Electroretinogram by Donnell J Creel

Figure Reference: Med.Utah.edu (linked, pl click)

In general, intraopertive neurophysiological monitoring teams do not conduct ERG or EOG in the Operating room set up, it is rather cumbersome and difficult to get a reliable readings combined with the difficulty of placing the recording electrode and risks that are associated with the procedure.  However, Donnell in its Chapter on"The electroretinogram" presents the latest developments that record the status of retinal function using skin electrodes and he also sheds light on the recent advancement in ERG the multifocal retiongram. Whether you are going to conduct this test or not, if you are interested in all the evoked potentials and the basics, this is an excellent reading material. Enjoy.

 The Electroretinogram: Clinical Applications by Donnell J. Creel

Electrophysiological testing of patients with retinal disease began in clinical departments in the late nineteen forties. Under the influence of the Swedish pioneers, Holmgren (1865) and Granit (1933), the electroretinogram was being dissected into component parts and early intraretinal electrode studies were beginning to tell which cells or cell layers gave rise to the various components. A detailed discussion of the electroretinogram, or ERG as it is commonly abbreviated, is found in the accompanying chapter by Ido Perlman. A little after the introduction of the ERG as a test of the state of the patient’s retina, another diagnostic test called the electrooculogram (EOG) was introduced to the clinic (Arden et al., 1962). The EOG had advantages over the ERG in that electrodes did not touch the surface of the eye. The changes in the standing potential across the eyeball were recorded by skin electrodes during simple eye movements and after exposure to periods of light and dark. Over the years ERG recording techniques have become progressively more sophisticated in the clinical setting. With the advent of perimetry, optical coherence tomography (OCT) and pattern ERG techniques, more precise mapping of dysfunctional areas of the retina is now possible. The most recent advance in ERG technology is the multifocal electroretinogram (mfERG). The mfERG provides a detailed assessment of the health of the central retina.

NEUROMONITORING COMPANIES IN AMERICA: How Many? & Who are they?

• Neuromonitoring1 ......is the only place on the internet or offline on any books where you will find list of companies that provide Neuromonitoring in America, it is not clear at this moment how many countries health care system applies this approach (there is no data on it, but I am sure there are only handful of nations like USA, Canada, UK, Sweden, Singapore so far known to employ or have companies doing this service, among them the most widely established neuromonitoring practices occur in US.
  
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• This list is by far the comprehensive, though it does not reflect one hundred percent of companies in US but certainly most of them with a webaddress and well known names are listed here.
  

A list of all these neuromonitoring companies are documented at the bottom of this blog under separate topic: Neuromonitoring Companies!!.

You will be able to get more details of those companies such as name brand, directors, office staff, company goals, operating areas and schedules etc., along with the link to each company at the very bottom of this blog under title Neuromonitoring Companies and Centers.

Two of the latest addition are Synapse neuromonitoring and Argos Neuromonitoring, the list will be updated periodically.