Symptomatic Tarlov cysts are often overlooked. Ten reasons why.
Several authors have observed that radicular pain is a commonly underrecognized
symptom of idiopathic intracranial hypertension. Of interest is that dilations of the nerve root
sheaths could be seen peroperatively or on MRI/CT imaging in these cases, and radicular
pain resolved immediately following CSF evacuation [15-18].
Thus, under hydrostatic and pulsatile CSF pressures, some nerve root sheaths may
dilate significantly. This mechanism is similar to the formation of vascular aneurysms under
increased blood pressure. High blood pressure also gradually damages the inner walls of the
vessels, whereas increased cerebrospinal pressure damages the axons [19].
It can be argued that most TC patients do not have papilledema, a hallmark of
intracranial hypertension [20]. However, papilledema is no longer required to diagnose
intracranial hypertension. Additionally, the arbitrary cut-off of 20 cm H2O to define
intracranial hypertension is probably too high. Rather, there may be a continuum between
normal and increased ICP [21].