painless diabetic motor neuropathy

Etiology

• diabetes mellitus type 2
  • median duration of diabetes = 5 years

Epidemiology

rare

Pathology

• ischemic injury
• microvasculitis
• perineural thickening
• neovascularization

Clinical manifestations

• insidious onset, slow evolution of symptoms
• presenting symptoms may be unilateral
  • progression to symmetric distribution
• painless
• upper extremity & lower extremity muscle weakness
  • subsacute bilateral foot drop
  • later involvement of proximal leg muscles
  • lesser involvement of upper extremities
• weight loss is common
• disability tends to be greater than diabetic polyneuropathy

Laboratory

• HbA1c: often normal, glycemic control tends to be good
• nerve biopsy

More general terms

• diabetic amyotrophy