Dear bionet.neuroscience colleagues,
I experienced sudden paralsis of several proximal muscles upon
awakening several days ago. After three days of hospitalization
and to my disappointment, the neurogists (12 of them) could not
identify the cause. Fortunately, I am almost completely recovered
now. However, it may strike again. As a biomedical engineer, I
want to track the cause down and prevent this from happening.
If you have heard of something similar or have any comments or
can answer some of my questions raised about localization and
EMG tests, I'd appreciate it.
Below, I am appending some more background information IF you are
interested in reading more about it. It is about 2-3 pages long.
Thanks for any information.
Edwin R. Yeh <ery2 at po.cwru.edu>
(Case Western Reserve Biomedical Engineering)
--- Enclosure Begins ---
I woke up  in the morning from a dream that was somewhat intense
and to my surprise I found myself paralyzed. I was unable to sit up.
I said to myself, no, not again.  However, I was able to roll myself
over and swing my legs down the floor. Using my arms, I was able to
push myself up. (However, I cannot stand up without my arms.) I was
able to compensate the lost muscular functions using other unimpaired
muscle groups and was therefore able to walk, by throwing my body forward
and swinging my limbs. The mechanism involeved in the posture of
standing was apparently unaffected since I had no trouble standing
and remain still. Perhaps due to the anguish of this sudden paralysis
or perhaps due to other reasons, I felt down and nauseated. I didn't
have numb or tingling sensation on the muscles that were affected nor
did I have any problems associated with internal organs what were
associated with autonomic system (i.e. I didn't have any problems
with breathing, natural reflexes, etc.)
Note:  This sudden paralysis always occured after I wake up from
sleeping. And always, I was fine the night before.
 This paralysis first occured when I was 14 years old and
has happened aperiodically. This is the fifth episode.
The muscle group that were affected were all proximal muscles. Most
severely affected were the hip flexors and hip abductors. Lower
abdominal, hamstring, and minor portion of deltoid were affected as
well. These muscle groups were identified by performing the standard
examination which I shall describe below:
When I was lying flat on the bed, I was unable to raise my leg at all
(hip flexors: 2/5). When I was assisted and my leg was now bend, if
the position was perpendicular or if was is near the inside, I can hold
the posture; however, if its greater than 90 degree, my leg would fall
outwards (hip abductor: 2/5). I can lift my head and upper portion of
my trunk up; however, I cannot sit up more than 15 degrees. (lower
abdominal muscles). When doing the butterfly exercise (i.e. raising
the arms up side ways while the examiner exerted some forces downward),
it was found those muscels were weak (I think, that's the deltoid?)
I retained full strength and control on my toes, fingers -- these were
tested by grabbing the examiner's fingers, pulling and pushing agasint
the examiner's strength, etc. My biceps were fine; however my triceps were
slightly weaker. Although I wasn't able to raise my legs while lying
down, I can _kick_ if I wass sitting. Thus, part of quadracep was very
functional and others weren't (that's why I used hip-flexors instead
of quads earlier.)
The blood and urine tests were normal -- there were no abnormality
in the potassium (K+) concentrations. Thyroid test were also performed
and was found to be normal. MRI scan of my neck (from C4-T2, I think)
was done. A second MRI with the injection of a dye (Gallanidium,
non-iodized substance, I think) were also performed. The result was
normal. A spinal tap (LP) was performed to retrieve some Cerebal
Spinal Fluid (CSF) from L3-L4 space. No blood were found (it was a
pure transparet liquid.) Again they were considered normal.
EMG tests were performed. It was concluded as normal by the neurologists.
But I didn't understand how they could have reached that decision.
Electrical stimulation of the muscles were also normal. The disagreement
between me and the doctors arised becasue all the muscles they stimulated
or recorded were already muscles that I had no problems with -- i.e. the
thumb, the shoulder, the feet. I was told the proximal muscles I was
affected cannot be stimulated since they were buried deep inside.
Nonetheless, they concluded that the muscle contraction was normal since,
I suspect, that the doctors think this was caused by an chemical
inbalance and therefore the mechanism afftected must be through out the
body. And therefore it was not localized.
Question about localization
Although I have some knowledge of the physiology and the neuralmuscular
system (my professors and advisor were experts in functional neural
muscular stimulation [FNS]), I am not yet trained in anatomical details.
My knowledge is not yet adequeate to comprehend the reasons behind the
conclusions they have drawn. Specifically, all bloods were drawn either
from my right or left arms (which were normal in function.) Now if the
muscle weakness/paralysis was caused by some _localized_ loss of function,
then wouldn't it be more meaningful to draw the blood (or rather, the
extracellular local fluids around those regions that were disabled?)
Perhaps, the _local_ [K+], [Ca2+], or even [ACH] Acetocholine
concentrations were abnormal but the overall concentration in the blood
was normal. The explanation one of the M.D. gave was that the blood
circulates throughout the body. Therefore, whether the blood was drawn
from the arm or the leg would be irrelevant in their analysis.
Question about EMG
Secondly, I was also not all convinced by the EMG study. The doctors
said the result was normal (i.e. I think they meant either the motoneurons
were in place and firing normally or the muscle was contracting, I forgot
which they said.) Again, I am confused because the tests that were performed
on _contractions_ were done on the normal muscles (thumb -- by placing
the stimulating electrode on the wrist area and applying 50mA, 100us
cathodic pulse. [sorry, I knew the mechanisms and physiology but like I
said earlier, I hadn't had anatomy so I can't give you the specific names
of the nerves and muscles.], fingers -- by giving a train of pulses
(I think same magnitude and duration but 50 of them in 5 seconds.),
toes -- by placing near the ankle, the shoulder -- by placing on the neck,
etc.) However, I do not feel this test proves that the muscle group that
I was disabled were functioning (or contracting) normally.
On the test of action potential firing (by sticking a needle deep down
into the muscles) and listening to the firing 'sound', the doctors also
felt everything was normal. Normal, I gather, meant the firing pattern
was normal. For instance, when the needle was placed on the shoulder
area slightly below deltoid ( I think, it was placed on the onset
of bicep ), when I flexed the bicep muscles, a sound was heard,
and as I increased the stregth of contraction, the sound occurred
even more frequently. But remember, my bicep was not affected
very much by this paralysis. However, when the needle was
placed in the areas to sense the hip-flexor and hip-abductor
muscles, the firing pattern never went to very high frequency.
I recalled that hip-abductor was firing but not very much and
I was barely moving against the examiner's force and I was
exerting what I think a lot of effort. The hip-flexor, on the
other hand, wasn't firing much at all. Although occasional
firing sound was heard (Remember, I cann't raise my leg at
all and on this exam, I was told to try my best to raise it.)
If I am correct with the neuromuscular physiology, what they
are examining is below the neuralmuscular junction (i.e. the
action potential that is detected is the local action potential
after the Acetocholine (ACH) was released from the motoneuron
and binded with the receptor site, created the local end-plate
potential, caused a change of [K+] and [Na+] permeabilities,
resulted in the generation of local action potential, etc.)
It is this local action potential which is to travel down through
the trasverse sacrolemic reticulum and causes musclue filament
contraction [Ca2+ -> troponine-C -> Actin-Myosin contraction ->
Power Stroke] that EMG is measuring.
Now, if I was hearing high frequency of firing as I was making
more effort to raise the leg that was paralyzed, I will be
convinced that the mechanism above the neuralmuscular junction
was intact (i.e. from motocortex through the spinal cord
and down to the point of presynatic transmission at the junction).
The problem then must lie somewhere local in the muscles (perhaps,
the release of ACH, the problems with the binding site, Ca2+
generation, availability of K+, or even in molecular level down
to actin and myosin or even the troponines...) However, it was
not clear at all.
This was the fifth episodes of this occurance over an eight year
period. It was aperiodic. The last time was a year and half ago.
Always, it happened all of a sudden without any known symptons,
causes, or patterns. It always occured after I woke up and always
that the day before I was fine. It isn't seasonal as it occured
throughout the year. I am trying to analyze some other things
now trying to see if there is any patterns at all but I have
failed to identify any. Each occurance lasts as long as
a month or so, never worsening, and always gradually improving.
This episode is one of the milder one as I am about 70% recoverd
now after four days.
On previous episodes, I have tried various treatments like
acupuncture and chiropracting after consulation with M.D.'s.
I wasn't sure in their effectiveness since I was already recovering
at those times -- I cannot attribute the recovery was necessarily
due to them because I was suspecting the natural mechanism to
maintain Homeostasis may be play in a role. In fact, in this
episode, I am recovering without any treatments or medications.
On one other occurance, the doctor prescribed some sort of
steroid, again it seemed to have helped at that time but it
again could have been my own mechanisms. But in all cases,
including this one, no one has figured the cause or have seen
anything silimar to this. Nonetheless, this time the doctors
took me pretty seriously and performed a number of tests and
discussed among 10-15 doctors and medical students. Unfortunately,
the result is still unknown.
I am now discharged from the hospital after three days of stay there.
All the exams they've performed were normal and the doctors felt
that there was nothing that can be done to prevent future occurance.
I am left with only a few clues: myosis, periodic paralysis, compression
paralysis, ischemic paralysis, myopathic paralasyis, sleep paralysis,
normaotalemic periodic parasis III (in which _NORMAL_ potassium
concentration is present). Most of them the doctors have ruled out.
Botulism was also ruled out since I wasn't eating any differently than
usual and I was not eating any toxic can food at all.
I will go to our medical libray and start some researches.
If you have any references, ideas, or any clues (especially, if you've
heard of illness of the similar kine), I'd appreciate it.
--- End of Enclosure ---
Edwin R. Yeh
E-mail: ery2 at po.cwru.eduxx288 at po.cwru.edu (Biomed. Engineering GSA SYSOP)