While infrequent, cerebrospinal fluid (CSF) leaks are known to occur after surgical resection of vestibular schwannomas. Early signs of CSF leak often include headache and altered mental status. If untreated, life-threatening complications can occur, including brainstem herniation and meningitis. The appropriate surgical treatment for a CSF leak requires accurate localization of the source. While the most likely location of a CSF leak after lateral skull base surgery is through the aerated portions of the temporal bone, we present a unique case of a man with a prolonged CSF leak after an acoustic tumor removal who was ultimately found to have an occult spinal perineural (Tarlov) cyst as the source. Accurate localization was ultimately achieved with CT myelogram after empirically obliterating his mastoid failed to restore intracranial CSF volume. Tarlov cysts are the most common cause of idiopathic intracranial hypotension, and this case highlights the importance of considering this entity in the differential diagnosis of postoperative CSF leaks.

Subjective tinnitus is an auditory phantom perceptual disorder without an objective biomarker. Bothersome tinnitus in single-sided deafness (SSD) is particularly challenging to treat because the deaf ear can no longer be stimulated by acoustic means. We contrasted an SSD cohort with bothersome tinnitus (TIN; N = 15) against an SSD cohort with no or non-bothersome tinnitus (NO TIN; N = 15) using resting-state functional magnetic resonance imaging (fMRI). All study participants had normal hearing in one ear and severe or profound hearing loss in the other. We evaluated corticostriatal functional connectivity differences by placing seeds in the caudate nucleus and Heschl's Gyrus (HG) of both hemispheres. The TIN cohort showed increased functional connectivity between the left caudate and left HG, and left and right HG and the left caudate. Within the TIN cohort, functional connectivity between the right caudate and cuneus was correlated with the Tinnitus Functional Index (TFI) relaxation subscale. And, functional connectivity between the right caudate and superior lateral occipital cortex, and the right caudate and anterior supramarginal gyrus were correlated with the TFI control subscale. These findings support a striatal gating model of tinnitus and suggest tinnitus biomarkers to monitor treatment response and to target specific brain areas for innovative neuromodulation therapies.