Increased mortality in patients with standard EEG findings of 'diffuse slowing'.

BACKGROUND: We aimed to confirm the association between slow brain wave activity typically described as "diffuse slowing" on standard electroencephalogram (EEG) and patient outcomes, including mortality. METHODS: This retrospective study was conducted with patient chart data from March 2015 to March 2017 at a tertiary care academic hospital in the midwestern United States. In total, 1,069 participants age ≥55 years on an inpatient floor or ICU received a standard 24-hour EEG. The primary outcome was all-cause mortality at 30, 90, 180, and 365 days. Secondary outcomes were time to discharge, and discharge to home. RESULTS: Having diffuse slowing on standard EEG was significantly associated with 30-, 90-, 180-, and 365-day mortality compared with patients who had normal EEG findings, after controlling for age, sex, and Charlson Comorbidity Index score. When controlling for these factors, patients with diffuse slowing had a significantly longer time to discharge and were significantly less likely to discharge to home. Our findings showed that a standard EEG finding of diffuse slowing for inpatients age ≥55 years is associated with poor outcomes, including greater mortality. CONCLUSIONS: This study suggested that the finding of diffuse slowing on EEG may be an important clinical marker for predicting mortality in geriatric inpatients.

Increased mortality in patients with standard EEG findings of 'diffuse slowing'.

BACKGROUND: We aimed to confirm the association between slow brain wave activity typically described as "diffuse slowing" on standard electroencephalogram (EEG) and patient outcomes, including mortality. METHODS: This retrospective study was conducted with patient chart data from March 2015 to March 2017 at a tertiary care academic hospital in the midwestern United States. In total, 1,069 participants age ≥55 years on an inpatient floor or ICU received a standard 24-hour EEG. The primary outcome was all-cause mortality at 30, 90, 180, and 365 days. Secondary outcomes were time to discharge, and discharge to home. RESULTS: Having diffuse slowing on standard EEG was significantly associated with 30-, 90-, 180-, and 365-day mortality compared with patients who had normal EEG findings, after controlling for age, sex, and Charlson Comorbidity Index score. When controlling for these factors, patients with diffuse slowing had a significant longer time to discharge and were significantly less likely to discharge to home. Our findings showed that a standard EEG finding of diffuse slowing for inpatients age ≥55 years is associated with poor outcomes, including greater mortality. CONCLUSIONS: This study suggested that the finding of diffuse slowing on EEG may be an important clinical marker for predicting mortality in geriatric inpatients.

Identification of Patients With High Mortality Risk and Prediction of Outcomes in Delirium by Bispectral EEG.

BACKGROUND: Delirium is common and dangerous, yet underdetected and undertreated. Current screening questionnaires are subjective and ineffectively implemented in busy hospital workflows. Electroencephalography (EEG) can objectively detect the diffuse slowing characteristic of delirium, but it is not suitable for high-throughput screening due to size, cost, and the expertise required for lead placement and interpretation. This study hypothesized that an efficient and reliable point-of-care EEG device for high-throughput screening could be developed. METHODS: This prospective study, which measured bispectral EEG (BSEEG) from elderly inpatients to assess their outcomes, was conducted at the University of Iowa Hospitals and Clinics from January 2016 to October 2017. A BSEEG score was defined based on the distribution of 2,938 EEG recordings from the 428 subjects who were assessed for delirium; primary outcomes measured were hospital length of stay, discharge disposition, and mortality. RESULTS: A total of 274 patients had BSEEG score data available for analysis. Delirium and BSEEG score had a significant association (P < .001). Higher BSEEG scores were significantly correlated with length of stay (P < .001 unadjusted, P = .001 adjusted for age, sex, and Charlson Comorbidity Index [CCI] score) as well as with discharge not to home (P < .01). Hazard ratio for survival controlling for age, sex, CCI score, and delirium status was 1.35 (95% CI,1.04 to 1.76; P = .025). CONCLUSIONS: In BSEEG, an efficient and reliable device that provides an objective measurement of delirium status was developed. The BSEEG score is significantly associated with pertinent clinical outcomes of mortality, hospital length of stay, and discharge disposition. The BSEEG score better predicts mortality than does clinical delirium status. This study identified a previously unrecognized subpopulation of patients without clinical features of delirium who are at increased mortality risk.

Delirium detection by a novel bispectral electroencephalography device in general hospital.

AIM: Delirium is common and dangerous among elderly inpatients; yet, it is underdiagnosed and thus undertreated. This study aimed to test the diagnostic characteristics of a noninvasive point-of-care device with two-channel (bispectral) electroencephalography (EEG) for the screening of delirium in the hospital. METHODS: Patients admitted to the University of Iowa Hospitals and Clinics were assessed for the presence of delirium with a clinical assessment, the Confusion Assessment Method for Intensive Care Unit and Delirium Rating Scale. Subsequently, we obtained a 10-min bispectral EEG (BSEEG) recording from a hand-held electroencephalogram device during hospitalization. We performed power spectral density analysis to differentiate between those patients with and without delirium. RESULTS: Initially 45 subjects were used as a test dataset to establish a cut-off. The BSEEG index was determined to be a significant indicator of delirium, with sensitivity 80% and specificity 87.7%. An additional independent validation dataset with 24 patients confirmed the validity of the approach, with a sensitivity of 83.3% and specificity of 83.3%. CONCLUSION: In this pilot study, the BSEEG method was able to distinguish delirious patients from non-delirious patients. Our data showed the feasibility of this technology for mass screening of delirium in the hospital.

Relationship between somatosensory event-related potential N140 aberrations and hemispatial agnosia in patients with stroke: a preliminary study.

PURPOSE: The somatosensory event-related potential N140 is thought to be related to selective attention. This study aimed to compare the somatosensory event-related potential N140 in healthy subjects to that in patients with stroke to determine whether N140 and attentiveness are associated in patients with stroke with or without hemispatial agnosia. MATERIALS AND METHODS: Normal somatosensory event-related potential N140 values were determined using data from ten healthy subjects. Fifteen patients with stroke were divided into two groups based on the presence of hemispatial neglect. Somatosensory event-related potential N140 components were compared between the two groups. RESULTS: Stimulation of the affected limb in the hemispatial agnosia group resulted in significantly longer N140 latency at the contralateral vs. the ipsilateral electrode. This was the inverse of the relationship observed in normal subjects, with stimulation of the intact side in patients with hemispatial agnosia, and with stimulation of both the intact and affected sides in patients without agnosia. In the hemispatial agnosia group, the peak latency of N140 following stimulation of the affected side was significantly longer than it was following stimulation of the intact side and when compared to that in patients without agnosia. In addition, abnormal N140 peak latencies were observed at the Cz and ipsilateral electrodes in patients with hemispatial agnosia following stimulation of the intact side. CONCLUSIONS: These findings suggest that somatosensory event-related potential N140 is independently generated in each hemisphere and may reflect cognitive attention.

A case of atypical tardive seizure activity during an initial ECT titration series.

Electroconvulsive therapy (ECT) has been used in this country for more than 70 years, is still the most effective treatment in all of psychiatry, and is considered a very safe procedure to have under general anesthesia. Although most patients tolerate this procedure very well without complications, prolonged and/or tardive seizures or even status epilepticus can develop, which is a rare but serious complication of ECT. Tardive seizures are typically associated with electroencephalographic evidence of ictal activity and motor manifestations of the tonic-clonic activity. Whereas there are instances of nonconvulsive status epilepticus after ECT, this is the first report of a patient developing autonomic and motor manifestations of a tardive seizure without electroencephalographic evidence of seizure activity during the initial titration series to establish seizure threshold for a course of ECT.

Mirror neuron function, psychosis, and empathy in schizophrenia.

Processing of social and emotional information has been shown to be disturbed in schizophrenia. The biological underpinnings of these abnormalities may be explained by an abnormally functioning mirror neuron system. Yet the relationship between mirror neuron system activity in schizophrenia, as measured using an electroencephalography (EEG) paradigm, and socio-emotional functioning has not been assessed. The present research measured empathy and mirror neuron activity using an established EEG paradigm assessing the integrity of the Mu rhythm (8-13Hz) suppression over the sensorimotor cortex during observed and actual hand movement in 16 schizophrenia-spectrum disorder (SSD) participants (n=8 actively psychotic and n=8 in residual illness phase) and 16 age- and gender-matched healthy comparison participants. Actively psychotic SSD participants showed significantly greater mu suppression over the sensorimotor cortex of the left hemisphere than residual phase SSD and healthy comparison individuals. The latter two groups showed similar levels of mu suppression. Greater left-sided mu suppression was positively correlated with psychotic symptoms (i.e., greater mu suppression/mirror neuron activity was highest among subjects with the greater severity of psychotic symptoms). SSD subjects tended to have significantly higher levels of Personal Distress (as measured by the Interpersonal Reactivity Index) than healthy participants. The present study suggests that abnormal mirror neuron activity may exist among patients with schizophrenia during the active (psychotic) phase of the illness, and correlates with severity of psychosis.

Evidence-based guideline update: intraoperative spinal monitoring with somatosensory and transcranial electrical motor evoked potentials*.

OBJECTIVE: To evaluate whether spinal cord intraoperative monitoring (IOM) with somatosensory and transcranial electrical motor evoked potentials (EPs) predict adverse surgical outcomes. METHODS: A panel of experts reviewed the results of a comprehensive literature search and identified published studies relevant to the clinical question. These studies were classified according to the evidence-based methodology of the American Academy of Neurology. Objective outcomes of postoperative onset of paraparesis, paraplegia, and quadriplegia were used because no randomized or masked studies were available. RESULTS AND RECOMMENDATIONS: Four class I and eight class II studies met inclusion criteria for analysis. The four class I studies and seven of the eight class II studies reached significance in showing that paraparesis, paraplegia, and quadriplegia occurred in the IOM patients with EP changes compared with the IOM group without EP change. All studies were consistent in showing all occurrences of paraparesis, paraplegia, and quadriplegia in the IOM patients with EP changes, with no occurrences of paraparesis, paraplegia, and quadriplegia in patients without EP change. In the class I studies, 16% to 40% of the IOM patients with EP changes developed postoperative-onset paraparesis, paraplegia, or quadriplegia. IOM is established as effective to predict an increased risk of the adverse outcomes of paraparesis, paraplegia, and quadriplegia in spinal surgery (four class I and seven class II studies). Surgeons and other members of the operating team should be alerted to the increased risk of severe adverse neurologic outcomes in patients with important IOM changes (level A).

Translumbar and transsacral motor-evoked potentials: a novel test for spino-anorectal neuropathy in spinal cord injury.

OBJECTIVES: Spinal cord injury (SCI) causes anorectal problems, whose pathophysiology remains poorly characterized. A comprehensive method of evaluating spino-anorectal function is lacking. The aim of this study was to investigate the neuropathophysiology of bowel dysfunction in SCI by evaluating motor-evoked potentials (MEP) of anus and rectum following transspinal magnetic stimulation and anorectal physiology. METHODS: Translumbar and transsacral magnetic stimulations, anorectal manometry, and pudendal nerve terminal motor latency (PNTML) were performed in 39 subjects with SCI and anorectal problems and in 14 healthy controls, and data were compared. MEPs were recorded with an anorectal probe containing bipolar ring electrodes. RESULTS: The MEPs were significantly prolonged (P<0.05) bilaterally, and at lumbar and sacral levels, as well as at rectal and anal sites in SCI subjects compared with controls. A total of 95% of SCI subjects had abnormal MEPs and 53% had abnormal PNTML. All subjects with abnormal PNTML also demonstrated abnormal MEP, but 16/17 subjects with normal PNTML had abnormal MEP. Overall, SCI patients had weaker anal sphincters (P<0.05), higher prevalence of dyssynergia (85%), and altered rectal sensation (82%). CONCLUSIONS: Translumbar and transsacral MEPs revealed significant and hitherto undetected lumbosacral neuropathy in 90% of SCI subjects. Test was safe and provided neuropathophysiological information that could explain bowel dysfunction in SCI subjects.

Effect of motor imagery and voluntary muscle contraction on the F wave.

We tested the validity of instructing patients to minimally contract the muscle to facilitate F-wave recording in clinical practice. In 12 healthy subjects, F waves were recorded from the first dorsal interosseous muscle at rest, during motor imagery, and at up to 30% of the maximal voluntary contraction (MVC). F-wave persistence increased significantly from 32.5 +/- 11.9% (mean +/- SD) at rest to 58.3 +/- 15.2% during motor imagery and 90.0 +/- 8.7% during 3% MVC. It then remained the same during stepwise changes to and from 30% MVC before decreasing significantly from 80.8 +/- 18.5% during 3% MVC to 48.7 +/- 23.8% during motor imagery and 27.0 +/- 16.0% at rest. The trial average of F-wave amplitude showed a similar pattern of facilitation. Motor imagery enhances F-wave persistence and amplitude, which further increase with a slight muscle contraction and show no additional change with a stronger effort.

Subgenual cingulate theta activity predicts treatment response of repetitive transcranial magnetic stimulation in participants with vascular depression.

Repetitive transcranial magnetic stimulation (rTMS) is an effective treatment for depression. Increased metabolism in the anterior cingulate cortex (ACC) is a known predictor for antidepressant response. The authors assessed whether increased theta power within the ACC predicts rTMS response in participants with vascular depression. Sixty-five participants were randomized to active or sham rTMS. Outcome was assessed using the Hamilton Depression Rating Scale. Electroencephalography was obtained, and comparisons were made among each group with a normative database using low-resolution electromagnetic tomography. Results suggest that vascular depression participants respond well to rTMS and that increased low-theta power in the subgenual ACC predicts response to rTMS.

Changes of recovery function in median nerve somatosensory evoked potentials from awake to sleep.

To investigate how the sleep affects the recovery functions of somatosensory evoked potential, we studied somatosensory evoked potential recovery functions of the median nerve during awake to sleep in eight healthy adults, using the paired conditioning and test stimulus paradigm. The most notable difference between wakefulness and sleep was the much greater enhancement of parietal P26 and frontal P22 in sleep than in awake state at interstimulus intervals of 20 to 100 milliseconds of paired stimulus paradigm. Although the enhanced P26 and P22 were observed in control somatosensory evoked potential during sleep, the augmentation was much greater when conditioned by preceding stimulus. In contrast, the parietal P40-N60 and frontal fP40-fN60 of test response were more depressed in sleep than in wakefulness. As a whole, the recovery curves in sleep appeared to be shifted to the right as compared with those in the awake, suggesting delayed recovery function in sleep. The augmentation of frontal P22 and parietal P26 in sleep, contrasting depressed other components, most notably fP40-fN60 and parietal P40-N60, imply that the former components reflect inhibitory and the latter to the excitatory process. This is the first study that demonstrates the somatosensory evoked potential recovery functions are different from those of awake state.

Serum melatonin levels in adolescent idiopathic scoliosis prediction and prevention for curve progression--a prospective study.

The correlation of serum melatonin levels and curve progression in adolescent idiopathic scoliosis, and the effects of melatonin therapy in scoliotic patients with reduced levels of endogenous melatonin were studied in 40 adolescent patients with moderate to severe idiopathic scoliosis. Of the scoliotic subjects, 28 had stable scoliosis and 12 had progressive scoliosis. Normal melatonin levels were derived from 25 age-matched control patients. Serum melatonin levels were monitored yearly in scoloiotic patients for a period ranging from 3 to 6 yr, revealing a diurnal pattern with low values during the day and high at night. Scoliotic patients with normal levels were not treated or were treated with a brace, and all but two patients with low endogenous melatonin were treated with oral supplements of the indole. Of the 22 patients with a normal melatonin level, 16 had stable scoliosis and six had progressive scoliosis. Of the 16 patients treated for a low melatonin level, 12 had stable scoliosis and four had a progressive course. The two untreated cases had a progressive course. Of the 12 patients who had progressive scoliosis, nine had >35 degrees of curve at initial examination. These findings suggest that melatonin deficiency plays a role in the prognosis of idiopathic scoliosis. Therefore, melatonin supplements may prevent the progression of scoliosis, especially in mild cases with less than a 35 degrees curve.

Motor imagery facilitates the spinal motor neurons without hemispheric asymmetry.

PURPOSE: To determine possible hemispheric differences of motor imagery in facilitating the anterior horn cells. METHODS: We conducted a side-to-side comparison of motor imagery to counter rest-induced suppression of spinal motor neurons in 10 right-handed healthy adults using the F wave as a measure of excitability. Studies consisted of sequential recording of F waves from the abductor pollicis brevis with 100 supramaximal stimuli applied to the median nerve on three consecutive sessions: (1) after standardized hand exercise to establish the baseline; (2) after immobilizing abductor pollicis brevis bilaterally for 3 hours, with one side assigned to relaxation task and the other side to motor imagery task; and (3) after standardized hand exercise to assess a recovery. The same sequence was repeated, switching the side of relaxation and motor imagery tasks. RESULTS: F-wave persistence and average amplitude showed a significant decrease (P < 0.01) from baseline after relaxation task, recovering quickly after exercise, but no change (P > 0.05) after motor imagery task. The results showed no significant differences (P > 0.05) between dominant and nondominant hands. CONCLUSION: Motor imagery facilitates the spinal motor neurons without hemispheric asymmetry.

Antipsychotic effect of electroconvulsive therapy is related to normalization of subgenual cingulate theta activity in psychotic depression.

OBJECTIVE: Electroconvulsive therapy (ECT) is one of the most effective options available for treating depressive and psychotic symptoms in a variety of disorders. While the exact mechanism of ECT is unclear, it is known to increase metabolism and blood flow specifically in the anterior cingulate cortex (ACC). The ACC is a cortical generator of theta rhythms, which are abnormal in patients with depression and psychotic disorders. Since patients with psychotic depression are known to respond particularly robustly to ECT, we investigated whether the therapeutic effect of ECT in this population was related to normalization of abnormal theta activity in the ACC. METHOD: We obtained 19-lead electroencephalography (EEG) data from 17 participants with psychotic depression before and 2-3 weeks after a full course of ECT. EEG data was analyzed with quantitative measures and low-resolution electromagnetic tomography (LORETA) compared to an age-adjusted normative database. RESULTS: Quantitative EEG analyses revealed that theta band (4-7 Hz) activity was the only frequency band that changed with ECT. LORETA analyses revealed that the primary site of theta activity change was within the subgenual ACC (Brodmann area 25). There was a positive association between increased subgenual ACC theta activity and decreased psychotic symptoms. The degree of low theta activity in the subgenual ACC prior to ECT predicted the antipsychotic response of ECT. CONCLUSIONS: The antipsychotic effect of ECT is related to normalization of subgenual ACC theta hypoactivity.

Rest-induced suppression of anterior horn cell excitability as measured by F waves: comparison between volitionally inactivated and control muscles.

To test the hypothesis that the anterior horn cells become hypoexcitable in the absence of central drive, we recorded F waves simultaneously from the first dorsal interosseous (FDI) and the abductor digiti minimi (ADM) before and after volitionally inactivating one muscle (target) while periodically contracting the other muscle (control). In 14 healthy subjects, F waves recorded from the target muscle showed a progressive decrease in persistence and amplitude (whether counting all 100 trials or only detectable responses) after muscle relaxation for 1, 3, and 6 hours, followed by a quick recovery upon brief muscle contraction. We conclude that volitional inactivation suppresses the F waves of the target muscle without equally affecting the control muscle innervated by the same nerve. The history of activity of a muscle should therefore be taken into account in clinical testing, especially when the study of a paretic muscle shows abnormal F-wave excitability.

Experimental scoliosis in melatonin-deficient C57BL/6J mice without pinealectomy.

The etiology of idiopathic scoliosis is unknown. Scoliosis with many characteristics closely resembling those seen in idiopathic scoliosis has been produced in young chickens and bipedal rats after pinealectomy. In this study, we induced experimental scoliosis in C57BL/6J mice without pinealectomy and melatonin treatment suppressed the development of scoliosis. A total of 100 mice were divided into four groups: 20 quadrupedal mice served as controls; 30 mice underwent resection of two forelegs and tail at 3 wk of age (bipedal mice); the remaining 20 quadrupedal and 30 bipedal mice received intraperitoneal melatonin (8 mg/kg BW) at 19:00 hr daily. Before killing, blood samples were collected in the middle of dark cycle and melatonin levels were measured by radioimmunoassay. Spine X-ray and helical 3D-CT were examined after killing at 5 months of age. The bipedal mice without a tail were able to walk with standing posture, whereas the quadrupedal mice did not walk with standing posture. In C57BL/6J mice, the serum melatonin was reduced to nearly zero; however, the normal level was restored in both bipedal and quadrupedal mice after the injection of melatonin. Scoliosis with rib humps developed in 29 of 30 bipedal and in five quadrupedal mice. None of mice with melatonin treatment developed scoliosis. The results suggest that melatonin deficiency in bipedal mice appears to play crucial role for development of scoliosis. Also the restoration of melatonin levels prevents the development of scoliosis.

REM alpha rhythm: diagnostic for narcolepsy?

SUMMARY: A young man, in whom narcolepsy was subsequently diagnosed, had the simultaneous onset of quadriparesis and a rapid eye movement (REM)-sleep polysomnographic pattern. During this REM-sleep pattern, a waking alpha EEG rhythm, appearing when he was asked to close his eyes, immediately attenuated when he was instructed to open his eyes, after which the REM-sleep pattern persisted. The juxtaposition of REM sleep patterns and reactive alpha rhythms are likely unique to sleep paralysis and may prove valuable in diagnosing narcolepsy.

Rib length in experimental scoliosis induced by pinealectomy in chickens.

STUDY DESIGN: This study was designed to investigate the difference of rib length of idiopathic scoliosis using experimentally induced scoliosis by pinealectomy in chickens. OBJECTIVE: To find whether the difference of rib length may play a role for the development of scoliosis in pinealectomized chickens. SUMMARY OF BACKGROUND DATA: In experimental and clinical studies, asymmetric growth of the rib has been considered to be one of factors for the development of idiopathic scoliosis. Pinealectomy in chickens consistently produces scoliosis with lordosis, vertebral rotations, and rib humps, which have anatomic characteristics similar to those of human idiopathic scoliosis. METHODS: A total of 30 chickens were divided into two groups: pinealectomy in 15 chickens and sham operation in 15 chickens served as control. The surgeries were performed on the second day after hatching. The chickens in both groups were killed at 3 months of age. The spines were examined radiologically for the presence of a scoliotic curve. Also, the ribs at each level were measured and compared between left and right sides. RESULTS: All pinealectomized chickens that developed scoliosis showed rib humps. In contrast, none of chickens in a sham operation developed scoliosis. In both groups, there were no significant asymmetries in the rib length. CONCLUSION: Our results indicated that rib length was not related to the experimental scoliosis examined in this study. Further study is encouraged to investigate if the asymmetric rib length plays a role in causing or promoting other types of scoliosis, especially in primate or human idiopathic scoliosis.