Differential Diagnosis for Vertigo Present Only in Supine Position

• Single most likely diagnosis
  • Benign Paroxysmal Positional Vertigo (BPPV): This condition is characterized by brief, intense episodes of vertigo triggered by specific head movements, including lying down (supine position). The symptoms typically last for seconds to minutes and can be diagnosed with the Dix-Hallpike maneuver. The fact that vertigo is present only in the supine position but not with right or left leaning suggests a possible involvement of the posterior semicircular canal, which is most commonly affected in BPPV.
• Other Likely diagnoses
  • Central Vertigo due to Chiari Malformation: Although less common, a Chiari malformation can cause vertigo that worsens or is triggered by certain positions, including lying down. This condition involves a structural defect in the cerebellum that can compress the brainstem and spinal cord, leading to various neurological symptoms.
  • Vestibular Migraine: While vestibular migraines can cause vertigo at any time, some patients may experience vertigo triggered by specific positions, including lying down. However, the presence of other migraine symptoms such as headache, photophobia, or phonophobia would support this diagnosis.
• Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
  • Posterior Inferior Cerebellar Artery (PICA) Stroke or Vertebrobasilar Insufficiency: Although rare, a stroke or transient ischemic attack in the posterior circulation can cause vertigo, among other symptoms. The vertigo can be position-dependent, and missing this diagnosis could have severe consequences.
  • Multiple Sclerosis (MS): MS can cause vertigo as part of its presentation, and while position-dependent vertigo is less common, it's crucial not to miss this diagnosis due to the implications for long-term management and treatment.
• Rare diagnoses
  • Perilymph Fistula: A rare condition where there is an abnormal connection (fistula) between the inner and middle ear, leading to vertigo that can be position-dependent. The symptoms can mimic those of BPPV but may also include hearing loss and tinnitus.
  • Superior Semicircular Canal Dehiscence (SSCD): This is a rare condition where there is an abnormal opening in the bone overlying the superior semicircular canal, leading to vertigo and hearing symptoms that can be triggered by sound or pressure changes, including those that occur with positional changes.