Interactive diabetes case 19: Pain and dysesthesias of the lower extremities in a 29-year-old woman with type 1 diabetes (distal sensory neuropathy)
- Lloyd Axelrod, MD
Lloyd Axelrod, MD
- Associate Professor of Medicine
- Harvard Medical School
A 29-year-old woman returns to you after an interval of nearly two years because of pain and dysesthesias of the lower extremities involving the feet and extending up to the mid-calf level. She often feels as if she is walking on pebbles. She is unable to sleep at night due to the pain and is fatigued during the day. The discomfort seems to be less bothersome when she walks. She is tearful during the visit and says she is depressed but denies suicidal ideation. She is an administrator at a nearby university and lives alone.
The patient was diagnosed with type 1 diabetes at age 10 years when she presented in diabetic ketoacidosis. Metabolic control was poor during her teen years and into her early 20s, with glycated hemoglobin (A1C) values in the 10 to 12 percent range. Control has been improved in the last two years, following the development of diabetic retinopathy with macular edema and decreased visual acuity, treated with laser therapy by her ophthalmologist.
She is treated with glargine insulin 18 units at bedtime and insulin aspart before meals and snacks. She injects 1 unit for every 15 grams of carbohydrate and uses a correction dose of 1 unit for every 50 mg/dL of blood glucose above 120.
On physical examination, her feet are warm and well perfused. The dorsal pedal and posterior tibial pulses are 2 + bilaterally. Neurologic examination is noteworthy for the following: vibration sense is absent at the great toes, markedly reduced at the medial malleoli, and mildly reduced at the tibial tubercles. Light touch perception with a nylon monofilament is absent to the knees. Ankle jerks and knee jerks are absent bilaterally.
The laboratory values are as follows: blood area nitrogen (BUN) 26 mg/dL (9.3 mmol/L), creatinine 1.4 mg/dL (123.8 micromol/L), potassium 4.8 mEq/L, A1C 7.8 percent, urine microalbumin/creatinine ratio 63 micrograms/mg (reference <30).