Differential Diagnosis for Patient with Uncontrolled CAD and Symptoms

The patient's symptoms of dizziness and vision changes when holding their head to the right and looking over their shoulder while driving suggest a condition that is exacerbated by specific head movements. Given the patient's history of uncontrolled coronary artery disease (CAD), the differential diagnosis should consider both cardiovascular and non-cardiovascular causes.

• Single Most Likely Diagnosis

  • Vertebrobasilar Insufficiency (VBI): This condition is characterized by transient symptoms due to decreased blood flow in the vertebrobasilar circulation, which can be precipitated by certain head movements. The patient's symptoms of dizziness and vision changes, especially when turning their head to the right, are consistent with VBI. The presence of uncontrolled CAD increases the risk of atherosclerotic disease, which can affect the vertebrobasilar arteries.

• Other Likely Diagnoses

  • Benign Paroxysmal Positional Vertigo (BPPV): Although BPPV typically presents with brief episodes of vertigo triggered by specific head movements, it could be considered, especially if the patient experiences vertigo without other neurological symptoms.
  • Cervicogenic Dizziness: This condition is related to neck movements and can cause dizziness, lightheadedness, and blurred vision. It might be considered if the patient's symptoms are primarily related to neck movements.

• Do Not Miss Diagnoses

  • Stroke or Transient Ischemic Attack (TIA): Although less likely given the specific trigger of head movement, it is crucial not to miss a stroke or TIA, as these conditions require immediate medical attention. The patient's history of uncontrolled CAD increases their risk.
  • Cardiac Arrhythmias: Certain arrhythmias, such as atrial fibrillation, can increase the risk of thromboembolic events, including stroke. Given the patient's CAD, an arrhythmia could potentially cause or contribute to their symptoms.
  • Subclavian Steal Syndrome: This rare condition involves reversal of blood flow in the vertebral artery due to significant stenosis or occlusion of the subclavian artery proximal to the origin of the vertebral artery. It could cause symptoms similar to VBI.

• Rare Diagnoses

  • Vascular Malformations or Aneurysms: Although rare, vascular malformations or aneurysms in the posterior circulation could potentially cause the patient's symptoms, especially if they are affected by head movements.
  • Chiari Malformation: This condition involves herniation of the cerebellar tonsils into the foramen magnum and can cause a variety of neurological symptoms, including those exacerbated by head movements. However, it is less likely to be directly related to CAD.