Review from Muscle and Nerve

Review from "Muscle & Nerve" - EMG on CD: Volumes I and II

( Vol. 22/ No. 10/ October 1999, page 1468)



Electronic Myoanatomic Atlas for Clinical Electromyography, Volume I
(Muscle localization for needle insertion in Clinical EMG CD-ROM)
by P.E. Barkhaus and S.D. Nandedkar, New York, CASA, 1997

Electronic Atlas of Electromyographic Waveforms
EMG on CD, Volume II, Parts I - IV

by P.E. Barkhaus and S.D. Nandedkar, New York, CASA, 1999


The two volumes under review are in the form of compact disks,
which combines video pictures and verbal text. Clinical electromyography
is mostly learned from watching and performing studies, as in an apprenticeship.
Reading should supplement knowledge, but there is no substitute for obeservation
and participation. The subject is thus ideally suited for computer-aided learning.

The CDs are played through PC based computers. There are minimal computing
requirements, which differ for the two columes; the most demanding requirements
are a PC computer with a 133- MHz processor (233 MHz for lap-top computers),
Windows 95 or 98, a 6X Cd-ROM, and 50 megabytes of free space on the hard drive
to run the program. Although I have minimal experience with PC computers and
windows operating systems, I was able easily to sort through the opening and
execution of the programs. Operations of the program are straightforward with
a table of contents on the opening screen of each CD-ROM, and the various
chapters are opened by marking them with the cursor and clicking with mouse.
Each chapter in turn may have several sections that can be opened similarly.
Only one sunsection of a chapter failed to open, and one error message occurred;
restarting the program solved the problem.

Electronic Myoanatomic Atals for Clinical Electromypgraphy
consists of one CD that inlcudes a book of text and a pictorial atlas of
muscles commonly used in clinical electromyography. The book covers general
techniques of electromyography as well as descriptors of muscles and how to
study them. It has many valuable tips and pointers about how to be a better
electromyographer. The book can be printed. The main body of the CD is an atlas
of upper and lower extremity muscles as well as cranial and paraspinal muscles.
The introduction acknowledges that the selection of muscles is not exhaustive,
but there are 23 muscles of the upper limb, and 7 cranial and paraspinal muscles.
In general, the selection of muscles is appropriate. The only muscle I found
lacking was the tibialis posterior.

For each muscle, there is a textual description if its innervation (nerve and
roots), origin, and insertion; the optimum positioning and method of activating
the muscle; and a description of where to insert the electrode with appropriate
cautions. There is a still image of the muscle, with arrows pointing to landmarks,
etc., and two live action videos, at different magnifications. I found reviewing
the different muscles very informative. Electromyographers are creatures of habit
(initial training), and viewing the CDs amounted to a 'busman's holiday,'
seeing how other electromyographers position and activate muscles. Two areas
were found wanting. One was that the resolution of the video pictures was
marginal and it was difficult to contours of muscles. The second was that it
would have been helpful to include a diagrammatic picture of the muscle beside
or after the live video to better visualize the muscle in question from
surrounding muscles. Nevertheless, I felt that this was an ideal way for the
electromyographers to learn and review muscles and for experienced
electromyographers to see another way to position the limb, activate the
muscle, and insert the electrode.

Electronic Atlas of Electromyographic Wave Forms, consisting
of four CDs, constitutes a unique tutorial in electromyography. Dr. Nandedkar is an
electrical engineer who has focused his career on the analysis of EMG waveforms.
Dr. Barkhaus is a clinical electromyographer with extensive experience with
quantitative EMG and electrode recording characteristics. They bring an
extraordinary amount of experience to these CDs. They are very good and clear
teachers.

The first CD contains a section on instrumentation, including a recording
characterisitcs of electrodes, a section on cables, the principles of amplifiers
and filters, and discussions on how to make manual measurements of motor unit
action potentials. With this as a background, the CD contains normal elctromyogrpahic
tracings from different muscles, showing characteristic differences with
respect to discharge frequency, amplitude, and waveform configuration. The
second CD focuses on spontaneous activity and it includes insertion activity,
endplate activity, fasciculation potentials, complex discharges, fibrillation
and positive waves and iterative discharges. It also includes a section on
the practical use of changing filter settings to clarify signals. The first
two CDs include assessment quizzes for recognizing sopntaneous activity and
motor unit waveforms.

The third CD focuses on motor unit potentials. It starts with a tutorial
discussing the generation of the motor unit potential and its relationship
to muscle architecture. It focuses on motor units seen in various disease
states including defects of neuromuscular transmission. It discusses specific
recording techniques, including the use of a delay line and triggering circuit
as well as multimotor unit analysis. The authors also introduce the concepts
of neuromuscular jitter and blocking as recorded by a 'poor persons'
single-fiber EMG (raising the filter to 500 Hz). The second half the disk
includes examples of motor units found in various disease states. The fourth
CD starts with a tutorial on the analysis of interference pattern. This
includes basic information about recruitment and firing rates at low levels
of contraction and ends with analysis of full interference pattern, including
analysis of turns and amplitude and precision decomposition. The second half
of the disk consists of examples of normal, neuropathic and myopathic
interference patterns.

All in all, I found the method of live presentation very effective. An apt
analogy is given in the introduction: if a picture is worth a thousand words,
a video is worth a million. Drs. Nandedkar and Barkhaus are pioneering a new
medium for teaching electromyography. It is like having a private tutorial
with an experienced engineer and clinitian, with a complete spectrum of patients.
This series of CDs will obviously appeal to residents and fellows as they start
their training, but it is also a refresher course for experienced electromyogaphers.
I highly recommend this for all teaching programs, for any trainee, and for
anyone who wishes to improve their skills. It will be especially valuable for
those who are taking certifying examinations.

Mark B. Bromberg, MD, PhD

- Reproduced with permission from 'Muscle and Nerve' publishers
and the reviewer (Mark B. Bromberg, MD, PhD)



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