Introduction: diabetes is one of the most common health problems in the world which requires proper therapeutic attention otherwise it could result in long term macro vascular and micro vascular complications. About 50% of diabetic patients develop long term complications. The most common type of neuropathy which accounts for 75% of diabetic neuropathy is the diabetic sensorimotor polyneuropathy defined as a diffused symmetrical and length dependent injury to peripheral nerve fibers. It commonly goes by the name of diabetic peripheral neuropathy (DPN). It causes pain and loss of sensation in hands, arms, fingers, toes, legs, feet and it is the major reason for non-traumatic lower limb amputations. Diabetic peripheral neuropathy is different from peripheral arterial disease (poor circulation), which affects the blood vessels rather than the nerves.
Etiology: various vascular factors and changes in metabolism (e.g. hyperglycemia, dyslipidemia) is the reason for the development of DPN. Impaired flow of blood and endoneurial hypoxia is one of the major contributing factors.
Clinical Presentation: mostly it is asymptomatic with only 10-20% of patients requiring intervention. The onset is usually gradual and presents as a painless loss of sensation. Newly diagnosed patients with Diabetes type 2 will present with some type of DPN at the time of diagnosis. Sensory symptomatology is of more significance as compared to the motor involvement. The unsteadiness which leads to balance problems and consequently increases the risks for falls is due to numbness and abnormal muscle sensory function.
The neuropathic pain is characterized by burning, electrical, stabbing feeling. The pain could worsen at night and could lead to sleep disturbances.
Management: two aspects are focused while treating DPN i.e. resolving the underlying cause and the relief of symptoms. The first one is usually achieved by tightly and effectively managing the patient’s glucose levels.
Pharmacologic agents: agents recommended by American Academy of Neurology (AAN) guidelines 2011 include;
DRUG | DOSAGE |
Anti convulsants | |
Pregabalin | 300-600 mg/day |
Gabapentin | 900-3,600 mg/day |
Sodium valproate | 500-1,200 mg/day |
Anti depressants | |
Amitriptyline | 25-100 mg/day |
Duloxetine | 60-120 mg/day |
Venlafaxine | 75-225 mg/day |
Opioids (for patients not responding to other options) | |
Morphine sulfate | Up to 120 mg/day |
Oxycodone | Up to 120 mg/day |
Tramadol | 210 mg/day |
Other | |
Capsaicin 0.075% | Four times daily |
Reference:
- American Academy of Neurology (AAN) guidelines 2011.