A less common form of neuropathy that can be unpredictable is called "focal neuropathy" in which only single specific nerves, sets of nerves or a specific part of the body is affected. Here again the cause is believed to be blockages or obstructions in small blood vessels supplying specific nerves. Occurring most often in older people with mild diabetes, the onset of focal neuropathy can be sudden with severe pain, commonly appearing in nerves in the legs, arms, head, torso, even in eye and facial muscles. Despite the fact that focal neuropathy can be quite painful, with preventative measures and treatment it can normally improve on its own following a period of weeks or months without causing long-term damage and can typically disappear over two to six months.
• Eyes - Double vision, inability to focus, or an aching behind one or both eyes
• Facial muscles - Paralysis can occur on one side of the face, also called "Bell's Palsy"
• Hearing - Focal neuropathy can cause difficulty with hearing
• Chest - People can experience pains in the chest that are frequently mistaken for a heart attack or angina
• Abdomen - Abdominal pain caused by focal neuropathy can often be mistaken for appendicitis
• Lower back and pelvis - Severe pain can be experienced in the pelvis and lower back as a result of focal neuropathy
• Thighs - Pain can be felt in the front of the thigh or an inability to lift the leg
People with diabetes are also more likely to develop another form of neuropathy called "compression neuropathy" also known as "entrapment neuropathy", which can occur as a result of prolonged forceful, repetitive stress and flexing of any group of joints. This can cause cumulative damage that may irritate ligaments, muscles and tendons causing them to swell and constrict passageways which some nerves pass through. The most widely known and common form of compression neuropathy is "carpal tunnel syndrome" which is thought to affect between twenty five to thirty percent of diabetic patients. The most common symptoms of carpal tunnel syndrome include numbness, tingling, pain and weakness in the hands and wrists. Nerves in the foot and on the outside of the shin are also another likely location to develop entrapment neuropathy.
If neuropathy has lead to a person losing their ability to sense pain, they can potentially fail to sense an injury or infection, or detect pains that are a prelude to a heart attack. Lower limb amputations are common among diabetics that suffer from neuropathy because many fail to detect an injury or infection in time to prevent it from worsening and becoming gangrenous. Depression is also common for people suffering from neuropathy because it can affect the quality of a persons life on a daily basis. Pain from neuropathy can often become worse during the night, causing interruptions that affects a persons ability to receive quality sleep and its regenerative benefits, which only adds additional burdens to their overall emotional well being. Also people that cannot feel sensation in their hands or feet are often unable to detect and recognize shapes by touch alone or sense just what position their hands or feet are in, making it difficult to perform tasks such as buttoning a shirt, walking, or keeping their balance with their eyes closed.
Diabetic neuropathy occurs because, nerve tissues are very susceptible to damage from diseases that impair the body's ability to properly process or use nutrients for energy, create the materials needed to support and build living tissue, or process and eliminate waste materials. Diabetes is one such disease, because it affects the body's ability to properly use or produce insulin,which is necessary to transfer glucose and nutrients into the cells of the body. Diabetes can lead to blood vessel constriction and is also characterized by high blood glucose levels (hyperglycemia) which has damaging effects to blood vessels and can also cause chemical changes in nerve tissues that can impair their ability to transmit signals. Should constriction or damage occur to the blood vessels that supply nerve tissues with the necessary nourishment and oxygen they need, it can lead to damage and even the death of those nerve tissues. Nerves that are affected by chemical changes can send the wrong signals, become slow or even fail to work. The longer someone has diabetes or the longer someone is exposed to hyperglycemia, the more likely they are to develop neuropathy.
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