Hypothermic peripheral neuropathy
A 21-year-old male suffered a hypothermic cardiac arrest and traumatic brain injury after being found down on a frozen lake for an unknown amount of time. Patient’s initial temperature was found to be 25 degrees Celsius. Patient was placed on VA ECMO and rewarmed slowly to 34 degrees Celsius. Upon cardiovascular stabilization, the patient noticed bilateral hand weakness and paresthesias. He had minimal improvement even with aggressive rehabilitation. Five months after the inciting event, nerve conduction studies (NCS) and needle EMG were performed due to persistent symptoms. NCS showed significantly reduced sensory and motor amplitudes in the ulnar, median, and radial nerves bilaterally with mildly prolonged latencies. EMG showed active denervation of FDI, APB, and ADQ with evidence of terminal reorganization. Although the patient refused testing of his lower extremities, he denied any symptoms in the legs.
Peripheral nerve injury from deep hypothermia has not been well-studied. There have only been a few case reports which showed similar NCS and EMG findings. In this patient, the mechanism of injury is thought to be direct axonal injury from cold causing nerve ischemia. There was some discussion if the patient has a component of critical illness neuropathy, although this is less likely the primary cause given that there was no evidence of sepsis during hospitalization, the lack of improvement over several months, and the preferential effects on the upper extremities. There may also be a secondary demyelinating process occurring from compression at the elbow and wrist due to prolonged swelling and positioning of extremities while in the ICU. The patient will be undergoing decompression surgery at these sites and will be followed to evaluate for changes.
This patient has severe bilateral axonal median, ulnar, and radial sensorimotor neuropathies likely secondary to severe hypothermia.