Mononeuropathy is one of the patterns of peripheral neuropathy. It affects a single nerve, i.e. only an isolated nerve is damaged. Mononeuropathy can have numerous causes and varied symptoms depending on which nerve is involved. Generally the symptoms depend on the nerve involved and the treatment depends on the underlying cause of the nerve damage.
Symptoms of a mononeuropathy will depend on the nerve involved and thus it will be dependent on the functions of the nerve. A motor nerve if involved is likely to present with symptoms like weakness or even paralysis of the muscles which were innervated by that nerve. Similarly if a sensory nerve is involved, the symptoms may vary from altered sensations like "pins-and-needle" sensations, pain (aching or burning or other type), tingling, crawling or loss of sensations like touch, pain, position sense (this causes ataxia) etc. Involvement of autonomic nerves may present with wide variety of symptoms like problems during urination (e.g. Incontinence), altered bowel movements (diarrhea or constipation), changes in blood pressure and heart rate (especially orthostatic hypotension, i.e. sudden fall in blood pressure on standing from a lying down position).
An example of a common type of mononeuropathy is Carpal Tunnel Syndrome. The nerve affected is the median nerve and its involvement in Carpal Tunnel Syndrome most commonly results in numbness and tingling in thumb and next two or three fingers and palm of hands. It may affect both hands and may have other associated features like pain and difficulty with fine finger movements and sometimes in more severe cases wasting of muscles under thumb and weak grip. Another similar disease is Tarsal Tunnel Syndrome causing pain in ankle and the sole of foot and paresthesia on walking. Another very common form of mononeuropathy is Radial Nerve Compression (e.g. Saturday Night Palsy) which commonly presents with wrist drop, numbness of the back of hand and wrist. Mononeuropathies affecting the muscles of eye (called ophthalmoplegias) may result in varied symptoms like double vision, drooping of one eyelid, headache or eye pain etc.
Treatment of mononeuropathy is dictated by the underlying cause. Often diabetes is cause of mononeuropathies hence tight control of blood glucose within desired limits is very important to prevent development of neuropathies and if already developed then treatment is mainly focused on preventing complications like foot ulcers and relieving pain if any. Myxedema (due to hypothyroidism) causes mononeuropathies due to entrapment of nerves, so treatment in this case would be to give patient Levothyroxine (to replace thyroid hormone). In cases of nerve entrapment, corticosteroids may be injected locally to reduce edema and pressure on the nerve.
Surgical measures may also be adopted to relieve the pressure on the nerve. For example Carpal Tunnel Syndrome can be relieved by surgical procedure called carpal tunnel release in which some ligaments are cut to reduce the pressure on median nerve. Medications like NSAIDs (e.g. Ibuprofen) can be used to relive the pain associated with neuropathies. Many times no treatment is necessary (as in mild compression injuries presenting with numbness or pins-and-needle sensations) and then recover on their own. If motor nerves are affected and there is weakness of muscles, then exercises of those muscles are advised.
