Nutcracker phenomenon with a daily persistent headache as the primary symptom: Case series and a proposed pathogenesis model based on a novel MRI technique to evaluate for spinal epidural venous congestion

Objective: To determine if a specific population of patients with a daily persistent headache from onset have underlying nutcracker physiology and to propose a pathogenesis model for their headaches utilizing a novel MRI protocol. Background: A single case report of a daily persistent headache associated with nutcracker syndrome was recently published. As the left renal vein has a connection to the spinal lumbar veins and secondarily to the spinal epidural venous plexus, one could hypothesize that renal vein compression could lead to persistent headache by altering spinal and cerebral venous pressure with secondary alterations in CSF pressure. The authors have published on a series of patients with a unique subtype of daily persistent headache from onset that appears to be caused by an abnormal reset of CSF pressure to an elevated state. The goal of the present study was to look for the presence of nutcracker physiology in this unique patient subgroup and to propose a pathogenesis model utilizing a novel MRI protocol to evaluate for retrograde lumbar vein flow and regional spinal epidural venous plexus congestion. Materials and methods: Case series of patients with a daily persistent headache from onset, head pressure, and whose headaches worsened in the Trendelenburg position. Patients were imaged with a 3 T MRI in the supine position from the lower diaphragm to the top of the pelvis with a dynamic angiogram centered over the left L2 lumbar vein. Results: 12 patients were studied of which 8 were positive for left renal vein compression, lumbar vein dilation and early spinal epidural venous plexus enhancement. All were women. Mean age of headache onset was 39 years. Six of the 8 patients had a lumbar puncture, and all had a normal opening pressure. All improved with CSF volume removal although pain resolution lasted from hours to 6 months. The patient's headaches were marked by holocranial pressure and the majority displayed migrainous associated symptoms although none had a prior headache history. They did not complain of typical symptoms or signs of nutcracker syndrome. Conclusion: We suggest that patients with a daily persistent headache from onset who worsen in the Trendelenburg position may have underlying nutcracker physiology. From our imaging findings, it can be hypothesized that left renal vein compression leads to retrograde flow through the valveless lumbar vein which then leads to spinal epidural venous congestion and subsequently causes congestion of the cerebral venous system leading to an elevation of CSF pressure and to a daily headache. What appears to be unique about these patients is that a daily headache is their only manifestation of nutcracker physiology.