Pulsatile tinnitus with pulsatile tympanic membrane without retrotympanic mass: A CARE case report.

INTRODUCTION

Giant arachnoid granulation can induce lateral sinus stenosis with sigmoid sinus dehiscence, causing pulsatile tinnitus with pulsatile tympanic membrane without retrotympanic mass.

CASE REPORT: A 78 year-old man presented unilateral left pulsatile tinnitus since 2009, with recent aggravation. Otoendoscopy showed a pulsatile tympanic membrane, in which movement was halted by jugular compression or Valsalva maneuver. CT angiography and MRI found large arachnoid granulation causing left lateral sinus stenosis and eroding the sigmoid sinus wall. Stenting resolved the tinnitus, while the eardrum remained pulsatile.

DISCUSSION: Giant arachnoid granulation can induce lateral sinus stenosis and sigmoid sinus dehiscence, with turbulent venous flow and pulsatile tinnitus. The erosion can transmit cerebrospinal fluid pulsation to the sigmoid sinus and then to the tympanic membrane, where it is visible on otoscopy when the membrane is fragile.