Nerve damage

Nerve damage from diabetes is called diabetic neuropathy and is also caused by disease of small blood vessels. In essence, the blood flow to the nerves is limited, leaving the nerves without blood flow, and they get damaged or die as a result (a term known as ischemia). Symptoms of diabetic nerve damage include numbness, burning, and aching of the feet and lower extremities. When the nerve disease causes a complete loss of sensation in the feet, patients may not be aware of injuries to the feet, and fail to properly protect them. Shoes or other protection should be worn as much as possible. Seemingly minor skin injuries should be attended to promptly to avoid serious infections. Because of poor blood circulation, diabetic foot injuries may not heal. Sometimes, minor foot injuries can lead to serious infection, ulcers, and even gangrene, necessitating surgical amputation of toes, feet, and other infected parts.

Diabetic nerve damage can affect the nerves that are important for penile erection, causing erectile dysfunction (ED, impotence). Erectile dysfunction can also be caused by poor blood flow to the penis from diabetic blood vessel disease.

Diabetic neuropathy can also affect nerves to the stomach and intestines, causing nausea, weight loss, diarrhea, and other symptoms of gastroparesis (delayed emptying of food contents from the stomach into the intestines, due to ineffective contraction of the stomach muscles).

The pain of diabetic nerve damage may respond to traditional treatments with:

• gabapentin (Neurontin),
  
  
• phenytoin (Dilantin),
  
  
• carbamazepine (Tegretol),
  
  
• desipramine (Norpraminine),
  
  
• amitriptyline (Elavil), or
  
  
• with topically-applied capsaicin (an extract of pepper).

Gabapentin (Neurontin), phenytoin (Dilantin), and carbamazepine (Tegretol) are medications that are traditionally used in the treatment of seizure disorders. Amitriptyline (Elavil) and desipramine (Norpraminine) are medications that are traditionally used for depression. While many of these medications are not FDA indicated specifically for the treatment of diabetes related nerve pain, they are used by physicians commonly.

The pain of diabetic nerve damage may also improve with better blood sugar control, though unfortunately blood glucose control and the course of neuropathy do not always go hand in hand. Newer medications for nerve pain have recently come to market in the US. Pregabalin (Lyrica) which has an indication for diabetic neuropathic pain and duloxetine (Cymbalta) are newer agents used in the treatment of diabetic neuropathy.