1625 - When Sweet Goes Sour: A Case Report of Diabetic Amyotrophy

A 59-year-old male with history of uncontrolled diabetes presented to EMG clinic for evaluation of bilateral lower extremity weakness, right more so than left.  6 months prior, he noted heaviness in his bilateral extremities and feeling his right hemi-body was weaker during a PT/OT evaluation, with unclear history of pain preceding his symptoms. After a brain MRI ruled out stroke, he was referred for electrodiagnostic evaluation.


Physical examination revealed altered sensation to light touch in the distal bilateral lower extremities, with strength ranging from 3 to 4-/5 throughout the L2-S1 myotomes. Nerve conduction studies demonstrated absent compound muscle and sensory nerve action potential amplitudes in the lower extremities bilaterally. Electromyography showed abnormal spontaneous activity in the distal bilateral lower extremity musculature, but also notably in the musculature innervated by the right L2-3 myotomes. Given the history and presentation, diagnoses of length-dependent large-fiber peripheral neuropathy and right diabetic amyotrophy were made.

Discussions: Diabetic amyotrophy, also known as diabetic lumbosacral radiculoplexus neuropathy (DLSRPN), is typically characterized by acute severe, proximal unilateral pain, followed by weakness and atrophy of the proximal lower extremity muscles. There can be involvement of the contralateral lower extremity. The condition’s reported incidence is approximately 0.8% of all patients with diabetes, with males typically more affected than females, and in the sixth decade of life. While the underlying mechanism is still debated, the condition is thought to occur due to inflammatory microvasculitis causing ischemic damage of the lumbar plexus.

Conclusions: While considerably less common than lumbosacral radiculopathy, diabetic amyotrophy as a possible cause of leg weakness preceded by acute leg pain must be considered, particularly in the setting of poorly controlled blood sugar. Maintenance of glucose control and physical therapy are mainstays of treatment.