TABLE 1.
Summary of magnetic resonance imaging studies of gray and white matter structures in people with hearing loss
| Studies | Groups | Age | Communication | Scanner strength |
Structure | Tissue | Measure | Analysis | Main result | Other results |
|---|---|---|---|---|---|---|---|---|---|---|
| Penhune, Cismaru, Dorsaint-Pierre, Petitto, and Zatorre (2003) | 12 DS vs. 10 | 29 | ASL or LSQ | 1.5 T | HG | GM and WM | Volume | ROI manual | No difference | Asymmetry preserved |
| PT | GM | Volume | ROI manual | No difference | Asymmetry preserved | |||||
| Left motor hand area | GM | Whole brain | VBM (SPM) | Larger density | Asymmetry preserved | |||||
| Emmorey, Allen, Bruss, Schenker, and Damasio (2003) | 25 DS vs. 25 | 23.8 ± 4.1 | ASL | 1.5 T | Temporal lobe | GM and WM | Volume | ROI manual | No difference in GM/WM ratio | |
| STG | GM and WM | Volume | ROI manual | Larger GM/WM ratio | ||||||
| HG | GM and WM | Volume | ROI manual | Larger GM/WM ratio | Asymmetry preserved | |||||
| PT | GM and WM | Volume | ROI manual | Left PT larger (GM) | ||||||
| Fine, Finney, Boynton, and Dobkins (2005) | 6 DS vs. 6 HS vs. 6 | 27 ± 5.7 | ASL | 1.5 T | Early visual areas | GM | Volume | Retinotopic fMRI | No difference | Only auditory area affected |
| Kara et al. (2006) | 18 DS vs. 18 | 41.2 ± 7.5 | TSL | 1.5 T | CC | WM | Length | ROI manual | No difference | |
| Width | ROI manual | No difference | ||||||||
| Area | ROI manual | No difference | ||||||||
| Shibata (2007) | 53 DS vs. 51 | 21 | ASL | 1.5 T | Left posterior STG | WM | Whole brain | VBM (SPM) | Focal deficit | |
| Posterior STG | WM | Whole brain | VBM (SPM) | Focal deficit in asymmetry | ||||||
| Frontal/temporal perisylvian | GM | Whole brain | VBM (SPM) | Asymmetry preserved | ||||||
| Meyer et al. (2007) | 6 DS vs. 6 | NR | DGS | 3 T | Left post-long uncinate fasisculus | WM | Whole brain | VBM (SPM) | Less | |
| Left post-inferior uncinate fasisculus | WM | Whole brain | VBM (SPM) | Less | ||||||
| Posterior Sylvian fissure | WM | Whole brain | VBM (SPM) | Steeper | ||||||
| Allen, Emmorey, Bruss, and Damasio (2008) | 25 DS vs 16 HS vs. 25 | 23.8 ± 4.1 | ASL | 1.5 T | Left posterior insula lobule | GM | Volume | ROI manual | Larger in DS | |
| Right insula | WM | Volume | ROI manual | Larger in DS and HS | ||||||
| Xia, Qi, and Li (2008) | 20 DS vs. 20 | 9–12 | CSL | 1.5 T | Left HG, right HG | GM/WM | Ratio | ROI manual | Larger in DS | |
| 20 DS vs. 20 | 19–22 | CSL | 1.5 T | Left HG and left STG | GM | Volume | ROI manual | Larger in DS | ||
| D. J. Kim, Park, Kim, Lee, and Park (2009) | 13 DS vs. 29 | 29.3 ± 6.8 | KSL | 3 T | STG | WM | Volume | VBM (SPM) | Smaller bilaterally | |
| Temporal sub-gyral | WM | Volume | VBM (SPM) | Smaller bilaterally | ||||||
| Left parietal | WM | Volume | VBM (SPM) | Smaller | ||||||
| Left superior frontal | WM | Volume | VBM (SPM) | Smaller | ||||||
| Left medial frontal | WM | Volume | VBM (SPM) | Smaller | ||||||
| Lepore et al. (2010) | 14 DS vs. 16 | 29.5 | LSQ | 1.5 T | Frontal lobe (Broca's) | WM | Volume | TBM (voxel-wise Jacobian) | Larger | |
| Adjacent: Motor | WM | Whole brain | TBM (voxel-wise Jacobian) | Larger | ||||||
| Adjacent: Language | WM | Volume | TBM (voxel-wise Jacobian) | Larger | ||||||
| CC (splenium: temporal/occipital) | WM | Manual | ROI manual | Difference | ||||||
| K. M. Smith et al., 2011 | 16 D vs. 26 | 12 ± 2.8 mo | NR | 3 T | HG | GM | Whole brain | VBM (SPM) | Increased | Asymmetry not preserved |
| WM | Whole brain | VBM (SPM) | Decreased | |||||||
| J. Li et al. (2012) | 16 DS vs. 16 | 14.56 ± 2.1 | CSL | 3 T | Left precentral gyrus | GM | Thickness | CIVET | Smaller | |
| Right postcentral gyrus | GM | Thickness | CIVET | Smaller | ||||||
| Left superior occipital gyrus | GM | Thickness | CIVET | Smaller | ||||||
| Left fusiform gyrus | GM | Thickness | CIVET | Smaller | ||||||
| Whole brain | GM | Thickness | CIVET | Smaller | ||||||
| Left middle frontal gyrus | WM | Volume | VBM (SPM) | Focal decrease | ||||||
| Right inferior occipital gyrus | WM | Volume | VBM (SPM) | Focal decrease | ||||||
| Allen, Emmorey, Bruss, and Damasio (2013) | 25 DS vs. 16 HS vs. 25 | 23.8 ± 4.1 | ASL | 1.5 T | Calcarine sulcus (VI) | GM | Volume | ROI manual | Larger in DS | Asymmetry in DS and HS |
| Pars Triangularis (Broca's) | GM | Volume | ROI manual | Larger in DS | ||||||
| Handknob (precentral gyrus) | GM | Volume | ROI manual | No difference | Asymmetry in DS and HS | |||||
| Boyen, Langers, de Kleine, and van Dijk (2013) | 16 HI vs. 24 | 63 ± 10 | Tinnitus stud | 3 T | STG, MTG | GM | Volume | VBM (SPM) | Increase | |
| SFG, occipital, hypothalamus | GM | Volume | VBM (SPM) | Decrease | ||||||
| Frontal | GM | Volume | ROI | Decrease | ||||||
| Limbic | GM | Volume | ROI | Increase | ||||||
| W. Li et al., 2013 | 16 DS vs. 16 | 14.56 ± 2.10 | CSL | 3 T | Cerebellum | GM | Volume | VBM (SPM) | Rightward asymmetrj | |
| Posterior cingulate gyrus | GM | Thickness | CIVET | Leftward asymmetry | ||||||
| Gyrus rectus | GM | Thickness | CIVET | Leftward asymmetry | Negatively correlated with HA | |||||
| Auditory cortex (HG) | GM | Thickness | CIVET | Asymmetry preserved | ||||||
| Penicaud et al. (2013). | 9 DS (birth) vs. 8 DS (early) vs. 6 DS (late) vs. 43 | 39.2 ± 12.3 | ASL | 1.5 T | Early visual areas | GM | Volume | VBM (SPM) | Later ASL: lower | Deaf not different from hearing |
| F. R. Lin et al. (2014) | 51 DS vs. 75 | 73.8 ± 7.3 | NR | 1.5 T | Right STG, right MTG, right ITG, right PHG | GM | Volume | RAVENS | Accelerated loss over time | |
| Hribar, Suput, Carvalho, Battelino, and Vovk (2014) | 14 DS vs. 14 | 35.4 ± 6 | SSL | 3 T | Left HG | WM | Volume | ROI manual | Less | |
| Middle medial left superior frontal gyrus | GM | Volume | FreeSurfer | Focal decrease | ||||||
| Left supramarginal gyrus | GM | Thickness | FreeSurfer | Focal decrease | ||||||
| Cerebellum | GM | Whole brain | VBM (FSL) | Increased volume | ||||||
| Olulade, Koo, LaSasso, and Eden (2014) | 15 DS vs. 15 HS vs. 15 DO | 23.4 ± 3.3 | ASL (DS/HS), oral/cued (DO) | 3 T | Early visual areas | GM | Volume | VBM (SPM) | Less in both DS and DO | |
| vs 15 | Left early auditory areas | GM | Volume | VBM (SPM) | Less in both DS and DO | |||||
| Left STG | WM | Volume | VBM (SPM) | Differences in DS | ||||||
| Left inferior frontal gyrus | WM | Volume | VBM (SPM) | Differences in DS | ||||||
| General | GM and WM | Volume | VBM (SPM) | DO less different than DS from controls | ||||||
| E. Kim et al. (2014) | 8 DS vs. 11 DO vs. 11 | 50.4 ± 6.1 | NR | 3 T | Primary auditory cortex | GM | Density | VBM (SPM) | No difference in DS | Decrease in DO |
| Primary auditory cortex | GM | Connectivity | Voxel-wise correlation | Correlated in DS | Increased bilateral temporal connectivity in DO | |||||
| Whole brain | GM | Connectivity | Brain connectivity toolbox | Connectivity measures increased in DS | Fronto-limbic and left temporal correlated and temporo-parietal weakly coupled in DS | |||||
| Tae (2015) | 8 DS vs. 9 | 15.6 | KSL | 1.5 T | Left anterior HG | GM | Volume | VBM | Decreased | |
| Left and right inferior colliculus | GM | Volume | VBM | Decreased | ||||||
| Lingual gyri, nucleus accumbens, thalamic reticular nucleus | GM | Volume | VBM | Decreased | ||||||
| Amaral et al. (2016) | 15 DS vs. 16 | 20.4 | CSL | 3 T | Thalamus | GM | Volume | Manual | Right > left | |
| Left geniculate nucleus | GM | Volume | Manual | Right > left | ||||||
| Inferior colliculus | GM | Volume | Manual | Right > left | ||||||
| Shiell, Champoux, and Zatorre (2016) | 11 DS vs. 11 | 28.2 | LSQ/ASL | 3 T | Right PT | GM | Thickness | FreeSurfer | Increased | |
| Smittenaar, MacSweeney, Sereno, and Schwarzkopf (2016) | 15 DS vs. 15 | 39 | BSL | 1.5 T | VI | GM | Thickness | FreeSurfer | Decreased | |
| Kumar and Mishra (2018) | 50 vs. 50 | 19.5 | Acquired ISL at age 10.8 years | 3 T | Bilateral STG, bilateral ITG, bilateral fusiform, bilateral MFG | WM/GM, GM, GM | Volume | VBM, SBM and PBCT | Decreased, increased, increased, increased | Increased thickness |
| Feng et al. (2018) | 37 vs. 40 | 17.9 mo | HA before CI | 3 T | Bilateral AC (middle part of STG) | GM/WM | Density | VBM and MVPS | Most significant, less significant—IFG, CG, occipital, hippocampus, precuneus | Regions unaffected by auditory deprivation provided good outcomes for CI |
| X. M. Xu et al. (2019a) | 35 vs. 54 | 56 | Postlingual | 3 T | Insula | GM | Density and connectivity | VBM | Insignificant differences | Reduced connectivity with other regions |
| X. M. Xu et al. (2019b) | 37 vs. 38 | 55.6 | Postlingual | 3 T | Thalamic subfield connectivity | GM | Relative volume | VBM | Decrease in right motor thalamus and somatosensory thalamus | |
| Pereira-Jorge et al. (2018) | 14 vs. 11 | 51.3 | Postlingual (before HA) | 1.5 T | PFC. precuneus. fusiform gyrus, and MTG; insula, supramarginal gyrus, medial temporal gyrus, occipital, posterior cingulate cortex, and claustrum | Thickness | FreeSurfer | Increase, decrease | After 1 year of HA, increase in multimodal integration regions | |
| Shiohama, McDavid, Levman, and Takahashi (2019) | 30 vs. 90 | 5.3–6.7 | NR | 3 T | Left middle occipital and left inferior occipital | GM | Thickness | CIVET | Smaller | |
| 35 vs. 23 | 39 ± 1.8 | NR | 3 T | GM | Volume | VBM (SPM) | Smaller | |||
| Qi, Su, Zou, Yang, and Zheng (2019) | Right fusiform and right middle occipital gyrus | |||||||||
| Ratnanather et al. (2019) | 5 DO vs. 5 | 31 | LSL and HA | 1.5 T | HG and PT | GM | Thickness | LCDM | Thicker | See also Dhir, Kutten, Li, Faria, and Ratnanather (2020) |
Note: Structures observed to be affected by hearing loss are shown in Figures 3 and 4. Gender information can be obtained from original papers and is not recorded here due to lack of correlation. Age is given as mean ± SD or mean.
Abbreviations: ACC, anterior cingulate cortex; ASL, American sign language; BSL, British sign language; CC, corpus callosum; CG, cingulate gyrus; CI, cochlear implant; CIVET, combined interoperability validation evaluation tool; CSL, Chinese sign language; D, deaf; DO, deaf oral; DS, deaf signing; DGS, German sign language; fMRI, functional MRI; FSL, FMRIB software library; GM, gray matter; HA, hearing aids; HG, Heschl's gyrus; HI, hearing impaired; HS, hearing signing; ISL, Indian sign language; ITG, inferior temporal gyrus; KSL, Korean sign language; LCDM, labeled cortical distance mapping; LSL, listening and spoken language; LSQ, langue signe quebecois; MFG, middle frontal gyrus; mo, month; MTG, middle temporal gyrus; MVPS, multivoxel pattern similarity; NR, not recorded; PBCT, projection-based cortical thickness; PFC, prefrontal cortex; PHG, parahippocampal gyrus; PT, planum temporale; RAVENS, regional analysis of volume examined in normal space; ROI, region of interest; SSL, Slovenian sign language; STG, superior temporal gyrus; SFG, superior frontal gyrus; SPM, statistical parametric mapping; TSL, Turkish sign language; TBM, tensor-based morphometry; VBM, voxel-based morphometry; WM, white matter.