Diabetic Neuropathic Pain
Introduction and Facts
Diabetic neuropathic pain (DNP) is one of the complications of diabetes mellitus and greatly interferes with the patient's daily activities. In addition, DNP is very difficult to treat and is often frustrating for both the patient and the doctor. The pathophysiology of DNP is still not fully known, so the pathological condition cannot be completely treated
Diabetic neuropathy is found in 50% of patients with diabetes mellitus, while DNP occurs in 16-26% of the total patients with diabetes mellitus. Diabetic neuropathy is most common in type II DM. Approximately 10% of patients complain of symptoms of neuropathy at the initial diagnosis of DM.
Pathophysiology
The mechanism of DNP is complex and not yet fully understood. Allegedly through 2 mechanisms, namely peripheral and central mechanisms. Peripheral mechanisms include: 1). Ectopic activity, 2). Nociceptor sensitization, 3). Abnormal interactions between nerve fibers, 4). Sensitivity to catecholamines, while the central mechanism includes: 1). Central sensitization, 2). Central reorganization, 3). Loss of inhibitory control. Until now it is not clear why one DM patient suffers from DNP while the other DM patient does not suffer from NND
A study found TNF-a levels, iNOS expression and TNF-a had a statistically significant relationship to the degree of pain in patients with DNP. TNF-a levels, TNF-a expression, and iNOS expression are important risk factors for the occurrence of DNP. Meanwhile, age, gender, duration of suffering from DM, fasting blood sugar, blood sugar 2 hours postprandial, HbA1c levels, were not associated with the incidence of DNP and were not as risk factors for DNP.
Clinical Symptoms and Complications
Clinical manifestations of DNP are mainly found in the lower limbs symmetrically, in the form of a burning, stabbed, stabbed, electrocuted, torn, tense, tied, allodynia, hyperalgesia and dysesthesia feeling. Complaints may be accompanied by numbness such as wearing gloves, loss of balance (eyes closed), lack of agility, astereognosis or painless ulcers. Complaints will get worse at night so it is not uncommon for patients to experience sleep disturbances, anxiety and depression which results in decreased quality of life
Diagnosis
Chronic hyperglycemia due to uncontrolled DM will cause peripheral nerve dysfunction and its distribution is generally bilaterally symmetrical including sensory, motor and autonomic disturbances. The distribution of DNP resembles the picture of socks and gloves (stocking and gloves) or also called Distal Symmetrical Polyneuropathy
The diagnosis of DNP was obtained from the anamnesis process with the complaints as above.
Motoric: impaired coordination and distal and/or proximal paresis, including difficulty climbing stairs, difficulty getting up from a chair/floor, falling, difficulty working or lifting the upper arm above the shoulder, impaired fine hand movements, difficulty turning keys, opening jars, bent thumbs, tripped, both feet collided
Autonomic: sweating disorders, sensation of floating in an upright position, syncope when defecating/coughing/physical activities, erectile dysfunction, difficulty orgasming, difficulty holding back a chapter/tub, bedwetting, anyang-anyangan (polakisuri), vomiting (when food is retained), nocturnal diarrhea , constipation. Pupillary disorders can be difficult to adapt in the dark or light
There are also several measures that can be used to help differentiate between neuropathic pain and nociceptive pain. The recommendation of The American Diabetes Association Consensus Statement, the diagnosis of NND is practically established based on the patient's clinical condition, such as a description of the patient's pain, distal symmetrical symptoms and exacerbations at night.
Physical examination
Inspection: Diabetic foot, neurarthropathy (Charcot joint) and claw toe deformity.
Neurologic examination: Motor examination and Sensory examination to see the distribution of nerve lesions. Autonomic examination, including: evaluation of orthostatic hypotension, pulse (reflex tachycardia), Valsalva test and sweat glands.
Supporting investigation
Electrophysiological examination
1. Motor: Nerve Conduction Velocity (NVC) latency, F-wave, Electromyography (EMG), Magnetic Evoked Potential (MEP).
2. Sensory : Sensory Nerve Action Potential (SNAP), Sensory Conduction Velocity (SCV), H-reflex, Somato Sensory Evoked Potential (SSEP), Laser-evoked potentials (LEPs), Positron Emission Tomography (PET), Small Fibers Nerve Conduction Velocity (small fiber check).
3. Quantitative Sensory Testing (QST). Is a psychophysiological measurement of perception of external stimuli whose intensity is controlled / regulated. Von Frey fibers or Semmes-Weinstein monofilaments are used. Can be used to assess the tactile feel of Aß nerve fibers which is quite useful as a means of early diagnosis of neuropathy
diabetic
Laboratory:
- Blood sugar level or glucose tolerance test, HbA1c.
- Laboratory to rule out differential diagnosis or early screening of subclinical cases.
In the Textbook of Diabetic Neuropathy, Dyck recommends a diagnosis of NND if there are at least one or 2 abnormalities (from complaints, clinical symptoms, abnormalities on nerve conduction tests (NCV) or quantitative sensory tests).
Management and Care
- Optimal control of blood sugar levels: should be close to normoglycemia, HbA1c levels should be maintained below 6-7% .
- Symptomatic therapy
Pharmacology:
Anticonvulsants include: pregabalin, gabapentin, carbamazepine, oxcarbasepine.
- NSAIDs: for musculoskeletal pain and neurarthropathy.
- Analgesics: tramadol, a combination of tramadol and acetaminophen.
- Antidepressants include: amitriptyline, imipramine, duloxetine.
- Antiarrhythmic: mexiletin.
- Topical drugs include: capsaicin.
Non-pharmacologic
Careful daily foot care.
- Shoes: do not be narrow, check for protrusions in the shoes.
- Local infection in therapy and weight loss.
- Foot pain: soak feet in hot-cold water alternately for 10 minutes (check hot water temperature).(Callaghan et al., 2012).
- Alternative therapies such as: acupuncture, infrared, laser therapy, TENS, frequencymodulated electromagnetic neural stimulation (FREMS) therapy, high frequency external muscle stimulation, electrical spinal cord stimulator implantation are still not conclusive
Non-surgical invasive, in the form of local nerve block.
Surgery, for indications such as amputation in gangrene.
References:
- Widyadharma IPE. Nyeri polineuropati diabetik. Pain Education Pustaka Bangsa Press. [Internet]. [Cited 26/8/2021]. Available from: https://www.researchgate.net/publication/320584600_Nyeri_Polineuropati_Diabetik
- Bodman MA, Dreyer MA, Varacallo M. Diabetic peripheral neuropathy [Internet]. 2024. Available from: https://www.ncbi.nlm.nih.gov/books/NBK442009/
