[Initial Management of Traumatic Brain Injury].

To reduce the number of preventable trauma deaths(PTD), a standardized approach has been established with various training courses and guidelines such as the Japan Advanced Trauma Evaluation and Care and Guidelines for the Diagnosis and Treatment of Traumatic Brain Injury. To prevent PTD, initial treatment, including resuscitation, is crucial in the care of traumatic brain injury(TBI). The Japan Neurotrauma Data Bank recently reported that the number of patients with TBI is increasing. Patients on antithrombotic drugs are also increasing. Although the mortality rate is decreasing, the percentage of patients with favorable outcomes is also decreasing. Therefore, to prevent secondary brain injury, rapid and systematic assessment of physiological abnormalities and resuscitation using the ABCDE approach, diagnosis and treatment of impending D, administration of tranexamic acid(an antifibrinolytic drug), and timely administration of anticoagulant neutralizers are important.

Abusive head trauma in Japan.

PURPOSE: Abusive head trauma (AHT) is a serious cause of morbidity and mortality in the pediatric population, especially in young infants. This review of the literature aimed to understand the characteristics of AHT in Japan. METHODS: PubMed and the Japanese database Ichuushi were searched to understand the differences in AHT between Japan and other countries. RESULTS: Shaking was identified as an uncommon cause of injury, while mothers were the most common perpetrator of pediatric AHT in Japan. Although uncommon in other countries, infantile subdural hematoma caused by an accidental slight head injury was reported in Japan. CONCLUSION: As in other countries, AHT is a major condition which pediatric neurosurgeons face in Japan. The mechanisms of injury and perpetrators of AHT seemed to differ slightly between western countries and Japan. Additionally, non-accidental infantile acute subdural hematoma was reported mainly in Japan. Therefore, further care and fair judgment is necessary when investigating child abuse in Japan.

Hypothermia for Patients Requiring Evacuation of Subdural Hematoma: A Multicenter Randomized Clinical Trial.

BACKGROUND: Hypothermia is neuroprotective in some ischemia-reperfusion injuries. Ischemia-reperfusion injury may occur with traumatic subdural hematoma (SDH). This study aimed to determine whether early induction and maintenance of hypothermia in patients with acute SDH would lead to decreased ischemia-reperfusion injury and improve global neurologic outcome. METHODS: This international, multicenter randomized controlled trial enrolled adult patients with SDH requiring evacuation of hematoma within 6 h of injury. The intervention was controlled temperature management of hypothermia to 35 °C prior to dura opening followed by 33 °C for 48 h compared with normothermia (37 °C). Investigators randomly assigned patients at a 1:1 ratio between hypothermia and normothermia. Blinded evaluators assessed outcome using a 6-month Glasgow Outcome Scale Extended score. Investigators measured circulating glial fibrillary acidic protein and ubiquitin C-terminal hydrolase L1 levels. RESULTS: Independent statisticians performed an interim analysis of 31 patients to assess the predictive probability of success and the Data and Safety Monitoring Board recommended the early termination of the study because of futility. Thirty-two patients, 16 per arm, were analyzed. Favorable 6-month Glasgow Outcome Scale Extended outcomes were not statistically significantly different between hypothermia vs. normothermia groups (6 of 16, 38% vs. 4 of 16, 25%; odds ratio 1.8 [95% confidence interval 0.39 to ∞], p = .35). Plasma levels of glial fibrillary acidic protein (p = .036), but not ubiquitin C-terminal hydrolase L1 (p = .26), were lower in the patients with favorable outcome compared with those with unfavorable outcome, but differences were not identified by temperature group. Adverse events were similar between groups. CONCLUSIONS: This trial of hypothermia after acute SDH evacuation was terminated because of a low predictive probability of meeting the study objectives. There was no statistically significant difference in functional outcome identified between temperature groups.

[Surgical Site Infections in Patients with Traumatic Brain Injury].

Patients with traumatic brain injury(TBI)have various pathological conditions, such as direct cell destruction by external force, compression by hematoma, vascular injury, ischemia, complicated hypoxia, and hypotension. These pathological conditions occur simultaneously at the time of injury. In some cases, contaminated wounds may be treated, and infection patterns different from the scheduled neurosurgical cases should be managed. In cases of severe TBI, immunocompromised patients are considered to be at high risk of infection. Infection control during the initial stage of treatment affects patient prognosis. In addition, large craniotomy, including decompressive craniectomy, is required to manage intracranial pressure(ICP), which causes skin infection due to delayed wound healing. Furthermore, placement of drainage tubes and transducers for a long period of time might be necessary to manage ICP, and the patient is likely to develop surgical site infection(SSI). In this paper, we describe the characteristic surgical procedure and discuss ways to control SSI in TBI cases.

High early phase hemoglobin level is associated with favorable neurological outcome in patients with severe traumatic brain injury.

BACKGROUND: The appropriate hemoglobin (Hb) level threshold for the early phase (i.e. from Emergency Department to ICU admission) in patients with severe traumatic brain injury (TBI) is still unknown. Therefore, we aimed to examine the association between Hb levels during the early phase and neurological outcomes in patients with severe TBI using data from the Brain Hypothermia (B-HYPO) Study Group. METHODS: We performed a post-hoc analysis of the B-HYPO study (a prospective, multicenter, randomized controlled trial on patients with severe TBI who received either mild therapeutic hypothermia [MTH; 32.0 °C-34.0 °C] or fever control [35.5 °C-37.0 °C]). We calculated Hb levels during early phase by the formula: (admission Hb + Hb on day 1) / 2. The primary outcome was the association between during early phase Hb levels and 6-month neurological outcome after the TBI based on the Glasgow Outcome Scale scores (a measure of functional recovery defined as moderate disability or good recovery). RESULTS: We reviewed data from 130 patients and found favorable neurological outcomes in 48.5% of them. We found significant differences between the favorable and unfavorable neurological outcome groups in terms of their Hb levels on admission and on day 1. But, we found no Hb level differences after day 3 (including 1 day after rewarming). Our multivariable analysis showed that Hb levels during early phase were significantly associated with favorable neurological outcomes (odds ratio, 1.387; 95% confidence interval, 1.057-1.858; P = 0.018). CONCLUSIONS: High early phase Hb levels are associated with favorable neurological outcomes after severe TBI.

[Dealing with Patients with Traumatic Brain Injury Receiving Antithrombotic Drugs].

More than half of the patients with severe head injuries are elderly people in Japan due to the impact of entering a super-aging society. Elderly people take antithrombotic drugs at a high rate. According to the Japan Neurotrauma Data Bank, many patients with head injuries taking antithrombotic drugs sustain falls, indicating an increased risk of deterioration due to low-energy trauma. It has also been pointed out that many hemorrhagic lesions occur due to the effects of antithrombotic drugs, and there is a risk that hematoma will increase later. As an appropriate response in such patients, if bleeding findings are noted on head CT, discontinuation/reversal of antithrombotic drugs should be considered even if the severity is mild. Reversal therapy should be performed in an appropriate manner as quickly and reliably as possible. Some effects of reversal therapy have been reported in small-scale observational studies. Discontinued antithrombotic drugs should be resumed in the neurotrauma subacute phase. Resuming antithrombotic drugs reduces the risk of ischemic complications, but increases the risk of bleeding complications. To summarize, the benefits of resuming antithrombotic drugs have been reported, and it is recommended that antithrombotic drugs be resumed 3-10 days after injury.

[Effect of Antithrombotic Drugs Reversal on Geriatric Traumatic Brain Injury].

BACKGROUND: As the aging rate in the traumatic brain injury population increases, the number of patients taking antithrombotic drugs is also expected to increase among the population with traumatic brain injury; however, the utility or risk of reversal of such drugs is unclear. Therefore, we performed a retrospective cohort study of the effect of reversal of antithrombotic drugs on geriatric traumatic brain injury at our hospital. METHODS: The study subjects included 83 patients(65 years or older)with intracranial traumatic lesions or skull fractures who were admitted to our hospital during 2013-2018. According to the hospital's protocol, we performed platelet transfusion in patients taking antiplatelet drugs, prothrombin complex concentrate(PCC)administration in patients taking warfarin and direct oral anticoagulants except dabigatran: factor IX complex before January 2018 and four-factor PCC after February 2018. We administered idarucizumab in the case of dabigatran. Fresh frozen plasma transfusion was additionally performed in operative cases. RESULTS: Twenty-six patients took antithrombotic drugs. There was no significant difference in the ratio of talk and deteriorate, favorable outcome(Glasgow Outcome Scale: good recovery+moderate disability), and hospitalization period between the non-antithrombotic and antithrombotic administration groups involving reversal. The timing of antithrombotic drug resumption varied, but no major embolic event occurred during the follow-up period. CONCLUSION: This study suggests that reversal of antithrombotic drugs in geriatric traumatic brain injury may contribute to suppression of talk and deteriorate and lead to more favorable outcomes. As there are also contradictory reports about the utility of reversal, additional studies should be performed for confirmation.

Cilostazol decreases duration of spreading depolarization and spreading ischemia after aneurysmal subarachnoid hemorrhage.

OBJECTIVE: Traditionally, angiographic vasospasm (aVS) has been thought to cause delayed cerebral ischemia (DCI) after aneurysmal subarachnoid hemorrhage (aSAH). However, successful treatment of aVS alone does not result in improved neurological outcome. Therefore, there may be other potential causes of poor neurological outcome, including spreading depolarization (SD). A recent study showed beneficial effects of cilostazol on DCI and neurological outcome. The present prospective clinical trial and experimental study focused on effects of cilostazol on SDs. METHODS: Fifty aSAH patients were treated with clip ligation and randomly assigned to a cilostazol (n = 23) or control group (n = 27). Effects of cilostazol on DCI, aVS, and SDs, measured with subdural electrodes, were examined. The effect of cilostazol on SD-induced perfusion deficits (spreading ischemia) was assessed in an aSAH-mimicking model. RESULTS: There was a trend for less DCI in the cilostazol group, but it did not reach our threshold for statistical significance (13.0% vs 40.0%, odds ratio = 0.266, 95% confidence interval [CI] = 0.059-1.192, p = 0.084). However, the total SD-induced depression duration per recording day (22.2 vs 30.2 minutes, ß = -251.905, 95% CI = -488.458 to -15.356, p = 0.043) and the occurrence of isoelectric SDs (0 vs 4 patients, ß = -0.916, 95% CI = -1.746 to -0.085, p = 0.037) were significantly lower in the cilostazol group. In rats, cilostazol significantly shortened SD-induced spreading ischemia compared to vehicle (Student t test, difference = 30.2, 95% CI = 5.3-55.1, p = 0.020). INTERPRETATION: Repair of the neurovascular response to SDs by cilostazol, as demonstrated in the aSAH-mimicking model, may be a promising therapy to control DCI. Ann Neurol 2018;84:873-885.

[Predictive Factors of Intracranial Pressure Elevation in Patients with Severe Acute Subdural Hematoma].

INTRODUCTION: Elevated intracranial pressure(ICP)can cause secondary brain injury after severe traumatic brain injury(TBI), and ICP is the key factor that determines the outcome. Therefore, prediction of elevation of ICP during the course of the injury would allow for more effective care of patients with severe TBI. In this study, we investigated predictive factors for elevation of ICP in patients with severe acute subdural hematoma(ASDH). METHODS: Twenty patients with severe isolated ASDH were admitted to our hospital between January 2009 and April 2016. The patients were divided into two groups with a maximum ICP of ≥20mmHg(elevated ICP group)and <20mmHg(normal ICP group). Age, mechanism of injury, Glasgow Coma Scale score on admission, initial head computed tomography findings, vital signs, serological and blood gas examinations, initial ICP, and clinical outcome were evaluated. RESULTS: The elevated ICP group had significantly higher initial ICP(5.0±3.1 vs. 30±22.4mmHg, p<0.01), arterial oxygen pressure(151.2±68.3 vs. 314.2±197.1mmHg, p<0.05), and activated partial thromboplastin time(APTT;28.17±3.1 vs. 35.96±8.0, p<0.05)at admission, and significantly lower fibrinogen level(273.3±65.1 vs. 188.1±82.4mg/dL, p<0.05)and favorable outcome rate(p<0.01). CONCLUSIONS: Our results show that high initial ICP, APTT, and arterial oxygen and low fibrinogen levels are associated with ICP elevation in patients with severe ASDH. These factors might be useful for the indication of therapeutic methods such as decompressive craniectomy.

Mild decrease in heart rate during early phase of targeted temperature management following tachycardia on admission is associated with unfavorable neurological outcomes after severe traumatic brain injury: a post hoc analysis of a multicenter randomized controlled trial.

BACKGROUND: The association between isolated admission heart rate (HR) and prognosis has been discussed, but not that between gross HR change and neurological outcome in patients with severe traumatic brain injury (TBI). In the acute phase of severe TBI, HR is influenced by several factors (e.g., pain, sympathetic activation, hypovolemia, fever, body temperature). Therefore, admission HR and gross HR change should be examined in patients with TBI treated with a well-designed protocol, such as was done in the Brain Hypothermia (B-HYPO) Study. METHODS: This was a post hoc analysis of the B-HYPO Study, which was conducted as a prospective, multicenter, randomized controlled trial in patients with severe TBI receiving mild therapeutic hypothermia (MTH; 32.0 °C-34.0 °C) or fever control (35.5 °C-37.0 °C) in Japan. Patients with MTH were examined, and HR change (%HR) in the early MTH phase was calculated as follows: [admission HR - HR at day 1]/admission HR × 100. Patients were divided into six groups, using admission HR (< 80, 80-99, ≤ 100) and median of %HR; i.e., group (Admission HR < 80 and %HR ≥ 18.6); group (Admission HR < 80 and %HR < 18.6); group (Admission HR 80-99 and %HR ≥ 18.6); group (Admission HR 80-99 and %HR < 18.6); group (Admission HR ≥100 and %HR ≥ 18.6); and group (Admission HR ≥100 and %HR < 18.6). The primary outcome was an adjusted predicted probability of unfavorable neurological outcome at 6 months after TBI according to Glasgow Outcome Scale score, which is a measure of functional recovery and defined as severe disability, persistent vegetative state, and death. RESULTS: Overall, 79 patients with MTH (52.7% of the original trial) were examined; among these, unfavorable neurological outcomes were observed in 53.2%. Among all the groups, group (Admission HR ≥100 and %HR < 18.6) exhibited the highest proportion of unfavorable outcomes, and 82.3% of patients had an adjusted predicted probability of unfavorable outcomes, whereas those in group (Admission HR < 80 and %HR ≥ 18.6) developed only 22.8% (p = 0.04). CONCLUSIONS: Mild HR decrease during the early phase of targeted temperature management following tachycardia at admission can be associated with unfavorable neurological outcomes after severe TBI.

Thrombolysis with rt-PA under Rivaroxaban Anticoagulation in a Hypertensive Rat Model of Intraluminal Middle Cerebral Artery Occlusion.

BACKGROUND: The aim of this study was to assess the risk and the threshold of hemorrhagic transformation (HT) after treatment with recombinant tissue plasminogen activator (rtPA) under the novel oral anticoagulant, rivaroxaban. METHODS: Fifty-three spontaneous hypertensive rats were used in this study. We performed transient middle cerebral artery occlusion for 270 minutes. Placebo, 10 mg/kg or 20 mg/kg rivaroxaban were administered via a stomach tube 180 minutes after induction of ischemia, and rtPA (10 mg/kg) was administered just before reperfusion. Ninety minutes after rivaroxaban administration we measured the rivaroxaban plasma concentration and prothrombin time (PT). HT volume was assessed by hemoglobin spectrophotometry. Additionally, infarct volume, IgG leakage volume, and neurological outcome were assessed. RESULTS: Rivaroxaban plasma concentration and PT increased in a dose dependent manner but were lower than human peak levels after a once-daily dose of 20 mg rivaroxaban. HT volume increased after treatment with 20 mg/kg rivaroxaban compared with placebo treated controls or those treated with 10 mg/kg rivaroxaban (26.5 ± 5.4, 26.8 ± 8.7, and 41.4 ± 12.6 µL in placebo, 10 mg/kg, and 20 mg/kg treated groups, respectively; P < .05). CONCLUSIONS: Our results suggest that even at therapeutic plasma concentrations, rivaroxaban may increase the risk of HT after thrombolysis in some conditions, such as hypertension and/or a prolonged ischemic period.

Effects of focal brain cooling on extracellular concentrations of neurotransmitters in patients with epilepsy.

OBJECTIVE: Brain hypothermia controls epileptic discharge and reduces extracellular concentrations of glutamate (Glu), an excitatory neurotransmitter. We aimed to determine the effects of focal brain cooling (FBC) on levels of γ-aminobutyric acid (GABA), which is a major inhibitory neurotransmitter. The relationship between Glu or GABA concentrations and the severity of epileptic symptoms was also analyzed. METHODS: Patients with intractable epilepsy underwent FBC at lesionectomized (n = 11) or hippocampectomized (n = 8) regions at 15°C for 30 min using custom-made cooling devices. Concentrations of Glu (n = 18) and GABA (n = 12) were measured in extracellular fluid obtained through microdialysis using high-performance liquid chromatography (HPLC). The reduction rate of neurotransmitter levels and its relationship with electrocorticography (ECoG) signal changes in response to FBC were measured. RESULTS: We found no relationship between the concentrations of Glu or GABA and seizure severity. There was a significant decrease in the concentration of Glu to 66.3% of control levels during the cooling period (p = 0.001). This rate of reduction correlated with ECoG power (r2 = 0.68). Cortical and hippocampal GABA levels significantly (p = 0.02) and nonsignificantly decreased to 47.7% and 32.4% of control levels, respectively. However, the rate of this reduction did not correlate with ECoG (r2 = 0.11). SIGNIFICANCE: Although the decrease in hippocampal GABA levels was not significant due to wide variations in its concentration, the levels of cortical GABA and Glu were decreased following FBC. FBC suppresses epileptic discharge and the release of both excitatory and inhibitory neurotransmitters. The reduction in Glu levels further contributes to the reduction in epileptic discharge. However, the reduction in the levels of GABA has no impact on ECoG.

Safety and Time Course of Drip-and-Ship in Treatment of Acute Ischemic Stroke.

BACKGROUND: The drip-and-ship approach allows intravenous tissue plasminogen activator therapy and adjuvant endovascular treatment in acute ischemic stroke, even in rural areas. Here, we examined the safety and time course of the drip-and-ship approach. METHODS: Fifty consecutive cases treated with the drip-and-ship approach (drip-and-ship group) in June 2009 to March 2016 were retrospectively examined. Changes in mean blood pressure, systemic complications, and neurological complications were compared according to method of transportation. Time courses were compared between drip-and-ship and direct admission groups during the same period. RESULTS: In the drip-and-ship group, 33 and 17 patients were transferred to hospital by ambulance and helicopter, respectively. One patient suffered hemorrhagic infarction during transportation by ambulance. Mean blood pressure change was lower in patients transferred by helicopter than ambulance (<5 mmHg versus 12.2 mmHg, respectively). The mean onset-to-door times in the drip-and-ship and direct admission groups were 71 and 64 minutes, respectively, and mean door-to-needle times were 70 and 47 minutes, respectively (P =.002). Although mean transportation time from the primary stroke hospital to our hospital was 32 minutes, the entry-to-exit time from the primary stroke hospital was 113 minutes. Thereafter, there was an average delay of 100 minutes until reperfusion compared with the direct admission group. CONCLUSIONS: Drip-and-ship was relatively safe in this small series. Transportation by helicopter was less stressful for acute ischemic stroke patients. It is important to reduce door-to-needle time and needle-to-departure time in the primary stroke hospital to minimize the time until treatment in cases of acute ischemic stroke.

Effects of Brain Temperature on Cerebrovascular Autoregulation During the Acute Stage of Severe Traumatic Brain Injury.

The pressure reactivity index (PRx) is calculated as a moving correlation coefficient between intracranial pressure (ICP) and mean arterial blood pressure (MABP), and this analytical value is viewed as reflecting a vasomotor response to MABP variability. At present, the factors influencing the PRx value during the acute stage of traumatic brain injury (TBI) are not known. We observed significant cases where changes in the calculated value of PRx seemed to be influenced by changes in brain temperature during the course of acute stage TBI. In one case, a patient was treated for 72 h with therapeutic brain hypothermia after a decompressive hemicraniectomy. During the hypothermic condition, the mean value of PRx was -0.019; however, after gradual rewarming, the value of PRx increased drastically, and the mean value during the rewarming period, when the brain temperature exceeded 35 °C, was 0.331. Similarly, in another case where the patient underwent therapeutic brain hypothermia, the PRx showed a mean value of -0.038 during the hypothermic condition, and a mean value of 0.052 during the rewarming period. In both cases, a trend toward a negative correlation between ICP and MABP during brain hypothermia shifted to a positive correlation upon rewarming.

Unique Distribution of Benzodiazepine Receptors in the Brain during the First Two Years of Life.

BACKGROUND: 123I-iomazenil (IMZ) single-photon emission computed tomography (SPECT) is a tool for evaluating epileptic foci and brain damage. To apply the method to children, information regarding the age-specific expression of benzodiazepine receptors (BDZ-Rs) is required. Unfortunately, there is no information currently available for children <2 years of age. METHODS: We used IMZ SPECT once in infants aged 3-8 months and again at 2 years of age in order to describe the maturational changes in BDZ-R distribution. RESULTS: No neurological deficits were found in any of the infants at the first examination. The BDZ-Rs were more dominantly distributed in the occipital lobe than in the frontal lobe before the age of 2 years. The frontal-occipital gradients of the distribution were obvious in children <8 months of age. Magnetic resonance imaging showed a spreading of myelination toward the frontal lobes simultaneously with BDZ-R expression. CONCLUSION: Information regarding the alteration in the BDZ-R distribution pattern is useful when assessing infantile epilepsy and brain injury. The age-related pattern of BDZ-R distribution could correspond with myelination, cerebral blood flow, metabolism and behavioral development.

Importance of Early Postoperative Body Temperature Management for Treatment of Subarachnoid Hemorrhage.

BACKGROUND: The importance of acute-phase brain temperature management is widely accepted for prevention of exacerbation of brain damage by a high body temperature. METHODS: In this study, we investigated the influence of body temperature in the early postoperative period on the outcomes of 62 patients with subarachnoid hemorrhage who were admitted to our department. Body temperature was measured from day 4 to day 14 after onset. The patients were divided into those treated with surgical clipping (clip group) and coil embolization (coil group), those graded I-III (mild) and IV-V (severe) based on the Hunt & Hess classification on admission, those with and without development of delayed cerebral ischemia (DCI), and those with favorable and poor outcomes. Body temperatures throughout the hospital stay were compared in each group. RESULTS: There was no significant difference in body temperature between the clip and coil groups or between the mild and severe groups, but body temperature was significantly higher in patients with DCI compared to those without DCI, and in patients with a poor outcome compared to those with a favorable outcome. CONCLUSIONS: Fever in the early postoperative period of subarachnoid hemorrhage is associated with development of DCI and a poor outcome.

Continuous Monitoring of Spreading Depolarization and Cerebrovascular Autoregulation after Aneurysmal Subarachnoid Hemorrhage.

Delayed cerebral ischemia (DCI) is a prominent complication after aneurysmal subarachnoid hemorrhage (aSAH). Although vasospasm of proximal cerebral arteries has been regarded as the main cause of DCI, vasospasm of distal arteries, microthrombosis, impaired autoregulation, cortical spreading depolarization (CSD), and spreading ischemia are thought to be involved in DCI after aSAH. Here, we describe a patient with aSAH in whom CSD and cerebrovascular autoregulation were evaluated using simultaneous electrocorticography and monitoring of the pressure reactivity index (PRx) after surgical clipping of a ruptured posterior communicating artery aneurysm. In this patient, a prolonged duration of CSD and elevation of PRx preceded delayed neurological deficit. Based on this observation, we propose a relationship between these factors and DCI. Assessment of cerebrovascular autoregulation may permit detection of the inverse hemodynamic response to cortical depolarization. Detection of DCI may be achieved through simultaneous monitoring of CSD and PRx in patients with aSAH.

Strategies and Pitfalls of Motor-Evoked Potential Monitoring during Supratentorial Aneurysm Surgery.

BACKGROUND: The aims of this study were to reveal the strategies and pitfalls of motor-evoked potential (MEP) monitoring methods during supratentorial aneurysm surgery, and to discuss the drawbacks and advantages of each method by reviewing our experiences. METHODS: Intraoperative MEP monitoring was performed in 250 patients. Results from 4 monitoring techniques using combinations of 2 stimulation sites and 2 recording sites were analyzed retrospectively. RESULTS: MEP was recorded successfully in 243 patients (97.2%). Direct cortical stimulation (DCS)-spinal recorded MEP (sMEP) was used in 134 patients, DCS-muscle recorded MEP (mMEP) in 97, transcranial electrical stimulation (TES)-mMEP in 11 and TES-sMEP in 1. TES-mMEP during closure of the skull was used in 21 patients. DCS-mMEP was able to detect waveforms from upper and/or lower limb muscles. Alternatively, DCS-sMEP (direct [D]-wave) could accurately estimate amplitude changes. A novel "early warning sign" indicating ischemia was found in 21 patients, which started with a transiently increased amplitude of D-wave and then decreased after proximal interruption of major arteries. False-negative findings in MEP monitoring in 2 patients were caused by a blood insufficiency in the lenticulostriate artery and by a TES-sMEP recording, respectively. CONCLUSIONS: The results of this study suggest that to perform accurate MEP monitoring, DCS-mMEP or DCS-sMEP recording should be used as the situation demands, with combined use of TES-mMEP recording during closure of the skull. DCS-sMEP is recommended for accurate analysis of waveforms. We also propose a novel "early warning sign" of blood insufficiency in the D-wave.

Adverse events after unruptured cerebral aneurysm treatment: a single-center experience with clipping/coil embolization combined units.

BACKGROUND: Indications of clipping (Clip) or coil embolization (Coil) for unruptured cerebral aneurysms (uAN) was not elaborated because prediction of rupture and risk of treatment are difficult. This study aims to determine the risk-benefit analysis of treating uAN by a comprehensive and retrospective investigation of the adverse events and sequelae in patients treated by our Clip/Coil combined units. METHODS: Clip and Coil were performed in 141 and 80 patients, respectively; Clip for middle cerebral artery AN and Coil for paraclinoid or basilar apex AN. Worsening of modified Rankin scale or mini-mental state examination was defined as major morbidity. Minor morbidity or transient morbidity was defined as other neurologic deficits. Mortality and these morbidities were considered as serious adverse events. Convulsion or events outside the brain were defined as mild adverse events. RESULTS: Total mortality and major morbidity were low. Incidence of serious adverse events was not significantly different between the Clip and Coil (17 patients [12.1%] and 6 patients [7.5%]), but the number of total adverse events was significantly different (32 patients [22.7%] in Clip vs. 8 patients [10.0%] in Coil). Because mild morbidities were significantly more frequent in the Clip (20 patients [14.2%]) compared with the Coil (2 patients [2.5%]). Convulsion occurred in 11 (7.8%) patients in the Clip but none in the Coil. CONCLUSIONS: Our combined unit decreased the occurrence of mortality/major morbidity; however, minor adverse effects were common, especially in the Clip group because of many intrinsic problems of Clip itself. This result suggests further consideration for the treatment modality for uAN.