Recurrent isolated abducens nerve paresis associated with persistent trigeminal artery variant

Area of Science:

• Neuroscience
• Vascular Neurology
• Neuroanatomy

Background:

• Abducens nerve paresis, or sixth cranial nerve palsy, can manifest as isolated or recurrent symptoms.
• Neurovascular compression is a recognized cause of cranial nerve dysfunction.
• Persistent trigeminal artery (PTA) is a rare embryological remnant of the primitive trigeminal artery.

Observation:

• A 74-year-old female patient presented with recurrent isolated abducens nerve paresis.
• Cranial MRI demonstrated the right abducens nerve entrapped between the right internal carotid artery and an aberrant PTA.
• This anatomical configuration suggested direct neurovascular conflict.

Findings:

• The study identified a specific anatomical variant of the persistent trigeminal artery (PTA) as the cause of abducens nerve compression.
• The right internal carotid artery and the PTA variant created a "sandwich" effect on the abducens nerve.
• This compression was directly correlated with the patient's recurrent abducens nerve paresis.

Implications:

• Normal variants of the persistent trigeminal artery (PTA) can cause significant neurological symptoms through neurovascular compression.
• Radiologists and neurologists must be vigilant in identifying and reporting PTA variants on cranial imaging.
• Awareness of this potential cause is crucial for accurate diagnosis and management of abducens nerve palsies.