Alternating Horner's syndrome: is it or isn't it?

Area of Science:

• Neurology
• Ophthalmology

Background:

• Horner's syndrome is a condition characterized by a classic triad of symptoms affecting the eye and surrounding facial structures.
• Alternating Horner's syndrome presents with symptoms that appear on different sides of the face at different times, posing diagnostic challenges.

Observation:

• Two patients with apparent alternating Horner's syndrome were evaluated.
• Standard pharmacologic pupillary testing using cocaine and hydroxyamphetamine did not definitively differentiate between a shifting lesion and a fluctuating unilateral lesion.

Findings:

• The diagnostic utility of cocaine and hydroxyamphetamine in resolving the etiology of alternating Horner's syndrome was limited in these cases.
• The observed presentation suggested either a mobile lesion causing a truly alternating effect or a unilateral lesion with intermittent hypoactivity and irritative phases.

Implications:

• Further investigation and potentially novel diagnostic approaches are needed to accurately diagnose alternating Horner's syndrome.
• Understanding the pathophysiology of this condition is crucial for appropriate patient management and treatment strategies.