In recent years, some taxonomic controversy has occurred over the genus of North American rat snakes. Based on mitochondrial DNA, Utiger et al. (2002) showed that North American rat snakes of the genus Elaphe, along with closely related genera such as Pituophis and Lampropeltis, form a monophyletic group separate from Old World members of the genus.
A pinched nerve is a type of injury or damage to a nerve or a group of nerves. The injury can result from compression, constriction, or stretching. A pinched nerve can lead to other conditions and cause temporary or permanent damage depending on the extent of the injury. pinched nerve is a type of injury or damage to a nerve or a group of nerves. The injury can result from compression, constriction, or stretching. A pinched nerve can lead to other conditions and cause temporary or permanent damage depending on the extent of the injury.
A pinched nerve can cause symptoms at the site of damage, or at any location farther down the path from the affected nerve. 1  A pinched nerve in the neck can cause neck pain or stiffness, along with symptoms down the arm. 2  A pinched nerve in the lower back causes back pain and stiffness with symptoms down the leg. A doctor can often identify which nerve is pinched in the neck or lower back based on what portion of the patient's arm or leg is affected.