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Malingering detected by electromyography (EMG)
s143 CLINICAL EMG DATABASE COMPUTER PROGRAM. M.A. Soza, G. Farias
and R. Santis
(Catholic
Santiago,
University;
Chile)
We have developed a computer program which allows on-line acquisition of information during an EMG examination. Multiple choices are offered to the user by displaying on the screen a variety of windows for each step of the procedure. The desired option is selected either with the keyboard arrows or with a computer mouse. The EMG findings and conduction studies are stored and submitted for comparison with user programmable normal values. The program can store nerve conduction and motor unit action potential waveforms. Calculations are automatically performed. There is a built-in word processor. All the information can be stored rapidly, modified and retrieved by name, ID or hospital number. At the end of the EMG procedure, different report forms can be chosen. The database can store thousands of EMG examinations. From the database, patients can be sorted according to diagnosis or specific EMG findings.
little amplitude variation and occurred in series which had durations up to more than one minute in the boy and up to several seconds in the man. In both cases no single CRD was found. The series appeared to consist of repetitive discharges of single muscle fibers. Whereas CRDs show very little interdischarge interval variations (typically less than 5 psec) this variation appeared to be very high in both patients. The mean consecutive difference between the components in the short discharge series of the older patient ranged from 90 to 450 psec, often combined with gradually increasing or decreasing intervals. In the first case the effects of curare and procainamide on the spontaneous activity were investigated. Curare had no effect, whereas procainamide administration reduced the spontaneous activity considerably.
ACCURATE PRESURGICAL SIMULTANEOUS LOCALIZATION OF ELECIXOGRAPHIC, METABOLIC AND ANATOMIC FEATURES IN EPILEPSY. J.-P. Spire, H. Hosny, D. Levin, Mullan, N. Yasillo and V.L. Towle (University
DEVELOPMENT OF A MAGNETIC STIMULATOR NEUROPHYSIOLOGY. M.A. Soza, G. Farias, (Catholic
University,
A. Fantin Santiago,
FOR
and L. Camilla Chile)
We have developed a magnetic stimulator for clinical neurophysiology. A high voltage electric discharge on a solenoid produces an intense magnetic field which is able to stimulate nervous tissue. Its construction is very simple as well as its coupling to conventional EMG equipment. We have started to do some studies with no complications so far. At the meeting, the circuitry will be shown as well as some results we have obtained.
ANALYSIS OF SPONTANEOUS CASES OF SCHWARTZ-JAMPEL
EMG ACTIVITY SYNDROME.
IN 2
F. Spaans (University
of Limburg,
Maastricht,
The Netherlands)
In recent publications the spontaneous activity in SchwartzJampel syndrome (SJS) has been described to consist partially or totally of complex repetitive discharges (CRDs). We studied 2 unrelated typical cases of SJS with CNEMG and SFEMG and found abundant spontaneous activity in the younger one (Cyear-old boy) and much less in the older one (23-year-old man). Needle insertion and other mechanical stimuli caused high voltage myotonic bursts in both cases. A second type of activity occurred without mechanical stimulation. It showed
of Chicago,
Chicago,
C. Pelizzari,
G. Chen,
J.
IL, USA)
True spatial resolution between CT, MRI, and PET has enabled us to accurately correlate these fundamental investigative elements with EEG (surface and subdural) in two patients. Two otherwise neurologically normal lo-year-old boys, without anatomic evidence (CT, MRI) for cortical abnormalities, presented lifelong focal and generalized seizures, frequent status epilepticus and complications of anticonvulsant toxicity. One child (R.T.) has a persistent right subfrontal surface EEG ictal and interictal epileptic focus. The other (J.B.) had similar findings in the left parietal region. Both children presented interictal hypometabolism on PET (F,s-FDG) in the same respective areas. Implanted subdural arrays were also spatially registered with the anatomic and metabolic data. At operation, cortical anatomy confirmed the presurgical spatial reconstructions and EEG localizations permitting accurate tissue removal. Conventional microscopy of the excised tissue was normal. No neurologic deficit exists in either boy: R.T. is completely seizure-free, while J.B. has had one seizure/month four months after operation (250 seizures/month preoperatively). While it is premature to conclude that inherent accuracy of this cortical localization promises better surgical outcomes, these results are encouraging. Four additional similar patients currently under investigation will also be presented.
GIANT EVOKED POTENTIALS CUS. J.-P.
Spire, V.L. Towle, S. Nader,
(University
of Chicago,
Chicago,
IN STATUS
H. Hosny
EPILEFTI-
and R. Maselli
IL, USA)
Giant scalp SEPs occur in some cortical diseases (reflex and progressive myoclonic epilepsy, early J-C disease, some storage
and R. Santis
(Catholic
Santiago,
University;
Chile)
We have developed a computer program which allows on-line acquisition of information during an EMG examination. Multiple choices are offered to the user by displaying on the screen a variety of windows for each step of the procedure. The desired option is selected either with the keyboard arrows or with a computer mouse. The EMG findings and conduction studies are stored and submitted for comparison with user programmable normal values. The program can store nerve conduction and motor unit action potential waveforms. Calculations are automatically performed. There is a built-in word processor. All the information can be stored rapidly, modified and retrieved by name, ID or hospital number. At the end of the EMG procedure, different report forms can be chosen. The database can store thousands of EMG examinations. From the database, patients can be sorted according to diagnosis or specific EMG findings.
little amplitude variation and occurred in series which had durations up to more than one minute in the boy and up to several seconds in the man. In both cases no single CRD was found. The series appeared to consist of repetitive discharges of single muscle fibers. Whereas CRDs show very little interdischarge interval variations (typically less than 5 psec) this variation appeared to be very high in both patients. The mean consecutive difference between the components in the short discharge series of the older patient ranged from 90 to 450 psec, often combined with gradually increasing or decreasing intervals. In the first case the effects of curare and procainamide on the spontaneous activity were investigated. Curare had no effect, whereas procainamide administration reduced the spontaneous activity considerably.
ACCURATE PRESURGICAL SIMULTANEOUS LOCALIZATION OF ELECIXOGRAPHIC, METABOLIC AND ANATOMIC FEATURES IN EPILEPSY. J.-P. Spire, H. Hosny, D. Levin, Mullan, N. Yasillo and V.L. Towle (University
DEVELOPMENT OF A MAGNETIC STIMULATOR NEUROPHYSIOLOGY. M.A. Soza, G. Farias, (Catholic
University,
A. Fantin Santiago,
FOR
and L. Camilla Chile)
We have developed a magnetic stimulator for clinical neurophysiology. A high voltage electric discharge on a solenoid produces an intense magnetic field which is able to stimulate nervous tissue. Its construction is very simple as well as its coupling to conventional EMG equipment. We have started to do some studies with no complications so far. At the meeting, the circuitry will be shown as well as some results we have obtained.
ANALYSIS OF SPONTANEOUS CASES OF SCHWARTZ-JAMPEL
EMG ACTIVITY SYNDROME.
IN 2
F. Spaans (University
of Limburg,
Maastricht,
The Netherlands)
In recent publications the spontaneous activity in SchwartzJampel syndrome (SJS) has been described to consist partially or totally of complex repetitive discharges (CRDs). We studied 2 unrelated typical cases of SJS with CNEMG and SFEMG and found abundant spontaneous activity in the younger one (Cyear-old boy) and much less in the older one (23-year-old man). Needle insertion and other mechanical stimuli caused high voltage myotonic bursts in both cases. A second type of activity occurred without mechanical stimulation. It showed
of Chicago,
Chicago,
C. Pelizzari,
G. Chen,
J.
IL, USA)
True spatial resolution between CT, MRI, and PET has enabled us to accurately correlate these fundamental investigative elements with EEG (surface and subdural) in two patients. Two otherwise neurologically normal lo-year-old boys, without anatomic evidence (CT, MRI) for cortical abnormalities, presented lifelong focal and generalized seizures, frequent status epilepticus and complications of anticonvulsant toxicity. One child (R.T.) has a persistent right subfrontal surface EEG ictal and interictal epileptic focus. The other (J.B.) had similar findings in the left parietal region. Both children presented interictal hypometabolism on PET (F,s-FDG) in the same respective areas. Implanted subdural arrays were also spatially registered with the anatomic and metabolic data. At operation, cortical anatomy confirmed the presurgical spatial reconstructions and EEG localizations permitting accurate tissue removal. Conventional microscopy of the excised tissue was normal. No neurologic deficit exists in either boy: R.T. is completely seizure-free, while J.B. has had one seizure/month four months after operation (250 seizures/month preoperatively). While it is premature to conclude that inherent accuracy of this cortical localization promises better surgical outcomes, these results are encouraging. Four additional similar patients currently under investigation will also be presented.
GIANT EVOKED POTENTIALS CUS. J.-P.
Spire, V.L. Towle, S. Nader,
(University
of Chicago,
Chicago,
IN STATUS
H. Hosny
EPILEFTI-
and R. Maselli
IL, USA)
Giant scalp SEPs occur in some cortical diseases (reflex and progressive myoclonic epilepsy, early J-C disease, some storage