BACKGROUND: Neurosensory changes are frequently observed in the patients with mid-face fractures, and these symptoms are often caused by infraorbital nerve (ION) damage. Although ION damage is a relatively common phenomenon, there are no established and objective methods to evaluate it. The aim of this study was to test whether trigeminal somatosensory evoked potential (TSEP) could be used as a prognostic predictor of ION damage and TSEP testing was an objective method to evaluate ION injury. METHODS: In this prospective TSEP study, 48 patients with unilateral mid-face fracture (only unilateral blow out fracture and unilateral zygomaticomaxillary fracture were included) and potential ION damages were enrolled. Both sides of the face were examined with TSEP and the non-traumatized side of the face was used as control. We calculated the latency difference between the affected and the unaffected sides. RESULTS: Twenty-four patients recovered within 3 months, and 21 patients took more than 3 months to recover. The average latency difference between the affected side and unaffected side was 1.4 and 4.1 ms for the group that recovered within 3 months and the group that recovered after 3 months, respectively. CONCLUSION: Patients who suffered ION damage showed prolonged latency when examined using the TSEP test. TSEP is an effective tool for evaluation of nerve injury and predicting the recovery of patients with ION damage.
Evoked Potentials, Somatosensory ; Humans ; Methods ; Orbital Fractures ; Prospective Studies ; Trigeminal Nerve Injuries

We report two cases of subacute combined degeneration (SCD) caused by nitrous oxide (N₂O) gas intoxication, which is rarely reported in Korea. Two patients recreationally inhaled N₂O gas daily for several months. They presented with paresthesia of limbs, voiding difficulty, and gait disturbance. The initial vitamin B₁₂ levels were normal or decreased, but homocysteine levels of the two patients were increased. Magnetic resonance imaging of the cervical spine showed T2-weighted hyperintensity in the bilateral dorsal columns of the cervical spinal cord. Electromyography and somatosensory evoked potential tests for both patients suggested posterior column lesion of the spinal cord combined with sensorimotor polyneuropathy. According to these findings, we concluded that the two patients had SCD. The patient’s symptoms partially improved after cessation of N₂O gas inhalation and the receiving of vitamin B₁₂ supplementation therapy. As the incidence of recreational N₂O gas inhalation is increasing in Korea, physicians must be alert to the N₂O induced SCD in patients presenting with progressive myelopathy.
Cervical Cord ; Electromyography ; Evoked Potentials, Somatosensory ; Extremities ; Gait ; Homocysteine ; Humans ; Incidence ; Inhalation ; Korea ; Magnetic Resonance Imaging ; Nitrous Oxide ; Paresthesia ; Polyneuropathies ; Recreation ; Spinal Cord ; Spinal Cord Diseases ; Spine ; Subacute Combined Degeneration ; Vitamin B 12 ; Vitamins

BACKGROUND AND PURPOSE: We aimed to determine the effectiveness of intraoperative neurophysiological monitoring focused on the transcranial motor-evoked potential (MEP) in patients with medically refractory temporal lobe epilepsy (TLE). METHODS: We compared postoperative neurological deficits in patients who underwent TLE surgery with or without transcranial MEPs combined with somatosensory evoked potential (SSEP) monitoring between January 1995 and June 2018. Transcranial motor stimulation was performed using subdermal electrodes, and MEP responses were recorded in the four extremity muscles. A decrease of more than 50% in the MEP or the SSEP amplitudes compared with baseline was used as a warning criterion. RESULTS: In the TLE surgery group without MEP monitoring, postoperative permanent motor deficits newly developed in 7 of 613 patients. In contrast, no permanent motor deficit occurred in 279 patients who received transcranial MEP and SSEP monitoring. Ten patients who exhibited decreases of more than 50% in the MEP amplitude recovered completely, although two cases showed transient motor deficits that recovered within 3 months postoperatively. CONCLUSIONS: Intraoperative transcranial MEP monitoring during TLE surgery allowed the prompt detection and appropriate correction of injuries to the motor nervous system or ischemic stroke. Intraoperative transcranial MEP monitoring is a reliable modality for minimizing motor deficits in TLE surgery.
Electrodes ; Epilepsy, Temporal Lobe ; Evoked Potentials, Somatosensory ; Extremities ; Humans ; Intraoperative Neurophysiological Monitoring ; Monitoring, Intraoperative ; Muscles ; Nervous System ; Stroke ; Temporal Lobe

A 34-year-old male was brought to the hospital with a chest gunshot wound. Pulseless upon arrival, blood pressure was absent for 10 minutes. A thoracotomy resulted in return of spontaneous circulation. On hospital day 5, with brainstem reflexes present, he was unresponsive to call or pain, exhibited generalized hyperreflexia and bilateral Babinskys. Median nerve somatosensory evoked potentials (mSSEPs) and brainstem auditory evoked potentials were obtained. International Federation of Clinical Neurophysiology recommendations for mSSEPs and brainstem auditory evoked potentials were followed. Despite absence of the N20 responses from cortical mSSEPs no withdrawal from care was agreed upon. After awaking on day 7, mSSEPs were repeated and present. The patient survived and was discharged with minor deficits. Bilateral absence of N20 responses from mSSEPs performed beyond 48 hours after resuscitation from cardiac arrest is highly associated with bad neurological outcomes. However, variation due to hypothermia, noisy signals, medications, and brain hypo-perfusion must be taken into account.
Adult ; Blood Pressure ; Brain ; Brain Stem ; Critical Care Outcomes ; Evoked Potentials, Auditory, Brain Stem ; Evoked Potentials, Somatosensory ; Heart Arrest ; Humans ; Hypothermia ; Male ; Median Nerve ; Nervous System Diseases ; Neurophysiology ; Prognosis ; Reflex ; Reflex, Abnormal ; Resuscitation ; Thoracotomy ; Thorax ; Wounds, Gunshot

Spinal cord stimulation (SCS) is a common therapeutic technique for treating medically refractory neuropathic back and other limb pain syndromes. SCS has historically been performed using a sedative anesthetic technique where the patient is awakened at various times during a surgical procedure to evaluate the location of the stimulator lead. This technique has potential complications, and thus other methods that allow the use of a general anesthetic have been developed. There are two primary methods for placing leads under general anesthesia, based on 1) compound muscle action potentials and 2) collisions between somatosensory evoked potentials. Both techniques are discussed, and the literature on SCS lead placement under general anesthesia using intraoperative neurophysiological mapping is comprehensively reviewed.
Action Potentials ; Anesthesia, General* ; Evoked Potentials, Somatosensory ; Extremities ; Humans ; Neurophysiology ; Spinal Cord Stimulation* ; Spinal Cord*

Background: Brain death is the irreversible cessation of the function of the brain including the brainstem. In 2013, the Brain Injury Evaluation Quality Control Centre (BQCC) of the National Health and Family Planning Commission issued criteria and practical guidelines for the determination of brain death. This study aimed to evaluate whether the institutions have adopted these guidelines and to make suggestions for the improvement of the current criteria and practical guidelines for brain death determination in China. Methods: Consecutive brain death cases from 44 hospitals were evaluated for summary statistics for the following data: the performance of BQCC criteria and practical guidelines, clinical examination, apnea testing, ancillary testing, and the number of examinations as well as the waiting periods between examinations and details of who determined brain death. Data analysis was conducted from January 2013 to December 2017. Results: A total of 550 cases were obtained. All patients were determined to have deep coma and met the prerequisites for clinical testing. The performance rates of four brainstem reflex examinations (except cough reflex) ranged from 97.5% to 98.0%, and the completion rate as well as the coincidence rate were both 100.0%. The 238 cases (50.7%) completed apnea testing, and 231 cases (42.0%) had to stop apnea testing during the examination because of instability. The performance rates of the three ancillary tests, including electroencephalogram, short-latency somatosensory evoked potential, and transcranial Doppler, were 89.5%, 67.5%, and 79.5%, respectively; furthermore, the coincidence rates were 98.6%, 96.5%, and 99.5%, respectively. The combination of two ancillary tests was more accurate than one single ancillary test. A total of 401 (72.9%) cases successfully underwent two separate examinations to determine brain death with at least a 12-h waiting period. All brain death cases were determined by at least two qualified physicians. Conclusion This study might provide suggestions for brain death determination in China.
Brain Death ; diagnosis ; physiopathology ; Electroencephalography ; Evoked Potentials, Somatosensory ; Humans ; Ultrasonography, Doppler, Transcranial

Herpes zoster is characterized by vesicular eruption and rash of the skin in the affected dermatomes. Sensory symptoms such as pain and hypesthesia are often accompanied in patients with herpes zoster. While motor paralysis is uncommon, abdominal paralysis can result in rare complications such as abdominal wall pseudohernia. In the present report, we discuss the case of a 62 year-old man who presented with abdominal wall protrusion after herpes zoster infection involving the right T10-T12 dermatomes. Magnetic resonance imaging findings were not specifically correlated with abdominal wall protrusion. Needle electromyography revealed abnormal spontaneous activity in the right paraspinal muscles at the T10-T12 levels, rectus abdominis, and external oblique muscles. Dermatomal somatosensory evoked potentials (SEPs) exhibited prolonged latency in the right T10 and T12 dermatomes. These findings suggest that herpes zoster infection can affect both motor and sensory nerves.
Abdominal Wall ; Electromyography ; Evoked Potentials, Somatosensory ; Exanthema ; Herpes Zoster ; Humans ; Hypesthesia ; Magnetic Resonance Imaging ; Muscles ; Needles ; Paralysis ; Paraspinal Muscles ; Paresis ; Rectus Abdominis ; Skin

Intraoperative monitoring (IOM) utilizes electrophysiological techniques as a surrogate test and evaluation of nervous function while a patient is under general anesthesia. They are increasingly used for procedures, both surgical and endovascular, to avoid injury during an operation, examine neurological tissue to guide the surgery, or to test electrophysiological function to allow for more complete resection or corrections. The application of IOM during pediatric brain tumor resections encompasses a unique set of technical issues. First, obtaining stable and reliable responses in children of different ages requires detailed understanding of normal ageadjusted brain-spine development. Neurophysiology, anatomy, and anthropometry of children are different from those of adults. Second, monitoring of the brain may include risk to eloquent functions and cranial nerve functions that are difficult with the usual neurophysiological techniques. Third, interpretation of signal change requires unique sets of normative values specific for children of that age. Fourth, tumor resection involves multiple considerations including defining tumor type, size, location, pathophysiology that might require maximal removal of lesion or minimal intervention. IOM techniques can be divided into monitoring and mapping. Mapping involves identification of specific neural structures to avoid or minimize injury. Monitoring is continuous acquisition of neural signals to determine the integrity of the full longitudinal path of the neural system of interest. Motor evoked potentials and somatosensory evoked potentials are representative methodologies for monitoring. Free-running electromyography is also used to monitor irritation or damage to the motor nerves in the lower motor neuron level : cranial nerves, roots, and peripheral nerves. For the surgery of infratentorial tumors, in addition to free-running electromyography of the bulbar muscles, brainstem auditory evoked potentials or corticobulbar motor evoked potentials could be combined to prevent injury of the cranial nerves or nucleus. IOM for cerebral tumors can adopt direct cortical stimulation or direct subcortical stimulation to map the corticospinal pathways in the vicinity of lesion. IOM is a diagnostic as well as interventional tool for neurosurgery. To prove clinical evidence of it is not simple. Randomized controlled prospective studies may not be possible due to ethical reasons. However, prospective longitudinal studies confirming prognostic value of IOM are available. Furthermore, oncological outcome has also been shown to be superior in some brain tumors, with IOM. New methodologies of IOM are being developed and clinically applied. This review establishes a composite view of techniques used today, noting differences between adult and pediatric monitoring.
Adult ; Anesthesia, General ; Anthropometry ; Brain Neoplasms ; Brain ; Child ; Cranial Nerves ; Electromyography ; Evoked Potentials, Auditory, Brain Stem ; Evoked Potentials, Motor ; Evoked Potentials, Somatosensory ; Humans ; Infratentorial Neoplasms ; Intraoperative Neurophysiological Monitoring ; Longitudinal Studies ; Monitoring, Intraoperative ; Motor Neurons ; Muscles ; Neurophysiology ; Neurosurgery ; Peripheral Nerves ; Prospective Studies

The nerve electrophysiological tests may differentiate the treatment of primary premature ejaculation (PPE) in our previous studies. However, no study verifies if the results will be affected by abstinence time. From January to December in 2016, fifty PPE patients ejaculated within 2 min and 28 control subjects were enrolled. The nerve electrophysiological tests, including dorsal nerve somatosensory evoked potential (DNSEP), glans penis somatosensory evoked potential (GPSEP), and penile sympathetic skin response (PSSR), were recorded before and immediately after ejaculation. The abstinence day was not correlated with the latencies of SEPs or PSSR neither in PE group (P = 0.170, 0.064, and 0.122, respectively) nor in control group (P = 0.996, 0.475, and 0.904, respectively). No statistically differences were found in the latencies of SEPs and PSSR before and after ejaculation in PE patients (P = 0.439, 0.537, and 0.576, respectively) or control subjects (P = 0.102, 0.198, and 0.363, respectively). Thus, abstinence time does not interfere with the nerve electrophysiological test, which is stable in determining the nerve function of PPE patients.
Adult ; Ejaculation ; Electric Stimulation ; Electrophysiological Phenomena ; Evoked Potentials, Somatosensory ; Humans ; Male ; Middle Aged ; Penis/physiopathology* ; Premature Ejaculation/physiopathology* ; Prospective Studies ; Sexual Abstinence ; Skin/innervation* ; Sympathetic Nervous System/physiopathology* ; Young Adult

OBJECTIVE: To investigate the feasibility of a knee proprioception evaluation using a dynamometer as a tool for evaluating proprioception of the lower extremities in patients with incomplete spinal cord injury (SCI), and to explore its usefulness in predicting the ambulatory outcome. METHODS: A total of 14 SCI patients (10 tetraplegic, 4 paraplegic; all AIS D) were included in this study. The passive repositioning error (PRE) and active repositioning error (ARE) were measured with a dynamometer, along with tibial somatosensory evoked potential (SSEP) and abductor hallucis motor-evoked potential (MEP). Ambulatory capacity was assessed with the Walking Index for Spinal Cord Injury II (WISCI-II), both at the time of the proprioception test (WISCI_i) and at least 6 months after the test (WISCI_6mo). RESULTS: The PRE showed a negative correlation with WISCI_i (r=-0.440, p=0.034) and WISCI_6mo (r=-0.568, p=0.010). Linear multiple regression showed the type of injury, lower extremities motor score, MEP, and PRE accounted for 75.4% of the WISCI_6mo variance (p=0.080). CONCLUSION: Proprioception of the knee can be measured quantitatively with a dynamometer in patients with incomplete SCI, and PRE was related to the outcome of the ambulatory capacity. Along with the neurological and electrophysiological examinations, a proprioception test using a dynamometer may have supplementary value in predicting the ambulatory capacity in patients with incomplete SCI.
Evoked Potentials, Somatosensory ; Humans ; Knee ; Lower Extremity ; Proprioception* ; Spinal Cord Injuries* ; Spinal Cord* ; Walking