Neoplasms

Symptoms and General Pathology

All Conditions

Nervous System Diseases

Neoplasm Metastasis

Hyperalgesia

Neoplastic Processes

Somatosensory Disorders

Sensation Disorders

Neurologic Manifestations

Thomas K Ringsted, Nurse,cand.

Assessments of mechanical skin sensitivity include psychophysical responses to stimulation with calibrated polyamide monofilaments.

One of the applications of polyamide monofilaments are the assessments of magnitude of secondary hyperalgesia areas (SHAs), i.e. areas in normal skin near an injury with increased mechanical sensitivity.

The objective of the study is to investigate the hypothesis, based on previous studies, that a light tactile stimulus delineates a larger SHA than stimulation with a more rigid monofilament.

Twenty-three healthy participants were included in this randomized, two-observer, test-retest study.

A highly significant positive correlation between the bending force of the polyamide filaments and the magnitude of SHA was demonstrated. The "weighted-pin" instrument showed significantly and consistently larger areas than the polyamide monofilaments.

The hypothesis was rejected: a light tactile stimulus did not delineate a larger secondary hyperalgesia area than stimulation with a more rigid monofilament. The "weighted-pin" instrument seems an alternative to the conventional polyamide monofilaments.

Introduction Assessments of mechanical skin sensitivity include psychophysical responses to stimulation with calibrated polyamide monofilaments. Although the theoretical background and the application of monofilaments are straightforward, inconsistencies of the method have been reported in the literature. One of the applications of polyamide monofilaments are the assessments of magnitude of secondary hyperalgesia areas (SHAs), i.e. areas in normal skin near an injury with increased mechanical sensitivity. Secondary hyperalgesia is a measure of central sensitization and reflects the effect of an injury on the central nervous system. The objective of the study is to investigate the hypothesis, based on previous studies, that a light tactile stimulus delineates a larger SHA than stimulation with a more rigid monofilament.

Method Twenty-three healthy participants were included in this randomized, two-observer, test-retest study. The volunteers were blinded to the test-results. The design was adjusted to examine intra-/inter-observer and intra-/inter-day variability in SHAs after a first degree burn injury was induced by a contact thermode (47ºC, 7 minutes, thermode area 12.5 cm2) on the lower leg. The SHAs were assessed 45 to 75 min (15 min for each observer) after the burn injury and delineated by 3 different polyamide monofilaments (50, 299, 986 mN) and a "weighted-pin" instrument (512 mN). The testing order of the monofilaments was randomized, and the observers were blinded to the study results of each other. The examination order of the observers on Day 1 was reversed on Day 2 (\> 6 weeks later).

Delineating Areas of Secondary Hyperalgesia: Influence of the Assessment Method

Rigshospitalet, Denmark

Cand. Scient. San.

Pain

All study participants will complete a MRI-scan of the brain

Magnetic resonance imaging scan of the brain

MRI-scan

The purpose of this prospective study is to investigate the degree of association between the volume of important pain-relevant structures in the brain and the size of the areas of secondary hyperalgesia.

The healthy study participants will be included from the cohort of a previous study (NCT02527395) where areas of secondary hyperalgesia, heat pain detection thresholds, pain during 1 min. thermal stimulation and test results from the Pain Catastrophizing Scale and the Hospital Anxiety and Depression Score will be retrieved. The study consists of 1 study day. The study day will be conducted at a maximum of 2 months and a minimum of 2 weeks after the completion of the previous study (NCT02527395).The results of the previous study (NCT02527395) will be blinded until all participants have completed the study day.

All study participants will complete a MRI-scan of the brain.

The MRI scans will be performed with a Siemens MAGNETOM Verio 3 tesla, with b17 software, and a 32-channel head coil. The MRI-scan sequence is as follows:

* 3D Localiser
* 3D T1 weighted iso
* AX Diffusion tensor imaging
* AX Epi resting state fMRI
* AX Gre field map
* AX Epi ASL
* AX T2-weighted blade
* AX T2-weighted flair
* AX T2-weighted\* Gre

Total MRI-scan time is estimated to approximately 40 minutes.

Is the Volume of the Caudate Nuclei Associated With Area of Secondary Hyperalgesia?

Is the Volume of the Caudate Nuclei Associated With Area of Secondary Hyperalgesia? - A Study of Healthy Volunteers

to investigate how close the volume of the Caudate nucleus of the right and left hemisphere is associated with the heat pain detection threshold.

To investigate how close the volume of the Caudate nucleus of the right and left hemisphere is associated with the maximum visual analog score (0-100mm) during 1 min. thermal stimulation (45 degrees celsius) of the skin.

To investigate how close the volume of the Caudate nucleus of the right and left hemisphere is associated with the area under the curve of the visual analog score (0-100mm) during 1 min. thermal stimulation (45 degrees celsius) of the skin.

To investigate how close the volume of Caudate nucleus of the right and left hemisphere is associated with the total score and subscores (rumination, magnification, and helplessness) of the Pain Catastrophizing Scale.

To investigate how close the volume of Caudate nucleus of the right and left hemisphere is associated with the total score and subscores (Anxiety and Depression) of the Hospital Anxiety and Depression Scale.

To investigate structural differences (volume) following whole brain analyses as well as association with the size of the area of secondary hyperalgesia. When comparing healthy volunteers with a large vs. small area of secondary hyperalgesia following brief thermal sensitization defined by the upper and lower quartile.

To investigate differences in the association between area of secondary hyperalgesia and regions of interest extracted from tract based spatial statistics, when comparing healthy volunteers with a large vs. small area of secondary hyperalgesia following brief thermal sensitization defined by the upper and lower quartile.

To investigate differences in white matter microstructure in connections between pain related areas (Primary somatosensory cortex, anterior and mid Cingulate cortex, Basal ganglia (Putamen, Accumbens nucleus, and Globus pallidus), Insula, and the Cerebellum) evaluated by white-matter tractography, When comparing healthy volunteers with a large vs. small area of secondary hyperalgesia following brief thermal sensitization defined by the upper and lower quartile.

To investigate differences in resting state networks as investigated by resting state functional MRI by independent component analysis (dual regression method), when comparing healthy volunteers with a large vs. small area of secondary hyperalgesia following brief thermal sensitization defined by the upper and lower quartile.

To investigate how close the volume of Caudate nucleus of the right and left hemisphere is associated with the size of the area of secondary hyperalgesia induced by Brief Thermal Sensitization.

To investigate the association between cortical and subcortical brain areas relevant for pain processing and the area of secondary hyperalgesia (Primary somatosensory cortex, anterior and mid Cingulate cortex, Basal ganglia (Putamen, Accumbens nucleus, and Globus pallidus), Insula, and the Cerebellum.

By Diffusion Tensor Imaging to investigate the association between area of secondary hyperalgesia and white matter microstructure using tract based spatial statistics (TBSS).

By Diffusion Tensor Imaging to conduct white-matter tractography to determine the connections between cortical and subcortical brain areas relevant for pain processing (Primary somatosensory cortex, anterior and mid Cingulate cortex, Basal ganglia (Putamen, Accumbens nucleus, and Globus pallidus), Insula, and the Cerebellum)

Study title	NCT ID	Conditions	Interventions	Eligibility	Organization	Link
Delineating Areas of Secondary Hyperalgesia: Influence of the Assessment Method	NCT02286037	Measurements of...		18 Years - 35 Years	Rigshospitalet, Denmark
Is the Volume of the Caudate Nuclei Associated With Area of Secondary Hyperalgesia?	NCT02567318	Pain Secondary Hyper... Healthy Volunte... Magnetic Resona...	MRI-scan	18 Years - 35 Years	Rigshospitalet, Denmark

Spots Global Cancer Trial Database for secondary hyperalgesia