Research Areas


Electrovestibulography (EVestG) Experiments

EvestG is a new vestibular driven test that measures spontaneous and driven field potential activity recorded in the external ear canal in response to vestibular stimuli. The EVestG test is similar to electrocochleography with the acoustic input replaced by a series of orthogonal tilts.

The EVestG signal is recorded during dynamic and static phases via an electrode resting proximal to the tympanic membrane [6,7]. The electrodes are simply and painlessly positioned and rested close to the left and right ear drums of the subject. Figures 2 and 3 show the recording system with the hydraulic chair.

EVestG technology has been applied towards diagnosis of and separation of Parkinson disease (PD) / Schizophrenia / Depression (Unipolar vrs Bipolar) / Meniere's Disease / Controls [6-19]. Sensitivities and specificities so far have been typically above 85%.

Here is a short video clip showing how EVestG signal is recorded in our lab at Riverview Health Center.

If you like to read more news about EVestG, you may read on the RHC newsletter (second page) and in this Radio Interview.

In our early studies, we focused on the diagnosis of Meniere’s disease, Parkinson’s, Depression and Bipolar disorders with EVestG. Later, we applied it to both the diagnosis of post-concussion syndrome (PCS) and monitoring the effect of rTMS treatment on PCS. The results of that work (funded by several MITACS projects in partnership with Manitoba Public Insurance, Riverview Health Center Foundation and NeuralDx) has been published in in 5 journal papers and 5 conferences. Since 2017, we have been using EVestG for diagnosis of Alzheimer’s and separating it from the mixed Alzheimer’s cases; the results so far has shown a high accuracy (>85%); we have submitted the results to a journal and it is under review. In addition, we have been using  predicting the response of Alzheimer’s patients to rTMS treatment at baseline as well as monitoring the treatment’s effect on Alzheimer’s, which is a novel work on its kind. No existing tool can currently predict the response of a patient to rTMS treatment at baseline. So, far our results indicate a high accuracy >76%; we have only presented and published part of our data in Brain stimulation conference so far. Overall, our works using EVestG for diagnostic and monitoring purposes have resulted in 17 journal and 19 conference papers in high-impact journals.

Some of our related journal publications using EVestG are:

  1. Ashiri M., Lithgow B., Suleiman A., Blakley B., Mansouri B. and Moussavi Z., “Differences between physical versus virtual evoked vestibular responses,” Annals of Biomedical Engineering (ABME), Jan. 2020. Z., Lithgow B., and Moussavi Z., "Diagnosis of Parkinson's Disease using Electrovestibulography", Med Biol Eng Comp, in press (DOI: 10.1007/s11517-012-0890-z), 2012.
  2. Lithgow B., Moussavi Z., “Effect of Multi-site Variabilities on Electrovestibulography: Environmental and Physical Factors,” J. Research and Development on Information and Communication Technology, Sept. 2019.
  3. Suleiman A., Lithgow B., Anssari N., Ashiri M., Moussavi Z., Mansouri B., “Correlation between ocular and vestibular abnormalities and convergence insufficiency in post-concussion syndrome,” J Neuro-Ophthalmology, Oct. 2019. doi:10.1080/01658107.2019.1653325
  4. Moussavi Z., Suleiman A., Rutherford G., Ranjbar-Pooya R., Dastgheib Z., Zhang W., Salter J., Wang X. Mansouri B., Lithgow B., “A pilot Randomized Double-Blind Study of the Tolerability and Efficacy of repetitive Transcranial Magnetic Stimulation on Persistent Post-Concussion Syndrome,” Scientific Reports, 9:5498, April 2019.
  5. Lithgow B., Moussavi Z., Fitzgerald P., “Quantitative separation of the depressive phase of Bipolar Disorder and Major Depressive Disorder using Electrovestibulography,” The World J Biological Psychiatry, 20(10):799-812, Dec. 2019, doi: 10.1080/15622975.2019.1599143
  6. Lithgow B., Moussavi Z., Gurvich C., Maller J, and Fitzgerald P., “Bipolar Disorder in the Balance”, European Archives of Psychiatry and Clinical Neuroscience, 269(7):761-775, Oct 2019.
  7. Ashiri M., Lithgow B., Suleiman A., Moussavi Z. and Mansouri B, “Visio-vestibular interaction in humans: changes in the vestibular response following visual stimuli of different colors,” Journal of Medicine and Biological Engineering (JMBE), 39(2):238-243, March 2019. 
  8. Suleiman A., Lithgow B., Mansouri B. and Moussavi Z., “Using EVestG assessment for detection of symptomology consequent to a lateral-impact concussion,” Journal of Medicine and Biological Engineering (JMBE), 39(2):218-223, March 2019.
  9. Blakley B., Sulieman A., Rutherford G., Moussavi Z. and Lithgow B., “EVestG recordings are Vestibuloacoustic signals,” Journal of Medicine and Biological Engineering (JMBE), 39(2):213-217, March 2019. DOI 10.1007/s40846-018-0398-6 .
  10. Suleiman A., Lithgow B., Mansouri B. and Moussavi Z., “Investigating the validity and reliability of Electrovestibulography (EVestG) for detecting post-concussion syndrome (PCS) with and without comorbid depression,” Scientific Reports (Nature), 8(1):14495, Sept. 27 2018.
  11. Lithgow B.J. and Moussavi Z., “Physiological differences between Follicular, Luteal and Menses phases of Healthy Women using Electrovestibulography; Depression, Anxiety or other?” J Neuropsychology, 76 (2):72–81, 2017.
  12. Suleiman A., Lithgow B., Dastgheib Z., Mansouri B., and Moussavi Z., “Quantitative measurement of post-concussion syndrome (PCS) using Electrovestibulography (EVestG),” Scientific Reports (Nature), 7 (1):16371, 2017.
  13. Dastgheib Z., Lithgow B., Blakley B. and Moussavi Z., “Application of Vestibular Spontaneous Response as a Diagnostic aid for Meniere's Disease,” J Annals of Biomed Eng., 44(5), 1672-1684, 2016. DOI: 10.1007/s10439-015-1441-1
  14. Kumaraganage C., Lithgow B. and Moussavi Z., “Investigation of a New Weighted Averaging Method to Improve SNR of Electrocochleography Recordings,” Trans. IEEE Biomed Eng., DOI: 10.1109/TBME.2015.2457412, 63(2):340-7, Feb 2016
  15. Lithgow B., Garrett A., Moussavi Z., Gurvich C., Kulkarni J., Maller J. and Fitzgerald P., “Major Depression and Electrovestibulography,” World Journal Biological Psychiatry, 16(5):334-50, 2015. doi:10.3109/15622975.2015.1014410
  16. Kumaraganage C., Lithgow B. and Moussavi Z., “A new Low Noise Signal Acquisition Protocol and Electrode Placement for Electrocochleography (ECOG) Recordings,” J Med Biol Eng Comp, 53(6):499:509, doi: 10.1007/s11517-015-1251-5, 2015
  17. Blakley B., Dastgheib Z., Lithgow B. and Moussavi Z., “Preliminary report: neural firing patterns specific for Meniere’s disease,” J. Otolaryngology - Head & Neck Surgery, 43: (52) Dec. 2014.
  18. Kumaraganage C., Lithgow B. and Moussavi Z., “Development of an Ultra-Low Noise, Miniature Signal Conditioning Device for Vestibular Evoked Response Recordings,” BioMedical Engineering Journal OnLine. 13(1) Jan. 2014.
  19. Dastgheib Z., Lithgow B., and Moussavi Z., "Diagnosis of Parkinson's Disease using Electrovestibulography", Med Biol Eng Comp, 50(5):483-91 (DOI: 10.1007/s11517-012-0890-z), May 2012