Category Archives: Product Updates

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.

What fMRI equipment do I need to do an fMRI scan?

In this article, you will get an overview of what equipment you need to be able to perform an fMRI exam. To perform  an fMRI exam four main components are required:

  1. MR scanner with EPI pulse sequence,
  2. Stimulus
  3. Peripheral fMRI equipment
  4. Post-processing and analysis software.

MR scanner with EPI pulse sequence

First, in order to acquire fMRI data, an MR scanner with fMRI specific pulse (Echo Planar Imaging) sequence is required. Most higher filed strength magnets (1.5T -3T) have the EPI sequence built into them.

The most common MR vendors are –

*All NordicNeuroLab products are compatible with all above.

Stimulus

Second, a library of paradigms designed to increase metabolic activity in the area of the brain responsible for a particular sensorimotor process is required. These tasks need to be presented to the patient while inside the MR scanner.

NordicNeuroLab can provide you with the stimulus presentation software nordicAktiva

Peripheral fMRI equipment

Third, and most importantly, MR-compatible hardware is needed to present auditory and visual stimulus to the patient. A response device is necessary to record patient responses, and a synchronization device is required to ensure precise timing between MR image acquisition with the onset of the stimuli.

Visual Stimulus equipment

NordicNeuroLab offers two types of visual stimulus hardware

Turnkey Solution

NordicNeuroLab provides a turnkey solution for clinical fMRI. It is a complete and user-friendly system for simplifying and standardizing implementation of functional MRI in clinical environments.

Post-processing and analysis software

Fourth, once the data is collected, a software is required to perform statistical analysis of fMRI data and overlay it on the high resolution anatomical MR images.

Additional equipment

Eye-tracking

The combination of fMRI and eye-tracking is a very powerful tool in neuroscience and has led to many advances in neuropsychology, neuropsychiatric, neurophysiology, and basic science (Bonhage et al. 2015; Tylen et al. 2012; Hausler et al. 2016; Kalpouzos et al. 2010; Kim et al. 2020)

The NordicNeuroLab VSHD are the only MR compatible goggles with integrated binocular eye-tracking. The video-based PCCR eye-tracking
technology uses two active glint points and an adjustable camera focus for precise and reliable tracking of each eye.

BESA statistics

BESA Statistics 2.1 released!

The successor to the ground-breaking BESA Statistics program is there! BESA Statistics 2.1 greatly enhances the options of the previous version 2.0. As before, dedicated workflows allow you to perform t-test, one-way ANOVA, and correlation analyses of your data using the parameter-free cluster permutation statistics which so elegantly solve the multiple-test problem. We have added several input data types to this pipeline, in order to ensure that time-frequency analyses and connectivity analyses are now fully supported.

The main highlights of the new release are:

  • In all workflows, the data type Connectivity can now be used. This enables direct import of results obtained by BESA Connectivity for group statistics on connectivity results in sensor space or source space.
  • For Image data, a configurable slice view is available that displays sequences in one of three available orthogonal orientation.
  • The color theme can be adjusted between BESA White and the previous BESA Standard.
  • Several new color maps are available.
  • The data values are displayed on mouse-over in the detail windows.
  • Time-frequency data stored by BESA Connectivity with wavelet analysis can now be read with the correct (logarithmic) frequency spacing.
  • Single-trial time-frequency data can now be read in the t-test workflow (.tfcs data format).
  • There is no upper limit on the number of data files imported into the workflow.
  • A new image export format is available (.svg).
  • Screenshots and cluster summary results can now be copied to the clipboard using the right mouse popup menu.
Spike2

The latest Spike2 updates for V10, V9 and V8, for Windows is available now

Features of version 10.07 include:

  • Video recording has a new option to fix timing problems with some cameras. It now compensates for time delays when starting to record video. It also can be used across a remote desktop. Video review has frame accurate video stepping for both MP4 and AVI files.
  • You can display axes in the data area of Time, Result and XY views. This is expected to be useful when generating figures for publication
  • In a time view you can add channels without a y axis to a group (as long as the group head has an axis). This allows you to colour the background of areas of a waveform with states and to superimpose TextMark data.
  • Many useful small improvements and fixes