Endocrinology 2

oelomar's version from 2016-02-27 14:44


Question Answer
What three major histological changes are seen in diabetic nephropathy?Mesangial expansion (induced by hyperglycaemia), thickening of the glomerular basement membrane, and glomerular sclerosis.
What are the stages of injury in diabetic nephropathy?The kidneys enlarge initially and there is glomerular hyperfiltration. The major early histological lesions seen are glomerular basement membrane thickening and mesangial expansion. Eventually there will be microalbuminuria, followed by macroalbuminuria, followed by proteinuria, followed by declining renal function.
What is diabetic neuropathy?Diabetic neuropathy is a type of nerve damage that can occur if you have diabetes. High blood sugar can injure nerve fibres throughout your body, but diabetic neuropathy most often damages nerves in your legs and feet.
What are the different varieties of diabetic neuropathy that may occur?Symmetrical polyneuropathy neuropathy, acute painful neuropathy, mononeuropathy and mononeuritis multiplex (multiple mononeuropathy), diabetic amyotrophy (asymmetrical motor diabetic neuropathy), autonomic neuropathy.
What is symmetrical polyneuropathy?Neuropathy involving multiple nerves in roughly the same areas on both sides of the body is called "symmetrical polyneuropathy".
What are the early clinical signs of symmetrical polyneuropathy?Early clinical signs are loss of vibration sense, pain sensation (deep before superficial) and temperature sensation in the feet.
What are the clinical signs of symmetrical polyneuropathy (not including the early ones)?Involvement of motor nerves to the small muscles of the feet gives rise to interosseous wasting. Unbalanced traction by the long flexor muscles leads to a characteristic shape of the foot, with a high arch and clawing of the toes, which in turn leads to abnormal distribution of pressure on walking, resulting in callus formation under the first metatarsal head or on the tips of the toes and perforating neuropathic ulceration. Neuropathic arthropathy (Charcot’s joints) may sometimes develop in the ankle. The hands show small muscle wasting as well as sensory changes.
What are the signs and symptoms of acute painful neuropathy?The patient describes burning or crawling pains in the feet, shins and anterior thighs. These symptoms are typically worse at night, and pressure from bedclothes may be intolerable.
Will acute painful neuropathy remit with good control?It usually remits spontaneously after 3–12 months if good control is maintained. A more chronic form, developing later in the course of the disease, is sometimes resistant to almost all forms of therapy.
What is the first line treatment for acute painful neuropathy?Duloxetine (an SNRI) or amitriptyline (a TCA) if duloxetine is contraindicated.


Question Answer
What is the second line treatment for acute painful neuropathy?If first-line treatment was with duloxetine, switch to amitriptyline or pregabalin, or combine with pregabalin. If first-line treatment was with amitriptyline, switch to or combine with pregabalin.
What is meant by the term “mononeuropathy”?Neuropathy affecting just one nerve.
What is meant by the term “mononeuritis multiplex”?When two or more (typically just a few, but sometimes many) separate nerves in disparate areas of the body are affected by neuropathy.
Which nerves of the body can be involved in diabetic mononeuritis?Any nerve. Isolated palsies of nerves to the external eye muscles, especially the 3rd and 6th nerves, are more common in diabetes.
What is diabetic amyotrophy and what are the signs and symptoms?Also known as proximal diabetic neuropathy, this is a nerve disorder that results as a complication of diabetes mellitus. Presentation is with painful wasting, usually asymmetrical, of the quadriceps muscles or occasionally in the shoulders. The wasting may be very marked and knee reflexes are diminished or absent. The affected area is often extremely tender.
Diabetic amyotrophy usually resolves in time with good metabolic control of the diabetes. True or false?True.
What is autonomic neuropathy?Autonomic neuropathy is a group of symptoms that occur when there is damage to the nerves that manage every day body functions such as blood pressure, heart rate, sweating, bowel and bladder emptying, and digestion.
When autonomic neuropathy affects the cardiovascular system, what are the symptoms?Tachycardia at rest, loss of sinus arrhythmia, postural hypotension, and loss of cardiovascular reflexes such as the Valsalva manoeuver.
When autonomic neuropathy affects the GI tract, what are the symptoms?Dysphagia, abdominal pain, nausea, vomiting, malabsorption, diarrhoea, gastroparesis.
When autonomic neuropathy affects the urinary bladder, what are the symptoms?Bladder incontinence, urinary retention.


Question Answer
What percentage of diabetics develop the “diabetic foot” at some stage in their lives?15%.
What are the main threats to the skin and subcutaneous tissue of the foot of a diabetic?Infection, ischaemia, and abnormal pressure (an ulcerated site must be kept non-weight bearing).
How are diabetic foot problems managed?Many diabetic foot problems are avoidable, so patients need to learn the principles of foot care. Once tissue damage has occurred in the form of ulceration or gangrene, the aim is preservation of viable tissue.
What skin infections are people with poorly controlled diabetes more susceptible to?Staphylococcus infections (boils, abscesses, carbuncles).
What GI tract infections are people with poorly controlled diabetes more susceptible to?Chronic periodontitis, rectal and ischiorectal abscess formation.
What urinary tract infections are people with poorly controlled diabetes more susceptible to?UTIs, pyelonephritis.
What lung infections are people with poorly controlled diabetes more susceptible to?Staphylococcal and pneumococcal pneumonia, gram-negative bacterial pneumonia, tuberculosis.
What is diabetic cheiroarthropathy?A cutaneous condition characterised by thickened skin and limited joint mobility of the hands and fingers, leading to flexion contractures.
Is diabetic cheiroarthropathy a common observation in diabetics?It is observed in roughly 30% of diabetic patients with longstanding disease.


Question Answer
Pituitary adenomas form primarily in the anterior pituitary gland or the posterior pituitary gland?Anterior.
What is the most common combination of hormones secreted by a pituitary adenoma?Prolactin and GH.
What are the “mass effects” of a pituitary adenoma?Headache, bitemporal hemianopsia (most common symptom – due to compression of optic chiasm), CN III, IV, V1, V2, VI palsy (compression of cavernous sinus).
What are the endocrine effects of a pituitary adenoma?Hyperprolactinaemia (prolactin production), Cushing’s disease (ACTH production), acromegaly (GH production), panhypopituitarism, MEN-1 syndrome, diabetes insipidus.
What is pituitary apoplexy and what are the symptoms?Bleeding into or impaired blood supply of the pituitary gland. It usually occurs in the presence of a pituitary tumour. The most common initial symptom is a sudden headache, often associated with a rapidly worsening visual field defect or double vision caused by compression of nerves surrounding the gland.
How is pituitary apoplexy treated?Administration of IV saline or dextrose solution followed by hydrocortisone administration. Surgical decompression of the pituitary gland (hypophysectomy) may then also be done (dependent on the severity of visual loss and visual field defects).
How is prolactinoma (pituitary adenoma that produces prolactin) treated (not including surgery)?Dopamine agonists, such as bromocriptine. Cabergoline (also a dopamine receptor agonist) is the best-tolerated and longest acting drug, and can also be used.
How is acromegaly treated (not including surgery)?Somatostatin analogues such as octreotide (somatostatin inhibits GH) ± dopamine agonists (e.g. bromocriptine), external radiotherapy. GH antagonists such as pegvisomant can also be used.
Surgically, how are pituitary adenomas treated?Trans-sphenoidal surgery.
What is a craniopharyngioma?A type of brain tumour derived from pituitary gland embryonic tissue (derived from “Rathke’s pouch”).
What does craniopharyngioma present with?Bitemporal inferior quadrantanopia leading to bitemporal hemianopia as the tumour may compress the optic chiasm.
What is Sheehan’s syndrome?Hypopituitarism caused by ischaemic necrosis of the pituitary gland due to blood loss and hypovolaemic shock during or after childbirth.
What is “empty sella syndrome”?Unexplained atrophy of the pituitary gland (more common in obese women).


Question Answer
Excess GH production in children is called what?Gigantism.
Excess GH production in adults is called what?Acromegaly.
What are the causes of acromegaly/gigantism?Pituitary tumour. Hyperplasia due to excess GHRH release is very rare.
What are the clinical features of acromegaly/gigantism?Many, some of which are enlargement of the jaw, hands, and feet; generalised expansion of the skull at the fontanelle, coarsening of the facial features; carpal tunnel syndrome, soft tissue swelling of internal organs, notably the heart with attendant weakening of its muscularity, and the kidneys, also the vocal cords resulting in a characteristic thick, deep voice and slowing of speech. Excess GH may also lead to glucose intolerance or diabetes.
What investigations can be done to help diagnose acromegaly?IGF-1 levels are almost always raised in acromegaly; a glucose tolerance test is diagnostic if there is no suppression of GH; MRI scan of pituitary to search for an adenoma; hyperprolactinaemia occurs in 30% of patients.
What are the main causes of death in patients with acromegaly?Heart failure, coronary artery disease, neoplasia (particularly colon cancer).
When would the GH antagonist pegvisomant be used in the treatment of acromegaly?It is used if the tumour of the pituitary gland causing the acromegaly cannot be controlled with surgery or radiation, and the use of somatostatin analogues is unsuccessful.
Name some common pathological causes of hyperprolactinaemia.Prolactinoma, co-secretion of prolactin in tumours causing acromegaly, polycystic ovary syndrome, primary hypothyroidism, and “idiopathic” hyperprolactinaemia. Dopamine antagonist drugs are a common iatrogenic cause.
What are the clinical features of hyperprolactinaemia?Hyperprolactinaemia stimulates milk production and inhibits GnRH. It presents with hypogonadism (manifested by infertility, oligomenorrhoea, or amenorrhoea), galactorrhoea (excessive milk production), bitemporal hemianopsia, decreased libido (in both sexes), osteoporosis (long-term).
What investigations are done in a patient with (suspected) hyperprolactinaemia?MRI of the pituitary, visual fields should be checked, hypothyroidism should be excluded (as this is a cause of hyperprolactinaemia), anterior pituitary function should be assessed if there is any clinical evidence of hypopituitarism.
High doses of cabergoline has been found to be associated with which disease as a side-effect?Valvular heart disease.


Question Answer
What is primary hypothyroidism as opposed to central hypothyroidism? Which is more common?Primary hypothyroidism is inadequate function of the thyroid gland itself whereas central hypothyroidism is due to reduced TSH secretion. Primary hypothyroidism is about a thousand-fold more common than central hypothyroidism.
What are the two categories of autoimmune thyroiditis and what is the difference between them?Hashimoto’s thyroiditis and atrophic thyroiditis. Goitres = Hashimoto’s; no goitres = atrophic.
What is Hashimoto’s disease?Hashimoto’s disease is an autoimmune disease in which the thyroid gland is attacked resulting in primary hypothyroidism. It is characterised by infiltration of the thyroid gland with T lymphocytes and autoantibodies against specific thyroid antigens such as thyroid peroxidase, thyroglobulin, and the TSH receptor.
What are the most common causes of hypothyroidism?Iodine deficiency and Hashimoto’s thyroiditis (more common in areas with sufficient dietary iodine).
What is thyroid dyshormonogenesis?This rare condition is due to genetic defects in the synthesis of thyroid hormones. Patients develop hypothyroidism with a goitre.
What is Pendred syndrome?Pendred syndrome is a genetic disorder leading to congenital bilateral sensorineural hearing loss and goitre with euthyroid or mild hypothyroidism.
What are the signs/symptoms of hypothyroidism?Cold intolerance (decreased heat production), weight gain, decrease in appetite, hypoactivity, lethargy, weakness, hyporeflexia, constipation, myxoedema (facial, periorbital); dry and cool skin; coarse and brittle hair. The classic picture of the slow, dry-haired, thick-skinned, deep-voiced patient with weight gain, cold intolerance, bradycardia, and constipation is characteristic of hypothyroidism.