UKMLA PLAB AMC USMLE Prometric MCQ

Question:217
A 24 yr old pregnant woman complains of hearing loss. This hearing loss has been progressive over a period of one year but has recently deteriorated. Her hearing becomes surprisingly better in the presence of background noise. She occasionally also suffers from tinnitus in her left ear, at which time she feels unsteady. The patient used to work as a diving instructor but is currently on pregnancy leave. Her father has been deaf since his teens.

a) acoustic neuroma
b) acute middle ear effusion
c) otosclerosis
d) acute suppurative otitis media
e) barotraumatic otitis media
f) congenital cholesteatoma
g) chronic serous middle ear effusion
h) otitis externa
i) Menieres disease
j) Foreign body in left ear

Question:218
A previously well 65 year old has has acute dysequilibrium and gaze-holding difficulties resulting in recurrent falls. He is noted to have a vertical positional nystagmus, pursuit defects, a right-sided Horner's syndrome and a head tilt to the right. On examination he is found to have rolling of both eyes towards the side of the ptosis. A likely diagnosis is

a) carotid sinus hypersensitivity
b) sick sinus syndrome
c) vasovagal episode
d) tricyclic antidepressants
e) normal pressure hydrocephalus
f) occlusion of the right posterior inferior cerebellar artery
g) occlusion of the left superior cerebellar artery
h) Meniere's disease
i) acute labyrinthitis
j) senile calcific aortic stenosis

Question:219
An elderly patient presents to his general practitioner complaining of seeing double On examination the doctor noted a drooping upper eyelid of the right eye. The eye itself eye looked laterally and downward. The pupil was unreactive to light and remained fixed and dilated. Which nerve is paralysed in this case?

a) Accessory nerve
b) Trochlear nerve
c) Vagus nerve
d) Oculomotor nerve
e) Trigeminal nerve
f) Great auricular nerve
g) Auriculotemporal nerve
h) Olfactory nerve
i) Abducent nerve
j) Facial nerve

Question:217
Correct Answer: C
Explanation:
Approximately 70% of otosclerosis cases have a hereditary basis. The remaining 30% of cases occur sporadically. In hereditary cases, inheritance is autosomal dominant, with a penetrance of 25% to 40%. Gradual hearing loss over months or years is the major symptom in otosclerosis. This pattern is consistent with the histologic findings. Fixation may progress to become complete, resulting in a maximum conductive hearing loss of 50 to 60db. Pregnancy accelerates hearing loss in otosclerosis. Paracusis of Willis is found in 20% to 78% of patients. The patient experiences better understanding of speech in a noisy environment. This phenomenon is characteristic of all patients with conductive hearing loss; it occurs because people speak louder in noisy surroundings. Tinnitus occurs in the majority of patients with otosclerosis, with or without accompanying sensorineural hearing loss. The tinnitus may be unilateral in bilateral disease and is invariably not severe. Vestibular complaints are more common in otosclerotic persons than in the general population, and they occur more often than most believe. Unsteadiness, frank short episodes of vertigo are encountered in 25% to 55% of untreated otosclerotic patients.
 
Question:218
Correct Answer: F
Explanation:
The posterior inferior cerebellar artery supplies the dorsal lateral medullary plate and portions of the posterior medial cerebellum (uvula, nodulus and probably portions of the paraflocculus). Occlusion of its distal cerebellar branches can produce a syndrome very difficult to distinguish from a peripheral labyrinthine disorder, with vertigo, dysequilibrium and spontaneous nystagmus (medial pica syndrome, distal pica infarct). Careful examination may show more evidence of ocular motor involvement (gaze-holding difficulties, vertical positional nystagmus, pursuit defects) than one normally finds with peripheral lesions, but one can not always confidently distinguish between a peripheral and a central cause. When the PICA is occluded at its origin Wallenberg's syndrome results with a characteristic neuroophthalmologic and neurootologic manifestations including Horner's syndrome Otolith syndrome (involvement of caudal vestibular complex) Skew deviation -- eye lower on the side of the lesion Head tilt -- to the side of the lesion Ocular counterroll -- both eyes roll (top of eye) toward the side of the lesion Disordered perceptions of verticality Pulsion of the body (vestibulospinal) toward the side of the lesion Saccade syndrome (interruption of inferior cerebellar peduncle (and climbing fibers) causing a functional inhibition of ipsilateral fastigial nucleus) of saccades Vertical saccades deviate toward the side of the lesion Steady-state deviation of the eyes toward the side of the lesion under closed lids Other vascular syndromes to keep in mind in the differential diagnosis of the patient with acute vertigo include the vestibular-masseter syndrome, due a branch occlusion (AICA or PICA) involving the vestibular afferents on their way to the vestibular nuclei as they pass the motor nucleus of the V nerve. Such patients have acute vertigo with weakness or deviation of the jaw. Occlusions of branches of the superior cerebellar artery involving the superior cerebellar peduncle may also cause vertigo . In patients above the age of 45 who develop acute vertigo, dysequilibrium without hearing symptoms, and are seen in the ER, it is often prudent to obtain a CT scan, especially if the patient has any vascular risk factors, to look for hemorrhage or swelling.
 
Question:219
Correct Answer: D
Explanation:
The eye itself eye looked laterally and downward his eye looked laterally, (external strabismus) due to the lateral rectus muscle acting on it; downward due to the action of the superior oblique. The patient sees double, drooping of the upper eyelid (ptosis) due to the paralysis of the levaror palpebrae superioris. Pupil fixed and dilated due to paralysis of the sphincter pupillae and the unopposed action of the dilator pupillae (sympathetic supply)