Endo Flashcards by H Jalisi

Causes of diabetes insipidus

Cranial (no ADH secretion)
- pituitary tumour
- infection (meningitis)
- sarcoidosis
Nephrogenic (insensitive to ADH)
- increased Ca2+
- decreased K+
- lithium
- inherited AVPV2 gene
- idiopathic

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Sx of DI

Polyuria (UO > 3L), nocturia, polydipsia, sx of hypernatraemia (lethargy, irritability, confusion)

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Ix for DI

U&Es, HbA1c (exclude DM), water deprivation test (diagnostic)

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Water deprivation test results for

a) normal
b) cranial
c) nephrogenic

a) ADH secretion occurs so increased plasma osmolality urine concentration
b) decreased urine osmolality [dilute]
c) decreased urine osmolality [dilute]
=> desmopression administered
b) urine osmolality increase >50%
c) urine osmolality increase <45%

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Mx for DI

TREAT CAUSE
Cranial => intranasal desmopressin
Nephrogenic => thiazide diuretic or NSAIDs (inhibit prostalgandin synthase as prostaglandin inhibits ADH)

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TIDM summary card

Hyperglycaemia due to deficiency of insulin production as a result of AI destruction of beta cells (90% cases)
PC: polyuria + polydipsia, tired, wt loss, DKA (N&V, abdo pain, Kussmaul breathing)
Associated w/ HLADR3/4 + other AI conditions
Tx: insulin, pt education, DKA (1st line - fluids)

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TIIDM summary card

Hyperglycaemia due to increased peripheral resistance to insulin action
PC: polyuria and polydipsia
RFs: obesity, FHx, ethnicity, drugs
Tx: 1st - diet and lifestyle, 2nd - metformin => sulphonylurea => insulin

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Which blood glucose measurements are diagnostic of diabetes mellitus?

Fasting blood glucose >/= 7mmol/L

Random blood glucose >/= 11.1mmol/L

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How may hypernatraemia present and how is it treated?

Rarer sodium imbalance
- lethargy, signs of dehydration, irritability, fits, confusion, coma
Replace water + treat cause

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What causes hypernatraemia?

D&V
Diabetes insipidus
Primary hyperaldosteronism

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What leads to hyponatraemia?

SIADH

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What causes hyponatraemia?

Causes can be split based on water status of the pt

1) Dry (hypovolaemic)
- D&V, diuretics
2) Normal (euvolaemic)
- hypothyroidism, hypoadrenalism, SIADH causes
3) Wet (hypervolaemic)
- HF, cirrhosis, nephrotic syndrome

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How may hyponatraemia present?

Presentations suggest water status of pt:

1) Dry => dry mucous membranes, tachycardia
2) Normal => other sx of endo cause
3) Wet => increased JVP

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Potential ix after bloods show hyponatraemia

TFTs, short synACHTen test

CXR, breast exam, brain MRI (SIADH malignancies)

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Possible causes of SIADHq

CNS pathology
Lung pathology
Drugs: SSRI, TCA, opiates, PPIs, carbamazepine
Tumours (don’t forget breast!)

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Mx of SIADH

Treat underlying cause
Fluid restriction 0.5-1L
If above ineffective: demeclocycline/vasopressin receptor antagonist (tolvaptan)

How may a prolactinoma present?

Headache, loss of visual fields
Women:
- galactorrhoea, amenorrhoea, infertility, loss of libido
Men:
- loss of libido, infertility, galactorrhoea common
*result of secondary hypogonadism

Causes of prolactinoma

Pituitary prolactionoma
Physiological (pregnancy, breastfeeding)
Hypothyroidism
Drugs (metocloporamide, antipsychotics; DA antagonists)

Ix and mx for prolactinomas

Ix => prolactin, TFTs, pituitary MRI
Mx
=> 1st line: DA agonist - bromocriptine, cabergoline
=> 2nd line: transphenoidal surgery

Compare hyper- and hypothroid presentations

Hyperthyroidism

sweating, heat intolerance
palpitations, irregular pulse
irritable
wt loss but good appetite
tremor, diarrhoea
menstrual irregularities/impotence

Hypothyroidism

cold intolerance
bradycardia, lethargy
wt gain but appetite loss
constipation
dry skin, cold hands
menstrual irregularities

Causes of hyperthyroidism and what they would show in a radioisotope scan

Grave's
- diffuse increased uptake; smooth goitre
Adenoma
- single area of uptake
Toxic multinodular goitre
- multiple places of increased uptake
De Quervain's thyroiditis
- no uptake

How may sx/examination/ix differentiate between the different causes of hyperthyroidism?

Grave’s
- exopthalmos, pretibial myoxedema, thyroid acropachy
Adenoma
- solitary nodule on palpation
Toxic multinodular goiter
- elderly + iodine deficient areas
De Quervain’s thyroiditis (self-limiting, treat w/ NSAIDs)
- post-viral, fever, painful goitre, increased ESR

Causes of hypothyroidism

Hashimoto's disease (autoimmune)
- no.1 cause in West
Iodine deficiency
- no.1 cause in world
Iatrogenic
- post-surgery, radioiodine, amiodarone
De Quervain's thyroiditis
- after hyper => hypo (self-resolving but may need thyroxine replacement for a few weeks)

Mx of hypothyroidism

Levothyroxine 25-200mg/day

- monitor TFTs at 6 weeks and adjust dose accordingly

Thyroid cancer summary card

Papillary (most common) - radiation exposure, psammomna bodies, Orphan Anne nuclei, younger pts Follicular - Hurthle cells, middle-aged women Medullary - MEN2, ?FHx Lymphoma - female > male, occurs after pre-existing Hashiomoto's Anaplastic - giant cells, pleomorphic hyperchromatic nuclei, elderly females

Presentation of acromegaly

``` Rings and shoes become tight Increased sweating Coarse facial features Sleep apnoea Weight gain Headaches/visual disturbance Carpal tunnel syndrome Hypertension Insulin resistance ```

Ix for acromegaly

Screen => IGF-1 serum levels DIagnostic => OGTT (result: fails to suppress GH) MRI => visualise pituitary tumour

Mx for acromegaly

1st line => transphenoidal hypophysectomy | 2nd line => somatostatin analouge; octeotride

Types of tumours/sx that occur in the different MENs

``` MEN1 (menin gene, chr 11) - parathyoid (adenoma/hyperplasia) - pancreas (gastrinoma/insulinoma) - pituitary (prolactin, acromegaly, adrenal) MEN2 (RET gene, chr 10) - thyroid (medullary) - adrenal (pheochromocytoma, 50%) - parathyroid hyperplasia MEN2b/3 - medullary thyroid cancer (MEN2) - mucoual neurones (bumps on lips/cheeks/tongue/eyelids) - Marfanoid appearance ```

What are common sites and humoral factors of carcinoid tumours?

Rectum and appendix | - serotonin, histamine, tachykinins, prostaglandin

Presentation of carcinoid syndrome

``` Paroysmal flushing Diarrhoea Crampy abdo pain Wheeze Sweating Palpitations ```

Ix for suspected carcinoid syndrome

24hr urine collection (increased 5-H1AA levels; serotonin metabolite) CT/MRI (localise tumour) Consider looking for underlying MEN1

A 49 year old woman presents with 4kg weight loss over 2 months. She complains of feeling hot all the time and her partner mentions that she’s been more irritable recently. On examination she has a smooth goitre, and you also notice proptosis and a rash on her shins. What is the most likely diagnosis? a) De Quervain’s thyroiditis b) Toxic multinodular goitre c) Grave’s disease d) Menopause e) Medullary thyroid cancer

c) Grave's disease

A 16 year old boy presents to the GP with polyuria and polydipsia. He is diagnosed with diabetes insipidus. This condition is characterized by overproduction of which of the following? a) Antibodies against insulin-producing beta cells of the pancreas b) Anti-diuretic hormone c) Brain natriuretic peptide d) Oxytocin e) Aldosterone

b) Anti-diuretic hormone

A 35 year old female presents with 4 month history of amenorrhoea. On examination, she is noted to have loss of peripheral vision. What is the most likely underlying problem? a) Second cranial nerve palsy b) Stroke c) Hyperparathyroidism d) Prolactinoma e) Pregnancy

d) Prolactinoma

A 49 year-old man presents with a history of difficulty sleeping. He reports feeling increasingly tired and general weakness which he attributes to his poor sleep pattern. Additionally, the patient has noticed he has gained weight and sweats more easily. On examination, the patient has coarse facial features. What is the most likely diagnosis? a) Hyperthyroidism b) Cushing’s disease c) Acromegaly d) Hypothyroidism e) Diabetes

c) Acromegaly

A 50 year old Asian man is referred to diabetes clinic after presenting with polyuria and polydipsia. He has a BMI of 30, a blood pressure measurement of 137/88 and a fasting plasma glucose of 7.7mmol/L. The most appropriate first-line treatment is: a) Dietary advice and exercise b) Sulphonylurea c) Exenatide d) Thiazolidinediones e) Metformin

a) Dietary advice and exercise

A 15 year old girl complains of headaches which started 6 weeks ago. The headaches initially occurred 1-2 times a week but now occur up to five times a week, they are not associated with any neurological problems, visual disturbances, nausea or vomiting. The girl also reports a white discharge from both of her nipples. She has not started menstruating. The most appropriate investigation is: a) Lateral skull X ray b) CT scan c) MRI scan d) Thyroid function tests e) Serum prolactin measurement

e) Serum prolactin measurement

A 58 year old woman presents with an acutely painful neck, the patient has a fever, blood pressure is 135/85, and heart rate is 102 bpm. The patient explains the pain started 2 weeks ago and has gradually become worse. She also experiences palpitations and believes she has lost weight. She presents one week later complaining of intolerance to cold temperatures. What would you see if you performed a radioisotope scan on her? a) Single area of increased uptake b) Multiple areas of increased uptake c) Diffuse increased uptake d) No uptake e) She does not need a radioisotope scan

d) No uptake