Journal of clinical neurophysiology : official publication of the American Electroencephalographic Society
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J Clin Neurophysiol · Aug 2013
Comparative StudyPreservation of motor evoked potentials under anesthesia in children with spinal muscular atrophy type II undergoing spinal deformity surgery.
Spinal muscular atrophy is a progressive condition in which movement is gradually lost as a result of the loss of spinal motor neurons. Individuals with this condition may require surgical correction of a secondary scoliosis. Motor evoked potentials were recorded using transcranial electrical stimulation in four such individuals undergoing surgery. ⋯ Motor evoked potentials were recordable in both upper and lower limb muscles, with similar stimulation parameters to control subjects undergoing surgery for idiopathic scoliosis. The amplitudes of the motor evoked potentials were similar to those in control subjects, although the latencies were shorter reflective of the smaller stature of the spinal muscular atrophy patients. The relative preservation of the motor evoked potentials despite the patients' poor voluntary motor control suggests that there is a selective preservation of the motor neurons mediating the motor evoked potential in spinal muscular atrophy and a maintenance of the conduction velocities of the corticospinal tract.
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J Clin Neurophysiol · Aug 2013
Spectrum of nonconvulsive status epilepticus in patients with cancer.
Determine incidence, clinical presentation, electrographic correlates, and outcome of nonconvulsive status epilepticus (NCSE) in cancer patients on whom an EEG was performed. ⋯ In our cohort, awake NCSE was more common than comatose NCSE. Treatment was successful in patients with heterogeneous central nervous system disease. EEG evaluation should be considered in patients with cancer because NCSE is treatable despite a high prevalence of structural brain disease. Nonconvulsive status epilepticus control did not always require intubation and burst suppression, but frequently required three or more antiepileptic drugs.
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J Clin Neurophysiol · Jun 2013
Alternative sites for intraoperative monitoring of cranial nerves X and XII during intracranial surgeries.
During intracranial surgeries, cranial nerve (CN) X is most commonly monitored with electromyographic endotracheal tubes. Electrodes on these endotracheal tubes may be displaced from the vocal folds during positioning, and there is a learning curve for their correct placement. Cranial nerve XII is most commonly monitored with electrodes in the dorsum of the tongue, which are also prone to displacement because of their proximity to the endotracheal tube. ⋯ In conclusion, during skull base surgeries, CN X may be monitored with electrodes in the cricothyroid muscle and CN XII with electrodes in the submental genioglossus. These alternative sites are less prone to displacement of electrodes compared with the more commonly used EMG endotracheal tube and electrodes in the dorsum of the tongue. The cricothyroid muscle should not be used when the recurrent laryngeal nerve is at risk.
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J Clin Neurophysiol · Jun 2013
Randomized Controlled TrialDifferences in spinothalamic function of cervical and thoracic dermatomes: insights using contact heat evoked potentials.
After spinal cord injury, contact heat evoked potentials (CHEPs) may represent a means to refine the clinical assessment of sensory function from each spinal cord segment by quantifying nociception, including conduction along the spinothalamic tract. ⋯ The study supports CHEPs as a feasible tool for assessing discrete dermatomes corresponding to spinal cord segments. The results suggest that the proximodistal pattern in the intensity of perceived pain and CHEP amplitudes is likely attributable to the distribution of heat nociceptors and the increase in conduction distance from proximal to distal dermatomes. The present findings emphasize on the importance that if patients are assessed segment by segment, the underlying topographical differences need to be accounted for.
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J Clin Neurophysiol · Jun 2013
Rhythmical and periodic EEG patterns do not predict short-term outcome in critically ill patients with subarachnoid hemorrhage.
Nonconvulsive seizures and nonconvulsive status epilepticus commonly occur in patients with aneurysmal subarachnoid hemorrhages. When continuous EEG is used in patients in the neuro-intensive care unit, rhythmical and periodic patterns of uncertain significance are frequently encountered. It is unknown how these findings impact patient outcome. ⋯ Using the ACNS Research Terminology, it is shown that rhythmical and periodic patterns are very common in critically ill patients with subarachnoid hemorrhage. However, the presence and the abundance of these patterns did not predict short-term outcome in this prospective, single-center observational study. We were unable to show that rhythmical and periodic EEG patterns are an independent predictor for outcome relative to other clinical features. Large multicenter studies will be required to determine if these patterns independently predict outcome and to demonstrate the impact of treatment interventions that are directed at rhythmical and periodic continuous EEG patterns.