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Acute focal vascular myelopathies, clinical and electrological assessment
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VIII C O N G R E S S O F E M G A N D R E L A T E D C L I N I C A L N E U R O P H Y S I O L O G Y
trauma, stroke or other causes should appear as abnormalities of the evoked responses. A serial study was conducted on 40 patients in non-traumatic and non-metabolic coma. The relative value of the Glasgow C o m a Scale (GCS), cold-caloric response and brain-stem auditory evoked responses (BAERs) as prognostic indicants, both individually and in relation to each other was assessed. The overall results indicate that abnormal BAERs in the majority of patients of non-traumatic coma, point to a significant brain-stem dysfunction in addition to the primary sites of pathology. A s compared to the BAERs, a good bedside clinical examination (GCS and vestibulo-ocular cold caloric response) still holds a slight advantage in prognosticating the outcome in patients of non-traumatic coma.
PS. Symbolic analysis of electromyographic data. P.W. J amieson (University of Pittsburgh, Dept. of Neurology, ~ PA 15261, U.S.A.) A computer program using artificial intelligence techniques to assist the physician in performing electromyographic examinations has been developed. The program aids in planning and sequencing of the examination, interpretation and classification of the data, and generation of reports. The program uses a semantic network to represent an anatomic model of the peripheral nervous system and a similar network called an augmented transition network (ATN) to recognize and understand patterns of electromyographic findings and evidence and relate them to appropriate justifications and advice. Heuristic procedures are included for applying the domain knowledge to the electromyographic examination. The program is implemented in c o m m o n LISP on an IBM PC-AT.
PS. How to reflect clinical reasoning in a causal network. F.V. Jem~a, SAC Andersen, U. Kjaerulff and F. Jensen
(Jedex Datasystemer, 9O0OAatbor~ Denmark) A causal network is a probabilistic model for how disorders cause affections in the h u m a n body. E.g., axonal neuropathy m a y cause loss of motor units in the m. extensor haltucis longus, and this may in turn cause a reduced interference pattern during maximal voluntary contraction. Loss of motor units is called a causal child of axonal neuropathy. However, clinical reasoning consists not only of causal reasoning, but it is strongly based on diagnostic reasoning: actual information on reduced interference pattern during maximal voluntary contraction gives diagnostic evidence for loss of motor units. Recent research on belief propagation in causal networks has provided calculation formulas for causal and diagnostic evidence. These are reflections of causal and diagnostic reasoning, respectively. A mathematically accurate and coherent method for combining causal and diagnostic evidence into a final conclusion results from this work. When the system has arrived at a conclusion on loss of
motor units in a certain muscle (say), then the reasoning behind the conclusion shall be explained, perhaps in verbal and categorical form. This can be done by explaining the causal evidence from the causal parents, the diagnostic evidence from the causal children, and how this evidence is combined.
SY. Acute focal vascular myeiopathies, clinical and electrologicai assessment. - M. Jesel, Ph. Vautravers, Ph. Wasser, M. Simon and E. ~ (Service E.NLG., Cliniqne NeuroIogiqne, C.H.U., 67091 Straslmm'g, France) Electrological investigation is helpful for clinical assessment of acute focal vascular myelopathies at cervical or lumbosacral segments. These are ischemic accidents in the anterior part of the medullary grey matter, vascularized by the sulco-commissural artery. This ischemia can induce, after a frequent inaugural rachialgia, a periarticular causalgia, an acute muscular atrophy whose severity and exact topography can be delimited by EMG, a well delimited toss of sensibility at pain and temperature. If this loss affects the fingers, sensory conduetion remains normal, These disorders can be isolated or associated. In cases of acute cervical myelopathy, pain and paresthesiae in the territory of the median or ulnar nerve can also occur. In these cases, electrological assessment can prevent an incorrect diagnosis. After a 3-month follow-up, prognostic assessment is available: If spontaneous evolution is favorable, pain and loss of sensibility will disappear. Muscle activity will show an interferential pattern, even when weakness still persists. Such an evolution can be expected if no spontaneous denervation activity appears in paralyzed muscles after a 3-week follow-up. If the evolution is unfavorable, recovery will be incomplete. Centro-medullary ischemic accidents are due to impairment of vertebro-medullary arterial circulation at radiculo-medullary or anterior spinal level. It is important to locate the site of impairment in order to guide treatment to prevent recurrent accidents.
PS. Evoked potentials in Puerto Rican male adults. - G, Jones and H.J. Flax ( R e h a ~ n Medicine Service, VAH, San Juan, Puerto Rico 00936, U.S,A.) (1) Standard value of median nerve SEPs was determined in normal Puerto Rican males. (2) A number of stroke patients were examined to observe any differences in SEP between right and left hemispheres. (3) Results will be presented and compared with similar published studies.
VIII C O N G R E S S O F E M G A N D R E L A T E D C L I N I C A L N E U R O P H Y S I O L O G Y
trauma, stroke or other causes should appear as abnormalities of the evoked responses. A serial study was conducted on 40 patients in non-traumatic and non-metabolic coma. The relative value of the Glasgow C o m a Scale (GCS), cold-caloric response and brain-stem auditory evoked responses (BAERs) as prognostic indicants, both individually and in relation to each other was assessed. The overall results indicate that abnormal BAERs in the majority of patients of non-traumatic coma, point to a significant brain-stem dysfunction in addition to the primary sites of pathology. A s compared to the BAERs, a good bedside clinical examination (GCS and vestibulo-ocular cold caloric response) still holds a slight advantage in prognosticating the outcome in patients of non-traumatic coma.
PS. Symbolic analysis of electromyographic data. P.W. J amieson (University of Pittsburgh, Dept. of Neurology, ~ PA 15261, U.S.A.) A computer program using artificial intelligence techniques to assist the physician in performing electromyographic examinations has been developed. The program aids in planning and sequencing of the examination, interpretation and classification of the data, and generation of reports. The program uses a semantic network to represent an anatomic model of the peripheral nervous system and a similar network called an augmented transition network (ATN) to recognize and understand patterns of electromyographic findings and evidence and relate them to appropriate justifications and advice. Heuristic procedures are included for applying the domain knowledge to the electromyographic examination. The program is implemented in c o m m o n LISP on an IBM PC-AT.
PS. How to reflect clinical reasoning in a causal network. F.V. Jem~a, SAC Andersen, U. Kjaerulff and F. Jensen
(Jedex Datasystemer, 9O0OAatbor~ Denmark) A causal network is a probabilistic model for how disorders cause affections in the h u m a n body. E.g., axonal neuropathy m a y cause loss of motor units in the m. extensor haltucis longus, and this may in turn cause a reduced interference pattern during maximal voluntary contraction. Loss of motor units is called a causal child of axonal neuropathy. However, clinical reasoning consists not only of causal reasoning, but it is strongly based on diagnostic reasoning: actual information on reduced interference pattern during maximal voluntary contraction gives diagnostic evidence for loss of motor units. Recent research on belief propagation in causal networks has provided calculation formulas for causal and diagnostic evidence. These are reflections of causal and diagnostic reasoning, respectively. A mathematically accurate and coherent method for combining causal and diagnostic evidence into a final conclusion results from this work. When the system has arrived at a conclusion on loss of
motor units in a certain muscle (say), then the reasoning behind the conclusion shall be explained, perhaps in verbal and categorical form. This can be done by explaining the causal evidence from the causal parents, the diagnostic evidence from the causal children, and how this evidence is combined.
SY. Acute focal vascular myeiopathies, clinical and electrologicai assessment. - M. Jesel, Ph. Vautravers, Ph. Wasser, M. Simon and E. ~ (Service E.NLG., Cliniqne NeuroIogiqne, C.H.U., 67091 Straslmm'g, France) Electrological investigation is helpful for clinical assessment of acute focal vascular myelopathies at cervical or lumbosacral segments. These are ischemic accidents in the anterior part of the medullary grey matter, vascularized by the sulco-commissural artery. This ischemia can induce, after a frequent inaugural rachialgia, a periarticular causalgia, an acute muscular atrophy whose severity and exact topography can be delimited by EMG, a well delimited toss of sensibility at pain and temperature. If this loss affects the fingers, sensory conduetion remains normal, These disorders can be isolated or associated. In cases of acute cervical myelopathy, pain and paresthesiae in the territory of the median or ulnar nerve can also occur. In these cases, electrological assessment can prevent an incorrect diagnosis. After a 3-month follow-up, prognostic assessment is available: If spontaneous evolution is favorable, pain and loss of sensibility will disappear. Muscle activity will show an interferential pattern, even when weakness still persists. Such an evolution can be expected if no spontaneous denervation activity appears in paralyzed muscles after a 3-week follow-up. If the evolution is unfavorable, recovery will be incomplete. Centro-medullary ischemic accidents are due to impairment of vertebro-medullary arterial circulation at radiculo-medullary or anterior spinal level. It is important to locate the site of impairment in order to guide treatment to prevent recurrent accidents.
PS. Evoked potentials in Puerto Rican male adults. - G, Jones and H.J. Flax ( R e h a ~ n Medicine Service, VAH, San Juan, Puerto Rico 00936, U.S,A.) (1) Standard value of median nerve SEPs was determined in normal Puerto Rican males. (2) A number of stroke patients were examined to observe any differences in SEP between right and left hemispheres. (3) Results will be presented and compared with similar published studies.