Cognitive impairment and tinnitus

By Marcello Cherchi, MD PhD

For patients

An individual suffering with tinnitus from any cause often complains of various problems with thinking, such as memory and concentration. The relationship between tinnitus and cognitive deficits is still poorly understood.

For clinicians

The relationship between tinnitus and cognitive deficits is poorly understood, and research on this topic is still in its early stages.

It has been well documented that individuals suffering with tinnitus exhibit measurable cognitive deficits (Andersson, Eriksson et al. 2000, Andersson and McKenna 2006).

Tinnitus is known to cause psychiatric disorders, and a number of psychiatric disorders can interfere with cognition. However, since some patients without psychiatric disease can also exhibit cognitive deficits, it is suspected that some degree of cognitive deficiency must be attributable to tinnitus itself, independent of any psychiatric mechanism (Jackson, Coyne et al. 2014).

Tinnitus often accompanies hearing loss (Lockwood, Salvi et al. 2002), and hearing loss has been shown to predispose to cognitive deficits (Jafari, Kolb et al. 2021), consequently it has been difficult to disentangle the cognitive effects of hearing loss and tinnitus. Somewhat surprisingly, one study concluded that normal hearing tinnitus patients (i.e., those who have tinnitus but no measurable hearing loss) do not have cognitive deficits (Waechter and Brannstrom 2015) though the authors acknowledge that this conclusion differs from that of other researchers.

What are the mechanisms by which tinnitus might cause cognitive deficits?

Some research postulates that tinnitus interferes with various facets of attention (Stevens, Walker et al. 2007, Mohamad, Hoare et al. 2016, Cardon, Jacquemin et al. 2019), perhaps by adversely affecting executive control (Tegg-Quinn, Bennett et al. 2016), which in turn causes “cognitive inefficiency” (Hallam, McKenna et al. 2004).

Other studies conclude that, “tinnitus affects cognition to the extent that it reduces cognitive capacity needed to perform tasks that require voluntary, conscious, effortful, and strategic control” (Rossiter, Stevens et al. 2006).

References