Is double vision a potential sign of a stroke?

Double Vision as a Potential Sign of Stroke

Double vision (binocular diplopia) is a recognized potential sign of stroke and should prompt immediate medical evaluation, especially when occurring suddenly and accompanied by other neurological symptoms.

Recognition of Stroke Symptoms

Double vision is specifically identified in stroke guidelines as a concerning neurological symptom that may indicate posterior circulation stroke 1. While it may not be as widely recognized by the public as other stroke symptoms, it represents an important warning sign that healthcare providers should be aware of.

Common Stroke Symptoms

• Sudden unilateral weakness (face, arm, and/or leg) 1
• Sudden speech disturbance 1
• Sudden facial drooping 1
• Sudden visual disturbances, including:
  • Double vision (binocular diplopia) 1, 2
  • Monocular vision loss 1
  • Visual field defects 2
• Sudden severe headache 1
• Sudden dizziness, loss of balance or coordination 1

Risk Stratification for Double Vision

The Canadian Stroke Best Practice Recommendations provide specific guidance on risk stratification for patients presenting with symptoms like double vision:

1. Very High Risk (symptoms within 48 hours):

   • Patients with binocular diplopia within the last 48 hours should be immediately sent to an emergency department with advanced stroke care capabilities 1
   • Urgent brain and vascular imaging should be completed within 24 hours 1

2. Moderate Risk (symptoms between 48 hours and 2 weeks):

   • Patients with binocular diplopia occurring between 48 hours and 2 weeks should receive comprehensive clinical evaluation by a healthcare professional with stroke expertise within 2 weeks 1

3. Lower Risk (symptoms more than 2 weeks ago):

   • Evaluation by a neurologist or stroke specialist within 1 month 1

Neuroanatomical Basis

Double vision as a stroke symptom typically indicates involvement of the brainstem or cerebellum (posterior circulation) 2. It can result from:

• Damage to cranial nerve nuclei controlling eye movements
• Disruption of pathways coordinating eye movements
• Cerebellar involvement affecting eye movement coordination

Diagnostic Approach

When a patient presents with sudden double vision:

1. Immediate Assessment:

   • Evaluate for other accompanying neurological symptoms
   • Perform a focused neurological examination using standardized scales like NIHSS 3
   • Check vital signs including heart rate, blood pressure, temperature, and oxygen saturation 3

2. Urgent Imaging:

   • Brain imaging (CT or MRI) should be completed urgently to rule out hemorrhage 3
   • Vascular imaging (CTA or MRA from aortic arch to vertex) should be performed without delay 1, 3

3. Laboratory Tests:

   • ECG should be completed without delay 1
   • Basic blood work including electrolytes, glucose, CBC, and coagulation studies 3

Clinical Pearls and Pitfalls

• Diagnostic Accuracy: The presence of acute facial paresis, arm drift, or abnormal speech significantly increases the likelihood of stroke (LR = 5.5), but the absence of these classic signs does not rule out stroke, especially in posterior circulation events where double vision may be the predominant symptom 4

• Stroke Mimics: Not all cases of double vision are due to stroke. Consider other causes such as:

  • Myasthenia gravis
  • Cranial nerve palsies from other causes
  • Orbital disease
  • Migraine with aura

• Public Awareness Gap: Research shows that while 72.4% of people would call 9-1-1 for speech difficulties, only 33.3% would do so for trouble seeing or double vision 5. This highlights the need for better public education about less recognized stroke symptoms.

• Aneurysm Warning: In rare cases, double vision can be a warning sign of impending aneurysmal rupture, as documented in case reports where ischemic stroke symptoms preceded subarachnoid hemorrhage 6

Conclusion

Double vision is an important potential sign of stroke that warrants immediate medical attention, particularly when it occurs suddenly and is accompanied by other neurological symptoms. Healthcare providers should maintain a high index of suspicion for stroke when evaluating patients with acute onset of binocular diplopia.