Logan Joseph Jackson

High resolution ultrasound (US) and magnetic resonance (MR) neurography are both imaging modalities that are commonly used for assessing peripheral nerves including the sural nerve (SN). The SN is a cutaneous sensory nerve which innervates the lateral ankle and foot to the base of the fifth metatarsal. It is formed by contributing nerves from the tibial and common peroneal nerves with six patterns and multiple subtypes described in literature. In addition to the SN being a cutaneous sensory nerve, the superficial location enables the nerve to be easily biopsied and harvested for a nerve graft, as well as increasing the susceptibility to traumatic injury. As with any peripheral nerves, pathologies such as peripheral nerve sheath tumors and neuropathies can also affect the SN. By utilizing a high frequency probe in US and high-resolution MR neurography, the SN can be easily identified even with the multiple variations given the standard distal course. US and MRI are also useful in determining pathology of the SN given the specific image findings that are seen with peripheral nerves. In this review, we evaluate the normal imaging anatomy of the SN and discuss common pathologies identified on imaging.

Acquired thrombotic thrombocytopenic purpura (TTP) is an uncommon microangiopathic disorder that can have variable presentations and can be precipitated by a multitude of stressors to the body, most commonly sepsis. TTP is caused by a deficiency of ADAMTS13 leading to intravascular clotting causing thrombocytopenia and microangiopathic hemolytic anemia. TTP can be associated with various other pathologic conditions. One such rare association has been reported with diabetic ketoacidosis (DKA). Here, we present an even less appreciated presentation in association with DKA. A 62-year-old African American male with previously diagnosed prediabetes presented with DKA and developed hemodynamically significant bleeding. He was confirmed to have TTP that responded to plasmapheresis. TTP is a life-threatening illness if not treated urgently with plasmapheresis with or without rituximab. As acquired TTP most commonly occurs during stress on the body, it is important to treat the underlying stressor. Early identification and initiation of appropriate interventions are crucial to reducing mortality associated with TTP. Furthermore, we need to appreciate less commonly associated conditions such as DKA among patients.