Somatosensory evoked potentials and magnetic resonance imaging in syringomyelia

Jabbari, Bahman; Geyer, Carl A.; Gunderson, Carl H.; Chu, Anita; Brophy, John D.; McBurney, John W.; Jonas, Bruce S.

doi:10.1016/0168-5597(90)90066-m

Cited by 34 publications

(11 citation statements)

References 15 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…16,18 In most studies, there was no reliable relation between clinical findings and neither diameter and length nor level of the syrinx as measured by MRI. 15,16,42,43 The present study in highly chronic and slowly-developing syringomyelia confirms this missing relation between the extent of a syrinx and clinical measures, which is probably most convincing in these presented cases with a holocord syrinx.…”

Section: Spinal Cord Plasticitysupporting

confidence: 73%

Preserved Sensory-Motor Function Despite Large-Scale Morphological Alterations in a Series of Patients with Holocord Syringomyelia

Awai

CurtArmin

2015

Journal of Neurotrauma

View full text Add to dashboard Cite

Although the central nervous system has a limited capacity for regeneration after acute brain and spinal cord injuries, it can reveal extensive morphological changes. Occasionally, the formation of an extensive syrinx in the spinal cord can be observed that causes no or only limited signs of functional impairment. This condition creates a unique opportunity to evaluate the mismatch between substantial morphological changes and functional outcomes. We identified seven patients with holocord syringomyelia affecting the cervical cord following chronic traumatic thoracic/lumbar spinal cord injury (19-34 years after injury) or holocord syringomyelia of non-traumatic origin, and anatomical syrinx dimensions (length, cross-sectional area) were determined using sagittal and axial magnetic resonance imaging scans. Motorand sensory-pathway integrity were evaluated using electrophysiological assessments (i.e., motor, dermatomal sensory, and dermatomal contact-heat [dCHEP] evoked potentials, as well as nerve conduction studies). These were specifically compared to clinical measures of upper-limb strength and grasping performance, including three-dimensional motion analysis. Despite extensive anatomical changes of the cervical cord (on average 26% reduction of residual spinal cord area and intrusion of almost the entire cervical spinal cord), a clinically relevant impairment of upper-limb motor function was absent while only subtle sensory deficits could be detected. dCHEPs revealed the highest sensitivity by disclosing impairments of spinothalamic pathways. Comparable to that of the brain, extensive anatomical changes of the spinal cord can occur with only subtle functional impairment. The time scale of slowly-emerging morphological alterations is essential to permit an enormous capacity for plasticity of the spinal cord. Although the central nervous system has a limited capacity for regeneration after acute brain and spinal cord injuries, it can reveal extensive morphological changes. Occasionally, the formation of an extensive syrinx in the spinal cord can be observed that causes no or only limited signs of functional impairment. This condition creates a unique opportunity to evaluate the mismatch between substantial morphological changes and functional outcomes. We identified seven patients with holocord syringomyelia affecting the cervical cord following chronic traumatic thoracic/lumbar spinal cord injury (19-34 years after injury) or holocord syringomyelia of non-traumatic origin, and anatomical syrinx dimensions (length, cross-sectional area) were determined using sagittal and axial magnetic resonance imaging scans. Motor-and sensorypathway integrity were evaluated using electrophysiological assessments (i.e., motor, dermatomal sensory, and dermatomal contact-heat [dCHEP] evoked potentials, as well as nerve conduction studies). These were specifically compared to clinical measures of upper-limb strength and grasping performance, including three-dimensional motion analysis. Despite extensive anatomical chang...

show abstract

Section: Spinal Cord Plasticitysupporting

confidence: 73%

Preserved Sensory-Motor Function Despite Large-Scale Morphological Alterations in a Series of Patients with Holocord Syringomyelia

Awai

CurtArmin

2015

Journal of Neurotrauma

View full text Add to dashboard Cite

show abstract

“…There is, however, evidence that the size and extension of a syrinx may be correlated with a neurologic deficit. Jabbari et al (1990) showed that pathologic somatosensory-evoked potentials correlated with the size of the syrinx. Isu et al (1990) reported a correlation between neurologic findings and eccentric extension of the syrinx.…”

Section: Discussionmentioning

confidence: 99%

Spinal cord and brain stem anomalies in scoliosis: MR screening of 26 cases

Samuelsson

Lindell

Kogler

1991

Acta Orthopaedica Scandinavica

View full text Add to dashboard Cite

“…32 The most common SSEP abnormality described in patients with syringomyelia is the attenuation or absence of N 13 -potential with a normal N 20 -potential, a parameter susceptible to spinal cord lesions involving the gray matter but sparing the dorsal columns. 16,28,33,39,42 With this finding even subclinical dysfunctions of the thoracic column pathways can be detected. 16,28,44 Although it has been proven that SSEPs do not reflect spinothalamic pathways, 29,33,36 several investigators have described a correlation between N 13 -negativity after pain stimuli to clinical loss of pain and temperature sensation.…”

Section: Discussionmentioning

confidence: 79%

“…16,28,33,39,42 With this finding even subclinical dysfunctions of the thoracic column pathways can be detected. 16,28,44 Although it has been proven that SSEPs do not reflect spinothalamic pathways, 29,33,36 several investigators have described a correlation between N 13 -negativity after pain stimuli to clinical loss of pain and temperature sensation. 15,17 The SSEP sensitivity for centromedullary symptoms such as hypalgesia or hypesthesia (54% and 81%, respectively), 21,28 are comparable to the results in the present study (40% and 80%, respectively).…”

Section: Discussionmentioning

confidence: 79%

A new concept in the electrophysiological evaluation of syringomyelia

Röser¹,

Ebner²,

Liebsch³

et al. 2008

SPI

View full text Add to dashboard Cite

Object The current neurophysiological assessment of syringomyelia is inadequate. Early-stage syringomyelia is anatomically predisposed to affect decussating spinothalamic fibers that convey pain and sensation primarily. Silent periods have been proven to be a sensitive tool for detecting alterations in this pathway. Methods Thirty-seven patients with syringomyelia were included in this prospective study. Routine electrophysiological measurements were applied including somatosensory evoked potential (SSEP) and motor evoked potential (MEP) recordings for all extremities. The silent periods were recorded from the pollicis brevis muscle, and electrical stimuli were applied to the ipsilateral digiti II. To establish baseline values, the authors had 28 healthy controls undergo monitoring. Sensitivity and specificity values were statistically evaluated according to the main clinical symptoms (paresis, dissociative syndrome, and pain). Results All control individuals had normal silent periods in voluntarily activated muscle. In syringomyelia patients, the affected limb showed pathological silent periods with all symptoms (sensitivity 30–50%). Pain was the most specific symptom (90%), despite SSEP and MEP values that were within the normal range. Conclusions Silent period testing is a sensitive neurophysiological technique and an invaluable tool for preoperative assessment of syringomyelia. Silent periods are associated with early dysfunction of thin myelinated spinothalamic tract fibers, even when routine electrophysiological measurements still reveal normal values. Conduction abnormalities that selectively abolish the silent periods can distinguish between hydromyelia (a physiologically dilated central canal) and space-occupying syringomyelia.

show abstract

Somatosensory evoked potentials and magnetic resonance imaging in syringomyelia

Cited by 34 publications

References 15 publications

Preserved Sensory-Motor Function Despite Large-Scale Morphological Alterations in a Series of Patients with Holocord Syringomyelia

Preserved Sensory-Motor Function Despite Large-Scale Morphological Alterations in a Series of Patients with Holocord Syringomyelia

Spinal cord and brain stem anomalies in scoliosis: MR screening of 26 cases

A new concept in the electrophysiological evaluation of syringomyelia

Contact Info

Product

Resources

About