The diagnosis of pain is based upon further assessment of a patient’s history. If underlying nerve damage is suspected, then evaluation of the nerves with testing may be warranted. The most common way to evaluate whether a nerve is injured is with electrodiagnostic medicine. This medical subspecialty uses techniques of a nerve conduction studies with electromyelography (NCS/EMG). Clinical evaluation may reveal some evidence of loss of function, and can include assessment of light touch, the ability to distinguish sharp from dull, the ability to discern temperature, and assessment of vibration. Once a thorough clinical examination is performed, the electrodiagnostic study can be planned. These studies are performed by specially trained neurologist and physiatrists.
If neuropathy is suspected, a search for reversible causes should be done. This can include blood work for vitamin deficiencies or thyroid abnormalities, and imaging studies to exclude a structural lesion impacting the spinal cord. Depending on the results of this testing, there may be a way to decrease the severity of the neuropathy and potentially decrease the pain that a patient is experiencing. Unfortunately, in many conditions, good control of the underlying cause of the neuropathy cannot reverse the neuropathy. This is commonly seen in patients with diabetic neuropathy.
In rare instances, there may be evidence of changes in the skin and hair growth pattern in an affected area. These alterations may be associated with changes in sweating or perspiration as well. When present, these changes can help identify the probable presence of neuropathic pain associated with a condition called complex regional pain syndrome.