Differential Diagnosis for Dizziness
The differential diagnosis for dizziness is broad and can be categorized based on the likelihood and potential impact of missing a diagnosis. Here's a structured approach:
- Single Most Likely Diagnosis
- Benign Paroxysmal Positional Vertigo (BPPV): This condition is characterized by brief, episodic vertigo triggered by specific head movements. It's a common cause of dizziness and can be diagnosed with a thorough history and physical examination, including the Dix-Hallpike maneuver.
- Other Likely Diagnoses
- Vestibular Migraine: A condition that presents with vertigo, often accompanied by headache, sensitivity to light and sound, and sometimes visual auras. Diagnosis is clinical, based on history and exclusion of other causes.
- Labyrinthitis: An inner ear disorder characterized by inflammation of the labyrinth, leading to vertigo, hearing loss, and tinnitus. It can be diagnosed with audiometry and imaging studies if necessary.
- Medication-induced Dizziness: Various medications can cause dizziness as a side effect, including antihypertensives, sedatives, and antidepressants. The diagnosis is based on the temporal relationship between medication use and the onset of symptoms.
- Do Not Miss Diagnoses
- Stroke or Transient Ischemic Attack (TIA): Although less common, vertigo can be a presenting symptom of a stroke or TIA, especially if accompanied by other neurological deficits. Immediate imaging (CT or MRI) is crucial for diagnosis.
- Meniere's Disease: A disorder of the inner ear that affects balance and hearing, leading to episodes of vertigo, tinnitus, hearing loss, and ear fullness. Diagnosis is clinical, supported by audiometry and sometimes imaging.
- Cardiac Causes (e.g., Arrhythmias, Cardiac Valve Problems): Dizziness can be a symptom of cardiac issues, particularly if there's a significant drop in cardiac output. Diagnosis involves cardiac monitoring, echocardiography, and other cardiac tests as indicated.
- Rare Diagnoses
- Multiple Sclerosis: Although rare, multiple sclerosis can present with vertigo among other neurological symptoms. Diagnosis involves MRI of the brain and spinal cord, along with clinical evaluation.
- Acoustic Neuroma: A benign tumor on the nerve connecting the inner ear to the brain, which can cause vertigo, hearing loss, and tinnitus. Diagnosis is made with MRI of the brain.
- Autoimmune Inner Ear Disease: A rare condition where the immune system attacks the inner ear, leading to vertigo, hearing loss, and sometimes tinnitus. Diagnosis involves clinical evaluation, audiometry, and sometimes blood tests for autoimmune markers.
Tests and Labs
- Complete Blood Count (CBC): To rule out anemia or infection.
- Electrolyte Panel: To check for electrolyte imbalances.
- Blood Glucose: To rule out hypoglycemia.
- ECG: To evaluate for cardiac arrhythmias.
- Imaging Studies (CT or MRI): Especially if a central cause of vertigo is suspected, such as stroke or multiple sclerosis.
- Audiometry and Electronystagmography: For evaluating hearing and balance function.
- Dix-Hallpike Maneuver and Roll Test: For diagnosing BPPV.
- Cardiac Monitoring: If a cardiac cause is suspected.
Each diagnosis should be considered based on the patient's history, physical examination, and the results of diagnostic tests. The approach to dizziness requires a systematic evaluation to identify the underlying cause and initiate appropriate treatment.