Neural Interconnections Between Portio Minor and Portio Major at the Porus Trigeminus

Introduction: Recalcitrant trigeminal neuralgia following surgical treatment can be a life-altering condition. To explore alternative anatomic reasons for such a complication, the potential for nerve connections between the sensory and motor roots (Wrisberg’s anastomosis) of the trigeminal nerve at the opening of Meckel’s cave were examined.

Materials and Methods: In 15 adult, embalmed cadavers (30 sides), microdissection was performed of the skull base and specifically at the opening of Meckel’s cave (porus trigeminus).

Results: Two sides (2.67%) were found to have interneural connections between the sensory and motor roots at Meckel’s cave. These occurred in one male and one female cadaver, both on right sides. Both connections were histologically verified to be neural and were 0.5 mm in diameter and 1.2 mm and 2 mm in length, respectively. Both connections traveled in an oblique fashion from the portio major proximally to the portio minor distally.

Conclusions: Based on our findings, the sensory and motor components of the trigeminal nerve at Meckel’s cave may be interconnected with neural tissue. Such findings may be of use during the surgical treatment of trigeminal neuralgia.