Novel Grading System of Sigmoid Sinus Dehiscence for Radiologic Evaluation of Pulsatile Tinnitus

Discussion in 'Support' started by Frédéric, Feb 23, 2020.

    1. Frédéric

      Frédéric Member Podcast Patron Benefactor Advocate

      Location:
      Marseille, France
      Tinnitus Since:
      11/19/2012
      Cause of Tinnitus:
      acoustic trauma
      I am confused since it also talks about non pulsatile tinnitus.

      Background: There is no consensus on the prevalence of sigmoid sinus dehiscence, with each study offering various definitions and mechanisms of symptoms. Patients who undergo resurfacing surgery for sigmoid sinus dehiscence do so for the defining symptom of pulsatile tinnitus that they experience. Few studies have considered the prevalence of this bony abnormality in asymptomatic populations and those that have find disparate results ranging from 1 to 18%. Understanding a nonpulsatile tinnitus population’s prevalence of sigmoid sinus dehiscence will clarify how distinct this abnormality is to pulsatile tinnitus patients and which types of sigmoid sinus dehiscence are less prevalent in nonsymptomatic patients and more likely to be contributing to symptoms. This study analyzes a cohort of patients without pulsatile tinnitus to characterize the prevalence and types of sigmoid sinus wall anomalies in a nonsymptomatic cohort. In this analysis, a grading system is developed to standardize sigmoid sinus dehiscence.

      Methods: In this retrospective study, temporal bone CT scans of 91 patients without pulsatile tinnitus at a single institution were analyzed for sigmoid sinus dehiscence. The dehiscence was divided into three grades: grade 1 indicating a micro dehiscence of <3.5 mm with an opening to the mastoid air cells, grade 2 indicating a major dehiscence of >3.5 mm with an opening to the mastoid air cells, and grade 3 indicating a sigmoid sinus wall dehiscence that significantly opens directly to the underlying tissue rather than into the mastoid air cells. Dehiscences were measured for their greatest distances.

      Results: In nonsymptomatic patients, sigmoid sinus dehiscence occurred in 34% of the cohort. Of these dehiscences, 75% were grade 1 and 25% were grade 2. The range of dehiscence measurements for grade 1 dehiscences was 0.9 to 3.4 mm. The range of dehiscence measurements for grade 2 was 4 to 7.5 mm. There were no cases of grade 3 dehiscence among this cohort.

      Conclusion: Sigmoid sinus dehiscence occurred in over a third of our nonsymptomatic cohort. While all grades of sigmoid sinus dehiscence may currently be treated surgically, it is important to consider that a large portion of nonpulsatile tinnitus patients may have these sigmoid sinus anomalies asymptomatically. This grading system allows for the standardization of sigmoid sinus dehiscence definition and severity in future studies. Grade 3 dehiscences were completely absent in this cohort of nonpulsatile tinnitus patients. This type of significant dehiscence through the temporal bone leaving the underlying tissue exposed with no bony covering over the sinus is rare and less likely an incidental finding. Larger cohort studies are necessary and should consider which grades of dehiscence are most common in patients with pulsatile tinnitus, particularly in patients undergoing sigmoid sinus wall reconstruction to clarify which grades of sigmoid sinus wall anomaly are most responsive to surgical repair.

      Source: https://www.thieme-connect.com/products/ejournals/abstract/10.1055/s-0040-1702499
       
    2. AUTHOR
      AUTHOR
      Frédéric

      Frédéric Member Podcast Patron Benefactor Advocate

      Location:
      Marseille, France
      Tinnitus Since:
      11/19/2012
      Cause of Tinnitus:
      acoustic trauma
      Pulsatile Tinnitus Secondary to Dehiscent Right Sigmoid Sinus

      Objective: Sigmoid sinus dehiscence (SSD) is an occasional but a treatable cause of tinnitus. Resolution of symptoms have been reported with surgical repair. We describe a case of a patient who developed pulsatile tinnitus as a result of SSD who underwent surgical repair with complete resolution of symptoms

      Background: A 33-year-old obese woman presented with right-sided pulsatile tinnitus for several months along with subsequent headaches. Symptoms were alleviated by neck turning to the right or manual compression of the jugular vein. Magnetic resonance imaging revealed a dominant right-sided sigmoid sinus which extended laterally towards the cortex of the mastoid segment of the temporal bone. Computed tomography of the temporal bone revealed significant thinning and an area of dehiscence along the posterior wall of the right mastoid bone in close association with the sigmoid sinus. Patient underwent a lumbar puncture which revealed an opening pressure of 18 cm H2O; a trial of acetazolamide did not alleviate her symptoms.

      The patient was evaluated by Otorhinolaryngology and was deemed a candidate for resurfacing of the dehiscence with an autogenous bone graft. The patient underwent complete mastoidectomy, cranioplasty, and repair of the malformation. Patient had complete resolution of symptoms in the post-operative period

      Design/Methods: NA

      Results: Up to 25% of cases of pulsatile tinnitus may be a consequence of bony anomalies of the sigmoid sinus including dehiscence or diverticula. SSD is effectively treated with a cortical mastoidectomy with resurfacing of the dehiscence with an autogenous bone graft or bone cement. Instant alleviation of the pulsatile tinnitus have been reported in up to 80% of cases.

      Conclusions: Our case report describes a case of a patient who developed tinnitus secondary to dehiscent right sigmoid sinus and thinning of temporal bone. Patient’s symptoms completely resolved following resurfacing the bone overlying the sinus.

      Disclosure: Dr. Purushothaman Ravichandran has nothing to disclose. Dr. Berman has nothing to disclose. Dr. Yacoub has nothing to disclose. Dr. Varrato has nothing to disclose.

      Source: https://n.neurology.org/content/94/15_Supplement/4083.abstract
       

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