Sensory Testing with the Sharp Point of A Folded Piece of Paper

2015 ◽  
Vol 56 (1) ◽  
pp. e28-e28 ◽  
Author(s):  
Hui Mei Cheng ◽  
Sujith Prasad Kumarasinghe
Keyword(s):  
Author(s):  
Jean-Paul Revel

The last few years have been marked by a series of remarkable developments in microscopy. Perhaps the most amazing of these is the growth of microscopies which use devices where the place of the lens has been taken by probes, which record information about the sample and display it in a spatial from the point of view of the context. From the point of view of the biologist one of the most promising of these microscopies without lenses is the scanned force microscope, aka atomic force microscope.This instrument was invented by Binnig, Quate and Gerber and is a close relative of the scanning tunneling microscope. Today's AFMs consist of a cantilever which bears a sharp point at its end. Often this is a silicon nitride pyramid, but there are many variations, the object of which is to make the tip sharper. A laser beam is directed at the back of the cantilever and is reflected into a split, or quadrant photodiode.


2018 ◽  
Author(s):  
B. Monteiro ◽  
M. Moreau ◽  
C. Otis ◽  
L. De Lorimier ◽  
J. Pelletier ◽  
...  

2021 ◽  
Vol 10 (2) ◽  
pp. 239
Author(s):  
Dalia Rega ◽  
Mika Aiko ◽  
Nicolás Peñaranda ◽  
Amparo Urios ◽  
Juan-José Gallego ◽  
...  

Cirrhotic patients may experience alterations in the peripheral nervous system and in somatosensory perception. Impairment of the somatosensory system could contribute to cognitive and motor alterations characteristic of minimal hepatic encephalopathy (MHE), which affects up to 40% of cirrhotic patients. We assessed the relationship between MHE and alterations in thermal, vibration, and/or heat pain sensitivity in 58 cirrhotic patients (38 without and 20 with MHE according to Psychometric Hepatic Encephalopathy Score) and 39 controls. All participants underwent attention and coordination tests, a nerve conduction study, autonomic function testing, and evaluation of sensory thresholds (vibration, cooling, and heat pain detection) by electromyography and quantitative sensory testing. The detection thresholds for cold and heat pain on the foot were higher in patients with, than those without MHE. This hyposensitivity was correlated with attention deficits. Reaction times in the foot were longer in patients with, than without MHE. Patients with normal sural nerve amplitude showed altered thermal sensitivity and autonomic function, with stronger alterations in patients with, than in those without MHE. MHE patients show a general decrease in cognitive and sensory abilities. Small fibers of the autonomic nervous system and thermal sensitivity are altered early on in MHE, before large sensory fibers. Quantitative sensory testing could be used as a marker of MHE.


Sign in / Sign up

Export Citation Format

Share Document