Johan P. Reyneke's Techniques, Tips, Tricks & Traps Vol 4:

The pterygopalatine ganglion (PPG), often described as the Piccadilly Circus of the Face, is of great importance to anesthesiologists, pain physicians, neurologists and surgeons, and its blockade is becoming more and more popular as our understanding of the cholinergic mechanisms of headache improve. It is also known as the sphenopalatine ganglion, Meckel's ganglion or the Nasal ganglion. Recent publications have shed important light on the neuroanatomy and neurophysiology of this...
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The pterygopalatine ganglion (PPG), often described as the Piccadilly Circus of the Face, is of great importance to anesthesiologists, pain physicians, neurologists and surgeons, and its blockade is becoming more and more popular as our understanding of the cholinergic mechanisms of headache improve. It is also known as the sphenopalatine ganglion, Meckel's ganglion or the Nasal ganglion. Recent publications have shed important light on the neuroanatomy and neurophysiology of this ganglion and its relationship with the trigeminal ganglion, and, more important, its role in the pathophysiology of vascular or primary headaches. This, and the applied macroanatomy, sonoanatomy, surface anatomy and microanatomy of this ganglion have been discussed in much detail in this book, as well as popular techniques of performing the pterygopalatine ganglion block.