The symptoms and signs depend on which nerve is affected, where along its length the nerve is affected, and how severely the nerve is affected. Positive sensory symptoms are usually the earliest to occur, particularly tingling and neuropathic pain, followed or accompanied by reduced sensation or complete numbness. Muscle weakness is usually noticed later, and is often associated with muscle atrophy. A<unk>  neuropathy can usually be diagnosed confidently on the basis of the symptoms and signs alone. However, nerve conduction studies are helpful in confirming the diagnosis, quantifying the severity, and ruling out involvement of other nerves (suggesting a mononeuritis multiplex or polyneuropathy). A scan is not usually necessary, but may be helpful if a tumour or other local compressive lesion is suspected. Nerve injury, as a mononeuropathy, may cause similar symptoms to<unk>  neuropathy. This may occasionally cause diagnostic confusion, particularly if the patient does not remember the injury and there are no obvious physical signs to suggest it. The symptoms and signs of each particular syndrome are discussed on the relevant pages, listed below.
Nerve compression syndrome
Calpainopathy
Complex regional pain syndrome
Radiation-induced lumbar plexopathy
Median nerve palsy
Pudendal nerve entrapment
Central pain syndrome
Accessory nerve disorder