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AOBNP Neurology & Psychiatry study materials
AOBNP Neurology & Psychiatry study resources

AOBNP Neurology & Psychiatry practice questions

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Question 1Neurology

A patient has a right homonymous hemianopia with macular sparing. Where is the lesion most likely located?

  1. Left optic nerve
  2. Left occipital lobe Correct answer.
  3. Right Meyer loop
  4. Right optic tract

Explanation

Posterior cerebral artery territory infarction of the occipital cortex often spares the occipital pole because of collateral supply from the middle cerebral artery, preserving central vision. A homonymous defect localizes contralateral to the visual loss.

Question 2Neurology

Which cranial nerve is most commonly affected in idiopathic Bell palsy?

  1. Facial nerve Correct answer.
  2. Hypoglossal nerve
  3. Trigeminal nerve
  4. Oculomotor nerve

Explanation

Bell palsy is an acute peripheral facial nerve (CN VII) paralysis, producing ipsilateral facial weakness, loss of the nasolabial fold, and inability to close the eye. Forehead involvement distinguishes it from an upper motor neuron lesion.

Question 3Neurology

A patient reports brief, electric shock-like pains in the cheek triggered by chewing. Which medication is first-line for this condition?

  1. Levodopa
  2. Carbamazepine Correct answer.
  3. Sumatriptan
  4. Propranolol

Explanation

Trigeminal neuralgia produces paroxysmal lancinating facial pain triggered by touch or chewing, and carbamazepine is the established first-line therapy. Oxcarbazepine and other agents are alternatives when carbamazepine is not tolerated.

Question 4Neurology

Which finding best distinguishes a generalized tonic-clonic seizure from a psychogenic nonepileptic spell?

  1. Closed eyes during the event
  2. Asynchronous limb movements
  3. Gradual onset over minutes
  4. Postictal confusion and disorientation Correct answer.

Explanation

True generalized tonic-clonic seizures are typically followed by a postictal state of confusion, drowsiness, and elevated prolactin. Features such as eyes held closed, asynchronous thrashing, and gradual buildup favor a nonepileptic event.

Question 5Neurology

A 70-year-old has a resting tremor, cogwheel rigidity, and bradykinesia. Which pathologic finding is characteristic of this disorder?

  1. Degeneration of anterior horn cells
  2. Demyelination of the optic nerve
  3. Loss of dopaminergic neurons in the substantia nigra Correct answer.
  4. Lewy bodies confined to the cortex

Explanation

Parkinson disease results from degeneration of dopaminergic neurons in the substantia nigra pars compacta, producing the classic triad of tremor, rigidity, and bradykinesia. Lewy bodies are found in surviving neurons but are not confined to the cortex.

Question 6Neurology

A patient with multiple sclerosis develops painful loss of vision in one eye with impaired color vision. Which structure is most directly affected?

  1. Optic nerve Correct answer.
  2. Lateral geniculate nucleus
  3. Optic chiasm
  4. Optic radiation

Explanation

Optic neuritis is inflammation of the optic nerve, producing monocular painful visual loss with reduced color perception and an afferent pupillary defect. It is a common presenting feature of multiple sclerosis.

Question 7Neurology

Which clinical feature most strongly suggests a migraine rather than a tension-type headache?

  1. Unilateral throbbing pain worsened by activity Correct answer.
  2. Bilateral pressing tightness
  3. No nausea or photophobia
  4. Mild intensity that does not limit activity

Explanation

Migraine is defined by unilateral, pulsating pain of moderate to severe intensity that is aggravated by routine activity and accompanied by nausea or photophobia. Tension-type headache is typically bilateral, pressing, and mild.

Question 8Neurology

A patient presents with sudden severe headache, neck stiffness, and photophobia. Which diagnostic test is most appropriate first?

  1. EEG
  2. Noncontrast head CT Correct answer.
  3. Carotid ultrasound
  4. Lumbar puncture without imaging

Explanation

Sudden severe headache with meningismus suggests subarachnoid hemorrhage, and emergent noncontrast head CT is the initial study. Lumbar puncture is reserved for cases with a negative CT and is performed only after imaging excludes mass effect.

Question 9Neurology

A patient has an acute ischemic stroke with symptom onset 2 hours ago. Which treatment is indicated if there are no contraindications?

  1. Intravenous alteplase Correct answer.
  2. Intravenous heparin
  3. Oral aspirin alone
  4. Surgical decompression

Explanation

Intravenous thrombolysis with alteplase or tenecteplase is indicated for acute ischemic stroke within the treatment window when contraindications are absent. Antiplatelet therapy is used but does not replace reperfusion in the acute window.

Question 10Neurology

A patient with a history of atrial fibrillation presents with acute stroke. Which mechanism best explains the stroke?

  1. Venous sinus thrombosis
  2. Carotid dissection
  3. Small vessel lipohyalinosis
  4. Cardioembolism Correct answer.

Explanation

Atrial fibrillation promotes stasis and thrombus formation in the left atrium, leading to cardioembolic stroke. Anticoagulation is the key preventive strategy in this setting.

Question 11Neurology

Which finding is most consistent with a lower motor neuron lesion?

  1. Hyperreflexia
  2. Babinski sign
  3. Spasticity
  4. Fasciculations and muscle atrophy Correct answer.

Explanation

Lower motor neuron lesions produce weakness, atrophy, fasciculations, and reduced reflexes. Upper motor neuron lesions produce spasticity, hyperreflexia, and an extensor plantar response.

Question 12Neurology

A patient has ascending symmetric weakness, areflexia, and recent diarrheal illness. Which diagnosis is most likely?

  1. Guillain-Barre syndrome Correct answer.
  2. Myasthenia gravis
  3. Spinal cord compression
  4. Polymyositis

Explanation

Guillain-Barre syndrome is an acute demyelinating polyneuropathy that often follows a gastrointestinal infection and presents with ascending symmetric weakness and areflexia. Cerebrospinal fluid shows albuminocytologic dissociation.

Question 13Neurology

Which antibody is most specifically associated with myasthenia gravis?

  1. Anti-GQ1b antibody
  2. Anti-Jo-1 antibody
  3. Anti-dsDNA antibody
  4. Acetylcholine receptor antibody Correct answer.

Explanation

Myasthenia gravis is caused by autoantibodies against the postsynaptic acetylcholine receptor at the neuromuscular junction, producing fatigable weakness. Anti-MuSK antibodies occur in a subset of seronegative patients.

Question 14Neurology

A patient with progressive cognitive decline has prominent visual hallucinations, parkinsonism, and fluctuating attention. Which diagnosis is most likely?

  1. Vascular dementia
  2. Dementia with Lewy bodies Correct answer.
  3. Frontotemporal dementia
  4. Alzheimer disease

Explanation

Dementia with Lewy bodies is characterized by fluctuating cognition, visual hallucinations, and parkinsonian features. Antipsychotic sensitivity is an additional supportive feature.

Question 15Neurology

Which medication is first-line for acute migraine attack in a patient without contraindications?

  1. Topiramate
  2. Amitriptyline
  3. Propranolol
  4. A triptan such as sumatriptan Correct answer.

Explanation

Triptans are effective acute migraine therapies that act as serotonin receptor agonists to abort an attack. Propranolol, topiramate, and amitriptyline are prophylactic agents used to reduce attack frequency.

Question 16Neurology

A patient has a sudden-onset severe headache, and head CT is negative. Which next step is most appropriate to evaluate for subarachnoid hemorrhage?

  1. Lumbar puncture for xanthochromia Correct answer.
  2. MRI of the brain in one month
  3. Repeat head CT in one week
  4. Start antibiotics empirically

Explanation

When subarachnoid hemorrhage is suspected and noncontrast CT is negative, lumbar puncture is performed to look for xanthochromia, which reflects bilirubin from lysed red cells. This finding remains positive for days after the hemorrhage.

Question 17Neurology

Which electrolyte abnormality most commonly causes confusion, seizures, and cerebral edema when corrected too rapidly?

  1. Hypercalcemia
  2. Hyponatremia Correct answer.
  3. Hyperkalemia
  4. Hypochloremia

Explanation

Severe hyponatremia causes cerebral edema with confusion and seizures, and overly rapid correction risks osmotic demyelination. Correction should be limited and monitored closely.

Question 18Neurology

Which nerve is most commonly injured in a humeral shaft fracture, causing wrist drop?

  1. Ulnar nerve
  2. Axillary nerve
  3. Median nerve
  4. Radial nerve Correct answer.

Explanation

The radial nerve spirals around the humeral shaft and is injured in midshaft fractures, producing wrist drop and sensory loss over the dorsal hand. The axillary nerve is more often injured with shoulder dislocation.

Question 19Neurology

A patient with a pontine lesion has horizontal gaze palsy toward the side of the lesion. Which structure is involved?

  1. Oculomotor nucleus
  2. Medial longitudinal fasciculus
  3. Abducens nucleus or paramedian pontine reticular formation Correct answer.
  4. Frontal eye field

Explanation

Horizontal gaze is generated by the paramedian pontine reticular formation and abducens nucleus, which project to the contralateral medial rectus subnucleus via the medial longitudinal fasciculus. A pontine lesion abolishes ipsilateral horizontal gaze.

Question 20Neurology

Which medication is used for status epilepticus after initial benzodiazepine therapy fails?

  1. Oral valproate
  2. Intramuscular haloperidol
  3. Intravenous levetiracetam Correct answer.
  4. Oral carbamazepine

Explanation

After benzodiazepines, a second-line intravenous antiseizure medication such as levetiracetam, fosphenytoin, or valproate is given to terminate status epilepticus. Oral agents are inappropriate in an emergency because of slow absorption.

Question 21Neurology

Which finding suggests normal pressure hydrocephalus rather than Alzheimer disease?

  1. Prominent cortical atrophy on imaging
  2. Gait apraxia with urinary incontinence Correct answer.
  3. Early severe memory loss
  4. Gradual language decline

Explanation

Normal pressure hydrocephalus presents with the triad of gait disturbance, urinary incontinence, and cognitive impairment, often with ventriculomegaly disproportionate to atrophy. Gait apraxia is typically the earliest and most prominent feature.

Question 22Neurology

Which structure is the primary relay for pain and temperature sensation from the face?

  1. Mesencephalic nucleus
  2. Spinal trigeminal nucleus Correct answer.
  3. Motor nucleus of the trigeminal nerve
  4. Chief sensory nucleus

Explanation

Pain and temperature fibers from the face descend to the spinal trigeminal nucleus before crossing to the contralateral side. The chief sensory nucleus mediates discriminative touch, and the mesencephalic nucleus carries proprioception.

Question 23Neurology

A patient has a lesion of the left optic tract. Which visual field defect is expected?

  1. Right homonymous hemianopia Correct answer.
  2. Bitemporal hemianopia
  3. Left homonymous hemianopia
  4. Monocular blindness of the left eye

Explanation

The optic tract carries fibers from the temporal retina of the ipsilateral eye and the nasal retina of the contralateral eye, which subserve the contralateral visual field. A left optic tract lesion therefore produces a right homonymous hemianopia.

Question 24Neurology

Which clinical sign is most characteristic of an upper motor neuron facial palsy?

  1. Weakness of the lower face with sparing of the forehead Correct answer.
  2. Absent corneal reflex
  3. Loss of taste over the anterior tongue
  4. Weakness of the entire face including the forehead

Explanation

Upper motor neuron lesions affect the contralateral lower face because the upper face receives bilateral cortical innervation. Peripheral facial nerve lesions affect both upper and lower face on the ipsilateral side.

Question 25Neurology

Which feature is most consistent with a diagnosis of delirium rather than dementia?

  1. Stable cognitive deficits over years
  2. Preserved level of consciousness
  3. Insidious progressive memory loss
  4. Acute onset with fluctuating attention Correct answer.

Explanation

Delirium is an acute, fluctuating disturbance of attention and awareness, often triggered by illness or medications. Dementia is a chronic, progressive decline in cognition with preserved consciousness until late stages.

Question 26Neurology

A patient develops a resting tremor, cogwheel rigidity, and bradykinesia. Degeneration of which neuronal population best explains these findings?

  1. Thalamic ventral lateral neurons
  2. Caudate nucleus GABAergic neurons
  3. Substantia nigra pars compacta dopaminergic neurons Correct answer.
  4. Cerebellar Purkinje cells

Explanation

Parkinson disease results from loss of dopaminergic neurons in the substantia nigra pars compacta, which removes facilitation of the direct striatal pathway and increases indirect pathway activity. The resulting imbalance produces the classic triad of tremor, rigidity, and bradykinesia.

Question 27Neurology

A patient reports episodes of vertigo, unilateral hearing loss, and tinnitus lasting hours, with symptom-free intervals between attacks. Which diagnosis is most likely?

  1. Benign paroxysmal positional vertigo
  2. Meniere disease Correct answer.
  3. Vertebrobasilar transient ischemic attack
  4. Vestibular schwannoma

Explanation

Meniere disease is caused by endolymphatic hydrops and presents with the tetrad of episodic vertigo, fluctuating sensorineural hearing loss, tinnitus, and aural fullness lasting minutes to hours. Symptoms resolve between attacks in early disease.

Question 28Neurology

A patient has bilateral proximal muscle weakness, a heliotrope rash, and Gottron papules. Which autoantibody is most commonly associated with this disorder?

  1. Anti-aquaporin 4
  2. Anti-acetylcholine receptor
  3. Anti-voltage-gated calcium channel
  4. Anti-Jo-1 Correct answer.

Explanation

Dermatomyositis is associated with anti-Jo-1 (anti-histidyl-tRNA synthetase) antibodies in a substantial proportion of patients and is a classic antisynthetase syndrome. The skin findings plus proximal weakness define the presentation.

Question 29Neurology

A patient with a history of recurrent sinus infections develops fever, headache, and a focal seizure. MRI shows a ring-enhancing lesion in the frontal lobe. Which organism is most likely responsible?

  1. Streptococcus milleri group Correct answer.
  2. Cryptococcus neoformans
  3. Herpes simplex virus
  4. Toxoplasma gondii

Explanation

Brain abscesses are often polymicrobial, and the Streptococcus milleri group is a leading cause of abscesses arising from contiguous sinus or dental infection. Ring enhancement with fever and headache in a sinusitis patient supports this diagnosis.

Question 30Neurology

A patient has a laceration of the medial wrist and cannot oppose the thumb to the little finger, with sensory loss over the palmar surface of the first three digits. Which nerve is injured?

  1. Median nerve Correct answer.
  2. Ulnar nerve
  3. Radial nerve
  4. Anterior interosseous nerve

Explanation

The median nerve supplies the thenar muscles via the recurrent branch, and its loss eliminates thumb opposition and sensation over the palmar aspect of the lateral three and a half digits. The injury site at the wrist fits a median nerve laceration.

Question 31Neurology

A patient develops jaundice, ataxia, and a low serum ceruloplasmin level. Slit-lamp examination shows copper deposition in the cornea. Which finding is expected on liver biopsy?

  1. Periportal lymphocytic infiltrates
  2. Bile duct proliferation with portal fibrosis
  3. Amyloid deposition in the space of Disse
  4. Hepatocyte steatosis with glycogenated nuclei Correct answer.

Explanation

Wilson disease reflects impaired copper excretion and produces hepatic steatosis with glycogenated nuclei, progressing to fibrosis. The Kayser-Fleischer ring and low ceruloplasmin confirm the diagnosis.

Question 32Neurology

A patient with a prior myocardial infarction has sudden onset of aphasia and right hemiparesis. Which vascular territory is most likely involved?

  1. Left posterior cerebral artery
  2. Left middle cerebral artery Correct answer.
  3. Left anterior cerebral artery
  4. Right middle cerebral artery

Explanation

The left middle cerebral artery supplies the dominant hemisphere's language cortex and the lateral motor strip, so occlusion produces aphasia with contralateral face and arm weakness. This pattern is classic for an embolic stroke from a cardiac source.

Question 33Neurology

A patient taking a first-generation antipsychotic develops fever, muscle rigidity, and altered mental status, with a creatine kinase of 4000 U/L. Which medication is the appropriate treatment?

  1. Propranolol
  2. Dantrolene Correct answer.
  3. Levodopa
  4. Bromocriptine

Explanation

Neuroleptic malignant syndrome is treated with dantrolene, which blocks ryanodine receptors and reduces calcium release from the sarcoplasmic reticulum, lowering muscle rigidity and heat production. Supportive care with cooling and hydration is also essential.

Question 34Neurology

A patient has bilateral lower extremity weakness, sensory loss below the umbilicus, and bowel incontinence after a thoracic spine injury. Which finding distinguishes an upper motor neuron lesion from a lower motor neuron lesion in this context?

  1. Fasciculations in the affected muscles
  2. Areflexia with preserved tone
  3. Hyperreflexia with extensor plantar responses Correct answer.
  4. Marked muscle atrophy within days

Explanation

Upper motor neuron lesions produce hyperreflexia, spasticity, and extensor plantar responses because cortical inhibition of spinal reflexes is lost. Lower motor neuron lesions cause hyporeflexia, flaccidity, and early atrophy.

Question 35Neurology

A patient with a long-standing seizure disorder presents with confusion, ataxia, and nystagmus. Serum sodium is 128 mEq/L. Which medication is the most likely cause?

  1. Levetiracetam
  2. Ethosuximide
  3. Carbamazepine Correct answer.
  4. Lamotrigine

Explanation

Carbamazepine can cause hyponatremia through SIADH, producing confusion, ataxia, and nystagmus when sodium falls. The syndrome resolves with discontinuation and fluid restriction.

Question 36Neurology

A patient has a rapidly progressive ascending paralysis with areflexia and a recent Campylobacter infection. Which finding on cerebrospinal fluid analysis is most consistent with this disorder?

  1. Low glucose with elevated lactate
  2. Elevated opening pressure with neutrophilic pleocytosis
  3. Oligoclonal bands with normal protein
  4. Albuminocytologic dissociation Correct answer.

Explanation

Guillain-Barre syndrome typically shows elevated CSF protein with a normal cell count, termed albuminocytologic dissociation, reflecting nerve root inflammation. It may be absent early in the course.

Question 37Neurology

A patient with a history of alcohol use presents with confusion, ataxia, and ophthalmoplegia. Which treatment should be given immediately?

  1. Intravenous thiamine Correct answer.
  2. Intravenous lorazepam
  3. Oral pyridoxine
  4. Oral folate

Explanation

Wernicke encephalopathy results from thiamine deficiency and is treated immediately with parenteral thiamine to prevent progression to Korsakoff syndrome. Glucose should be given only after thiamine in this setting.

Question 38Neurology

A patient has progressive weakness and muscle wasting in the hands with fasciculations, and examination shows both hyperreflexia and atrophy in the same limb. Which diagnosis is most likely?

  1. Chronic inflammatory demyelinating polyneuropathy
  2. Amyotrophic lateral sclerosis Correct answer.
  3. Myasthenia gravis
  4. Polymyositis

Explanation

Amyotrophic lateral sclerosis affects both upper and lower motor neurons, producing the combination of hyperreflexia and atrophy with fasciculations in the same region. Sensory findings are typically absent.

Question 39Neurology

A patient has a head injury with clear fluid leaking from the nose that tests positive for beta-2 transferrin. Which complication should be monitored for?

  1. Diabetes insipidus
  2. Meningitis Correct answer.
  3. Subdural hematoma
  4. Carotid-cavernous fistula

Explanation

Positive beta-2 transferrin confirms CSF rhinorrhea from an anterior skull base fracture, which creates a direct communication between the subarachnoid space and the nasal cavity. This predisposes to ascending bacterial meningitis.

Question 40Neurology

A patient has an acute ischemic stroke with a large vessel occlusion and arrives 8 hours after symptom onset with a favorable perfusion scan. Which treatment is most appropriate?

  1. Intravenous alteplase
  2. Endovascular thrombectomy Correct answer.
  3. Therapeutic anticoagulation with heparin
  4. Aspirin alone

Explanation

Endovascular thrombectomy is indicated for large vessel occlusion up to 24 hours in selected patients with favorable imaging, including those beyond the IV thrombolysis window. IV thrombolysis is generally limited to 4.5 hours.

Question 41Neurology

A patient has progressive bilateral leg weakness, spasticity, and urinary urgency, and MRI shows hyperintensity of the spinal cord over several segments. Which finding would support a diagnosis of neuromyelitis optica spectrum disorder?

  1. Anti-aquaporin 4 antibodies Correct answer.
  2. Anti-ganglioside GQ1b antibodies
  3. Anti-Hu antibodies
  4. Anti-NMDA receptor antibodies

Explanation

Neuromyelitis optica spectrum disorder is caused by antibodies against aquaporin 4 on astrocyte foot processes and produces longitudinally extensive transverse myelitis and optic neuritis. Seropositivity is highly specific.

Question 42Neurology

A patient has a seizure disorder and develops gingival hyperplasia and hirsutism. Which medication is most likely responsible?

  1. Valproate
  2. Gabapentin
  3. Phenytoin Correct answer.
  4. Topiramate

Explanation

Phenytoin causes gingival hyperplasia, hirsutism, and coarsening of facial features with chronic use, in addition to ataxia and nystagmus at toxic levels. These effects are dose- and duration-related.

Question 43Neurology

A patient presents with a pupil-sparing third nerve palsy and contralateral hemiparesis. Which localization is most likely?

  1. Orbit
  2. Neuromuscular junction
  3. Cavernous sinus
  4. Midbrain Correct answer.

Explanation

A midbrain lesion involving the fascicle of the third nerve and the adjacent cerebral peduncle produces an ipsilateral third nerve palsy with contralateral hemiparesis (Weber syndrome). The pupil is often spared because the lesion affects the fascicle rather than the compressive superficial fibers.

Question 44Neurology

A patient with a known seizure disorder has a prolonged convulsion lasting more than 5 minutes. After two doses of a benzodiazepine, the seizure continues. Which medication is next appropriate?

  1. Phenytoin
  2. Carbamazepine
  3. Levetiracetam Correct answer.
  4. Lorazepam

Explanation

After benzodiazepines fail in status epilepticus, a second-line antiseizure medication is given; levetiracetam is one of the recommended options with a favorable safety profile. Fosphenytoin and valproate are alternatives.

Question 45Neurology

A patient has sudden painless loss of vision in one eye with a pale retina and a cherry-red spot at the macula. Which diagnosis is most likely?

  1. Central retinal vein occlusion
  2. Retinal detachment
  3. Vitreous hemorrhage
  4. Central retinal artery occlusion Correct answer.

Explanation

Central retinal artery occlusion causes sudden painless monocular vision loss with a pale, edematous retina and a cherry-red macular spot where the choroidal circulation shows through. It is often embolic from a cardiac or carotid source.

Question 46Neurology

A patient has a hemisensory loss involving the face and contralateral body, with dysarthria and ataxia. MRI shows a lesion in the lateral medulla. Which artery is most likely occluded?

  1. Anterior spinal artery
  2. Anterior inferior cerebellar artery
  3. Superior cerebellar artery
  4. Posterior inferior cerebellar artery Correct answer.

Explanation

Lateral medullary syndrome results from occlusion of the posterior inferior cerebellar artery or the vertebral artery, producing ipsilateral facial sensory loss and Horner syndrome with contralateral body sensory loss. Dysarthria and ataxia reflect involvement of the nucleus ambiguus and inferior cerebellar peduncle.

Question 47Neurology

A patient has a chronic progressive myelopathy with sensory ataxia and a positive Romberg sign, and serum vitamin B12 is low. Which finding is expected on examination?

  1. Unilateral foot drop with preserved proprioception
  2. Loss of pain and temperature sensation with areflexia
  3. Loss of vibration and proprioception with brisk reflexes Correct answer.
  4. Proximal muscle weakness with preserved sensation

Explanation

Vitamin B12 deficiency causes subacute combined degeneration of the dorsal columns and corticospinal tracts, producing loss of vibration and proprioception with upper motor neuron signs such as brisk reflexes and extensor plantar responses. Sensory ataxia with a positive Romberg reflects dorsal column involvement.

Question 48Neurology

A patient has a slowly enlarging pituitary mass with bitemporal hemianopia. Which structure is compressed?

  1. Optic nerve
  2. Optic chiasm Correct answer.
  3. Optic tract
  4. Lateral geniculate nucleus

Explanation

The optic chiasm lies above the sella, and a pituitary mass compressing it damages decussating fibers from the nasal retina, producing bitemporal hemianopia. This is the classic visual field defect of a pituitary adenoma.

Question 49Neurology

A patient with a traumatic brain injury develops a fixed dilated pupil and progressive decline in consciousness. Which mechanism best explains the pupillary finding?

  1. Uncal herniation compressing the third nerve Correct answer.
  2. Occipital lobe contusion
  3. Direct injury to the optic nerve
  4. Sympathetic pathway interruption

Explanation

Expanding supratentorial mass lesions cause uncal herniation, which compresses the ipsilateral third nerve and its parasympathetic fibers, producing a fixed dilated pupil. This is a neurosurgical emergency.

Question 50Neurology

A patient has episodic vertigo triggered by rolling over in bed, lasting seconds, with a positive Dix-Hallpike maneuver. Which mechanism is most likely?

  1. Endolymphatic hydrops
  2. Vestibular nerve demyelination
  3. Canaliths displacing within the posterior semicircular canal Correct answer.
  4. Cerebellar vermis degeneration

Explanation

Benign paroxysmal positional vertigo results from otoconia dislodged into the posterior semicircular canal, which move with head position and produce brief vertigo. The Dix-Hallpike maneuver reproduces the symptoms and identifies the affected canal.