Free UKMLA practice questions

C. Altered sensation when wiping after defaecation

Cauda equina syndrome compresses the sacral roots, so its earliest warning signs are perianal or saddle sensory change, new bladder or bowel dysfunction, bilateral leg symptoms and loss of sexual sensation. Any of these needs same-day emergency assessment and MRI, because the outcome depends on decompression before bladder function is lost. Unilateral root signs such as an absent ankle jerk or weak toe dorsiflexion indicate a single-level radiculopathy, which is painful but not an emergency on its own. Altered sensation on wiping is the clue patients rarely volunteer, so it must be asked about directly in every back pain consultation.

E. Forced vital capacity

Ascending symmetrical weakness with areflexia after a diarrhoeal illness is Guillain-Barré syndrome, and about a quarter of patients need ventilation because the paralysis reaches the diaphragm and intercostal muscles. Neuromuscular respiratory failure is detected by serial forced vital capacity (typically every 4 to 6 hours), because a falling FVC precedes any change in oxygen saturation or blood gases; by the time hypoxia or hypercapnia appears the patient is close to arrest. An FVC below about 15 to 20 mL/kg, or falling rapidly, prompts critical care review for elective intubation. Peak flow measures airway calibre, not respiratory muscle strength, and is unhelpful here.

E. CT venography of the cerebral venous sinuses

A young overweight woman on oestrogen with a raised-pressure headache and papilloedema could have idiopathic intracranial hypertension, but that diagnosis can only be made once venous sinus thrombosis has been excluded, and the combined pill makes thrombosis more likely. A normal plain CT does not exclude it, so CT venography, or MRI with MR venography, is the next step and shows the filling defect directly. Lumbar puncture is part of the work-up for idiopathic intracranial hypertension but must follow venous imaging, because a thrombosed sinus also raises the opening pressure and the finding would be misattributed. Arterial imaging looks at the wrong circulation for this presentation.

C. Abscess spreading from the aortic valve ring

Fever, splinter haemorrhages, a new regurgitant murmur and positive cultures indicate infective endocarditis of the abnormal aortic valve. Virulent organisms, especially Staphylococcus aureus, can destroy the valve ring and spread into the surrounding tissue as a perivalvular (aortic root) abscess. The atrioventricular bundle runs in the membranous septum just beneath the junction of the right and non-coronary cusps, so an abscess here disrupts conduction, first as a lengthening PR interval and then as complete block. Degenerate valve calcium can also invade the conducting tissue, but slowly and in older patients. Takeaway: New atrioventricular block in aortic valve endocarditis signals an abscess spreading from the valve ring into the conducting tissue.

D. Reduced baroreceptor reflex sensitivity

On standing, several hundred millilitres of blood pool in the legs, venous return and stroke volume fall, and arterial pressure dips. Normally the carotid sinus and aortic arch baroreceptors sense the fall within seconds, vagal tone is withdrawn and sympathetic outflow rises, so heart rate and vascular resistance increase and pressure recovers. With age, baroreflex sensitivity declines, partly because stiffer arterial walls stretch less and partly through central changes, so the heart rate response is small and pressure falls further. A weaker muscle pump or a stiff ventricle deepens the fall in pressure, but on its own would provoke a brisker rise in pulse.

Takeaway: Reduced baroreflex sensitivity in older people blunts the heart rate response to standing.

D. Alpha-1 adrenoceptor blockade

Amitriptyline blocks several receptors as well as inhibiting monoamine reuptake. Standing unloads the baroreceptors, and the reflex response depends on noradrenaline reaching alpha-1 receptors on arterioles and veins. The drug blocks those receptors, so reflex constriction fails and the pressure falls, giving near-syncope. The dry mouth comes from a different receptor, the muscarinic, and is the tempting distractor. Older patients are affected most because their baroreflex is already blunted, and the resulting falls are the main harm from tricyclics in old age. Takeaway: postural hypotension on a tricyclic reflects alpha-1 adrenoceptor blockade, not its antimuscarinic action.

E. Issue a fit note stating he may be fit for work with amended duties and a phased return

The fit note offers two options: "not fit for work" and "may be fit for work taking account of the following advice", with tick boxes for a phased return, altered hours, amended duties and workplace adaptations plus free text. Early, graded return to work is therapeutic in mechanical back pain and prolonged absence predicts chronic disability, so a "may be fit" note describing what he can and cannot do (no prolonged driving or heavy lifting, shorter shifts at first) lets the employer arrange lighter duties; if the employer cannot accommodate the advice, the note is treated as "not fit". There is no "fit for work" option and a fit note is never required to return, but a note is needed here because he cannot yet do his full job. Occupational health can help with complex cases but is not a precondition for return.

C. Illness anxiety disorder

Illness anxiety disorder (hypochondriasis) is a preoccupation with having a serious disease in the absence of significant physical symptoms, with body checking, reassurance seeking and transient relief that soon gives way to renewed fear. Somatic symptom disorder, by contrast, requires distressing bodily symptoms to be present and the anxiety centres on them. The belief here is held with some doubt and responds briefly to reassurance, so it is an overvalued idea rather than a delusion. Obsessive-compulsive disorder involves intrusive thoughts and rituals across broader themes, and generalised anxiety disorder is diffuse worry across many life domains rather than one disease. Cognitive behavioural therapy focused on health anxiety is the treatment of choice.

B. Pretectal nucleus

Loss of sight in both eyes with brisk pupil reactions, normal fundi and denial of blindness points to bilateral occipital infarction, cortical blindness with Anton's syndrome. The pupils still react because the afferent fibres for the light reflex leave the optic tract before the lateral geniculate nucleus. They pass through the brachium of the superior colliculus to synapse in the pretectal nucleus of the midbrain. Each pretectal nucleus projects to both Edinger-Westphal nuclei, whose parasympathetic fibres relay in the ciliary ganglion to sphincter pupillae. A lesion beyond the lateral geniculate nucleus therefore leaves this reflex intact.

Takeaway: Pupillary light reflex fibres synapse in the pretectal nucleus, so cortical blindness spares the pupils.

A. Reassure and review annually

A testis that can be manipulated into the scrotum without tension and remains there until the cremasteric reflex pulls it up is retractile, not undescended: it is a normal variant caused by an active cremaster in boys aged roughly one to seven years, and it needs no surgery. It is not simply discharged, though, because a proportion of retractile testes later ascend and become truly undescended, so annual examination until puberty is advised, with referral if the testis can no longer be brought down or stops growing. An undescended testis, by contrast, cannot be brought to the scrotum or springs straight back under tension, and needs orchidopexy.