Tag Archives: NeuroStimulation

thermal taster

Do you know what your thermal taster status is?

Thermal taster status (TTS) is a phenomenon in which thermal stimulation of specific areas of the tongue, causes a sensation of a distinct taste in the absence of a gustatory stimulus. Reports vary on what percentage of the general population is a thermal taster, occurrence of thermal tasters in research cohorts of between 20% and 50% has been reported.

thermal taster

Not all Thermal Tasters taste alike

Even within the group of thermal tasters, there are subgroups. These groups differ from one another in responsiveness to thermal stimuli in different areas of the tongue and the phantom taste that each type of stimulation arouses. Green and George report that “thermal sweetness” is a common taste occurring in half the thermal tasters in response to warming after the tongue was cooled, while Skinner et al. reported 25% of tasters tasting “bitter” while another 25% tasting “sour” in cooling trials.

How to assess Thermal Taste

In general, TTS is assessed by applying a thermode with a warming and a cooling stimulus, as each temperature change direction and specific temperatures elicits a different taste sensation in thermal tasters. Thermal taste is classically tested on the tip of the tongue, and some studies report findings from areas lateral of the tip or the back of the tongue. Several studies on thermal tasters have used Medoc’s Pathway 16*16 mm thermode or the Intra-oral thermode. An example of a testing protocol for TTS could be found in Eldeghaidy et al.’s study in which both warming trials and cooling trials were applied. A warming trial would start at 35°C, cooled down to 15°C and go up to 40°C, and held there for 10 sec., with a ramp of 1 °C/sec.

Tongue taste innervation

In Thermal tasters, the anterior part of the tongue, innervated by the chorda tympani nerve, shows a typical reaction to heating and to cooling, while the posterior part of the tongue, innervated by the glossopharyngeal nerve, reacts less typically, Cruz and Green found[7]. Thermal taster status, along with another measure, 6-npropylthiouracil (PROP) taster status, form the taste phenotype.

Do fungiform papillae matter?

A hypothesis existed that the fungiform papillae of the tongue would be responsible for thermal taste because of their high density at the tip of the tongue, and their dual role: as they contain both taste buds and mechanoreceptors that are innervated by gustatory and trigeminal nerve fibers. Eldeghaidy et al. found that TTS did not seem to be correlated to fungiform papillae density in contrast to PROP taster status, and thus must have a different mechanism. The taste phenotype as a whole, and the thermal taster status specifically, increasingly allure both neurology researchers and the food and beverage industry alike. Temperature may be actively integrated as a contributor in the totality of the gustatory experience when new taste product are planned to be released to market.



Medoc Thermodes

Fit to a T(hermode)

Medoc Thermodes

We are often asked by our customers: “what thermode should I use?” Our answer is usually: “it depends”.

This is one of the most common questions we are asked when a customer approaches us, intending to buy a thermal quantitative sensory testing (QST) device.

The thermode is the probe that is attached to the participants’ skin, that on command of the computer program changes its temperature to hot or cold.

There are several types of thermodes; which one fits you best, depends mostly on your intended use.

Let’s start with the basics:

Comparing and contrasting

The classic thermode size is the 30mm by 30mm contact surface thermode, or for short: the 30*30. This thermode size has been around for decades and has therefor gathered quite the following.

Most of the normative data that has been gathered with Medoc devices around the world, and specifically by the German Research Network on Neuropathic Pain, the DFNS, has been gathered with this 30*30 thermode[1],[2],[3]. If you intend to compare your QST results to normative values that have been collected from healthy participants, you may want to consider using the 30*30.

Another quite common thermode size is the 16*16. This thermode has been in use with researchers and clinicians who wish to stimulate smaller areas, like the face[4] or the tongue[5], or perform QST on children[6].

Need for speed

One of the most asked-about thermodes is the CHEPS thermode. This thermode is special, because its technology allows working at very high speeds, for both heat and cold stimulation.

These high speeds are especially important for researchers who want to use a fast thermal stimulation in order to record Contact Heat Evoked Potentials (CHEPs)[7],[8],[9] or Cold Evoked Potentials (CEPs)[10]. Others may be interested in an application called: phasic heat temporal summation, in which very fast noxious heat pulses are applied in order to test for the wind-up phenomenon[11],[12].

Visualizing pain

The above thermode types (30*30, 16*16, CHEPS) are also available in fMRI versions. fMRI thermodes are different from normal thermodes for having additional 10 meters cable length, allowing the device to be placed outside the magnetic chamber and only the thermode to pass through the waveguide, reducing noise artifacts and insuring safety. These thermodes have undergone thorough testing and validation in different MRI environments.

Thermal stimulation is used in many trials that examined psychology (including reward processing, mindfulness, and more)[13],[14] and pain neurophysiology[15],[16].

Not your run of the mill thermode..

Then there are the specialized thermodes. Some quantitative sensory testing has been conducted on the most uncommon places in the body, to elucidate specific issues.

Intra-oral testing is conducted with a small diameter Intraoral thermode for varying purposes like; tooth sensitivity[17],[18], pain disorders involving the mouth or the face[19]and thermal taster status.

Medoc’s Intravaginal thermode, formerly known as the Genito-sensory-analyzer (GSA) is utilized in studies which seek to assess somatosensory function and pain of the genital area in women[20],[21],[22] and men[23].


References: [1]Hafner, J., Lee, G., Joester, J., Lynch, M., Barnes, E. H., Wrigley, P. J., & Ng, K. (2015). Thermal quantitative sensory testing: a study of 101 control subjects. Journal of Clinical Neuroscience, 22(3), 588-591. [2] Blankenburg, M., Boekens, H., Hechler, T., Maier, C., Krumova, E., Scherens, A., … & Zernikow, B. (2010). Reference values for quantitative sensory testing in children and adolescents: developmental and gender differences of somatosensory perception. PAIN®, 149(1), 76-88. [3]Yarnitsky, D., & Sprecher, E. (1994). Thermal testing: normative data and repeatability for various test algorithms. Journal of the neurological sciences, 125(1), 39-45. [4] Sampaio, F. A., Sampaio, C. R., Cunha, C. O., Costa, Y. M., Alencar, P. N., Bonjardim, L. R., … & Conti, P. C. (2019). The effect of orthodontic separator and short‐term fixed orthodontic appliance on inflammatory mediators and somatosensory function. Journal of oral rehabilitation, 46(3), 257-267. [5] Yang, Q., Dorado, R., Chaya, C., & Hort, J. (2018). The impact of PROP and thermal taster status on the emotional response to beer. Food Quality and Preference, 68, 420-430. [6] Hainsworth, K. R., Simpson, P. M., Ali, O., Varadarajan, J., Rusy, L., & Weisman, S. J. (2020). Quantitative Sensory Testing in Adolescents with Co-occurring Chronic Pain and Obesity: A Pilot Study. Children, 7(6), 55. [7] Rosner, J., Hostettler, P., Scheuren, P. S., Sirucek, L., Rinert, J., Curt, A., … & Hubli, M. (2018). Normative data of contact heat evoked potentials from the lower extremities. Scientific reports, 8(1), 1-9. [8] Jutzeler, C. R., Rosner, J., Rinert, J., Kramer, J. L., & Curt, A. (2016). Normative data for the segmental acquisition of contact heat evoked potentials in cervical dermatomes. Scientific reports, 6, 34660. [9] Granovsky, Y., Anand, P., Nakae, A., Nascimento, O., Smith, B., Sprecher, E., & Valls-Solé, J. (2016). Normative data for Aδ contact heat evoked potentials in adult population: a multicenter study. Pain, 157(5), 1156-1163. [10]Hüllemann, P., Nerdal, A., Binder, A., Helfert, S., Reimer, M., & Baron, R. (2016). Cold‐evoked potentials–Ready for clinical use?. European Journal of Pain, 20(10), 1730-1740. [11]Staud, R., Weyl, E. E., Riley III, J. L., & Fillingim, R. B. (2014). Slow temporal summation of pain for assessment of central pain sensitivity and clinical pain of fibromyalgia patients. PloS one, 9(2), e89086. [12]Bar-Shalita, T., Vatine, J. J., Yarnitsky, D., Parush, S., & Weissman-Fogel, I. (2014). Atypical central pain processing in sensory modulation disorder: absence of temporal summation and higher after-sensation. Experimental brain research, 232(2), 587-595. [13] Elman, I., Upadhyay, J., Langleben, D. D., Albanese, M., Becerra, L., & Borsook, D. (2018). Reward and aversion processing in patients with post-traumatic stress disorder: functional neuroimaging with visual and thermal stimuli. Translational psychiatry, 8(1), 1-15. [14] Harrison, R., Zeidan, F., Kitsaras, G., Ozcelik, D., & Salomons, T. V. (2019). Trait mindfulness is associated with lower pain reactivity and connectivity of the default mode network. The Journal of Pain, 20(6), 645-654. [15]Russo, A., Tessitore, A., Esposito, F., Di Nardo, F., Silvestro, M., Trojsi, F., … & Tedeschi, G. (2017). Functional changes of the perigenual part of the anterior cingulate cortex after external trigeminal neurostimulation in migraine patients. Frontiers in neurology, 8, 282. [16] Grahl, A., Onat, S., & Büchel, C. (2018). The periaqueductal gray and Bayesian integration in placebo analgesia. Elife, 7, e32930 [17] Baad-Hansen, L., Lu, S., Kemppainen, P., List, T., Zhang, Z., & Svensson, P. (2015). Differential changes in gingival somatosensory sensitivity after painful electrical tooth stimulation. Experimental Brain Research, 233(4), 1109-1118 [18] Rahal, V., Gallinari, M. D. O., Barbosa, J. S., Martins-Junior, R. L., Santos, P. H. D., Cintra, L. T. A., & Briso, A. L. F. (2018). Influence of skin cold sensation threshold in the occurrence of dental sensitivity during dental bleaching: a placebo controlled clinical trial. Journal of Applied Oral Science, 26. [19] Mo, X., Zhang, J., Fan, Y., Svensson, P., & Wang, K. (2015). Thermal and mechanical quantitative sensory testing in chinese patients with burning mouth syndrome–a probable neuropathic pain condition?. The journal of headache and pain, 16(1), 84. [20] Gruenwald, I., Mustafa, S., Gartman, I., & Lowenstein, L. (2015). Genital sensation in women with pelvic organ prolapse. International urogynecology journal, 26(7), 981-984. [21]Reed, B. D., Sen, A., Harlow, S. D., Haefner, H. K., & Gracely, R. H. (2017). Multimodal vulvar and peripheral sensitivity among women with vulvodynia: a case-control study. Journal of lower genital tract disease, 21(1), 78. [22] Lesma, A., Bocciardi, A., Corti, S., Chiumello, G., Rigatti, P., & Montorsi, F. (2014). Sexual function in adult life following Passerini-Glazel feminizing genitoplasty in patients with congenital adrenal hyperplasia. The Journal of urology, 191(1), 206-211. [23] Chen, X., Wang, F. X., Hu, C., Yang, N. Q., & Dai, J. C. (2018). Penile sensory thresholds in subtypes of premature ejaculation: implications of comorbid erectile dysfunction. Asian journal of andrology, 20(4), 330.

Applications of Non-invasive Neuromodulation for the Management of Disorders Related to COVID-19

Repetitive transcranial magnetic stimulation of the prefrontal cortex for fibromyalgia syndrome: a randomised controlled trial with 6-months follow up

Neuronavigation in Covid-19

Perspectives on the use of neuromodulation in Covid-19

Tips & tricks for setting up a TMS practice

Tips & Tricks to set up a TMS Practice


Introduction to TMS – from research to clinical application

Simultaneous TMS & EEG

Methodology for characterizing network activations with neuro-navigated TMS and EEG

Melbourne Visit 2020

National CME & TMS training workshop

The 5Th National CME and 2nd Hands-on-Training workshop is one of its kind in India delivering hands-on training in administration of rTMS Therapy. This year we welcome practitioners and researchers from across the country and world-wide to enlighten using the field of Transcranial Magnetic Stimulation.

This workshop creates a diverse platform for novel and keen individuals as well as
renowned national and international experts to collaborate together to further their knowledge.

Thus, this program not only sets up a platform to acquire skills evaluating TMS from
both clinical and research perspectives, but also sets an opportunity for networking.

The didactic sessions in program tend to cover series of topic relevant to running a
TMS clinical service or rTMS based research project, including:

  • Introducing Neuromodulation: Beginning of Interventional Psychiatry
  • Neurophysiology of rTMS: Recent Updates
  • Clinical Applications of rTMS
  • Personalisation and Optimisation of TMS through Neuronavigation
  • COVID 19 Pandemic and Neuromodulation: What Future Beholds
  • TMS: From Books to Bed

Download Brochure

Virtual Alzheimers`s Disease International Conference, 10 – 12 December 2020

Transcranial Pulse Stimulation in patients with Alzheimer‘s disease« by Prof. Roland Beisteiner

Interleaved TMS/fMRI

Study human brain functionality in real-time

Stimulation of the brain with magnetic pulses while depicting what happens in the brain at the same time with  functional magnetic resonance imaging (functional MRI) That is the essense of interleaved TMS/fMRI. 

With this complete turnkey TMS/fMRI research solution, it is possible to induce neural activity safely into targeted cortical regions, directly in the MRI scanner. Features of the MagVenture TMS/fMRI solution further include: The integration of TMS with functional MRI provides researchers with a unique tool to study human brain functional connectivity in real-time and assess how it can be altered by certain interventions, behaviour, or pathologies.

Features of the MagVenture TMS/fMRI solution include:

  • Special TMS coils for use inside the MRI scanner
  • Reduced RF noise filters and controllers
  • Built-in dynamic leakage current reduction for minimizing artefacts
  • Stimulator-controlled recharge delay and parameters
  • High quality imaging
  • Ability to add inside/inbore neuronavigation
  • Full control via synchronization of TMS, scanner and peripheral equipment, incl. neuronavigation and functional data formats (Analyze, DICOM, MNI, IfTI)
  • EEG electrode localization and position export in flexible data format
  • Export of stimulation parameters (e.g. EMG, amplitude, mapping results) along  with the acquired stimulation location as functional image data
  • Open documentation format: All data stored is written in XML format for easy post processing
  • The MRI compatible solution can easily be extended to a 2-in-1 solution for navigation outside the MRI environment

Stimulate multiple sites

Small research coils allows for stimulation at multiple sites at the same time

The small geometry of the B35 coil enables you to place multiple coils simultaneously on the head providing a focal, yet powerful stimulation. The B35 coil comes in different versions to suit your specific needs:

• MC-B35
• Cool-B35
• Cool B35-HO (with handle turning upwards for easy coil placement)
• Cool-B35 RO (Robotic edition to be used with the Axilum robot)

 Another option

Another option is the D-shaped Cool-D50 coil with the stimulation center being placed at the edge of the coil. This allows for alternating stimulation of two centers in the brain only 2-3 cm apart.

Smaller circular coils like the MMC-90 coil or MCF-75 coil are also available for less selective stimulation, but still allow for multiple coils to be placed close to one another.

Robotic TMS solutions

Movement controlled, highly accurate TMS without compromising on safety and comfort

Head motion compensation monitors the coil’s position, orientation and contact to the head at all times and actively follows any possible head movement during TMS. It ensures a high level of repeatability between TMS sessions, is integrable with MagVenture stimulators and coils and may be piloted by a neuronavigation system from Localite.

Highlighted features

  • Maintain position, orientation and tilt of the TMS coil during the session
  • Compensate for potential head motion during the TMS session
  • Maintain contact between coil and head (integrated contact sensor)
  • Plan fully automated image-guided TMS sessions when piloted by a compatible neuronavigation system
  • Plan and execute predefined stimulation paths when piloted by a compatible neuronavigation system
  • Ensure identical setups in multi-center studies
  • Reduce inter-operator variability
  • Double-blind study support
  • Reduce interactions between operator and patient during the session (no need for coil adjustment)

Robotic solutions

There are two different robotic solutions available depending on your need: TMS-Robot and TMS-Cobot.

Clinical TMS research

The most comprehensive solution for double-blinded TMS studies

MagVenture offers a highly flexible solution which addresses all your requirements for accuracy, reliability and consistency in clinical research and thus, ultimately, help facilitate new treatment options. This even includes the possibility to perform true randomized, double-blinded, multi-center studies.A robotic solution and/or neuronavigation may easily be added to further enhance the reproducibility of your research.

  • Coils with both active and sham sides (or with only a placebo side)
  • Software for complete study control by study master or principal investigator
  • Patient and operator codes to ensure true double-blinding
  • Sham noise generation
  • Electric masking

Active/Placebo coils

MagVenture offers a number of coils with both an active and a placebo side for true double-blinded TMS studies: Cool D-B80 A/PMMC-140 A/PCool-B65 A/P and Cool-B70 A/P.
MagVenture also offers a number of placebo coils for single-blinded research: MC-P-B70MCF-P-B70 and MCF-P-B65

Neuronavigation with Localite

Stimulate selected brain regions with high precision and reliability every time

Plan stimulation areas, visualise the stimulation spot, and monitor and record the precise position of the research subject and coil with complete replicabibility. The turnkey solution provides full integration with MagVenture stimulators, allowing for automatic and easy exchange of all the needed information such as intensity, coil and stimulator type, MEPs, and temperature.

Our partner Localite offers a range of different neuronavigation systems (ClassicMRI Edition and Robotic Edition). They are all precise, intuitive and scalable.

 Highlighted features:

  • Easily scalable: From MR-less system to MR-based system extendable by attractive soft and hardware
  • Tracking of up to 4 coils at the same time
  • More than 30 MagVenture coils ready to use in the software
  • Import of multiple morphological and functional data formats (DICOM, MNI, NIfTI)
  • EEG electrode localization and position export in flexible data format
  • Export of stimulation parameters (e.g. EMG, amplitude, mapping results) along with the acquired stimulation location as functional image dataOpen documentation format: All data stored is written in XML format for easy post processing
  • The MRI compatible solution can easily be extended to a 2-in-1 solution for navigation outside the MRI environment

TMS Translational research

Complete TMS solution for animal model research

MagVenture offers a specifically dedicated coil for animal model research. It provides a unique opportunity to study the effects of TMS within a wide range of fields including behavioural, metabolic, (epi) genetics, molecular, and biochemical pathways. This research solution overcomes previously known challenges pertaining to focality, overheating, shape, and size. It provides complete replicability and reliability and, due to the small coil size, it will even fit inside a PET or SPECT imaging scanner with a minimum ø120mm bore which for some research purposes is important.

Overcoming the barriers in TMS for rodents

The number of stimuli available in small coils like the Cool-40 Rat Coil is a huge barrier for performing real TMS due to the heating of the TMS coil. The Cool-40 Rat coil overcomes this barrier as it operates with the special High-Performance Cooling System. This will allow for a high number of stimuli before overheating.

The small dimensions of the rat brain compared to the human brain makes it very challenging to provide efficient TMS stimulation using human coils, as they typically lack focus of the magnetic fields and largely out-limit the dimensions of the rat’s head. Further, the smaller coils that are currently available do not induce electrical fields in the brain that are comparable to the electrical fields elicited with human coils in the patient’s brain. All of these issues have been solved with the Cool-40 Rat coil due to the special design of the windings, the High-Performance Cooling System, and the bended shape.

Soterix Medical publications library