Transcranial segment of the trigeminal nerve: macro-/microscopic anatomical study using sheet plastination

Area of Science:

• Anatomy
• Neurosurgery
• Pain Medicine

Background:

• Trigeminal neuralgia (TN) is often linked to mechanical compression of the trigeminal nerve.
• Previous research focused on subarachnoid vascular compression, neglecting skull base structures.
• The relationship between the trigeminal nerve and surrounding skull base anatomy requires further investigation.

Purpose of the Study:

• To meticulously examine the trigeminal nerve's root, ganglion, and divisions within the skull base.
• To identify and map potential mechanical compression points along the nerve's course.
• To understand the interplay between the trigeminal nerve and adjacent soft and bony structures.

Main Methods:

• Dissection and sheet plastination techniques were employed on 26 adult cadavers.
• Detailed anatomical examination focused on the trigeminal nerve and surrounding skull base.
• Cadavers included ten females and 16 males, aged 45-81 years.

Main Results:

• Four critical anatomical sites predisposing the trigeminal nerve to entrapment were identified.
• These sites include the mouth of Meckel's cave, middle cranial fossa dura, internal carotid artery wall, foramen rotundum, and foramen ovale.
• Specific structures like the twisted periosteum and venous plexus at the foramen ovale were implicated.

Conclusions:

• The study pinpoints four likely mechanical compression points in the skull base for trigeminal neuralgia.
• This anatomical knowledge aids skull base surgeons in TN treatment.
• Findings are valuable for researchers developing TN animal models, especially those excluding vascular compression.