Prevalence, Surgical Management, and Audiologic Impact of Sigmoid Sinus Dehiscence Causing Pulsatile Tinnitus.

OBJECTIVE: To evaluate the prevalence, surgical management, and audiologic impact of pulsatile tinnitus caused by sigmoid sinus dehiscence. STUDY DESIGN AND SETTING: Retrospective chart review at a tertiary care hospital. PATIENTS: Adults with unilateral pulsatile tinnitus attributable to sigmoid sinus dehiscence who underwent resurfacing between January 2010 and January 2020. INTERVENTIONS: Transmastoid sigmoid resurfacing. MAIN OUTCOME MEASURES: Resolution of pulsatile tinnitus; audiologic outcomes; complications; tinnitus etiologies. RESULTS: Nineteen patients (89.4% women) had surgery for suspected sigmoid sinus dehiscence. The mean dehiscence size was 6.1 mm (range, 1-10.7 mm). Eight patients had concurrent sigmoid sinus diverticulum and one patient also had jugular bulb dehiscence. Only two patients (10.5%) had the defect identified by radiology. Low-frequency pure-tone average, measured at frequencies of 250 and 500 Hz, showed a significant median improvement of 8.8 dB following resurfacing (18.8 dB versus 10.0 dB, p = 0.02). The majority of patients had complete resolution of pulsatile tinnitus (16/19, 84.2%). Of those without complete resolution, two patients had partial response and one patient had no improvement. There were no significant complications. Of 41 consecutively tracked patients with a pulsatile tinnitus chief complaint, sigmoid pathology represented 32% of cases. CONCLUSIONS: Sigmoid sinus dehiscence represents a common vascular cause of pulsatile tinnitus that, if properly assessed, may be amenable to surgical intervention. Sigmoid sinus resurfacing is safe, does not require decompression, and may improve low-frequency hearing. Radiographic findings of dehiscence are often overlooked without a high index of clinical suspicion. Its relationship with transverse sinus pathology and idiopathic intracranial hypertension remain unclear.

Radiologic features of vascular pulsatile tinnitus - suggestion of optimal diagnostic image workup modalities.

OBJECTIVES: The aim of this study was to determine the optimal diagnostic workup modalities for vascular pulsatile tinnitus through analysis of clinical and radiologic findings. MATERIALS AND METHODS: A total of 49 patients diagnosed with vascular pulsatile tinnitus along with their medical records and radiologic findings were thoroughly reviewed. RESULTS: Of these patients, 84% had venous lesions. The jugular bulb variants (67%) were the most common venous lesions followed by sigmoid sinus variants (12%). About 88% (43/49) of these lesions were detected with computed tomography of the temporal bone (TBCT) alone and the lesions were either venous or intratemporal artery in origin. Simple manual neck compression test was 93% sensitive in predicting venous lesions. A high suspicion for venous lesion coupled with manual neck compression test and selection of the optimal imaging technique are useful for the proper evaluation of vascular pulsatile tinnitus at the initial visit. CONCLUSION: Our stepwise strategy may increase the cost-effectiveness of the chosen imaging workup by reducing redundancy of multiple and simultaneous radiologic tests in patients with vascular pulsatile tinnitus.

Dural arteriovenous fistula masquerading as pulsatile tinnitus: radiologic assessment and clinical implications.

Pulsatile tinnitus (PT) is often an initial presenting symptom of dural arteriovenous fistula (dAVF), but it may be overlooked or diagnosed late if not suspected on initial diagnostic work-up. Here, we assess anatomical features, treatment outcomes, and clinical implications of patients with PT due to dAVF. Of 220 patients who were diagnosed with dAVF between 2003 and 2014, 30 (13.6%) presented with only PT as their initial symptom. The transverse-sigmoid sinus (70.0%) was the most common site, followed by the hypoglossal canal (10.0%) and the middle cranial fossa (6.7%) on radiologic evaluation. Regarding venous drainage patterns, sinus or meningeal venous drainage pattern was the most common type (73.3%), followed by sinus drainage with a cortical venous reflux (26.7%). PT disappeared completely in 21 (80.8%) of 26 patients who underwent therapeutic intervention with transarterial embolization of the fistula, improved markedly in 3 (11.5%), and remained the same in 2 (7.7%). In conclusion, considering that PT may be the only initial symptom in more than 10% of dAVF, not only otolaryngologists but also neurologists and neurosurgeons should meticulously evaluate patients with PT. In most cases, PT originating from dAVF can be cured with transarterial embolization regardless of location and venous drainage pattern.

Evaluating the role of single-photon emission computed tomography in the assessment of neurotologic complaints.

We conducted a retrospective study to reexamine the value of single-photon emission computed tomography (SPECT) in the evaluation of patients with neurotologic complaints, and to assess the intra- and inter-radiologist variability of SPECT readings. Our study population was made up of 63 patients--23 men and 40 women, aged 34 to 91 years (mean: 59)--who had presented to a tertiary care otolaryngology practice and university hospital for evaluation of head trauma, sensorineural hearing loss, tinnitus, and/or vertigo. All patients had undergone brain scanning with SPECT during their evaluation, and almost all had also undergone magnetic resonance imaging (MRI) and standard computed tomography (CT). We compared the findings of all three imaging modalities in terms of their ability to detect neurotologic abnormalities. We found that detection rates were very similar among the three modalities; abnormalities were found in 24% of SPECT scans, 26% of MRIs, and 23% of CTs. Nevertheless, we did find that among 60 patients who underwent all three types of imaging, 13 (22%) exhibited areas of cerebral hypoperfusion on SPECT while their MRIs and CTs were read as either normal or nonspecific. In all, 18 of these 60 patients (30%) exhibited normal or nonspecific findings on all three types of imaging. In addition, when SPECT scans were read by the same radiologist at different times, different results were reported for 17 of the 63 scans (27%). Likewise, when SPECT scans were read by different radiologists, different results were reported for 21 of 63 scans (33%). We conclude that SPECT may be a valuable complementary diagnostic modality for making a comprehensive neurotologic evaluation and that it may detect abnormalities in some patients whose other imaging is read as normal. However, we did not find that SPECT was the most sensitive of the three modalities in neurotologic evaluation, as we had previously found in a preliminary study that the senior author (R.T.S.) published in 1996. In addition, with respect to our radiologists, both their intra- and inter-reader reliability was low, and we recommend additional study on this matter.

Single-photon-emission computed tomography (SPECT) in neurotologic assessment: a preliminary report.

The single-photon-emission computed tomography (SPECT) scan enables clinicians to probe dynamic and metabolic changes in brain tissue through measurement of regional cerebral blood flow (rCBF). Diagnostic benefits of the SPECT scan in clinical neurology have been demonstrated. SPECT scanning has been shown to be more sensitive than morphologic imaging techniques [magnetic resonance imaging (MRI) and computed tomography (CT)] in many conditions. However, the use of the scan in assessing neurotologic complaints remains inadequately investigated. Few studies have explored the value of SPECT in establishing the causes of dizziness, hearing loss, and tinnitus. We studied SPECT along with MRI, CT scan, electroencephalogram (EEG), and other evaluations in patients with these neurotologic complaints, SPECT abnormalities were more frequent and prominent than those visualized by other imaging modalities. Overall, 78% of SPECT scans revealed abnormalities. Abnormalities were found in 46% of MRIs, 40% of CTs, and 29% of EEGs. The disparity between SPECT scanning and other procedures was also seen once patients were divided by their chief complaints. This study illustrates the sensitivity of SPECT scanning in evaluating neurotologic complaints and highlights the need for additional research into the importance of SPECT scanning in comprehensive neurotologic evaluation.