18.Painful Diabetic Polyneuropathy

In the industrialized world, polyneuropathy induced by diabetes mellitus (DM) is one of the most prevalent forms of neuropathy. Diabetic neuropathy can result from a direct toxic effect of glucose on nerve cells. Additionally, the damage of the nerve structures (central and peripheral) is accompanied by a microvascular dysfunction, which damages the vasa nervorum. More than 80% of the patients with DM-induced polyneuropathy have a distal and symmetric presentation. The initial symptoms are: signs of diminished sensation, burning feet, which may occur particularly during the night and worsen when touched, and tingling sensation in the feet. Attacks of shooting pain may also occur. Proper control of DM is mandatory. Based on the recently published National Institute for Health and Clinical Excellence guidelines, treatment of painful diabetic neuropathy should start with duloxetine or amitriptyline if duloxetine is contraindicated. If pain relief is inadequate, monotherapy with amitriptyline or pregabalin, or combination therapy with amitriptyline and pregabalin should be considered. If pain relief is still insufficient, tramadol instead of or in combination with a second-line agent should be considered. In patients who are unable to take oral medication, topical lidocaine can be considered for localized pain. There are currently four studies showing that spinal cord stimulation can potentially provide pain alleviation for the longer term in patients with painful diabetic polyneuropathy. Complications are mainly implant related, though infections also occur. The available evidence (2 C+) justifies spinal cord stimulation to be considered, preferably study related.