Apraxia of lid opening

Area of Science:

• Ophthalmology
• Neurology
• Movement Disorders

Background:

• Apraxia of lid opening (ALO) is a rare condition characterized by the inability to voluntarily open the eyelids after closure.
• It is often associated with involuntary levator palpebrae inhibition (ILPI) and orbicularis oculi (OO) muscle contraction.

Observation:

• The case describes an 80-year-old man with ALO, presenting with difficulty initiating lid elevation after voluntary closure.
• Symptoms included forceful frontalis muscle contraction, head thrusting, and prolonged lid closure, but preserved spontaneous blinking and ability to maintain manually opened lids.
• Normal pursuit eye movements, vestibulo-ocular reflex, and saccades were noted, ruling out broader oculomotor deficits.

Findings:

• Botulinum toxin injections into the orbicularis oculi muscle did not alleviate the primary difficulty in lid opening.
• The patient experienced some benefit from using lid crutches to assist in maintaining eyelid elevation.
• ALO is hypothesized to stem from abnormal supranuclear control of eyelid movement, potentially involving a disruption in the balance between levator palpebrae excitation and orbicularis oculi inhibition.

Implications:

• This case highlights the complex supranuclear control mechanisms governing eyelid movements.
• Understanding the interplay between inhibitory and excitatory pathways is crucial for diagnosing and managing ALO and related disorders.
• Further research into pre-motor structures may elucidate the pathophysiology of ALO and inform therapeutic strategies.