Differential Diagnosis for 78 YOM with Lightheadedness and Brain Fog

Single Most Likely Diagnosis

• Benign Paroxysmal Positional Vertigo (BPPV) or Orthostatic Hypotension: Although the patient denies vertigo, BPPV can sometimes present with non-specific symptoms like lightheadedness and imbalance, especially in the elderly. Orthostatic hypotension is also common in this age group and can cause similar symptoms due to decreased blood flow to the brain upon standing.

Other Likely Diagnoses

• Viral or Post-Viral Syndrome: A recent viral infection could lead to symptoms of lightheadedness and brain fog without other systemic symptoms like fever.
• Medication Side Effects: Many medications, especially antihypertensives, sedatives, and antidepressants, can cause lightheadedness and cognitive impairment as side effects.
• Anemia or Electrolyte Imbalance: Conditions like anemia or electrolyte disturbances (e.g., hyponatremia, hypokalemia) can lead to symptoms of lightheadedness and brain fog.
• Sleep Disorders: Sleep apnea, insomnia, or other sleep disorders can cause daytime symptoms of brain fog and lightheadedness.

Do Not Miss Diagnoses

• Transient Ischemic Attack (TIA) or Stroke: Although the neuro exam is normal, TIAs can have transient symptoms, and some strokes (especially those involving the brainstem or cerebellum) might not have obvious focal neurologic deficits initially.
• Cardiac Arrhythmias: Conditions like atrial fibrillation can cause intermittent lightheadedness due to irregular heart rhythms, even if the heart rhythm is regular at the time of examination.
• Hypoglycemia: Low blood sugar can cause lightheadedness, confusion, and imbalance, and it's crucial to consider this, especially if the patient has diabetes or is on medications that can lower blood sugar.
• Carbon Monoxide Poisoning: This can cause non-specific symptoms like headache, dizziness, and confusion, although it's less likely without a clear exposure history.

Rare Diagnoses

• Multiple System Atrophy (MSA): A rare neurodegenerative disorder that can present with orthostatic hypotension, balance problems, and cognitive impairment.
• Vestibular Migraine: Although the patient denies headaches, some forms of migraines can present with vestibular symptoms like imbalance and lightheadedness without headache.
• Chronic Subdural Hematoma: More common in the elderly, especially after minor trauma, and can present with non-specific symptoms like lightheadedness and confusion.