1. Answer D. (From Merritt’s Neurology 14th edition, Chapter 3; MN-3) Progressive development of vertigo accompanied by double vision is concerning for an intracranial mass lesion. Localization depends on the nature of the extraocular defect and should raise concern for a focal brainstem lesion or compression on the pons or midbrain due to a mass or hydrocephalus. In patients presenting with the broad syndrome of “dizziness,” a key first step in determining localization and differential diagnosis is to attempt categorization into vertigo, imbalance, orthostasis, or dizziness not otherwise specified. Other common features to explore include age of onset, course of symptoms, precipitating factors, frequency and intensity of events, treatments and their responses, focal neurological features, and impact on daily activities. Concerning features accompanying dizziness may include headache, cranial neuralgia, focal neurological findings (other than diplopia), progressive pulsatile tinnitus or deafness, hoarseness or other speech changes, and catastrophic vertigo attacks leading to injury. Periods of vertigo that have occurred every few months over the past 5 years and episodes that resolve over the course of several days could suggest benign paroxysmal positional vertigo (BPPV). Such attacks are usually provoked by certain head movements such as arising from bed. Tinnitus commonly co-occurs with vertigo in Ménière disease. Headaches predictably accompanying vertigo for years may suggest migraine or related headache disorder.

(For further review in Merritt’s Neurology 14th edition, see Chapter 5: Dizziness, Vertigo, and Hearing Loss and Chapter 62: Ménière Syndrome, Benign Paroxysmal Positional Vertigo, and Vestibular Neuritis for more information on Vertigo.)

2. Answer A. (MN-3) Focal neurological deficits occurring in the context of headache are concerning for a mass lesion and should prompt urgent attention. All other answers are common features of migraine. Complicated migraine can present with focal neurological deficits including hemiplegia but should be a diagnosis of exclusion; focal deficits in complicated migraine should resolve within 24 hours of headache onset and may predictably recur with other attacks. In taking a headache history, common features to explore include headache quality (location, symptoms at onset, timing, and duration), frequency and intensity, severity, associated symptoms during the headache (visual, visceral, and cognitive), medication response, autonomic features, other precipitating factors (diet, sleep, stress, head position, and activities), and the functional impact of frequent headaches. Concerning features for headache include new-onset symptoms, worsening/new symptoms in patient with a preexistent headache syndrome, age of onset at 50 years or older, abrupt onset, positional features, constitutional symptoms to suggest systemic illness, focal neurologic features, and mental status changes.

(See Chapter 9: Headache and Facial Pain and Section VIII: Headache and Pain Syndromes for more information on headache.)

3. Answer C. (MN-3) Constitutional features including fever and weight loss are concerning for an underlying systemic illness such as undiagnosed infection or malignancy. Key features to explore with low back pain include onset and chronicity, risk factors for chronic trauma including occupational history, location of pain, the quality of the pain (exploring severity, intensity, duration, and associated features), radiation of pain, weakness, numbness, precipitating and alleviating factors, urination and sexual function, strength, balance, possible contributing factors including ongoing litigation or sources of potential secondary gain.

(See Chapter 8: Pain, Numbness, and Paresthesias and Section XVI: Spinal Cord Disorders for more information on back pain, underlying causes, and related anatomy.)

4. Answer A. (MN-3) A rapidly progressive neurological syndrome should be considered an emergency. Focal symptoms progressing to coma are concerning for acute disseminated encephalomyelitis (ADEM); the differential should also include infection and malignancy among other serious conditions. All other answers are common features of multiple sclerosis, including corticosteroid responsiveness and heat sensitivity (Uhthoff phenomenon). In persons being evaluated for demyelinating neurological conditions, key features to explore include age at onset of first relatable symptoms, tempo and duration of attacks, and progression between each event. A history of certain specific neurological syndromes can also be strongly suggestive of multiple sclerosis, including optic neuritis, internuclear ophthalmoplegia, hemiparesis, hemisensory syndrome, mobility and gait disturbance, incontinence, and cognitive impairment. Concerning features for demyelinating disease and its differential include poor response to therapy, severe burden of illness at onset, and systemic features or other organ involvement.

(See Section XI: Demyelinating and Inflammatory Diseases for more information on multiple sclerosis, ADEM, and related conditions.)

5. Answer A. (MN-3) The question should prompt a primary consideration of dementia. An acute change in cognition, particularly if there is restriction of attention or depressed level of alertness, should warrant prompt assessment for possible delirium. Timely diagnosis of delirium is critical given high morbidity and mortality associated with delirium and potential for an underlying treatable cause. All other answers are common features of Alzheimer disease (memory loss and logopenia) or Lewy body diseases (REM-sleep behavior problems). Incontinence is nonspecific and can be a feature of late-stage dementia of any kind or an early feature of normal pressure hydrocephalus. In persons being evaluated for dementia, key features to explore include assessment of which cognitive domains are affected, duration and pace of changes, concomitant psychiatric features, and parkinsonian features. Features that may suggest a structural cause include focal neurologic features, such as new weakness or incontinence. Seizures may also suggest a focal structural problem but are also common in degenerative causes of dementia. Rapid onset or progression may suggest an atypical cause of dementia such as an autoimmune encephalitis or prion disease. Understanding the social support system available to a person with dementia is critical to anticipating and addressing potential barriers to care.

6. Answer E. (MN-3) Dysphagia and choking pose a risk for aspiration, which, if unrecognized, can cause effects including pneumonia and respiratory failure. The case presented should otherwise prompt a consideration for Parkinson disease of which all other answers are common but not life threatening. In persons being evaluated for movement disorders, key features to explore include gait changes including a history of tripping or falling, fidgeting (chorea) and jerking (myoclonus) among other observable movements, voice changes including hypophonia and dysphonia, medication history and responses, review of medical history for systemic illness that may present with movement disorders (hepatic and renal disease, parathyroid disorders, diabetes, HIV, cardiac disease, and syncope), toxic exposures, and a detailed family history. Concerning features for an atypical presentation of a movement disorder include young onset, recent febrile illness, constitutional symptoms, rapid progression, poor medication responsiveness, and early cognitive impairment or behavioral changes.

7. Answer C. (MN-3) The presented case is most suggestive of diabetic polyneuropathy. The development of dysphagia or dysarthria is not typically part of this condition and should prompt consideration of an unrelated cause of bulbar weakness such as stroke or rapidly progressive neuromuscular disorder, among other causes. All other answers are common in diabetic neuropathy including autonomic involvement (constipation) and a history of mononeuropathy (Bell palsy). In persons being evaluated for peripheral neuropathy and neuromuscular disorders, key features to explore include localization and pattern of primary features (laterality, proximal vs distal, diffuse vs focal/segmental), age and pattern at onset, progression and course, a pattern of recovery versus cumulative burden, review of spontaneous sensory symptoms (paresthesias, allodynia, dysesthesia, hyperalgesia, hyperpathia, and spontaneous pain), review of motor symptoms (weakness, speech, swallowing, diplopia, diurnal variability, influence of activity, fasciculations, cramps/pain, and balance), review of medical history for systemic disease, recent infections, and a recent history of vaccinations, rash, or travel. Concerning features include constitutional symptoms or rapid progression.

8. Answer D. (MN-3) The case presentation strongly suggests an acute spinal cord injury in the lower thoracic cord. Trauma in motor vehicle accidents are often multifocal and may involve other fractures including an arm or leg (suggested by choice E), which should also be appropriately addressed. Prior occupational and medical histories are important to collect but may not ultimately impact decision making about localization or etiology in cases like this one. Intact sensation to the legs and perineal area would be encouraging features. In persons being evaluated for diseases of the spinal cord, key features to explore include onset and course, precipitating factors, aggravating or positions leading to symptoms, location and quality of pain, autonomic function (bowel, bladder, and sexual functions), and other medical history (including malignancy, history of infection or immunosuppression, or recent spinal instrumentation). Concerning features include acute presentation for any disorder, any presentation suggesting spinal cord localization, urinary retention or loss of bowel/bladder function, a pattern of pain suggesting localization involving the spinal cord or canal (including central spinal, cauda equina, or conus medullaris localization), and respiratory compromise suggesting diaphragmatic weakness.

9. Answer D. (MN-3) Seizures in a patient with known metastatic cancer should prompt concern for brain metastasis. All other features are nonspecific but common in persons with systemic malignancy. In persons being evaluated for possible brain tumor, key features of the history to explore include new-onset headache, seizures, cognitive decline, seizures, and focal or multifocal neurologic symptoms. Concerning features include new headache or unusual headaches relative to preexisting headache history (eg, longstanding migraine) and aggravation of symptoms with Valsalva or position to suggest increased intracranial pressure.

10. Answer B. (MN-3) Decreased level of alertness may be concerning for delirium due to systemic infection, but it may also suggest meningitis or an intracranial mass lesion. All other answers are nonspecific but common in persons with a systemic infection or poorly controlled HIV. A rash may indicate an opportunistic infection. In persons being evaluated for possible infection of the nervous system, key features to explore include establishing onset and progression, headache, neck pain or other signs of meningismus, head trauma or recent neurosurgical instrumentation, sick contacts or travel to endemic areas of suspected infection, IV drug abuse, and ongoing systemic infection. Concerning features include rapid onset of symptoms, declining level of alertness, possible or obvious seizures, and hypotension.

11. Answer D. (MN-3) Development of new interictal features after decades of well-controlled epilepsy should raise concern for a new neurological problem. The case presented suggests an intracranial mass lesion, presumably coincidental with epilepsy. Aside from focal symptoms and headaches, other interictal features that may suggest structural brain disease include sensory changes, imbalance, and cognitive or personality changes. Epilepsy is somewhat common, affecting 1% to 2% of the population, and with increasing age other unrelated neurological problems become concerning. All other answers are nonspecific but may be seen in persons with epilepsy. In persons being evaluated for seizures, key features to explore include age at onset, seizure semiology (localization/onset including “aura,” progression of observable features, subtle features), timing and frequency of seizures, duration of seizure and its recovery period, symptoms known to be associated with various epilepsy syndromes, associated cognitive and other neurologic disorders, seizure mimics (headache, stroke, syncope), anticonvulsant medication history including responses (control, side effects, and compliance), precipitating factors (fever, medication, sleep deprivation, photic stimulation), risk factors for epilepsy including focal or diffuse brain injury across a lifespan, developmental milestones if known, chronic medical problems (metabolic, psychiatric, malignant, infections), and the psychosocial impact of recurrent seizures. Concerning features include new onset of seizures, worsening seizure control with established epilepsy, and constitutional symptoms.

12. Answer B. (MN-3) Depressed level of alertness during hospitalization for acute ischemic stroke could suggest evolving brain edema, hemorrhagic transformation of the initial stroke, recurrent stroke, or a complication such as infection causing delirium. MCA territory strokes may also have features of numbness. A workup for etiology of stroke may reveal cardioembolic sources including atrial fibrillation or carotid stenosis. A history of amaurosis fugax in the same carotid territory as the current presentation reinforces the importance of addressing it to prevent future ischemic events. In persons being evaluated for stroke, key features to explore include timing and duration including last observed normal point in time, contraindications to acute thrombolytic care and/or thrombectomy, etiology and risk factors for stroke, localization based on syndromes with known vascular territory, and stroke mimics or other neurologic features (headache, stroke, seizures, known recent history of severe hypoglycemia). Concerning features include large territory infarct or posterior fossa localization (high risk of herniation, especially if in a younger person), rapid clinical worsening, and hemodynamic instability.

13. Answer A. (MN-3) The history suggests a sudden catastrophic neurological event. A strong family history for aneurysms or polycystic kidney disease would raise the possibility of a ruptured intracranial aneurysm. The time when they were last known normal is helpful should an ischemic brainstem stroke instead be identified. Recent travel history is unlikely to be helpful in this case given the patient was just seen going about their normal morning routine. Depression is a common condition, and there is not a clear indication in the history of substance abuse (gainfully employed, preparing for work, no response to naloxone). Fever is nonspecific but could be an important factor. Other factors to explore in someone in coma include potential precipitating factors or any known subtle recent symptoms, constitutional symptoms, and a history of alcohol abuse, among other factors. Other concerning features may include recurrent seizures or status epilepticus, suggestion of herniation syndrome or other indicators of critical intracranial pressure, and apnea.