Int Tinnitus J. 2021 Mar 1;25(1):39-45. doi: 10.5935/0946-5448.2021009.
INTRODUCTION: Our initial study reported consecutive patients with constant cardiac synchronous subjective tinnitus (pulsatile tinnitus without an identifiable acoustic source (P)) all of whom could suppress their pulsations with head and neck intense muscle contractions (“somatic testing” (ST)). The term somatosensory pulsatile tinnitus syndrome (SSPT) was coined to refer to this type of P. With now more than a decade of clinical experience with P, herein are reported (a) other ways P can present, beside SSPT, (b) how P is related to the somatosensory system and recumbency, and (c) what treatments have been effective.
METHODS: Retrospective case series of 58 adults with P encountered in an outpatient clinic or through telemedicine.
RESULTS: P could be constant or intermittent, with or without non-pulsatile tinnitus (nP). 90% of cases could suppress their pulsations with ST; 9% could not. In 7 of 11 cases that had no P at time of testing, ST elicited P. The most common type of P was SSPT (constant pulsatile tinnitus suppressible by ST) (60%). Treatment of head and neck muscle dysfunction (muscle dry needling and Botulinum toxin injection) has abolished P; auricular electrical stimulation was effective in 2 cases.
CONCLUSION: Suppression of pulsations by ST, eliciting P by ST, and abolishment of P by head and neck muscle treatments all support a major role of the craniocervical somatosensory system in the etiology of most, if not all, cases of P. Three mechanisms are proposed: (A) somatosensory afferents causing dysfunction of the CNS mechanisms that normally suppress self-generated cardiac and vascular sounds, (B) cardiac synchronous disinhibition of the auditory CNS by somatosensory afferents and (C) some combination of A and B.