Makindo Medical Notes

Related Subjects: Type 1 DM | Type 2 DM | Diabetes in Pregnancy | HbA1c | Diabetic Ketoacidosis (DKA) Adults | Hyperglycaemic Hyperosmolar State (HHS) | Diabetic Nephropathy | Diabetic Retinopathy | Diabetic Neuropathy | Diabetic Amyotrophy | Maturity Onset Diabetes of the Young (MODY) |

Diabetic neuropathy is a diagnosis of exclusion. Nondiabetic neuropathies may be present in patients with diabetes and may be treatable by specific measures

Prevention

• Optimize glucose control as early as possible to prevent or delay the development of distal symmetric polyneuropathy and cardiovascular autonomic neuropathy in people with type 1 diabetes.
• Optimize glucose control to prevent or slow the progression of distal symmetric polyneuropathy in people with type 2 diabetes

Detection

• All patients should be assessed for distal symmetric polyneuropathy starting at diagnosis of T2DM and 5 years after the diagnosis of T1DM and at least annually thereafter.
• Consider screening patients with prediabetes who have symptoms of peripheral neuropathy.
• Assessment should include a careful history and either temperature or pinprick sensation (small-fiber function) and vibration sensation using a 128-Hz tuning fork (large-fiber function).
• All patients should have an annual 10-g monofilament testing to assess for feet at risk for ulceration and amputation.
• Electrophysiological testing or referral to a neurologist is rarely needed for screening, except in situations where the clinical features are atypical, the diagnosis is unclear, or a different etiology is suspected.
• Atypical features include motor greater than sensory neuropathy, rapid onset, or asymmetrical presentation.

Types

• Symmetric sensory polyneuropathy
  • Clinical: Distal numbness, tingling and often pain at night.
  • Management: Consider Paracetamol or Amitriptyline 10-25 mg ON
  • Alternatives: Duloxetine, Gabapentin, or Pregabalin and even Opiates.
• Mononeuritis multiplex:
  • Clinical: affects cranial nerves III, IV, VI, and VII; and usually resolve spontaneously over several months
  • Investigations: EPS can help identify nerve conduction slowing or conduction block
  • Management: Often none. Immunosuppresion may help
  • Alternatives include corticosteroids, IV immunoglobulin, ciclosporin
• Amyotrophy
  • Clinical: Painful wasting of quadriceps and other pelvic and femoral muscles.
  • Investigations: EMG/NCS shows lumbosacral radiculopathy, plexopathy, or proximal crural neuropathy.
  • Management: IV immunoglobulins have been used
• Autonomic neuropathy
  • Clinical
    • Postural BP drop due to altered cerebrovascular autoregulation
    • Gastroparesis (early satiety, post-prandial bloating, nausea/vomiting)
    • Erectile dysfunction, Gustatory sweating
    • Diarrhoea
  • Investigations
    • ECG: Loss of sinus arrhythmia (vagal neuropathy)
    • Gastroparesis: measure gastric emptying with scintigraphy (99 Technietrium meal) at 15-min intervals for 4 h after food intake or use a 13C-octanoic acid breath test.
  • Management
    • Gastroparesis: anti-emetics, erythromycin, or gastric pacing. Consider short-term metoclopramide.
    • Postural hypotension: Stop BP meds, Salt loading, Fludrocortisone or Midodrine
    • Diarrhoea: try codeine phosphate.
    • Erectile dysfunction: Check LH/Testosterone, free testosterone, prolactin) to rule out hypogonadism. Consider sildenail. Others are transurethral prostaglandins, intracavernosal injections, vacuum devices, and penile prosthesis in more advanced case

Overall management

• Tight glucose control targeting near-normal glycemia in patients with T1DM dramatically reduces the incidence of distal symmetric polyneuropathy and is recommended for distal symmetric polyneuropathy prevention in T1DM.
• In patients with T2DM with more advanced disease and multiple risk factors and comorbidities, intensive glucose control alone is modestly effective in preventing distal symmetric polyneuropathy and patient-centreed goals should be targeted.
• Lifestyle interventions are recommended for distal symmetric polyneuropathy prevention in patients with prediabetes/metabolic syndrome and type 2 diabetes.
• Consider either pregabalin or duloxetine as the initial approach in the symptomatic treatment for neuropathic pain in diabetes
• Gabapentin may also be used as an effective initial approach, taking into account patients’ socioeconomic status, comorbidities, and potential drug interactions.
• Although not approved by the U.S. FDA, tricyclic antidepressants are also effective for neuropathic pain in diabetes but should be used with caution given the higher risk of serious side effects.
• Given the high risks of addiction and other complications, the use of opioids, including tramadol, is not recommended as first- or second-line agents for treating the pain associated with DSPN.

Refernces

• Diabetic Neuropathy: A Position Statement by the American Diabetes Association 2017