PURPOSE: To evaluate the prognostic value of multimodal evoked potentials in predicting both awakening and failure to awake from coma due to cardiac arrest. METHODS: Multimodal evoked potentials composed of somatosensory evoked potentials (SEPs), visual evoked potentials (VEPs) and brainstem auditory evoked potentials (BAEPs) were recorded for 46 patients with anoxicischemic encephalopathy who had coma duration>24 h. Patients with trauma, stroke, malignancy, or age<14 y were excluded. Outcomes were categorized as awakening (GOS 3-5) vs. vegetative state or death (GOS 1-2). RESULTS: Forty-one percent of patients regained consciousness, and 59% died or remained vegetative. Bilaterally absent SEP N20 peaks predicted non-awakening with a sensitivity of 52% and a specificity of 100%. Unilaterally or bilaterally absent BAEP III-V predicted non-awakening with a sensitivity of 12% and a specificity of 100%. Using bilaterally absent SEP N20 peaks, unilaterally or bilaterally absent BAEP III-V, or both of the above predicted non-awakening with a sensitivity of 56% and a specificity of 100%. Bilaterally present SEP N20 peaks predicted awakening with a sensitivity of 100% and a specificity of 63%. However, the combination of bilateral presence of SEP N20 and VEP P100 in predicting awakening increased the specificity to 74%, reaching a sensitivity of 89%, a PPV of 71% and a NPV of 91%. CONCLUSION: Non-awakening in postanoxic coma can be reliably predicted with SEPs and BAEPs. Bilaterally preserved SEPs and VEPs predicted awakening with an accuracy of 80% at 1~4 days after cardiopulmonary resuscitation.
Coma ; Consciousness ; Evoked Potentials ; Evoked Potentials, Auditory, Brain Stem ; Evoked Potentials, Somatosensory ; Evoked Potentials, Visual ; Heart Arrest ; Humans ; Persistent Vegetative State ; Prognosis ; Sensitivity and Specificity ; Stroke ; Survivors

OBJECTIVE: This study was performed to investigate the prognostic value of multi-sensory evoked potentials (MSEPs) in neonatal period for the early diagnosis of delayed motor development, especially cerebral palsy. METHOD: The MSEPs studies composed of auditory brainstem evoked potentials (AEPs), visual evoked potentials (VEPs) and somatosensory evoked potentials were taken on 237 neonates, 136 boys and 101 girls, using Viking IV machine. Follow up MSEPs were repeated in every 4 or more weeks for those who showed abnormal responses in any of the MSEPs. Each neonate was also evaluated for motor development as an outpatient or by telephone interview. RESULTS: Among 237 neonates, 6.4% showed delayed development, and 4.6% were cerebral palsy: 3.8%, spastic type; 0.8%, athetoid type, and the others revealed normal motor development. AEP was useful method to predict motor development when this was done at 39.7 0.4 weeks of postmenstrual age (PMA). VEPs failed to show the validity, but there was the typical waveform change in accordance with increase of the postmenstrual age. Median nerve SEPs were valuable for prediction of motor development which were taken at PMA 40.7 0.6 weeks. After 45.3 1.5 weeks of PMA, median nerve SEPs did not reflect motor development outcome significantly. However, posterior tibial SEPs significantly reflect motor outcome regardless of the time of examination. CONCLUSION: Median and posterior tibial SEPs done before 40weeks of PMA are useful tool to predict motor development outcome. When any of these tests showed abnormal findings, follow up study is recommended and posterior tibial SEP study is thought to be the most useful for its predictability. It is necessary to correlate the AEPs and VEPs with hearing and vision whenever abnormal findings are found.
Brain Stem ; Cerebral Palsy ; Early Diagnosis ; Evoked Potentials* ; Evoked Potentials, Auditory ; Evoked Potentials, Somatosensory ; Evoked Potentials, Visual ; Female ; Follow-Up Studies ; Hearing ; Humans ; Infant, Newborn* ; Interviews as Topic ; Median Nerve ; Muscle Spasticity ; Outpatients

With 4 channel Nicolet-CA 1000 clinical averager and 133 Xenon inhalation method, somatosensory evoked potentials (SSEP), brainstem auditory evoked potentials (BAEP) and regional cerebral blood flow (r-CBF) were studied in 30 patients with ruptured cerebral aneurysms. 8 out of 30 patients had abnormal SSEP, 11 out of 30 patients had abnormal BAEP and 4 out of 14 patients had decreased r-CBF. The SSEP was abnormal in 6 out of 10 patients with severe vasospasm but in only 2 out of 20 patients without vasospasm or with mild and moderate spasm. The BAEP was abnormal in 5 out of 10 patients with severe vasospasm but 6 out of 20 patients without spasm or with mild and moderate spasm. Regional CBF was decreased in 3 out of 4 patients with severe vasospasm but only 1 out of 10 patients without spasm or with mild and moderate spasm. Abnormal SSEP, BAEP & decreased r-CBF in patients with severe vasospasm indicated a poor prognosis. We got the results as follows ; 1) Abnormal SSEP, BAEP and decreased r-CBF are correlated with severity of vasospasm in SAH patients. 2) Abnormal SSEP and BAEP correlated with the clinical status. 3) Brain stem transmission time (BTT) is less sensitive than central conduction time (CCT) as indicator of vasospasm.
Brain Stem ; Evoked Potentials* ; Evoked Potentials, Auditory, Brain Stem ; Evoked Potentials, Somatosensory ; Humans ; Inhalation ; Intracranial Aneurysm ; Prognosis ; Spasm ; Xenon

OBJECTIVE: The present study was undertaken to determine the value of developmental assessment, multimodality evoked potentials, brain magnetic resonance image (MRI) and electroencephalography (EEG) and to identify correlations between each evaluation. METHOD: Developmental assessments such as Bayley scales of infant development and Vineland social maturity scale, brain MRI, EEG and evoked potentials findings were evaluated in 45 children with spastic cerebral palsy to assess the developmental level and abnormalities of the anatomical structure of the brain and to elucidate the relationship between the test methods. RESULTS: 1) Mean mental developmental index (MDI) and psychomotor developmental index (PDI) were 69.6 and 68.6, respectively and mean Vineland social maturity quotient (SQ) was 76.1 and there was a significant correlation between the MDI, PDI, and SQ in cerebral palsied children. 2) Abnormal findings of brain MRI and EEG were found in 73.3% and 44.4% of the cases, respectively. 3) There was significant correlation between findings of brain MRI, auditory evoked potentials, visual evoked potentials, median somatosensory evoked potentials and social quotient. CONCLUSION: Developmental assessment, multimodality evoked potentials, EEG, and brain MRI would be a useful method to evaluate the maturity of brain and estimate the level of development.
Brain* ; Cerebral Palsy* ; Child Development ; Child* ; Electroencephalography* ; Evoked Potentials* ; Evoked Potentials, Auditory ; Evoked Potentials, Somatosensory ; Evoked Potentials, Visual ; Humans ; Magnetic Resonance Imaging* ; Weights and Measures

BACKGROUNDNeurophysiologic monitoring during surgery is to prevent permanent neurological injury resulting from surgical manipulation. To improve the accuracy and sensitivity of intraoperative neuromonitoring, combined monitoring of transcranial electrical stimulation motor evoked potentials (TES-MEPs), somatosensory evoked potentials (SSEPs) and brainstem auditory evoked potentials (BAEPs) was attempted in microsurgery for lesions adjacent to the brainstem and intracranial aneurysms.

METHODSMonitoring of combined TES-MEPs with SSEPs was attempted in 68 consecutive patients with lesions adjacent to the brainstem as well as intracranial aneurysms. Among them, 31 patients (31 operations, 28 of posterior cranial fossa tumors, 3 of posterior circulation aneurysms) were also subjected to monitoring of BAEPs. The correlation of monitoring results and clinical outcome was studied prospectively.

RESULTSCombined monitoring of evoked potentials (EPs) was done in 64 (94.1%) of the 68 patients. MEPs monitoring was impossible for 4 patients (5.9%). No complication was observed during the combined monitoring in all the patients. In 45 (66.2%) of the 68 patients, EPs were stable, and they were neurologically intact. Motor dysfunction was detected by MEPs in 8 patients, SSEPs in 5, and BAEPs in 4, respectively.

CONCLUSIONSA close relationship exists between postoperative motor function and the results of TES-MEPs monitoring. TES-MEPs are superior to SSEPs and BAEPs in detecting motor dysfunction, but combined EPs serve as a safe, effective and invasive method for intraoperative monitoring of the function of the motor nervous system. Monitoring of combined EPs during microsurgery for lesions adjacent to the brainstem and intracranial aneurysms may detect potentially hazardous maneuvers and improve the safety of subsequent procedures.

Adolescent ; Adult ; Aged ; Brain Stem ; physiopathology ; Evoked Potentials, Auditory, Brain Stem ; Evoked Potentials, Motor ; Evoked Potentials, Somatosensory ; Female ; Humans ; Intracranial Aneurysm ; physiopathology ; surgery ; Male ; Microsurgery ; Middle Aged ; Monitoring, Intraoperative ; Sensitivity and Specificity

OBJECTIVETo investigate the variations of sensory evoked potentials (SEPs) in patients with affective disorders accompanying suicidal behavior.

METHODS39 depressive patients, 22 manic patients and 33 normal controls were included in the study. Visual, auditory and somatosensory evoked potentials (VEP, AEP & SSEP) were recorded from every subject using a Nicolet Spirit Instrument.

RESULTSBoth the depressive and manic groups presented prolonged latencies and decreased amplitudes of major components of SEPs as compared to that of normal controls. Depressive patients with suicidal behavior had decreased P(3) amplitude of VEP (P < 0.05), while maniacs with suicidal behavior had decreased P(2) amplitudes of VEP & AEP (P < 0.05 or 0.01). Compared with patients without suicidal behavior, patients with suicidal behavior had significantly decreased P(3) amplitudes of VEP & SSEP.

CONCLUSIONSThe variations of SEPs in patients with affective disorders is closely associated with a history of suicidal behavior. Their clinical significance and biological correlates with suicidal behavior need further study.

Adult ; Bipolar Disorder ; physiopathology ; Depressive Disorder ; physiopathology ; Evoked Potentials, Auditory ; Evoked Potentials, Somatosensory ; Evoked Potentials, Visual ; Female ; Humans ; Male ; Middle Aged ; Suicide, Attempted

BACKGROUND: P300 component of the long latency auditory evoked potentials (LLAEPs) provides information on conscious and cortical funtion. The P300 wave occures only for stimuli that somehow capture the patients attention. Therefore LLAEPs implys a degree of cognitive processing. We studied sedation scale and P300 wave to determine if LLAEPs could be utilized as electrophysiologic predictors of sedation. METHODS: The P300 component of LLAEPs from vertex was recorded from 10 ASA physical status I and II patients undergoing elective surgery while they listened via headphones to a series of clicks which were interrupted unpredictably by a tone burst (2 KHz) before and after diazepam 0.04 mg/kg and 0.08 mg/kg IV. The patients were asked to concentrate on the clicks and to press a button whenever they detected a 2 KHz tone. And sedation scale also was measured. RESULTS: Amplitude of P300 was decreased and latency of P300 was increased in a dose-dependent manner with IV diazepam. Amplitude was greatest and latency was shortest in awake. And sedation scale also was increased according to increased IV diazepam adminstration. CONCLUSIONS: Both amplitude and latency may be highly related to the sedation scale with progressively increasing dose of diazepam. Therefore we conclude that P300 component of LLAEPs can be utilized as an electrophysiologic predictor of awareness and sedation.
Diazepam* ; Event-Related Potentials, P300* ; Evoked Potentials, Auditory* ; Humans

In the present study the activity of the gamma oscillation synchronized with the stimuli and ERP is investigated by means of unimodal and bimodal experiments. The multiresolution wavelet algorithm is used for signal extraction and Gabor transform is employed to represent the temporal evolution of the selected frequency components. The results show that the gamma oscillation is strongly phase-locked not only with the exogenous stimuli in the three experiments, but also with the endogenous components of ERPs (N2b, P300). And the ERP and the gamma oscillation induced by the bimodal stimuli show the audio-visual bisensory integration and relationship. In addition, the results from the experiments with the auditory stimuli show that the gamma oscillation may be closely related to the perception of auditory signals.
Adult ; Algorithms ; Electroencephalography ; methods ; Event-Related Potentials, P300 ; physiology ; Evoked Potentials, Auditory ; physiology ; Evoked Potentials, Visual ; physiology ; Female ; Humans ; Male ; Signal Processing, Computer-Assisted

In general, surgical approaches to intrinsic lesions of the brain stem are problematic. We encountered two cases of pontine cavernous hemangioma in which successful removal was possible with the help of intraoperative electrophysiological monitoring. During surgery, somatosensory and auditory evoked potentials, were subject to intraoperative bimodal monitoring. Before the removal of hemangiomas, monopolar stimulation and monitoring of the facial EMG identified facial colliculus on the floor of the fourth ventricle. During and after surgery, there was some increase in the amplitude of BAEP and SSEP, and the authors recognized that post-surgical E-P information correlated well with surgical outcome. We observed marked improvement of preoperative neurological deficits, and follow-up brain MRI showed that the hemangiomas had been completely removed. These favorable results demonstrate the usefulness of intraoperative electrophysiological monitoring, and indicate the appropriacy of more aggressive surgical treatment of symptomatic cavernous hemangioma of the brain stem.
Brain ; Brain Stem ; Evoked Potentials, Auditory ; Evoked Potentials, Somatosensory ; Follow-Up Studies ; Fourth Ventricle ; Hemangioma ; Hemangioma, Cavernous* ; Magnetic Resonance Imaging

PURPOSE: Cerebral palsy is a group of conditions characterized by nonprogressive motor and posture dysfunction developing during perinatal period due to brain damage. Combined sensory and cognitive disorders can evolve the secondary mental retardation or speech disorder. Brain evoked potential can evaluate the visual, auditory, somatosensory neuropathway, and the response of frontal, temporal, occipital lobe. We studied the usefulness of brain pvoked votential as a tool in the early diagnosis and treatment of sensory disorders in cerebral palsy. METHODS: We retrospectively reviewed the records of 86 cerebral palsy patients who were practiced brain evoked potential study in Chungnam National University Hospital from July, 1995 to June, 1999. We analyzed the visual, auditory, somatosensory evoked potential result and the correlations between the electroencephalography, radiologic brain imaging study and the brain evoked potential. RESULTS: 1) Clinical types of cerebral palsy were spastic type(85.0%), athetoid type(3.5%), mixed type(3.5%) and the remaining cases did not manifest any one the types above. 2) Abnormal evoked potential fingings were 25 cases(29.4%) in visual evoked potential, 16 cases(18.8%) in auditory evoked potential, 28 cases(37.8%) in median nerve evoked potential, 39 cases(52.7%) in tibial nerve evoked potential. 3) Electroencephalography, radiologic brain imaging study manifested no statistically significant correlations with the brain evoked potential result(P>0.05). CONCLUSION: As a noninnvasive neurophysiologic study, Brain evoked potential is a useful method predicting neurologic developmental progress and helpful to early diagnosis of sensory disorder in cerebral palsy patients.
Brain* ; Cerebral Palsy* ; Chungcheongnam-do ; Early Diagnosis ; Electroencephalography ; Evoked Potentials* ; Evoked Potentials, Auditory ; Evoked Potentials, Somatosensory ; Evoked Potentials, Visual ; Humans ; Intellectual Disability ; Median Nerve ; Muscle Spasticity ; Neuroimaging ; Occipital Lobe ; Posture ; Retrospective Studies ; Sensation Disorders ; Tibial Nerve