50 Case-Based Neurology MCQs for Medical Students
Case 1
A 68-year-old man with hypertension presents with sudden onset of left-sided weakness lasting 4 days. He had intermittent headaches for the past month. On examination, he has left hemiparesis, left-sided sensory loss, and left-sided neglect.
What is the MOST appropriate initial imaging study? A. MRI brain with contrast B. CT head without contrast C. Carotid duplex ultrasound D. CT angiography of the neck only
Explanation: The American College of Radiology recommends non-contrast head CT as the first-line imaging study in acute stroke settings to rapidly exclude hemorrhage and identify large territory infarction 1, 2. This should be followed by CT angiography from aortic arch to vertex to assess both extracranial and intracranial vasculature 1. The 4-day duration of fixed neurological deficits indicates completed stroke rather than TIA (which resolves within 24 hours) 1.
Case 2
A 45-year-old woman presents with sudden onset vertigo, nausea, and inability to walk. CT head performed 6 hours ago was normal. She continues to have severe truncal ataxia and horizontal nystagmus.
What is the NEXT most appropriate step? A. Discharge with meclizine prescription B. Repeat CT head immediately C. Obtain MRI brain without contrast urgently D. Perform Dix-Hallpike maneuver and discharge if positive
Explanation: CT brain has only 20-40% sensitivity for detecting posterior circulation pathology and misses most causes of persistent dizziness 3. MRI brain without contrast is essential for evaluating cerebellar and brainstem pathology 1, 3. The American College of Radiology recommends MRI as the preferred imaging modality for ataxia when stroke intervention is not an immediate consideration 1. A normal CT does not exclude serious neurological causes, particularly posterior fossa lesions 3.
Case 3
A 34-year-old man presents with sudden onset of the worst headache of his life, followed 2 hours later by confusion and left arm weakness. CT head shows no hemorrhage.
What is the MOST likely diagnosis requiring immediate investigation? A. Migraine with aura B. Cerebral venous thrombosis C. Tension-type headache D. Cluster headache
Answer: B 2
Explanation: The American Heart Association states that cerebral venous thrombosis can present with prolonged headache followed by acute focal neurological deficits 2. Standard CT may miss this diagnosis, and the American College of Cardiology recommends CT venography or MR venography if there is any suspicion for CVT 2. The combination of severe headache with subsequent focal deficits is a critical red flag requiring urgent vascular imaging 2.
Case 4
A 29-year-old woman presents with 15 minutes of right eye vision loss described as "a curtain coming down." Vision has now returned to normal. She smokes 1 pack per day.
What is the MOST appropriate initial diagnostic test? A. Ophthalmology referral only B. Carotid duplex ultrasonography C. MRI brain with contrast D. Lumbar puncture
Answer: B 1
Explanation: This presentation is classic for amaurosis fugax (transient monocular blindness), which represents a TIA in the retinal artery territory supplied by the ipsilateral internal carotid artery 1. The American Heart Association recommends duplex ultrasonography to detect carotid stenosis in patients who develop focal neurological symptoms corresponding to the territory supplied by the internal carotid artery 1. The risk of permanent blindness or stroke is significant, particularly in patients with multiple vascular risk factors like smoking 1.
Case 5
A 72-year-old man presents 3 hours after sudden onset of right-sided weakness and aphasia. He is a candidate for thrombolytic therapy. CT head shows no hemorrhage.
What additional imaging should be obtained BEFORE thrombolysis decision? A. MRI brain with diffusion-weighted imaging B. CTA head and neck C. Carotid duplex ultrasound D. No additional imaging needed
Answer: B 1
Explanation: The American College of Radiology recommends CTA head and neck with IV contrast after non-contrast CT in patients with acute stroke within 6 hours, as vascular imaging helps identify large vessel occlusion that may benefit from endovascular therapy 1. CTA from aortic arch to vertex assesses both extracranial and intracranial vasculature 1, 2. This information is critical for treatment decisions in the hyperacute setting 1.
Case 6
A 55-year-old woman with history of breast cancer presents with progressive gait ataxia, dysarthria, and diplopia over 3 weeks. She has no history of trauma.
What is the MOST likely diagnosis? A. Cerebellar metastases B. Paraneoplastic cerebellar degeneration C. Multiple sclerosis D. Vertebrobasilar insufficiency
Answer: B 1
Explanation: Paraneoplastic cerebellar degeneration is clinically characterized by subacute or acute onset of gait and limb ataxia, dysarthria, and ocular dysmetria 1. The time course of weeks in a patient with known malignancy strongly suggests this diagnosis 1. MRI brain should be obtained to exclude cerebellar metastases, but the clinical presentation is more consistent with paraneoplastic syndrome 1.
Case 7
A 19-year-old man presents to the emergency department after a motor vehicle collision. He has a GCS score of 15 and reports brief loss of consciousness. CT head is normal. Neurological examination is completely normal.
What is the MOST appropriate disposition? A. Discharge home with head injury instructions B. Admit for 24-hour observation C. Repeat CT in 6 hours D. Obtain MRI brain before discharge
Answer: A 1
Explanation: Patients with GCS score of 15, normal neurological examination, and normal CT scan findings can be safely discharged 1. The negative predictive value of CT in this setting is 99.7% 1. Follow-up should be arranged, and patients should receive clear head injury precautions 1. Routine admission or repeat imaging is not indicated in this low-risk population 1.
Case 8
A 62-year-old man with hypertension and diabetes presents with sudden onset of slurred speech and difficulty swallowing. Examination reveals dysarthria, dysphagia, and right-sided ataxia. CT head shows no acute findings.
What vascular territory is MOST likely affected? A. Left middle cerebral artery B. Right middle cerebral artery C. Posterior circulation (vertebrobasilar) D. Anterior cerebral artery
Answer: C 1
Explanation: The combination of dysarthria, dysphagia, and ipsilateral ataxia suggests a lateral medullary (Wallenberg) syndrome or other posterior circulation stroke 1. These symptoms correspond to brainstem and cerebellar dysfunction supplied by the vertebrobasilar system 1. CT has poor sensitivity for posterior fossa lesions, and MRI brain should be obtained 1, 3.
Case 9
A 28-year-old woman presents with 2 months of daily headaches that worsen when lying down, associated with dizziness, neck pain, and occasional diplopia. CT head is normal.
What is the MOST appropriate next diagnostic step? A. Lumbar puncture with opening pressure B. MRI brain without contrast C. Carotid duplex ultrasound D. EEG
Answer: B 3
Explanation: This presentation is concerning for spontaneous intracranial hypotension, which can present with non-orthostatic headaches, dizziness, neck pain, and skull base symptoms 3, 4. MRI findings include diffuse dural and leptomeningeal enhancement, brain sagging, and venous engorgement 3, 4. Lumbar puncture could worsen intracranial hypotension and should not be performed before imaging 3.
Case 10
A 58-year-old man presents with sudden onset of confusion and inability to speak coherently. He can follow commands and write normally. Audiometry shows normal hearing bilaterally.
What is the MOST likely diagnosis? A. Broca aphasia B. Wernicke aphasia C. Pure word deafness D. Global aphasia
Answer: C 5
Explanation: Pure word deafness is marked by complete deafness to spoken language with conserved ability to understand and read written words and no speech production disorders 5. This syndrome typically results from bilateral temporal cortex lesions affecting auditory processing while sparing other language functions 5. Neuroimaging with MRI should be obtained to identify bilateral temporal lesions 5.
Case 11
A 76-year-old woman is brought to the ED for "confusion." She repeatedly says "I don't know" to questions but appears alert. She can write coherent responses. She has hypertension and quit drinking alcohol 5 days ago.
What is the MOST likely diagnosis? A. Alcohol withdrawal delirium B. Broca aphasia C. Wernicke encephalopathy D. Hepatic encephalopathy
Answer: B 6
Explanation: Broca aphasia presents with impaired expression of spoken language while comprehension and writing may be relatively preserved 6. This case demonstrates that stroke can present with isolated language deficit that may be misinterpreted as confusion 6. MRI brain should be obtained urgently to identify infarction in the Broca area (left frontal lobe) 6.
Case 12
A 53-year-old man with hypertension presents with progressive speech difficulties over 6 months. Examination reveals dysarthria, hypophonia, imprecise articulation, and short rushes of speech with palilalia. MRI shows diffuse white matter lesions.
What is the MOST likely underlying pathology? A. Multiple sclerosis B. Small vessel ischemic disease C. Primary progressive aphasia D. Amyotrophic lateral sclerosis
Answer: B 7
Explanation: Subcortical white matter lesions secondary to small vessel disease in patients with vascular risk factors commonly cause dysarthria, dysphonia, and subcortical dysphasia 7. The combination of speech disturbances with white matter lesions and lacunar infarcts on MRI in a hypertensive patient is characteristic of vascular cognitive impairment 7. This differs from cortical aphasias which result from cortical lesions 8, 7.
Case 13
A 42-year-old man presents with strictly unilateral left periorbital headache with severe lacrimation. The pain radiates from occiput to frontal region and lasts 45 minutes. He has had 3 similar episodes this week. Yesterday he had a near-syncope episode.
What is the MOST important next step? A. Start high-flow oxygen and sumatriptan B. Obtain MRI brain without contrast urgently C. Prescribe NSAIDs and follow up in 1 week D. Start verapamil prophylaxis
Answer: B 4
Explanation: While the headache characteristics suggest cluster headache (strictly unilateral, periorbital, with lacrimation) 4, the syncope/near-syncope episodes are atypical for primary headache disorders and mandate urgent neuroimaging 4. The American College of Radiology advises that syncope with headache requires MRI brain to evaluate for spontaneous intracranial hypotension, posterior circulation pathology, or structural lesions 4. Syncope should not be dismissed as vasovagal without excluding structural causes 4.
Case 14
A 67-year-old woman presents with transient episodes of right arm weakness lasting 5-10 minutes, occurring 4 times over the past 2 days. Carotid duplex shows 85% left internal carotid artery stenosis.
What is the MOST appropriate management? A. Aspirin and outpatient neurology follow-up in 2 weeks B. Urgent carotid endarterectomy within 2 weeks C. Start clopidogrel and schedule elective CEA in 3 months D. CT angiography and observation
Answer: B 1
Explanation: Patients with high-grade (70-99%) symptomatic carotid stenosis causing TIAs have a very high risk of stroke 1. The American Heart Association recommends urgent revascularization (carotid endarterectomy or stenting) within 2 weeks of symptom onset for symptomatic high-grade stenosis 1. Dual antiplatelet therapy should be initiated immediately while awaiting surgery 1.
Case 15
A 59-year-old man presents with acute confusion and aphasia. He has no focal motor deficits. EEG shows slow background activity. MRI brain shows bilateral cortical T2 hyperintensities with diffusion restriction involving the insula and cingulate gyrus.
What additional test is MOST likely to establish the diagnosis? A. Lumbar puncture with CSF analysis B. Repeat MRI in 48 hours C. Carotid duplex ultrasound D. Electroencephalography with video monitoring
Answer: A 9
Explanation: Acute encephalopathy with aphasia and bilateral cortical T2 hyperintensities with diffusion restriction involving specific regions (insula, cingulate) suggests autoimmune encephalitis, Creutzfeldt-Jakob disease, or other inflammatory/infectious etiologies 9. CSF analysis is critical for identifying inflammatory markers, infectious agents, or specific antibodies 9. The bilateral symmetric involvement and specific anatomic distribution narrow the differential significantly 9.
Case 16
A 35-year-old woman presents with 6 months of progressive gait ataxia. She has a family history of similar symptoms in her father and brother. Examination reveals dysmetria, intention tremor, and absent ankle reflexes.
What is the MOST likely diagnosis? A. Multiple sclerosis B. Friedreich ataxia C. Cerebellar tumor D. Spinocerebellar ataxia
Answer: B 1
Explanation: Friedreich ataxia is a genetic inherited syndrome characterized by progressive ataxia with onset typically before age 25, though adult-onset forms exist 1. The combination of cerebellar signs (ataxia, dysmetria, intention tremor) with areflexia suggests both cerebellar and peripheral nerve involvement, which is characteristic of Friedreich ataxia 1. Family history of similar symptoms supports an inherited disorder 1.
Case 17
A 48-year-old man with no past medical history presents with sudden onset of severe occipital headache, vomiting, and inability to walk. Examination reveals truncal ataxia and horizontal nystagmus. CT head shows no hemorrhage.
What is the MOST appropriate next step? A. Discharge with antiemetics B. MRI brain without contrast C. Lumbar puncture D. Observation for 24 hours
Answer: B 1
Explanation: Acute cerebellitis presents with truncal ataxia, dysmetria, and headache 1. In severe cases, there may be altered consciousness, increased intracranial pressure, hydrocephalus, and herniation 1. MRI brain is essential to evaluate for cerebellar edema, mass effect, and hydrocephalus 1. CT has poor sensitivity for posterior fossa pathology 3.
Case 18
A 71-year-old man presents with 1 year of progressive hearing loss and gait ataxia. MRI brain shows hemosiderin deposition on the surface of the brainstem and cerebellum.
What is the MOST likely diagnosis? A. Acoustic neuroma B. Superficial siderosis C. Multiple sclerosis D. Normal pressure hydrocephalus
Answer: B 1
Explanation: Superficial siderosis presents with slowly progressive ataxia and hearing loss due to recurrent, often silent, subarachnoid hemorrhage that results in hemosiderin deposition on the sub-pial layers of the brain and spinal cord 1. MRI findings of hemosiderin deposition (T2* hypointensity) on the surface of the brainstem and cerebellum are pathognomonic 1.
Case 19
A 25-year-old woman presents with acute onset of ataxia, areflexia, and diplopia following a recent upper respiratory infection. CSF shows albuminocytologic dissociation.
What is the MOST likely diagnosis? A. Multiple sclerosis B. Guillain-Barré syndrome C. Miller Fisher syndrome D. Acute disseminated encephalomyelitis
Answer: C 1
Explanation: Miller Fisher syndrome is a variant of Guillain-Barré syndrome characterized by the triad of ataxia, areflexia, and ophthalmoplegia 1. It typically follows an infection and is associated with anti-GQ1b antibodies 1. The CSF finding of elevated protein with normal cell count (albuminocytologic dissociation) supports the diagnosis 1.
Case 20
A 44-year-old woman with Fabry disease presents with sudden onset of right-sided weakness and aphasia. She is 34 years old. What is her risk of having a stroke?
What percentage of Fabry patients experience at least one stroke? A. 5% B. 12% C. 24% D. 40%
Answer: C 1
Explanation: In a cohort of 33 Fabry patients, 24% suffered at least one stroke at first occurrence mean age of 29 years 1. CNS symptoms occur earlier in males (age 34) than in females (age 40) 1. The burden of CNS complications increases with age, and all patients older than 54 years had cerebrovascular involvement in one study 1.
Case 21
A 52-year-old man with Fabry disease complains of constant burning pain in his feet and hands. He also reports episodes of severe sharp pain lasting several days.
What is the MOST appropriate initial treatment? A. Opioid analgesics B. Carbamazepine or gabapentin C. NSAIDs D. Tricyclic antidepressants alone
Answer: B 1
Explanation: Episodic acroparesthesias in Fabry disease relate to small-fiber involvement and can manifest as constant burning pain and episodic severe neuropathic pain crises 1. Phenytoin, carbamazepine, oxcarbazepine, gabapentin, and/or topiramate are used for treatment of painful crises and acroparesthesias 1. Patients should also avoid factors that precipitate pain, limit exposure to extreme temperatures, and maintain hydration 1.
Case 22
A 38-year-old man with known Fabry disease presents with TIA. What prophylactic medication should be started?
What is the MOST appropriate prophylactic therapy? A. Warfarin B. Aspirin C. No prophylaxis needed D. Heparin
Answer: B 1
Explanation: Aspirin and other platelet-inhibiting agents (such as clopidogrel and ticlopidine) are recommended as prophylaxis to minimize the risk of stroke in Fabry disease 1. Clopidogrel should be used if aspirin is not tolerated, and both drugs may be indicated in patients who have had a thrombotic stroke or TIA 1. Proper hydration and avoidance of hypotension and hypertension are important for maintaining adequate cerebral perfusion 1.
Case 23
A 65-year-old woman presents with sudden onset of left-sided weakness. CT head shows a right frontal hemorrhage. She is on warfarin for atrial fibrillation with INR of 3.2.
What is the MOST appropriate immediate management? A. Continue warfarin and observe B. Reverse anticoagulation with vitamin K only C. Reverse anticoagulation with PCC or FFP and vitamin K D. Stop warfarin and repeat CT in 6 hours
Answer: C 1
Explanation: Intracranial hemorrhage in the setting of anticoagulation requires immediate reversal 1. Prothrombin complex concentrate (PCC) or fresh frozen plasma (FFP) should be administered along with vitamin K for rapid reversal of warfarin 1. Vitamin K alone takes hours to days to work and is insufficient for acute management 1.
Case 24
A 70-year-old man undergoes transcatheter aortic valve implantation (TAVI). Post-procedure MRI shows multiple small areas of diffusion restriction without corresponding neurological deficits.
What term describes these findings? A. Overt stroke B. Subclinical or covert brain injury C. Transient ischemic attack D. Normal post-procedure findings
Answer: B 1
Explanation: Procedure-related acute brain injury can remain clinically asymptomatic, termed subclinical or covert ABI 1. This comprises brain lesions on neuroimaging that are not accompanied by congruent signs of focal neurological dysfunction 1. These lesions are common after invasive cardiovascular procedures like TAVI 1.
Case 25
A 45-year-old woman presents with functional dysphonia. During laryngoscopy, the therapist observes sudden relaxation of tightly constricted false vocal folds, revealing normal true vocal fold function.
What does this finding demonstrate? A. Structural vocal fold paralysis B. Laryngeal dystonia C. Potential for normal function in functional disorder D. Need for surgical intervention
Answer: C 1
Explanation: In functional communication disorders, it is possible to see sudden relaxation of tightly constricted false vocal folds that was inhibiting the function of the true vocal folds, thus revealing the potential for normal function 1. This demonstrates that the "machinery is still present and whole" but has a functional problem rather than structural damage 1.
Case 26
A 58-year-old recently retired man presents with sudden onset of moderate-to-severe stuttering with whole word and initial phoneme repetition. When asked to tap his fingers sequentially while speaking, his stuttering dramatically improves.
What does this response indicate? A. Structural brain lesion B. Psychogenic stuttering C. Functional stuttering responsive to distraction D. Parkinson disease
Answer: C 1
Explanation: The dramatic reduction in stuttering moments from 25 to 2 per minute when using finger-tapping demonstrates the effect that distraction has and the ability to easily produce smooth, stutter-free speech 1. This is characteristic of functional stuttering, where symptoms are caused by abnormal brain functioning rather than structural damage 1.
Case 27
A 32-year-old woman diagnosed with functional voice disorder asks what is wrong with her. How should you explain the diagnosis?
What is the MOST appropriate explanation? A. "It's all in your head" B. "You have a software problem, not a hardware problem" C. "There is structural damage to your vocal cords" D. "This is a psychiatric condition"
Answer: B 1
Explanation: When explaining functional disorders, it is important to explain the diagnosis in terms of what it is rather than what it is not 1. Appropriate explanations include "a software problem, not a hardware problem" or "the symptoms are caused by abnormal brain functioning rather than structural damage or disease" 1. It is critical to take the problem seriously and state "these symptoms are real and not 'in your head'" 1.
Case 28
A 28-year-old woman with functional dysphonia is being considered for speech therapy. She does not believe the diagnosis and thinks she has vocal cord paralysis despite normal laryngoscopy.
What factor suggests POOR prognosis for therapy? A. Young age B. Female gender C. Lack of understanding and agreement with diagnosis D. Presence of anxiety
Answer: C 1
Explanation: Factors important for engagement with treatment include a reasonable degree of understanding and agreement with the diagnosis, and motivation and agreement to treatment 1. Circumstances suggesting guarded or poor prognosis include lack of acceptance of the diagnosis, severe psychiatric comorbidity, and unresolved litigation related to symptoms 1.
Case 29
A 55-year-old man presents with vertigo and ataxia. CT head is normal. He is told to return if symptoms worsen. Three days later he returns with worsening ataxia and new dysarthria.
What was the ERROR in initial management? A. Should have obtained MRI initially B. Should have admitted for observation C. Should have started vestibular suppressants D. CT was sufficient
Explanation: CT brain has only 20-40% sensitivity for detecting posterior circulation pathology 3. MRI brain is essential for evaluating cerebellar and brainstem pathology in patients with ataxia 1, 3. A normal CT does not exclude serious neurological causes, particularly posterior fossa lesions 3. The American College of Radiology recommends MRI as the preferred imaging modality for ataxia 1.
Case 30
A 40-year-old woman presents with episodic dizziness, headache, photophobia, and neck tension. Dix-Hallpike maneuver is negative. She has been taking meclizine without improvement.
What is the MOST likely diagnosis? A. Benign paroxysmal positional vertigo B. Vestibular migraine C. Meniere disease D. Vestibular neuritis
Answer: B 3
Explanation: Vestibular migraine is characterized by dizziness with headache, photophobia, phonophobia, and temple/neck tension 3. It requires migraine prophylaxis and lifestyle modifications, not vestibular suppressants 3. Negative Dix-Hallpike maneuver rules out BPPV 3. Lack of response to vestibular suppressants suggests either incorrect diagnosis or that the condition requires different treatment 3.
Case 31
A 62-year-old man with hypertension presents with sudden onset of dysarthria and dysphagia. Examination reveals right-sided facial numbness, right Horner syndrome, right-sided ataxia, and left-sided loss of pain and temperature sensation.
What is the MOST likely diagnosis? A. Right middle cerebral artery stroke B. Left medial medullary syndrome C. Right lateral medullary (Wallenberg) syndrome D. Basilar artery occlusion
Answer: C 1
Explanation: This classic presentation of lateral medullary syndrome includes ipsilateral facial numbness, Horner syndrome, and ataxia, with contralateral loss of pain and temperature sensation 1. Dysarthria and dysphagia result from involvement of cranial nerve nuclei in the medulla 1. This syndrome is typically caused by vertebral or posterior inferior cerebellar artery occlusion 1.
Case 32
A 75-year-old man presents with transient episodes of bilateral leg weakness and confusion. Carotid duplex shows 60% bilateral carotid stenosis.
Are these symptoms likely related to carotid stenosis? A. Yes, bilateral carotid stenosis causes these symptoms B. No, these are nonfocal symptoms with uncertain relationship to carotid disease C. Yes, this is typical for carotid disease D. No, but carotid endarterectomy is still indicated
Answer: B 1
Explanation: Nonfocal neurological events, including acute confusion, bilateral weakness, or paresthesias, have uncertain relationship to extracranial carotid disease 1. Most studies of TIA natural history have included patients with focal transient ischemic events 1. When symptoms are nonfocal, other etiologies such as cardiac arrhythmia, seizure, or metabolic disturbances should be considered 1.
Case 33
A 50-year-old woman presents with transient global amnesia lasting 4 hours. She has no other neurological symptoms. Carotid duplex shows 40% stenosis.
What is the relationship between transient global amnesia and carotid disease? A. Strong causal relationship B. Requires urgent carotid endarterectomy C. Pathophysiological mechanism not established D. Always indicates posterior circulation stroke
Answer: C 1
Explanation: The pathophysiological mechanism responsible for transient global amnesia has not been elucidated, and it is not clear whether this syndrome is related to extracranial carotid and vertebral artery disease at all 1. While patients with transient neurological attacks face increased risk of stroke compared to those without symptoms, the specific relationship of transient global amnesia to vascular disease remains unclear 1.
Case 34
A 68-year-old man with 90% left carotid stenosis presents with memory, speech, and hearing difficulty without focal motor deficits.
What is the MOST likely mechanism of these symptoms? A. Embolic stroke B. Hypoperfusion of dominant hemisphere C. Seizure activity D. Dementia unrelated to stenosis
Answer: B 1
Explanation: A small proportion of patients with critical (70% and usually 90%) carotid stenosis present with memory, speech, and hearing difficulty related to hypoperfusion of the dominant cerebral hemisphere 1. This represents a hemodynamic mechanism rather than embolic stroke 1. These symptoms may improve with revascularization 1.
Case 35
A 45-year-old man presents with brief, stereotyped, repetitive episodes of right arm jerking lasting 30 seconds, occurring multiple times per day. He has 70% left carotid stenosis.
What diagnostic test should be performed? A. Repeat carotid duplex B. Electroencephalography C. CT angiography D. Echocardiography
Answer: B 1
Explanation: Brief, stereotyped, repetitive symptoms suggestive of transient cerebral dysfunction raise the possibility of partial seizure, and electroencephalography may be useful in such cases 1. While carotid stenosis can cause TIAs, the stereotyped repetitive nature of these episodes is more suggestive of seizure activity 1.
Case 36
A 72-year-old man presents with right-sided weakness. Carotid duplex shows 75% left internal carotid stenosis. MRA shows 80% left M1 segment stenosis.
What is the significance of the intracranial stenosis? A. No significance, treat carotid stenosis only B. High-grade tandem lesion with implications for management C. Intracranial stenosis is not real, artifact on MRA D. Proceed with carotid endarterectomy without further workup
Answer: B 1
Explanation: Evaluation of the intracranial vasculature may be important in patients with extracranial carotid and vertebral artery disease to exclude high-grade tandem lesions that have implications for clinical management 1. Tandem lesions (both extracranial and intracranial stenosis) may require different treatment strategies and have different prognosis 1.
Case 37
A 58-year-old woman presents with right-sided weakness. Carotid imaging shows 65% left carotid stenosis. Echocardiography shows left atrial thrombus.
What is the MOST appropriate next step? A. Urgent carotid endarterectomy B. Anticoagulation for cardiac source C. Dual antiplatelet therapy D. Observation
Answer: B 1
Explanation: When extracranial or intracranial cerebrovascular disease is not severe enough to account for neurological symptoms of suspected ischemic origin, echocardiography should be performed to search for a source of cardiogenic embolism 1. In this case, the left atrial thrombus is a clear cardioembolic source that requires anticoagulation 1. The 65% carotid stenosis is moderate and not the primary cause of symptoms 1.
Case 38
A 35-year-old man presents after head trauma with GCS 14 (confused but following commands). CT head shows small frontal contusion. He is admitted for observation.
At what time point do MOST patients with traumatic brain injury deteriorate? A. Within 6 hours B. Within 24 hours C. Between days 2-7 D. After 1 week
Answer: B 1
Explanation: Of patients who deteriorated after mild traumatic brain injury, 57% did so within 24 hours, and 18% between days 2-7 1. This supports the practice of observation for at least 24 hours in patients with abnormal CT findings or GCS <15 1. Most deterioration occurs early, but delayed deterioration can occur 1.
Case 39
A 25-year-old man presents after assault with GCS 15 and normal neurological examination. CT head shows no acute findings. He is intoxicated with blood alcohol level of 250 mg/dL.
What is the MOST appropriate disposition? A. Discharge immediately B. Observe until sober, then discharge if examination remains normal C. Admit for 24 hours regardless D. Repeat CT in 6 hours
Answer: B 1
Explanation: While patients with GCS 15 and normal CT can generally be discharged safely 1, intoxication complicates neurological assessment 1. The patient should be observed until sober enough for reliable neurological examination 1. If examination remains normal when sober and CT is normal, discharge is appropriate with head injury precautions 1.
Case 40
A 50-year-old woman presents with sudden onset of severe headache and vomiting. CT head shows subarachnoid hemorrhage. She becomes drowsy with GCS 13.
What is the MOST appropriate classification of this event? A. Transient ischemic attack B. Ischemic stroke C. Intracranial hemorrhage D. Covert brain injury
Answer: C 1
Explanation: Intracranial hemorrhage is defined as any bleeding within the intracranial vault, including the brain parenchyma and surrounding meningeal spaces (epidural, subdural, or subarachnoid space) 1. Subarachnoid hemorrhage is a type of intracranial hemorrhage 1. The clinical deterioration with decreased GCS indicates significant hemorrhage requiring urgent neurosurgical evaluation 1.
Case 41
A 60-year-old man presents with 30 minutes of right arm weakness that completely resolved. MRI brain shows acute infarction in left corona radiata.
What is the MOST accurate diagnosis? A. Transient ischemic attack B. Ischemic stroke C. Resolved stroke D. Covert brain injury
Answer: B 1
Explanation: Infarction of the central nervous system is defined as brain, spinal cord, or retinal cell death attributable to ischemia, based on pathological, imaging, or other objective evidence of focal ischemic injury 1. Even though symptoms resolved, the presence of infarction on imaging defines this as stroke, not TIA 1. The modern tissue-based definition of stroke includes imaging evidence of infarction regardless of symptom duration 1.
Case 42
A 55-year-old man presents with 10 minutes of right arm weakness that resolved completely. MRI brain shows no acute infarction.
What is the MOST accurate diagnosis? A. Ischemic stroke B. Transient ischemic attack C. Normal variant D. Functional neurological disorder
Answer: B 1
Explanation: Transient ischemic attack is defined as a brief episode of neurological dysfunction resulting from focal brain, spinal cord, or retinal ischemia, not associated with permanent cerebral infarction 1. The absence of infarction on MRI distinguishes TIA from stroke 1. However, TIA still carries significant risk of subsequent stroke and requires urgent evaluation 1.
Case 43
A 70-year-old woman with atrial fibrillation presents with acute confusion and agitation. She has no focal neurological deficits. This developed over 6 hours.
What is the MOST likely diagnosis? A. Ischemic stroke B. Delirium C. Dementia D. Transient ischemic attack
Answer: B 1
Explanation: Delirium is a clinical state characterized by disturbance in attention and awareness with additional disturbance in cognition that develops over a short period (hours to a few days) and tends to fluctuate 1. The acute onset over hours and fluctuating course distinguish delirium from dementia 1. However, stroke can present with isolated confusion, so neuroimaging should be obtained 6, 9.
Case 44
A 75-year-old man with history of multiple strokes presents with progressive memory loss and functional decline over 2 years. He can no longer manage his medications or finances.
What is the MOST likely diagnosis? A. Delirium B. Dementia C. Depression D. Normal aging
Answer: B 1
Explanation: Dementia is a clinical syndrome characterized by progressive acquired global impairments of cognitive skills and ability to function independently 1. The progressive course over years with functional decline distinguishes dementia from delirium 1. Vascular dementia is common after multiple strokes 1.
Case 45
A 65-year-old man undergoes coronary angiography. Post-procedure, he has no neurological symptoms. MRI brain shows multiple small areas of diffusion restriction.
What is the clinical significance of these findings? A. No significance, normal post-procedure finding B. Requires immediate thrombolysis C. Subclinical brain injury with uncertain long-term implications D. Artifact, not real lesions
Answer: C 1
Explanation: Subclinical or covert brain injury comprises brain lesions on neuroimaging that are not accompanied by congruent signs of focal neurological dysfunction 1. These lesions are common after invasive cardiovascular procedures 1. The long-term clinical significance remains uncertain, but they may contribute to cognitive decline 1.
Case 46
A 45-year-old woman presents with progressive ataxia and hearing loss over 5 years. MRI shows hemosiderin deposition on the surface of the brainstem and cerebellum. No source of bleeding is identified.
What is the MOST appropriate next step? A. Observation only B. Spinal MRI to evaluate for spinal source of bleeding C. Lumbar puncture D. Cerebral angiography
Answer: B 1
Explanation: Superficial siderosis results from recurrent, often silent, subarachnoid hemorrhage 1. When no intracranial source is identified, spinal imaging should be performed to evaluate for spinal vascular malformations or other spinal sources of bleeding 1. Identifying and treating the source of bleeding may prevent progression 1.
Case 47
A 30-year-old woman presents with acute onset of ataxia, dysarthria, and headache. She is afebrile. MRI shows cerebellar edema with mass effect on the fourth ventricle.
What is the MOST important immediate concern? A. Infectious workup B. Risk of herniation and hydrocephalus C. Stroke workup D. Lumbar puncture
Answer: B 1
Explanation: Acute cerebellitis can cause cerebellar edema with mass effect, leading to increased intracranial pressure, hydrocephalus, and herniation 1. This is a neurosurgical emergency 1. Lumbar puncture is contraindicated in the presence of mass effect 1. Neurosurgical consultation should be obtained urgently 1.
Case 48
A 55-year-old man with chronic alcohol abuse presents with progressive ataxia over 6 months. MRI shows cerebellar atrophy.
What is the MOST likely cause? A. Cerebellar tumor B. Alcohol-related cerebellar degeneration C. Multiple sclerosis D. Spinocerebellar ataxia
Answer: B 1
Explanation: Ataxia may be seen with substance abuse, toxicity, or nutritional deficiencies, such as with chronic ethanol abuse 1. Cerebellar atrophy is a common finding in chronic alcoholics 1. Thiamine deficiency (Wernicke encephalopathy) should also be considered and treated 1.
Case 49
A 40-year-old woman with Fabry disease presents with episodic severe burning pain in her hands and feet triggered by exercise and heat exposure. She also reports decreased sweating.
What is the pathophysiology of these symptoms? A. Large fiber neuropathy B. Small fiber neuropathy and autonomic dysfunction C. Central pain syndrome D. Psychogenic pain
Answer: B 1
Explanation: The earliest symptoms of Fabry disease are episodic acroparesthesias related to small-fiber involvement in the peripheral nervous system 1. These manifest as constant burning pain and tingling, with episodic severe attacks 1. Autonomic dysfunction includes hypo- or anhidrosis, poor temperature and exercise tolerance 1. Pain may be triggered by physical activity, exercise, cold or heat exposure, fever, and stress 1.
Case 50
A 28-year-old man with Fabry disease is being evaluated before starting enzyme replacement therapy. What neurological assessments should be performed?
What is the MOST comprehensive neurological evaluation? A. Neurological examination only B. Brain MRI, pain assessment, and nerve fiber function testing C. CT head only D. EEG
Answer: B 1
Explanation: Comprehensive neurological evaluation before enzyme replacement therapy should include history of pain frequency and severity using tools like the Brief Pain Inventory, brain imaging by MRI with T1, T2, and FLAIR-weighted images, and test methods for monitoring nerve fiber dysfunction 1. MRA may be indicated to exclude cerebral vasculopathy 1. Laboratory evaluation of comorbid stroke risk factors should also be performed 1.