EFA 6 Flashcards
A 35 year old woman, with primary hypothyroidism diagnosed 13 years ago, complains of feeling exhausted for several months. She also complains of weight loss and dizziness. Blood pressure in clinic is 110/80 mmHg lying and 90/70 mmHg standing. Blood tests show: Sodium 128 mmol/L (133 – 146) Potassium 5.5 mmol/L (3.5 – 5.3) fT4 18 pmol/L (9 - 23) TSH 3.9 mU/L (0.3 – 4.2) What is the next step in her management?
A Increase her thyroxine dose
B Measure 9AM cortisol and ACTH
C Measure a full blood count
D Measure plasma osmolality
E Reduce her thyroxine dose
=B Measure 9AM cortisol and ACTH
Diagnosis is Addison’s disease (primary adrenocortical failure) – autoimmune is the most common cause, so the previous diagnosis of primary hypothyroidism is a clue (primary hypothyroidism is most commonly also autoimmune and autoimmune diseases often cluster together in a patient, so a patient with one autoimmune disease is at increased risk of another autoimmune disease). The thyroid function tests are normal, so no need to adjust the thyroxine dose. The clues that this is Addison’s are: weight loss and dizziness (secondary to postural hypotension, due to the lack of aldosterone). The combination of a low serum sodium and a high serum potassium must always make you think of Addison’s (loss of aldosterone).
A 55 year old man sustains a head injury in a road traffic injury. A few days afterwards, he notices that he is very thirsty and passes lots of urine, both during the day and at night. After several weeks of these symptoms, he sees his GP who performs some investigations. Sodium 150 mmol/L (133 – 146) Potassium 4.9 mmol/L (3.5 – 5.3) Random glucose 6.9 mmol/L HbA1c 38 mmol/mol (10 - 41) Plasma osmolality 300 mOsm/kg H2O (275 - 295) What is the most likely diagnosis?
A Cranial diabetes insipidus
B Diabetes mellitus
C Post-traumatic stress disorder
D Psychogenic polydipsia
E Syndrome of Inappropriate Anti Diuretic Hormone
A Cranial diabetes insipidus
This is not diabetes mellitus due to normal glucose and HbA1c. Syndrome of Inappropriate Anti Diuretic Hormone results in water reabsorption at the kidney, so sodium will be low not high. In this patient, there is hypernatraemia (a high serum sodium). The plasma osmolality is also high. The symptoms plus the high serum sodium and high plasma osmolality plus the symptoms are most likely due to cranial diabetes insipidus caused by a head injury. Stress alone would not cause a high sodium and a high plasma osmolality. Psychogenic polydipsia, there is no problem with ADH, so in response to drinking a lot (which is the problem in this condition), the serum sodium and plasma osmolality are low.
At his annual diabetes review, 55 year old man with a 10 year history of well controlled type 2 diabetes mellitus complains of erectile dysfunction. He takes metformin only. His GP checks some bloods. HbA1c 48 mmol/mol (20-41) Testosterone 3 nmol/L (10-20) Prolactin 25 000 IU/mL (45-375) FSH 0.1 mIU/mL (1.6-11) LH 0.2 mIU/mL (1.3-8) What should the GP do next?
A Arrange a pituitary MRI
B Counsel him that erectile dysfunction is common in type 2 diabetes mellitus
C Intensify his glycaemic control
D Perform a testicular examination
E Repeat the blood tests at a different time of day
A Arrange a pituitary MRI
The diagnosis here is a prolactinoma due to the very high prolactin level causing secondary hypogonadism (and hence, erectile dysfunction). Therefore, the next step is to see on a pituitary MRI whether there is a prolactinoma visible on MRI. Erectile dysfunction can occur with diabetes mellitus (a combination of microvascular disease and neuropathy). It’s always good practice to double check for other causes as you can see from this scenario. Prolactin doesn’t have a diurnal variation (unlike eg cortisol) so it doesn’t matter what time of day you measure it. The testicular examination is more relevant to primary rather than secondary hypogonadism eg to assess testicular volume – this would be low potentially eg in there was long standing primary hypogonadism secondary to mumps.
A 67-year old man visits his opticians after noticing that he finds it increasingly difficult to focus on the words in his books and newspapers, even when wearing his glasses. What is a likely cause of this?
A. Astigmatism
B. Emmetropia
C. Hypermetropia
D. Myopia
E. Presbyopia
E. Presbyopia – this is the gradual loss of the ability to focus on nearby objects
Rupture of a weakened arterial wall in one of the vessels in the circle of Willis will result in bleeding into which anatomical space?
A. Epidural
B. Extradural
C. Subarachnoid
D. Subdural
E. Subpial
Subarachnoid – ruptured weakened arterial wall is an aneurysm. This, in an artery of the circle of Willis, will bleed into this space.
A 65 year old woman presents to the Accident and Emergency department with vomiting and constipation. She has a previous history of lung cancer which was treated by surgery and chemotherapy 1 year ago. On examination, she looks dehydrated. Routine biochemistry shows: normal renal function, calcium 2.90 (reference range 2.15-2.60 mmol/L), phosphate 0.90 (reference range 0.80-1.40 mmol/L), 25 hydroxyvitamin D 60 (reference range 70-150 mmol/L), PTH <0.1 (reference range 1.1-6.8 mmol/L). Abdominal x ray is normal. What treatment should she receive next?
Intravenous/IV fluids.
The diagnosis is hypercalcaemia of malignancy (hypercalcaemia, suppressed PTH, previous history of cancer). The first step is rehydration and due to the vomiting, this should be intravenous. Bisphosphonates can be given, but only once adequate intravenous rehydration has happened first.
A 34 year old woman presents to her GP with weight loss and palpitations. Her GP checks some thyroid function tests: fT4 32 pmol/L (9 - 23) fT3 13 pmol/L (3.1 – 6.8) TSH <0.01 mU/L (0.3 – 4.2) Prior to this, she has been fit and well, with no medical problems and is not taking any medications. What two medications should the GP start?
A 29 year old woman misses her period. She calculates that her last menstrual period was nine weeks ago. She organises a home urine pregnancy test. What hormone (full name, not abbreviated) will be measured in the urine to confirm pregnancy?
Beta human chorionic gonadotrophin
Early pregnancy hormone, maximal for the first 12 weeks (trimester) of pregnancy, forms the basis of the urine pregnancy test.
The amnestic presentation of Alzheimer’s disease is related to atrophy of which temporal lobe structure?
Hippocampus
A patient is due to undergo neurosurgery in an attempt to prevent the spread of electrical activity during epileptic seizures from one hemisphere to the other. Which white matter tract will be severed during this surgical procedure?
Corpus callosum
Callosal fibres connect hemispheres. The major tract connecting the left and right hemispheres is the corpus callosum.
End of endo TBL questions
- List 3 of the main risk factors for stroke. (3 marks)
Max 3 from: Age, Hypertension, Cardiac disease, Smoking, Diabetes mellitus
- List 2 symptoms that might be associated with a thrombo-embolic stroke affecting the vessels perfusing areas A (2 marks) and B (2 marks) in the diagram above.
2 from: Paralysis of contralateral leg > arm, face, Disturbance of intellect, executive function and judgement (abulia), Loss of appropriate social behaviour
The motor supply to the leg derives from the more medial aspect of the primary motor cortex, hence the leg would be more affected than other parts of the body. Also, this artery supplies most of the superior-medial parietal lobes and portions of the frontal lobes, hence the frontal lobe-associated disturbances.
