g. breast cancer
Haematological malignancy
- Increased calcitriol e.g. lymphoma, granulomatous disease
- Bone lysis e.g. multiple myeloma
What is the mMRC dyspnoea score?
I only get breathless with strenuous exercise 0
I get short of breath when hurrying on level ground or walking up a slight hill 1
On level ground, I walk slower than people of my age because of breathlessness, or I have to stop for breath when walking at my own pace on the level 2
I stop for breath after walking about 100 yards or after a few minutes on level ground 3
I am too breathless to leave the house or I am breathless when dressing/undressing 4
What criteria can you use to differentiate between mild, moderate and severe ulcerative colitis in adults?
Modified Truelove and Witt’s criteria
The components are the daily frequency of bloody stool, temperature, heart rate, haemoglobin level and inflammatory marker levels.
How do you manage a patient who has had an ultrasound which is consistent with a diagnosis of non-alcoholic fatty liver disease (NAFLD)?
Calculate the NAFLD Fibrosis Score. This helps to identify patients at risk of advanced fibrosis
- Score 0.672: high risk of fibrosis.
- -Usually considered for a liver biopsy
The FIB-4 score can alternatively be used.
Without imaging, how do you know if it is the right or left carotid artery which has caused the neurological features of a TIA?
Facial/ limb weakness
-Opposite side to the weakness
Monocular blindness
-Same side of blindness
Aphasia/ Dysphasia
-Usually the left ICA
(could be the right if the speech centre is on the right).
What 3 electrolyte abnormalities can lead to long QT syndrome?
Hypokalaemia
Hypomagnasaemia
Hypocalcaemia
What are the features of a severe C, Difficile infection?
Temperature >38.5 degrees C
WCC >15
Acute Kidney Injury
Hypotension and lactic acidosis
Evidence of severe colitis (e.g. abdo pain)
Radiological features of ileus or toxic megacolon
What is the best diagnostic test for dengue fever in someone with only a couple days of symptoms?
Allows rapid detection within the first few days of the fever as antibodies do not appear for up to 5 days or more.
Which congenital condition is associated with long QT syndrome and deafness?
Jervell-Lange Nielsen Syndrome due to mutations in the KCNE1 and KCNQ1 genes.
These genes code for potassium channels in the inner ear and cardiac muscle
How can HSV-2 meningitis recur?
To cause Mollaret’s Meningitis.
What 4 autoimmune diseases are associated with primary biliary cirrhosis?
CREST syndrome
Sjogren’s syndrome
Rheumatoid arthritis
Hashimoto’s thyroiditis
What are iron study results in haemochromatosis?
Increased Ferritin
Increased transferrin saturation
Decreased TIBC
What are some indications for liver transplantation in primary biliary cirrhosis?
Bilirubin >100 mmol/L
Recurrent bacterial cholangitis
Refractory ascites and itching
What are the indications for treating sarcoidosis with steroids?
Brain: neurosarcoid Eyes: uveitis Face: lupus pernio Heart: blocks, cardiomyopathy Lungs: worsening lung function Blood: hypercalcaemia
What are the differences between Heerfordt-Waldenstrom and Lofgren’s syndrome when seen as extrapulmonary manifestations of sarcoidosis?
Heerfordt-Waldenstrom
- Parotid Enlargement
- Uveitis
- Cranial nerve palsies
- Fever
Lofgren’s
- Bilateral hilar lymphadenopathy
- Polyarthritis
- Erythema Nodosum
What artery causes complete heart block after inferior MI?
Posterior interventricular artery (branch of the right coronary artery)
Supplies the AV node
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Fluids can be used to optimise RV filling pressures and ionotropes can be considered in refractory hypotension
What ECG changes occur in hypothermia?
Bradycardia and first degree heart block
Long QT interval
Osborn Wave: small positive J wave at the end of the QRS complex
Atrial and ventricular arrhythmias.
What are the 4 paraneoplastic syndromes associated with small cell lung cancer?
SIADH - Ectopic ADH
Cushing’s - Ectopic ACTH
Lambert Eaton - Antibodies to voltage gated calcium channels
Peripheral Neuropathy - Neuronal nuclear antibody (Hu antibody)
What 2 complications of haemochromatosis can resolve with effective treatment?
Cardiomyopathy and testicular atrophy
Irreversible complications include arthropathy, diabetes, liver cirrhosis and hypogonadotrophic hypogonadism
What are the 3 histological types of mesotheliomas?
Mixed
Sarcomatous (worse prognosis)
Epithelial
What chelation agent is used in Wilson’s disease and Haeochromatosis?
Wilson's = Penicillamine Haemochromatosis = Desferrioxamine
From which cell type does bronchial carcinoid originate?
Kulchitsky cells - these arise from the APUD system, just like small cell lung cancer
Bronchoscopy identifies most of these as highly vascular “cherry like” tumours that cause recurrent haemoptysis and bronchial obstruction
It is rare to develop carcinoid syndrome with these tumours.
What features suggest VT rather than SVT with aberrant conduction?
AV dissociation QRS concordance in chest leads Left axis deviation QRS >160ms Capture beats (intermittent conduction) No response to adenosine/ carotid sinus massage
What causes Farmer’s lung?
spores of saccharopolyspora rectivirgula in hay/ straw
What causes Bird fancier’s lung?
Avian serum proteins in faeces
What causes Bagassosis?
Thermoactinomyces sacchari in sugar cane workers
type of hypersensitivity pneumonitis
What causes Malt Worker’s Lung?
Aspergillus clavatus
What causes Mushroom worker’s lung?
Thermophilic actinomycetes
What causes Psittacosis?
Chlamydia psittaci from birds
At what pulmonary artery pressure can you make a diagnosis of pulmonary artery hypertension?
PA pressure >25 mmHg at rest
PA pressure >30 mmHg after exercise
Which condition in females causes recurrent pneumothoraces and chylorous effusions?
This is where there is progressive growth of smooth muscle cells throughout the lungs, pulmonary blood vessels, lymphatics and pleurae due to mutations in the tuberous sclerosis genes
If these clinical features are seen in males, then the diagnosis to consider is tuberous sclerosis - an autosomal dominant disorder of genes located on chromosome 9 and 16.
Why do patients with Hayde’s syndrome have GI bleeding?
Heyde’s syndrome is the combination of microcytic anaemia and calcific aortic stenosis.
Patients commonly have angiodysplasia which can be diagnosed with a mesenteric angiogram.
The mechanism of bleeding is through the destruction of von Willebrand factor as the blood flows over the stenosed aortic valve.
The combination of vWF deficiency and angiodysplasia results in GI bleeding.
What are the clinical features of pulmonary hypertension?
Exertional dyspnoea Syncope Loud P2 Left parasternal heave (due to RVH) Large a waves in JVP (due to tricuspid regurgitation)
Which antibodies are usually positive in the three types of autoimmune hepatitis?
Type 1
- Anti-nuclear antibody (ANA)
- Anti-smooth muscle antibody (SMA)
Type 2
-Anti-liver kidney microsomal antibodies (LKM-1)
Type 3
-Anti-soluble liver antigen (SLA)
What is the mechanism of renal injury with aciclovir in the presence of dehydration?
Aciclovir is renally eliminated
In the presence of dehydration, aciclovir can precipitate as crystals in the kidney tubules causing AKI
What is the mechanism of action of alteplase?
Human tissue plasminogen activator. It accelerates the conversion of plasminogen to plasmin.
It binds to fibrin-rich clots and cleaves plasminogen to form plasmin which then degrades the fibrin matrix of the thrombus
Which organism is implicated if a young patient has a diarrhoeal illness, right iliac fossa pain and mesenteric adenitis?
Yersinia enterocolitica - a gram-negative bacillus-shaped bacterium
acquire this after consumption of contaminated food and through blood transfusions. Diagnosis is predominantly based on positive stool cultures. It mimics appendicitis and a flare of Crohn’s disease.
How would you manage the rash in discoid lupus erythematosus if it has not responded to potent topical steroids and photoprotection?
Hydroxychloroquine
Discoid lupus erythematosus can cause scarring so early treatment is important. Acitretin is of similar efficacy to hydroxochloroquine but has far more adverse effects including teratogenicity.
Why do people with primary hyperparathyroidism have hypophosphataemia?
Increased phosphate excretion
Excess PTH decreases reabsorption of phosphate at the proximal tubule of the kidney. Therefore, more phosphate is excreted into the urine.
How is Dubin Johnson Syndrome inherited and which protein is implicated?
Autosomal recessive defect in cMOAT
This causes defective hepatic excretion of conjugated bilirubin. As a result, the urine is dark. Liver biopsy shows dark granules (melanin) within hepatocytes.
What are the extracolonic manifestations of FAP Coli?
Retinal pigment hypertrophy
Fibromas and epidermoid cysts
Supernumery teeth and dentigerous cysts
Osteomas of the skull and mandible
How do you calculate osmolality?
2 (Na and K) + glucose + Urea (all in mmol/L)
Which conditions are associated with an aortic dissection?
Hypertension Trauma Bicuspid Aortic Valve Marfan and Ehlers-Danlos Syndrome Turner and Noonan's syndrome Pregnancy Tertiary Syphilis
When is it possible to have a haemoglobin and haematocrit within normal levels in a patient with polycythaemia rubra vera (PRV)?
If there is co-existing severe iron deficiency
Normally in PRV there will be:
Increased haemoglobin, increased haematocrit, increased WCC, increased platelet count.
What did the RALES study show about using spironolactone in patients with heart failure?
A substantially decreased mortality by 30% from the addition of spironolactone to patients with heart failure (LV ejection fraction <35%) on otherwise “optimal” conventional treatment.
How does a Glomus jugulare tumour present?
Gradual onset of right conductive hearing loss, right palatal palsy, dysphonia, bovine cough and wasting of the right side of tongue
Typically insidious onset over years with unilateral lower cranial nerve involvement.
What is the definitive diagnostic test for pemphigus vulgaris?
Direct immunoflourescence of skin
Where in the brain does the D2-receptor antagonist, haloperidol, predominantly exert its antiemetic action?
Area Postrema in the medulla.
What are some of the complications of Mycoplasma Pneumonia?
Blood
- Haemolytic anaemia (cold agglutinins IgM)
- DIC
Skin
-Erythema multiform and nodosum
CNS
-Meningoencephalitis, Guillain Barre syndrome, transverse myelitis and cerebellar ataxia
Heart
-Pericarditis and Myocarditis
GIT
-Hepatitis and Pancreatitis
Renal
-Glomerulonephritis
A defect in which gene causes Cowden syndrome?
Defect in PTEN tumour suppressor gene
This syndrome is a hamartomatous polyposis syndrome of the gastrointestinal tract with characteristic mucocutaneous lesions e.g. oral mucosal papillomas, palmoplanter keratosis and trichilemmomas
There is increased risk of malignancy especially of the breast and thyroid glands.
Which type of streptococcus viridans commonly is associated with infective endocarditis following dental work?
Streptococcus mitis
How is Gardener’s syndrome inherited and what are some of its features?
- Multiple adenomatous intestinal polyps of the small and large bowel. 90% of patients will develop bowel cancer by the age of 45 years. Colectomy is recommended once these polyps appear
- Osteomas
- Soft tissue tumours i.e. fibromas, lipomas
- Increased risk of papillary carcinoma of the thyroid
How is Peutz-Jegher’s syndrome inherited and what are its features?
- Hamartomatous polyps in the GI tract which increase the risk of cancer
- Pigmented freckles (melanocytic macules) on lips, face, palms, and soles
- Increased incidence of GI bleeding and intussusceptions.
Why do patients with renal impairment develop opioid toxicity?
Morphine is metabolised to active glucuronide metabolites with are excreted renally
Renal impairment leads to accumulation of morphine-6-glucuronide which is a potent opioid agonist with a higher affinity than morphine.
Which commonly used antimicrobials can cause QT prolongation?
Quinolones e.g. levofloxacin, moxifloxacin
Macrolides e.g. erythromycin, clarithromycin
Antimalarials e.g. quinine
Antiprotozoal e.g. pentamidine
Azole antifungals e.g. fluconazole, ketoconazole
What organism commonly causes athlete’s foot?
Trichophyton rubrum
What is the first line treatment for erythrodermic psoriasis?
This partially decreases inflammation, improves the skin barrier (which is generally defective in erythroderma) and helps decrease water loss to prevent dehydration
Erythrodermic psoriasis may be associated with systemic upset.
What are the components of the Waterlow Score in assessing the risk of developing a pressure sore?
Age Sex Body Weight Nutritional Status Continence Skin type Mobility
What is lipodermatosclerosis and which layers of the skin does it affect?
Lipodermatosclerosis is a chronic sclerosing panniculitis of the lower legs and is related to venous hypertension.
Fibrous tissue replaces the hypodermis and if extensive, it also replaces the papillary dermis. Patients experience pain, hardening of the skin, redness, swelling and a tapering of the legs above the ankles.
If someone presents with a STEMI which is presumed to be related to stent thrombosis, which antiplatelets do you give before angiography if they are already taking aspirin and clopidogrel?
Aspirin and Prasugrel
Stent thrombosis may be related to some degree to clopidogrel resistance/ failure
How do you differentiate between MEN 1 and MEN 2?
Genetics
- MEN 1 = MEN1 gene Chromosome 11q13
- MEN 2 = RET oncogene Chromosome 10
Tumours
- MEN 1 = Pancreatic tumours and pituitary tumours
- MEN 2 = Phaeochromocytomas and Medullary thyroid
What is the normal function of BRCA-1?
BRCA-1 is a tumour suppressor gene which codes for a DNA repair protein.
What are the features of Gertmann syndrome?
Parietal lobe is implicated
- Dysgraphia or agraphia (inability to write)
- Acalculia (inability to do maths)
- Finger agnosia (inability to identify one’s own or another’s fingers)
- Limb disorientation (Inability to make the distinction between the right and left side of the body)
Which antibody can be found to be positive in ulcerative colitis?
In UC there is an increased incidence of PSC, PBC and chronic active hepatitis.
What is the first line diagnostic investigation of coronary artery disease?
CT calcium scoring
- If Ca score is between 1-400 then do a CT coronary angiogram
- If Ca score is >400 then perform an invasive coronary angiogram.
Which 4 GI diseases are associated with H. Pylori infection?
MALT lymphoma
Peptic ulcers disease
Gastric carcinoma
Atrophic gastritis
In neuromuscular weakness, at what level of forced vital capacity (FVC) should you be concerned about impending respiratory failure?
FVC <15-20 mls/kg of ideal body weight
(usually this is around <1L
What are the complications of Meckel’s diverticulum?
Diverticulitis Intussusception Perforation Obstruction ---------------------------
Meckel’s diverticulum is the vestigial remnant of the omphalomesenteric duct.
It is normally located in the terminal ileum within around 60 cm of the ileoceacal valve and it averages 6cm in length.
About half of them contain ectopic gastric mucosa commonly leading to clinical presentations of peptic ulceration and haemorrhage
Tc-99m pertechnetate accumulates in gastric mucosa and is the study of choice for identifying this ectopic gastric mucosa.
How do you treat acute pancreatitis which has been caused by excess triglycerides?
Insulin
Insulin decreases triglyceride levels by activating lipoprotein lipase which metabolises chylomicrons.
If the glucose is normal or insulin doesn’t bring down the triglycerides adequately then plasmapheresis is an appropriate alternative
Which antibody can be found to be positive in Crohn’s disease?
ASCA favours Crohn’s while UC is strongly associated with pANCA.
How does the shape of the crystals differ between gout and pseudogout?
Pseudogout = Rhomboid-shaped with positive birefringence
Gout = needle-shaped with negative birefringence
What is the duration for post exposure prophylaxis in needle stick injury from an HIV positive patient?
Three drug antiretroviral treatment within 1-2 hours for a total of 28 days (may be started up to 72 hours following exposure).
This decreases risk of transmission by 80%. Serological testing should be performed at 12 weeks following completion.
What is the treatment of schistosomiasis?
Praziquantel as a single dose and a short course of steroids to control the inflammatory reaction.
The dose of praziquantel should be repeated after 6 weeks when flukes are fully mature because immature flukes are sometimes resistant to treatment.
What is the difference between burst suppression and background suppression in the context of treating status epilepticus?
Burst suppression: Treatment has induced a sufficiently deep coma
Background suppression: Excess sedation (deeper level of coma than in burst suppression)
What are the possible auscultatory findings in mitral valve prolapse?
Mid systolic click (occurs later if squatting)
Late systolic murmur (longer if standing)
What is the most appropriate antihypertensive to use in bipolar patients who take lithium?
CCBs e.g. amlodipine (even in under 55)
-Does not cause increased serum lithium concentration
ACEi, ARBs and thiazide diuretics can all cause lithium
How can you clinically differentiate an L5 radiculopathy from a common peroneal nerve palsy in someone with foot drop?
Weakness of ankle inversion is present in an L5 radiculopathy but is not seen in a common peroneal nerve palsy.
This is because the tibialis posterior muscle is supplied by the tibial nerve (L4/5).
Which pulmonary function test is most helpful in monitoring the progression of usual interstitial pneumonitis (UIP)?
Transfer factor (TLCO or KCO)
This measures how effectively oxygen diffuses from the alveoli into the blood. It is used to determine the severity of the fibrosis and can be used to monitor progression of disease.
What is the mechanism through which clopidogrel inhibits platelet aggregation?
Clopidogrel irreversibly inhibits platelet aggregation via the P2Y12 ADP receptor. The predominant receptor involved in ADP-stimulated activation of glycoprotein IIb/IIIa receptor.
This results in decreased platelet degranulation, thromboxane production and platelet aggregation.
Why should you not give flecainide to pts with AF and LVSD?
An echo must be carried out prior to prescription to rule out structural heart disease or IHD
What is the most likely cause for chronic pale and bulky diarrhoea in someone with systemic sclerosis?
Small intestinal bacterial overgrowth
In systemic sclerosis, the small bowel wall is infiltrated with fibrous tissue. This results in dysmotility, dilatation and alterations in bacterial flora. This manifets with abdominal discomfort, flatulence, steatorrhoea and malabsorption.
Which imaging modality best differentiates knee pain related to psoriatic arthritis from mechanical pain?
Gadolinium contrast MRI scan of the knee
Which chemotherapy-sensitive tumours can cause superior vena cava obstruction (SVCO)?
Small cell lung cancer
Lymphomas
Germ cell tumours
Patients have dilated neck veins and pulseless JVP distension. It is an oncological emergency. The most common cause of SVCO is non-small cell lung cancer (not chemotherapy-sensitive).
Scrub typhus is spread by which mite?
Trombiculid mite
What are some examples of serotonergic drugs?
SSRIs SNRIs TCAs Litium Tramadol Amphetamine MAO inhibitors
What are the components of the disaccharides lactose, maltose and sucrose?
Maltose = glucose and glucose Lactose = glucose and galactose Sucrose = glucose and fructose
What classically happens to the creatinine kinase in anticholinergic poisoning?
Although anticholinergic poisoning can be associated with hyperpyrexia and tachycardia, the CK is not significantly elevated. This is in contrast to the increased CK that occurs in serotonin syndrome and in neuroleptic malignant syndrome.