How should I evaluate and manage a 20‑year‑old man presenting with one‑day dizziness, 2–3 episodes of vomiting, mild headache, and normal vital signs (SpO₂ 98 %, pulse 75 bpm, temperature 36.5 °C, blood pressure 130/80 mmHg)?

Approach to a 20-Year-Old Male with Dizziness, Vomiting, and Headache

Use the timing-and-triggers approach to classify this patient's presentation, perform targeted bedside examination including HINTS-Plus if indicated, and rule out dangerous central causes before attributing symptoms to benign peripheral vestibular disorders or viral illness 1, 2.

Initial Classification by Timing and Triggers

This patient presents with continuous symptoms lasting 1 day, which places him in the transient acute vestibular syndrome category (symptoms <24 hours) 1, 2. The key decision point is determining whether this represents:

• Peripheral vestibular disorder (vestibular neuritis, labyrinthitis)
• Central cause (posterior circulation stroke/TIA)
• Non-vestibular cause (viral gastroenteritis, metabolic disorder)

Critical Red Flags to Assess Immediately

Perform a focused neurologic examination looking specifically for 3, 4, 5:

• Focal neurologic deficits: dysarthria, dysphagia, dysmetria, sensory/motor loss, Horner's syndrome
• Gait instability: inability to walk independently suggests central pathology
• Severe headache: particularly if sudden-onset or "worst headache of life"
• Hearing loss: assess bilaterally (unilateral suggests labyrinthitis or stroke)

Bedside Examination Protocol

If Patient Has Ongoing Nystagmus or Vertigo:

Perform HINTS-Plus examination (validated for acute vestibular syndrome with persistent symptoms) 4, 5:

1. Head Impulse Test (HIT): Normal (corrective saccade absent) suggests central cause; abnormal (corrective saccade present) suggests peripheral
2. Nystagmus direction: Direction-changing nystagmus without head position change, downbeating nystagmus, or gaze-evoked nystagmus suggests central cause
3. Test of Skew: Vertical misalignment suggests central cause
4. Plus (hearing loss): New unilateral hearing loss increases stroke concern

CRITICAL CAVEAT: HINTS-Plus has NOT been validated in patients whose symptoms have already resolved or who present between episodes 1. Do not rely on it if the patient is currently asymptomatic.

Positional Testing:

Perform Dix-Hallpike maneuver bilaterally 3, 1:

• Positive with typical torsional upbeating nystagmus: BPPV (benign paroxysmal positional vertigo)
• Downbeating nystagmus without torsional component: suggests central pathology, not BPPV 3
• Immediate and sustained response to liberation maneuvers: strongly supports BPPV over other causes 1

Risk Stratification for Stroke

Even with normal vital signs and no focal deficits, stroke remains possible. In patients presenting with acute vestibular syndrome, 25% have posterior circulation infarct, and 75-80% of these may lack focal neurologic deficits 4. Consider:

• Age (20 years = lower vascular risk, but not zero)
• Vascular risk factors (smoking, family history, hypercoagulable states)
• Associated symptoms (severe headache, neck pain suggesting dissection)

Imaging Decisions

When to Image:

MRI with diffusion-weighted imaging (DWI) is preferred over CT for suspected central causes 4, 6:

• Any abnormal HINTS-Plus findings suggesting central pathology
• Focal neurologic deficits present
• High vascular risk factors
• Failure to improve or worsening symptoms
• Severe, persistent headache

CT has very low yield (<1% detection rate) in patients with normal neurologic examination and isolated dizziness 4.

When Imaging May NOT Be Needed:

• Classic BPPV with typical nystagmus on Dix-Hallpike and complete resolution with repositioning maneuvers 3, 4
• Clear viral prodrome with dehydration and orthostatic symptoms
• Young patient with no vascular risk factors, normal neurologic exam, and improving symptoms

IMPORTANT LIMITATION: Early MRI can be false-negative in 20-50% of small brainstem strokes within first 24-48 hours 1. If clinical suspicion remains high despite negative initial MRI, repeat imaging in 24-48 hours or admit for observation.

Differential Diagnosis for This Patient

Most Likely Given Age and Presentation:

1. Viral gastroenteritis with dehydration: vomiting predominates, mild dizziness from volume depletion
2. Vestibular neuritis: if true vertigo with nystagmus present
3. Vestibular migraine: if history of migraines, photophobia/phonophobia present

Must-Not-Miss Diagnoses:

1. Posterior circulation TIA/stroke: even at age 20 (consider dissection, hypercoagulable states)
2. Adrenal insufficiency: especially if weight loss, hyperpigmentation, or persistent orthostatic hypotension develops 7
3. Cardiac arrhythmia: check ECG if presyncope component 1

Immediate Management Steps

1. Check orthostatic vital signs: significant drop suggests volume depletion or autonomic dysfunction
2. Basic labs: electrolytes (hyponatremia can cause dizziness), glucose, CBC
3. ECG: if any presyncope or palpitations
4. Rehydration: IV fluids if unable to tolerate oral intake
5. Antiemetics: ondansetron or metoclopramide for symptomatic relief

Disposition Decision

Safe for Discharge If:

• Normal neurologic examination including gait
• No HINTS-Plus red flags (if testable)
• Tolerating oral fluids
• Improving symptoms
• Reliable follow-up available
• No high-risk features for stroke

Requires Admission or Prolonged Observation If:

• Any focal neurologic deficits
• Abnormal HINTS-Plus suggesting central cause
• Inability to ambulate safely
• Persistent vomiting with dehydration
• High suspicion for stroke despite negative initial imaging
• Deteriorating clinical status 7

Follow-Up

Instruct patient to return immediately if:

• New focal neurologic symptoms develop
• Severe worsening of headache
• Inability to walk
• New hearing loss or tinnitus
• Symptoms persist beyond 48-72 hours without improvement

Arrange outpatient follow-up within 24-48 hours if discharged, with neurology or ENT if vestibular disorder suspected.