What is the initial test order for a patient presenting with dizziness?

Initial Diagnostic Testing for Dizziness

The initial diagnostic approach for a patient presenting with dizziness should focus on a structured clinical assessment including timing and triggers of symptoms, followed by targeted physical examination maneuvers such as the Dix-Hallpike test, orthostatic blood pressure measurement, and HINTS examination when indicated, rather than routine imaging or laboratory testing. 1

Diagnostic Algorithm

Step 1: Classify the Type of Dizziness

Based on the patient's description of symptoms, classify dizziness into one of four categories:

• Vertigo: Sensation of spinning or rotation
• Presyncope: Feeling of impending faintness
• Disequilibrium: Unsteadiness when walking
• Lightheadedness: Vague sensation of disconnection 2, 3

Step 2: Focused Physical Examination

Select appropriate examination components based on the dizziness classification:

1. For suspected vertigo:

   • Check for nystagmus (spontaneous or gaze-evoked)
   • Perform Dix-Hallpike maneuver to diagnose BPPV
   • Conduct HINTS examination (Head-Impulse, Nystagmus, Test of Skew) if acute vestibular syndrome is suspected 1, 3

2. For suspected presyncope:

   • Measure orthostatic blood pressure (drop of ≥20 mmHg systolic or ≥10 mmHg diastolic within 3 minutes of standing is diagnostic for orthostatic hypotension)
   • Perform cardiovascular examination including heart rate, rhythm, and carotid bruits 1

3. For disequilibrium:

   • Conduct neurological examination focusing on gait, coordination, and proprioception
   • Consider validated assessment tools such as the Timed Up & Go test 1

4. For lightheadedness:

   • Assess for hyperventilation, anxiety symptoms
   • Review medication list thoroughly 2

Step 3: Selective Testing Based on Clinical Findings

Imaging is NOT routinely indicated for isolated dizziness without concerning features. CT or MRI should only be ordered when specific indications are present:

• Acute vestibular syndrome with abnormal HINTS examination
• Presence of neurological deficits
• High vascular risk patients with acute vestibular syndrome
• Age >60 years with severe headache, vomiting, or focal neurological deficits 1

Laboratory testing has low diagnostic yield in unselected patients and should be ordered selectively based on clinical suspicion 4.

Key Diagnostic Tests by Suspected Etiology

• BPPV: Dix-Hallpike maneuver (diagnostic and can lead directly to treatment with Epley maneuver)
• Orthostatic hypotension: Orthostatic blood pressure measurement
• Vestibular neuritis/labyrinthitis: HINTS examination
• Stroke concern: HINTS examination (more sensitive than early MRI for posterior circulation stroke) 1, 3

Common Pitfalls to Avoid

• Focusing on the quality of dizziness rather than timing and triggers
• Failing to perform the Dix-Hallpike maneuver in patients with positional vertigo
• Ordering unnecessary imaging studies in patients with clear peripheral vertigo
• Missing central causes of vertigo by not performing the HINTS examination when indicated 1

Important Considerations

• The history and physical examination lead to a diagnosis in approximately 75% of patients 4
• Peripheral vestibulopathies account for 35-55% of dizziness cases, while serious central causes like cerebrovascular disease (5%) and brain tumors (<1%) are relatively uncommon 4
• At least 10% of patients may remain without a definitive diagnosis despite thorough evaluation 4

Remember that dizziness is usually a benign, self-limited complaint, but careful evaluation is necessary to identify the small percentage of patients with potentially serious underlying conditions 4.