Differential Diagnosis for Horizontal Nystagmus with Smooth Pursuits

• Single Most Likely Diagnosis
  • Benign paroxysmal positional vertigo (BPPV): This condition is characterized by brief, episodic vertigo triggered by head movements, and it can present with horizontal nystagmus. The presence of smooth pursuits suggests that the vestibular-ocular reflex is intact, which is consistent with BPPV.
• Other Likely Diagnoses
  • Vestibular migraine: This condition can cause episodic vertigo, nystagmus, and smooth pursuits. It is often accompanied by headache, sensitivity to light and sound, and other migraine symptoms.
  • Labyrinthitis: Inflammation of the inner ear can cause vertigo, nystagmus, and smooth pursuits. It may be accompanied by hearing loss and tinnitus.
  • Medically treated vestibular disorder: Certain conditions, such as vestibular neuritis, can cause nystagmus and smooth pursuits. These conditions may be treated with medication or vestibular rehabilitation.
• Do Not Miss Diagnoses
  • Stroke or cerebellar infarction: Although less likely, a stroke or cerebellar infarction can cause sudden onset of vertigo, nystagmus, and smooth pursuits. It is essential to rule out this life-threatening condition with immediate imaging and evaluation.
  • Multiple sclerosis: This demyelinating disease can cause a wide range of neurological symptoms, including vertigo, nystagmus, and smooth pursuits. A thorough neurological examination and imaging studies are necessary to diagnose multiple sclerosis.
• Rare Diagnoses
  • Congenital nystagmus: This is a rare condition characterized by involuntary eye movements present at birth. It can cause horizontal nystagmus and smooth pursuits.
  • Acquired pendular nystagmus: This is a rare condition characterized by involuntary eye movements that can cause horizontal nystagmus and smooth pursuits. It is often associated with multiple sclerosis or other neurological conditions.