Novel Use of Time-Resolved Magnetic Resonance Angiography to Evaluate Retrograde Lumbar Vein Flow and Epidural Venous Plexus Enhancement in Chronic Headache Patients With and Without Nutcracker Physiology

Abstract

Objective: Compression of the left renal vein by the superior mesenteric artery, known as nutcracker phenomenon (NCP), can cause retrograde flow and congestion in communicating venous systems. It has recently been speculated that NCP can result in retrograde flow and congestion of the lumbar veins and epidural venous plexus (EVP), thereby affecting the central nervous system. This study describes the novel use of time-resolved magnetic resonance angiography (trMRA) to evaluate for retrograde left second lumbar vein (L2LV) flow and early EVP enhancement in patients with chronic daily headache (CDH) with and without NCP.Methods: A retrospective analysis was performed of 31 patients with CDH (27 females and 4 males; median age, 38 years [range, 18-63 years]) who underwent trMRA centered over the L2LV to evaluate the direction of blood flow and presence of early EVP enhancement from May 2020 to March 2022. Descriptive statistics were performed, and anatomic associations were analyzed in patients with and without retrograde L2LV flow and early EVP enhancement. The accuracy of magnetic resonance imaging findings in detecting these flow patterns was also assessed. Results:Patients with NCP who demonstrated narrowing of the left renal vein, a positive beak sign ( P = 0.052), decreased aortomesenteric distance ( P = 0.038), and decreased SMA angle demonstrated increased rates of retrograde L2LV flow and early EVP enhancement. A positive beak sign was 83% specific, and an aortomesenteric distance of ≤6.5 mm was 61% sensitive and 83% specific for identifying retrograde L2LV flow with early regional EVP enhancement in patients with CDH.Conclusions: Retrograde L2LV flow with early EVP enhancement in CDH patients can be effectively evaluated using trMRA and was seen with greater propensity in those patients with NCP.

A secondary daily persistent headache from onset with underlying nutcracker physiology and spinal epidural venous congestion: case series with lumbar vein embolization as a therapeutic approach

“…It is important to note that from our small investigations so far, the majority of patients with daily headache and NP do not have congestion of the spinal EVP and thus some other cause for their headaches needs to be elucidated. 2,3 From our current case series, it appears that early dramatic improvement post-embolization procedure maybe a positive predictive factor for longterm improvement. This may suggest that immediately post-embolization there are no other secondary collaterals present causing spinal EVP congestion, but as we saw with patient 3 (Table 1), collaterals may develop with headache recurrence.…”

“…13,14 We have subsequently published on a series of patients, utilizing a novel time-resolved MR angiography technique, that was able to identify patients with spinal EVP congestion. 2,3 We then hypothesized that the spinal cord venous plexus engorgement secondarily led to cerebral venous congestion and that caused the patient’s CSF pressure/volume to rise above a pain threshold point leading to a daily persistent headache. 2,15 Three of our patients had lumbar punctures with opening pressures (17–23 cm H 2 O) falling within the established normal range of 10–30 cm H 2 O (Table 1).…”

“…It is important to note that from our small investigations so far, the majority of patients with daily headache and NP do not have congestion of the spinal EVP and thus some other cause for their headaches needs to be elucidated. 2,3…”

“…To be considered for treatment each patient had to demonstrate NP with early retrograde L2LV flow and spinal EVP enhancement on our novel time-resolved MRA technique. 2,3 To be considered for coil embolization, the case patients had to be treatment refractory failing at least four headache preventive medications and to be disabled by their headache syndrome. To verify the MRA findings each patient underwent catheter-based venography.…”

“…The authors A secondary daily persistent headache from onset with underlying nutcracker physiology and spinal epidural venous congestion: case series with lumbar vein embolization as a therapeutic approach 2 journals.sagepub.com/home/tan have recently published on a unique subset of patients with persistent headaches whose head pain worsened in the Trendelenburg position and who on time-resolved magnetic resonance angiography (MRA) demonstrated left renal vein (LRV) compression by the superior mesenteric artery and the aorta [nutcracker physiology (NP)] with retrograde left second lumbar vein (L2LV) flow and regional spinal epidural venous plexus (EVP) congestion. 2,3 Interestingly the patients all possessed NP, but they did not have true nutcracker syndrome (flank pain, proteinuria, and hematuria) just a daily headache. 2,4 We hypothesized based on our imaging findings that LRV compression leads to retrograde flow through a valveless L2LV, which then leads to spinal EVP congestion and subsequently causes a secondary congestion of the cerebral venous system, which then leads to an elevation of cerebrospinal fluid (CSF) pressure above that individuals CSF pressure set point.…”