MICROSURGICAL RELATIONSHIPS OF THE ARTERIES AT THE BASE OF THE BRAIN AND THE TRIGEMINAL NERVE / 解剖学报

ABSTRACT

1. Microsurgical relationships of the arteries at the base of the brain and the trigeminal nerve were studied bilaterally on 30 brains. Twenty seven trigeminal nerves made contact with the arteries 33 times which represents 55 percent of the cases. Six of 27 trigeminal nerves had double contact.2. Of 33 arteries in contact with 27 nerves, seventeen involved the superior cerebellar arteries (SCA) (28.33?5.82%), seven the anterior inferior cerebellar arteries (AICA) (11.67?4.15%) and nine the middle inferior cerebellar arteries (MICA) (15.0?4.61%).3. The outer diameter of the superior cerebellar artery is the largest averaging 1.41?0.20 mm; the anterior inferior cerebellar artery comes next averaging 1.06?0.36 mm and the middle inferior cerebellar artery the smallest, averaging 0.62?0.14 mm.4. 27 trigeminal arteries arising from the upper or middle segement of the basal artery were found on the ventral surface of the trigeminal nerves in 17 brains, and 16 trigeminal branches arising from the AICA. MICA. and PICA were also found at the roots of 16 trigeminal nerves. Anastomoses were noted between the trigeminal arteries and the trigeminal branches in four cases of 16 trigeminal nerves.5. The association between the neurovascular contact and the trigeminal neuralgia are discussed. It is suggested that the neurovascular contact either from dorsal or ventral aspects may be the anatomical cause of the trigeminal neuralgia.6. The neurovascular contact of the trigeminal nerve with the SCA was usually on the dorsal or dorsalmedial aspect of the nerve, but the point of contact with AICA or MICA was mainly on the ventral aspect of the nerve. Besides, there are trigeminal arteries and trigeminal branches at the ventral surface of the nerve. All these topographic observations provide microsurgical information for neurosugeons.