Fig. 32. Exposure of the Qasserian Ganglion. Natural Size. 



On the right side an incision, curvilinear with its base at the Zygoma, has been 

 carried through the soft parts. The bone has been chiselled through and the 

 osteoplastic flap, broken at its base, is turned downwards. The Dura Mater of 

 the Middle Fossa and the Temporal Lobe are raised so that after division 

 of the Middle Meningeal Artery, the Gasserian Ganglion and the ^rd division 

 of the Vth Nerve are exposed outside the Dura Mater. (As the bone was 

 removed the Anterior Division of the Middle Meningeal Artery was lacerated 



in its bony canal.) 



Persistent Facial Neuralgia which is unrelieved even by extensive resection 

 of the peripheral branches of the Vth Nerve as they emerge from the skull and 

 which is unrelieved by medicaments has recentl}^ been dealt with by removal of 

 the Gasserian Ganglion. Two methods may be adopted either (Rose) the 

 Zygoma may be temporarily resected, when after exposure of the Foramen Ovale 

 from below the base of the skull is opened up; or the skull may be opened in 

 the Temporal region (Hartley, Krause) and the Ganglion with its branches 

 exposed. This latter method is perhaps the better one; moreover, it may be 

 employed for removing tumours of the Middle Fossa or for ligature of the Middle 

 Meningeal Artery. After turning down an osteoplastic flap as described above, 

 the Dura Mater covering the Temporal Lobe is lifted away from the Skull. Con- 

 siderable haemorrhage follows from the laceration of numerous small veins. At 

 a depth of one inch from the Squamous portion of the Temporal Bone, just above 

 the root of the Z^^goma lies the Middle Meningeal Arter}'. This vessel is divided 

 between two ligatures in order to expose the Foramen Ovale which lies Vioth 

 inch internal and in front of the Foramen Spinosum ; ^/sth inch forwards and nearer 

 to the middle line than the Foramen Ovale is situated the Foramen Rotundum 

 through which the 2nd division of the Vth Nerve passes; Ysth inch from the 

 Foramen Ovale and ^gth inch from the Foramen Rotundum is the Convex margin 

 of the Gasserian Ganglion. It lies in an impression on the upper surface of 

 the petrous bone and covered by Dura Mater in Meckel's Cave (cf. Fig. 23). 



The trunk of the Vth Nerve enters its Dural Sac by passing through a slit 

 in the Dura Mater at the attachment of the Tentorium Cerebelli to the superior 

 border of the petrous bone. The Gasserian Ganglion and its three divisions 

 are outside the Dura Mater and can be operated upon without opening the 

 meninges or exposing the brain. 



Particular attention should be paid to the first division of the Vth Nerve, 

 as it lies in the outer wall of the Cavernous Sinus; so that in freeing this division 

 the Sinus is necessarily injured. (Cf. Fig. 17.) 



Another method, devised by LEXER, is still less liable to injure the brain 

 whereas it gives a good exposure of the Ganglion. LEXER makes a smaller 

 temporal flap but enlarges the area of operation downwards by temporarily resecting 

 the Zygoma and removing the base of the skull as far as the Foramen Ovale. 



