Cerebellar Gray Matter Volume in Tinnitus

Lilian M Mennink; Elouise A Koops; Dave R M Langers; Marlien W Aalbers; J Marc C van Dijk; Pim van Dijk

doi:10.3389/fnins.2022.862873

Cerebellar Gray Matter Volume in Tinnitus

Front Neurosci. 2022 Apr 29:16:862873. doi: 10.3389/fnins.2022.862873. eCollection 2022.

Authors

Lilian M Mennink^{1

2

3}, Elouise A Koops^{2

3}, Dave R M Langers⁴, Marlien W Aalbers^{1

3}, J Marc C van Dijk^{1

3}, Pim van Dijk^{2

3}

Affiliations

¹ Department of Neurosurgery, University Medical Center Groningen, University of Groningen, Groningen, Netherlands.
² Department of Otorhinolaryngology, Head and Neck Surgery, University Medical Center Groningen, University of Groningen, Groningen, Netherlands.
³ Research School of Behavioral and Cognitive Neurosciences, University Medical Center Groningen, University of Groningen, Groningen, Netherlands.
⁴ Department of Bio-informatics, Hanze University of Applied Sciences Groningen, Groningen, Netherlands.

Abstract

Tinnitus is the perception of sound without an external source. The flocculus (FL) and paraflocculus (PFL), which are small lobules of the cerebellum, have recently been implicated in its pathophysiology. In a previous study, the volume of the (P)FL-complex correlated with tinnitus severity in patients that had undergone cerebellopontine angle (CPA) tumor removal. In this study, the relation between tinnitus and gray matter volume (GMV) of the (P)FL-complex, GMV of the other cerebellar lobules and GMV of the cerebellar nuclei is investigated in otherwise healthy participants. Data was processed using the SUIT toolbox, which is dedicated to analysis of imaging data of the human cerebellum. GMV of all cerebellar lobules and nuclei were similar between tinnitus and non-tinnitus participants. Moreover, no relation was present between tinnitus severity, as measured by the Tinnitus Handicap Inventory, and (P)FL-complex GMV, tonsil GMV, or total cerebellar cortical GMV. These results suggest that in otherwise healthy participants, in contrast to participants after CPA tumor removal, no relation between the GMV of neither the (P)FL-complex nor other cerebellar lobules and tinnitus presence and severity exists. These findings indicate that a relation only exists when the (P)FL-complex is damaged, for instance by a CPA tumor. Alternatively, it is possible that differences in (P)FL-complex GMVs are too small to detect with a voxel-based morphometry study. Therefore, the role of the (P)FL-complex in tinnitus remains to be further studied.

Keywords: cerebellum; flocculus; gray matter volume; hearing loss; paraflocculus; tinnitus.