Neurology, diuretics and salivary assessment

Correct answer: A. Visual loss

• A. Correct — this is the exception. Parkinson disease does not cause loss of vision. It is a movement disorder from dopaminergic degeneration in the substantia nigra.
• B. Bradykinesia, the slowness of movement once begun, is required for the clinical diagnosis.
• C. Akinesia — difficulty initiating movement — is a cardinal feature and shows up as the characteristic hesitancy in starting to walk.
• D. A resting tremor, classically pill-rolling and improving with voluntary movement, is the third cardinal sign alongside rigidity.

Note: Practical implications: reduced blink and drooling, difficulty with oral hygiene, and a real risk of orthostatic hypotension from levodopa when the chair is raised.

Correct answer: A. Hypokalaemia

• A. Correct. Thiazides waste potassium. Triamterene is potassium-sparing, so combining the two offsets the loss and keeps serum potassium in range — which is precisely why the two are formulated together.
• B. For the same reason, hypercalcaemia is a possible thiazide effect rather than something triamterene guards against.
• C. Thiazides actually reduce urinary calcium excretion and tend to raise serum calcium slightly.
• D. Hyperkalaemia is the risk of triamterene given alone or with an ACE inhibitor, not something it prevents.

Correct answer: A. Focal lymphocytic infiltration of the glandular tissue

• A. Correct. Focal lymphocytic sialadenitis — dense aggregates of lymphocytes around ducts and acini — is the histologic hallmark of Sjögren syndrome, and the focus score from a lower labial biopsy is part of the classification criteria.
• B. Mucin extravasation with a granulation tissue wall describes a mucocele, a completely different lesion.
• C. Granulomas would suggest sarcoidosis, which can mimic Sjögren clinically but is histologically distinct.
• D. Fatty replacement occurs with age and with chronic obstruction, and it is not diagnostic on its own.

Correct answer: D. Cevimeline

• A. Amitriptyline is a tricyclic antidepressant with strong anticholinergic activity and is a classic cause of dry mouth.
• B. Oxybutynin is an antimuscarinic given for overactive bladder; dry mouth is its most common side effect.
• C. Diphenhydramine is a first-generation antihistamine, also markedly anticholinergic.
• D. Correct — this is the exception. Cevimeline is a muscarinic M3 agonist that stimulates salivary secretion. It is prescribed to treat xerostomia in Sjögren syndrome, not to cause it.

Note: Pilocarpine is the other sialogogue in this class. Both are contraindicated in uncontrolled asthma and narrow-angle glaucoma.