QuestionSBA
QuestionChoice
Stroke often presents with new-onset unilateral facial weakness. However, as this is an upper motor neuron facial palsy, motor innervation to the forehead would be spared in an acute stroke. Furthermore, the other features (meiosis, anhidrosis) of the presenting history and examination are not typical of a stroke.
10008009
e
Stroke
QuestionChoice
Bell's palsy is an idiopathic syndrome affecting the facial nerve. It is characterised by: unilateral facial weakness, ear pain, hyperacusis, altered taste and dry eyes/mouth. While this patient demonstrates eyelid droop, there is no evidence of generalised facial weakness or other features of Bell’s palsy.
10008006
b
Bell’s palsy
QuestionChoice
Myasthenia gravis is an autoimmune disorder resulting in insufficient functioning of the acetylcholine receptors to allow muscle contraction. While this condition does present with ptosis, it does not affect the pupil or sweat glands and therefore would not produce meiosis or anhydrosis.
10008008
d
Myasthenia gravis
QuestionChoice
Horner's syndrome is characterised by ptosis (eyelid droop) and meiosis (pupillary constriction), with or without anhydrosis (a lack of sweating), as demonstrated by this patient. It is caused by an interruption of the sympathetic nerve supply to the eye.
10008005
a
Horner’s syndrome
QuestionChoice
CN III is responsible for pupillary constriction. In CN III palsy, the pupil would be dilated and the patient would be experiencing symptoms such as double vision and strabismus.
10008007
c
Third cranial nerve palsy
Concept
Chapter
2693
4636
Horner’s syndrome
Topic
141
Neurology
14148
A 55-year-old man presents to the Medical Assessment Unit with a drooping eyelid on his right side. On examination, his right pupil is constricted and despite it being a very hot day, he is not producing any sweat on the right side of his forehead. The rest of the examination is unremarkable.

Which of the following is the most likely diagnosis?
a