Functional outcomes, extent of resection, and bright/vague fluorescence interface in resection of glioblastomas involving the motor pathways assisted by 5-ALA.

BACKGROUND: 5-Aminolevulinic acid (5-ALA) fluorescence can maximize perirolandic glioblastoma (GBM) resection with low rates of postoperative sequelae. Our purpose was to present the outcomes of our experience and compare them with other literature reports to investigate the potential influence of different intraoperative monitoring strategies and to evaluate the role of intraoperative data on neurological and radiological outcomes in our series. METHODS: We retrospectively analyzed our prospectively collected database of GBM involving the motor pathways. Each patient underwent tumor exeresis with intraoperative 5-ALA fluorescence visualization. Our monitoring strategy was based on direct stimulation (DS), combined with cortical or transcranial MEPs. The radiological outcome was evaluated with CRET vs. residual tumor, and the neurological outcome as improved, unchanged, or worsened. We also performed a literature review to compare our results with state-of-the-art on the subject. RESULTS: Sixty-five patients were included. CRET was 63.1%, permanent postoperative impairment was 1.5%, and DS's lowest motor threshold was 5 mA. In the literature, CRET was 25-73%, permanent postoperative impairment 3-16%, and DS lowest motor threshold was 1-3 mA. Our monitoring strategy identified a motor pathway in 60% of cases in faint fluorescent tissue, and its location in bright/faint fluorescence was predictive of CRET (p < 0.001). A preoperative motor deficit was associated with a worse clinical outcome (p < 0.001). Resection of bright fluorescent tissue was stopped in 26%, and fluorescence type of residual tumor was associated with higher CRET grades (p < 0.001). CONCLUSIONS: Based on the data presented and the current literature, distinct monitoring strategies can achieve different onco-functional outcomes in 5-ALA-guided resection of a glioblastoma (GBM) motor pathway. Intraoperatively, functional and fluorescence data close to a bright/vague interface could be helpful to predict onco-functional outcomes.

Electrodiagnostic findings in patients with non-COVID-19- and COVID-19-related acute respiratory distress syndrome.

BACKGROUND: Critical illness polyneuropathy and myopathy (CIPNM) is a frequent neurological manifestation in patients with acute respiratory distress syndrome (ARDS) from coronavirus disease 2019 (COVID-19) infection. CIPNM diagnosis is usually limited to clinical evaluation. We compared patients with ARDS from COVID-19 and other aetiologies, in whom a neurophysiological evaluation for the detection of CIPNM was performed. The aim was to determine if there were any differences between these two groups in frequency of CINPM and outcome at discharge from the intensive care unit (ICU). MATERIALS AND METHODS: This was a single-centre retrospective study performed on mechanically ventilated patients consecutively admitted (January 2016-June 2020) to the ICU of Careggi Hospital, Florence, Italy, with ARDS of different aetiologies. Neurophysiological evaluation was performed on patients with stable ventilation parameters, but marked widespread hyposthenia (Medical Research Council score <48). Creatine phosphokinase (CPK), lactic dehydrogenase (LDH) and mean morning glycaemic values were collected. RESULTS: From a total of 148 patients, 23 with COVID-19 infection and 21 with ARDS due to other aetiologies, underwent electroneurography/electromyography (ENG/EMG) recording. Incidence of CIPNM was similar in the two groups, 65% (15 of 23) in COVID-19 patients and 71% (15 of 21) in patients affected by ARDS of other aetiologies. At ICU discharge, subjects with CIPNM more frequently required ventilatory support, regardless the aetiology of ARDS. CONCLUSION: ENG/EMG represents a useful tool in the identification of the neuromuscular causes underlying ventilator wean failure and patient stratification. A high incidence of CIPNM, with a similar percentage, has been observed in ARDS patients of all aetiologies.

Early-SEPs' amplitude reduction is reliable for poor-outcome prediction after cardiac arrest?

OBJECTIVE: The bilateral absence of cortical Somatosensory Evoked Potentials (SEPs), after cardiac arrest (CA), is a high reliable predictor of poor outcome but it is present in no more than 40% of patients. An amplitude reduction of cortical SEPs was found in about 30% of subjects, but few papers analysed its prognostic significance. The aim of our study is to identify a value of SEP amplitude reduction below which all the CA patients had poor outcome and the relationship between SEP and Electroencephalogram (EEG) patterns. MATERIAL AND METHODS: We analysed comatose patients in whom SEPs and EEG were recorded at 6-12 hours after CA. We evaluated the sensitivity at specificity of 100% of SEP amplitude in predicting the non-recovery of consciousness by plotting Receiver Operating Characteristic (ROC) curves. We also analysed the relationship between SEP amplitude and EEG patterns. Outcome was evaluated at 6 months by Glasgow Outcome Scale. RESULTS: We analysed 119 subjects. According to the ROC analysis (area under the curve = 0.95/CI 0.91-0.99), all patients with a cortical SEP amplitude <0.65 µV did not recover consciousness (GOS 1-2), with a sensitivity of 71.8%. Severe EEG abnormalities (suppression and burst-suppression patterns) were also observed in all these patients. CONCLUSION: Not only the absence but also a bilateral amplitude reduction of cortical SEPs (<0.65 µV) is associated with ominous prognosis (death or non-recovery of consciousness) with a very high predictive value. However, we emphasize that great caution should be applied before adopting amplitude reduction as a criterion for the poor prognosis of CA patients.

Intraoperative seizures during neuro-oncological supratentorial surgery: the role of prophylaxis with levetiracetam and intraoperative monitoring in a consecutive series of 353 patients.

BACKGROUND: The aim of this paper was to understand the role of prophylaxis with levetiracetam at skin incision in preventing convulsive intraoperative seizures (IOS) during neurosurgical procedures with and without intraoperative neuromonitoring (IONM). METHODS: Authors retrospectively reviewed the Institutional database for cases of supratentorial brain tumors undergoing surgical resection performed from January 2021 to October 2022. Patients were operated on both under general anesthesia and awake, using motor-evoked potentials (MEP) and direct cortical stimulation for cortical mapping. 1000 mg ev of Levetiracetam before skin incision in case of a history of seizures was administrated. We excluded all infratentorial cases. RESULTS: Three hundred fisty three consecutive cases were retrieved. IOS occurred in 22 patients (6.2%). Prophylaxis with Levetiracetam was administered in 149 patients, and IOS occurred in 16 cases (10.7%) in this group of patients. The IOS rate in the case of no Levetiracetam prophylaxis administration (3.5%) was significantly lower (P<0.001, OR=3.38 [1.35-8.45], RR=3.12 [1.32-7.41]). The Penfield technique stimulation evoked seven of all 22 IOS reported (31.8%) (P=0.006, RR 5.4 [1.44 -20.58], OR 21 [2.3-183.9]), and the train-of-five technique stimulation caused two of all registered IOS (8.7%) (P=0.2, RR 2.3 [0.99-5.67], OR 6.5 [0.55-76.17]). Transcranial MEPs evoked no IOS. CONCLUSIONS: Under levetiracetam prophylaxis, the IOS rate was not significantly lower than in the group of patients without Levetiracetam prophylaxis, regardless of the histology of the tumor and IONM. Neither the transcranial stimulation (MEP) nor train-of-five technique stimulation increases the risk of convulsive IOS, as Penfield technique stimulation does.

Heads-Up Micronavigation Reliability of Preoperative Transcranial Magnetic Stimulation Maps for the Motor Function: Comparison With Direct Cortical Stimulation.

BACKGROUND AND OBJECTIVES: We aimed to assess the reliability of preoperative navigated transcranial magnetic stimulation (nTMS) maps for motor function as visualized intraoperatively with augmented reality heads-up display and to assess its accuracy via direct point-by-point comparison with the gold-standard direct cortical stimulation (DCS). METHODS: From January 2022 to January 2023, candidates for surgical removal of lesions involving the motor pathways underwent preoperative nTMS assessment to obtain cortical maps of motor function. Intraoperatively and before tumor removal, nTMS maps were superimposed on the cortical surface, and DCS was performed on positive points with increasing current intensity until obtaining a positive response at 16 mA. The outcome of each stimulation was recorded to obtain discrimination metrics. RESULTS: Twelve patients were enrolled (5 females [42%] vs 7 males [58%], mean age 62.9 ± 12.8 years), for a total of 304 investigated points. Agreement between nTMS and DCS was moderate (κ = 0.43, P < .005), with 0.66 (0.53-0.78) sensitivity, 0.87 (0.82-0.90) specificity, 0.50 (0.39-0.62) positive predictive values, 0.93 (0.89-0.95) negative predictive value, and 0.83 (0.79-0.87) accuracy. A loss of accuracy was observed with higher DCS current intensities. CONCLUSION: We performed a point-by-point validation of preoperative nTMS maps for motor function using augmented reality visualization. The high negative predictive value and low positive predictive values highlight nTMS reliability to visualize safe cortical zones but not to identify critical functional areas, confirming previous findings of nTMS maps for the language function and suggesting the need for combined use of nTMS maps and DCS for optimal maximal safe resection.

Brain tumor surgery guided by navigated transcranial magnetic stimulation mapping for arithmetic calculation.

OBJECTIVE: The onco-functional balance represents the primary goal in neuro-oncology. The increasing use of navigated transcranial magnetic stimulation (nTMS) allows the noninvasive characterization of cortical functional anatomy, and its reliability for motor and language mapping has previously been validated. Calculation and arithmetic processing has not been studied with nTMS so far. In this study, the authors present their preliminary data concerning nTMS calculation. METHODS: The authors designed a monocentric prospective study, adopting an internal protocol to use nTMS for preoperative planning, including arithmetic processing. When awake surgery was possible, according to the patients' conditions, nTMS points were used to guide direct cortical stimulation (DCS), i.e., the gold standard for cortical mapping. Navigated TMS-based tractography was used for surgical planning. Statistical analyses on the nTMS and DCS points were performed. RESULTS: From February 2021 to October 2023, 61 procedures for nTMS calculation mapping were performed. The clinical evaluation, including pre- and postoperative evaluations (3 months after surgery), demonstrated a good clinical outcome with preservation of arithmetic function and recovery (92.8% of patients). Between the awake and asleep surgery groups, the postoperative clinical results were comparable at the 3-month follow-up, with > 90% of the patients achieving improved calculation function. The surgical strategy adopted was aimed at sparing nTMS positive points in asleep procedures, whereas nTMS and DCS positive points were not removed in awake procedures. Overall, 62% of the positive points for calculation functions were exposed by craniotomy and 85% were spared during surgery. None of the patients developed nTMS-related seizures. Diffusion tensor imaging fiber tracking based on nTMS positive points for calculation was used. The white matter fiber tracts involved in calculation functions were the arcuate fasciculus (56%) and frontal aslant tract (22%). When nTMS and DCS points were compared in awake surgery (n = 10 patients), a sensitivity of 31.71%, specificity of 85.76%, positive predictive value of 22.41%, negative predictive value of 90.64%, and accuracy of approximately 69% were achieved. CONCLUSIONS: Based on the authors' preliminary data, nTMS can be an advantageous tool to study cognitive functions, aimed at minimizing neurological impairment. The postoperative clinical outcome for patients who underwent operation with nTMS was very good. Considering these results, nTMS has proved to be a feasible method to map cognitive areas including those for calculation functions. Further analyses are needed to validate these data. Finally, other cognitive functions (e.g., visuospatial) may be explored with nTMS.

Spatial and Temporal Gait Characteristics in Patients Admitted to a Neuro-Rehabilitation Department with Age-Related White Matter Changes: A Gait Analysis and Clinical Study.

BACKGROUND: Patients with age-related white matter changes (ARWMC) frequently present a gait disorder, depression and cognitive impairment. Our aims are to define which alterations in the gait parameters are associated with motor or neuro-psychological impairment and to assess the role of motor, mood or cognitive dysfunction in explaining the variance of the gait parameters. METHODS: Patients with gait disorders admitted to a Neuro-rehabilitation Department, affected by vascular leukoencephalopathy who had ARWMC confirmed by a brain MRI, were consecutively enrolled, classified by a neuroradiological scale (Fazekas 1987) and compared to healthy controls. We excluded subjects unable to walk independently, subjects with hydrocephalus or severe aphasia, with orthopaedic and other neurological pathologies conditioning the walking pattern. Patients and controls were assessed by clinical and functional scales (Mini Mental State Examination, Geriatric Depression Scale, Nevitt Motor Performance Scale, Berg Balance Scale, Functional Independence Measure), and computerised gait analysis was performed to assess the spatial and temporal gait parameters in a cross-sectional study. RESULTS: We recruited 76 patients (48 males, aged 78.3 ± 6.2 years) and 14 controls (6 males, aged 75.8 ± 5 years). In the multiple regression analysis, the gait parameter with overall best model summary values, associated with the ARWMC severity, was the stride length even after correction for age, sex, weight and height (R2 = 0.327). The motor performances justified at least in part of the gait disorder (R2 change = 0.220), but the mood state accounted independently for gait alterations (R2 change = 0.039). The increase in ARWMC severity, the reduction of motor performance and a depressed mood state were associated with a reduction of stride length (R = 0.766, R2 = 0.587), reduction of gait speed (R2 = 0.573) and an increase in double support time (R2 = 0.421). CONCLUSION: The gait disorders in patients with ARWMC are related to motor impairment, but the presence of depression is an independent factor for determining gait alterations and functional status. These data pave the way for longitudinal studies, including gait parameters, to quantitatively assess gait changes after treatment or to monitor the natural progression of the gait disorders.

A Diffusion Tensor Imaging-Based Prognostic Classification for Surgery of Intrinsic Lesions Involving the Motor Pathways.

BACKGROUND: The critical role of different adjuncts in improving the neurological outcome in intrinsic brain lesions affecting eloquent areas is demonstrated by their more diffuse utilization. Neurosurgeons often rely on preoperative and intraoperative diffusion tensor imaging tractography to improve the operative strategy and prognosis. We aimed to identify and validate a diffusion tensor imaging-based classification considering the relationship between the brain lesion and the corticospinal tract to predict a >50% reduction of motor evoked potentials (MEPs) during surgical excision of lesions involving the motor pathways. METHODS: We included patients consecutively enrolled at our institution between April 2020 and September 2022 with 3 patterns of increasing complexity according to the relationship between the lesion and the corticospinal tract as identified on preoperative diffusion tensor imaging. Outcome measures were >50% reduction in intraoperative MEPs and neurological outcome defined as unchanged, improved, or worsened. RESULTS: The study included 83 patients. A statistically significant linear trend between higher rates of reduction of MEPs and higher classification grades was observed (P = 0.001), with sensitivity 0.60, specificity 0.88, accuracy 0.83, and area under the curve 0.75. Higher grades were associated with worse neurological outcomes (P = 0.02). CONCLUSIONS: The classification proved reliable in anticipating reduction in intraoperative MEPs and in predicting neurological outcome. Using this classification in patients undergoing surgery for lesions involving the motor pathways could help in counseling the patient, surgical planning, enhancing teamwork of operating room personnel, and improving the patient's prognosis.

Intraoperative Mapping of the Sensory Root of the Trigeminal Nerve in Patients with Pontocerebellar Angle Pathology.

OBJECTIVE: The aim of the present study was to determine the position of the 3 sensory branches of the trigeminal nerve in the preganglionic tract using intraoperative neurophysiological mapping. METHODS: We included consecutive adult patients who underwent neurosurgical treatment of cerebellopontine angle lesions. The trigeminal nerve was antidromically stimulated at 3 sites along its circumference with different stimulus intensities at a distance of ≤1 cm from the brainstem. The sensory nerve action potentials (SNAPs) were recorded from each main trigeminal branch (V1 [ophthalmic branch], V2 [maxillary branch], and V3 [mandibular branch]). RESULTS: We analyzed 13 patients. The stimulation points at which we obtained the greatest number of congruous and exclusive SNAPs (SNAPs only on the stimulated branch) was the stimulation point for V3 (20.7%). The stimulation intensity at which we obtained the highest number of congruent and exclusive SNAPs with the stimulated branch was 0.5 mA. CONCLUSIONS: Using our recording conditions, trigeminal stimulation is a reliable technique for mapping the V3 and V1 branches using an intensity not exceeding 0.5. However, reliable identification of the fibers of V2 is more difficult. Stimulation of the trigeminal nerve can be a reliable technique to identify the V3 and V1 branches if rhizotomy of these branches is necessary.

Feasibility of Intraoperative Visual Evoked Potential Monitoring by Cortical Strip Electrodes in Patients During Brain Surgery: A Preliminary Study.

OBJECTIVE: The role of visual evoked potentials (VEPs) monitoring during neurosurgical procedure in patient remains unclear. The purpose of our study was to determine the feasibility of intraoperative VEP recording using a strip cortical electrode during surgical resection of intracranial lesions. METHODS: In this prospective, monocentric, observational study, we enrolled consecutive patients undergoing neurosurgical procedure for intracranial lesions. After dural opening, a cortical strip was positioned on the lateral occipital surface. Flash VEPs were continuously recorded using both subdermal corkscrew electrodes and strip electrodes. An electroretinogram was also recorded to guarantee delivery of adequate flash stimuli to the retina. RESULTS: We included 10 patients affected by different intracranial lesions. Flash VEPs were recorded using subdermal corkscrew electrodes in all patients except 1 in whom they were never identified during the recording. Flash VEPs were recorded using strip electrodes in all patients and showed a polyphasic morphology with a significantly larger amplitude compared with that of flash VEPs measured using subdermal corkscrew electrodes. No patient reported worsened postoperative vision and a >50% decrease in the VEPs amplitude was never registered. CONCLUSIONS: We have reported for the first time in the literature that VEP monitoring during a neurosurgical procedure is feasible via a cortical strip located on the occipital surface. The technique demonstrated greater stability and a larger amplitude compared with recordings with scalp electrodes, facilitating identification of any changes. Studies with more patients are needed to assess the clinical reliability of the technique.

Is the Patient State Index a reliable parameter as guide to anaesthesiology in cranial neurosurgery? A first intraoperative study and a literature review.

BACKGROUND: Patient State Index (PSI) and Suppression Ratio (SR) are two indices calculated by quantitative analysis of EEG used to estimate the depth of anaesthesia but their validation in neurosurgery must be done. Our aim was to investigate the congruity PSI and SR with raw EEG monitoring in neurosurgery. METHODS: We included 34 patients undergoing elective cranial neurosurgery. Each patient was monitored by a SedLine device (PSI and SR) and by raw EEG. To appraise the agreement between PSI, SR and EEG Suppr%, Bland-Altman analysis was used. We also correlated the PSI and SR recorded at different times during surgery to the degree of suppression of the raw EEG data by Spearman's rank correlation coefficient. For a comparison with previous data we made an international literature review according to PRISMA protocol. RESULTS: At all recording times, we found that there is a strong agreement between PSI and raw EEG. We also found a significant correlation for both PSI and SR with the EEG suppression percentage (p < 0.05), but with a broad dispersion of the individual values within the confidence interval. CONCLUSION: The Masimo SedLine processed EEG monitoring system can be used as a guide in the anaesthetic management of patients during elective cranial neurosurgery, but the anaesthesiologist must be aware that previous correlations between PSI and SR with the suppression percentage may not always be valid in all individual patients. The use of an extended visual raw EEG evaluated by an expert electroencephalographer might help to provide better guidance.

Surgery of optic-chiasmatic tumors assisted by sodium fluorescein yellow fluorescence and visual evoked potentials monitoring.

BACKGROUND: Tumours of the anterior visual pathways are challenging to operate because of the crucial balance between extent of resection and sight preservation. Sodium Fluoresceine (SF) has already been reported in maximizing brain tumour resection but not when the optic-chiasmatic region is involved. The role of Visual Evoked Potentials (VEPs) in optic-chiasmatic tumours is still debated. The simultaneous use of both technique in this setting has not been reported so far. The aim of our work is to analyse the intraoperative combination of the use of SF and VEPs in the anterior visual pathway tumour surgery. METHODS: Clinical and Intra-operative data from six surgical procedures on four patients affected by optic-chiasmatic tumours with preoperative visual deficits were retrospectively analysed. RESULTS: In 5 procedures VEPs remained intraoperatively stable and no postoperative worsening of visual function was reported. In 1 case an intraoperative VEPs deterioration was predictive of a postoperative visual worsening. In all cases, tumour was fluorescent, and SF was intraoperatively helpful in guiding resection. The pattern of fluorescence was different according to the lesion histology. CONCLUSIONS: Based on our preliminary experience, the simultaneous combination of SF and VEPs in surgery of the optic pathway tumours seems helpful to maximize tumour resection and predict postoperative functional outcome. Since we presented a small series, larger studies are needed to confirm our data.

Eye-opening in brain death: A case report and review of the literature.

Background: According to Italian law, brain death is diagnosed when the patient is in a coma, showing the absence of respiratory drive under specific clinical conditions, and without any brain stem reflexes. On the other hand, presence of spinal reflexes, when correctly identified, does not hamper the diagnosis. Case report: We present a case of eyelid elevation two seconds after thoracic pain stimulation in a patient who otherwise fulfilled all clinical and instrumental brain-death criteria due to a residual preserved function of the superior cervical ganglion. Conclusion: Although the observed reflex is to be considered extracerebral, and therefore it should not hamper the diagnosis of BD, the authors propose implementing cerebral flow evaluation, considered "prudential", as a preliminary assessment before determining BD.

Do changes in SSEP amplitude over time predict the outcome of comatose survivors of cardiac arrest?

AIM: To assess if the amplitude of the N20 wave (N20Amp) of somatosensory evoked potentials (SSEPs) changes between 12-24 h and 72 h from the return of spontaneous circulation (ROSC) after cardiac arrest and if an N20Amp decrease predicts poor neurological outcome (CPC 3-5) at six months. SETTING: Retrospective analysis of the ProNeCA multicentre prognostication study dataset. (NCT03849911). METHODS: In adult comatose cardiac arrest survivors whose SSEPs were recorded at both 12-24 h and 72 h after ROSC, we measured the median N20Amp at each timepoint and the individual change in N20Amp across the two timepoints. We identified their cutoffs for predicting poor outcome with 0% false positive rate (FPR) and compared their sensitivities. RESULTS: We included 236 patients. The median [IQR] N20Amp increased from 1.90 [0.78-4.22] µV to 2.86 [1.52-5.10] µV between 12-24 h and 72 h (p = 0.0019). The N20Amp cutoff for 0% FPR increased from 0.6 µV at 12-24 h to 1.23 µV at 72 h, and its sensitivity increased from 56[48-64]% to 71[63-77]%. Between 12-24 h and 72 h, an N20Amp decrease > 53% predicted poor outcome with 0[0-5]% FPR and 26[19-35]% sensitivity. Its combination with an N20Amp < 1.23 µV at 72 h increased sensitivity by 1% to 72[64-79]%. CONCLUSION: In comatose cardiac arrest survivors, the median N20Amp and its cutoff for predicting poor neurological outcome increase between 12-24 and 72 h after ROSC. An N20Amp decrease greater than 53% between these two timepoints predicts poor outcome with 0% FPR, confirming the unfavourable prognostic signal of a low N20Amp at 72 h.

The role of early electroclinical assessment in improving the evaluation of patients with disorders of consciousness.

We all share the need to optimise the evaluation of patients with disorders of consciousness (DOC), given the high rate of misdiagnosis of vegetative state based on clinical examination. We believe that one way to do this is to optimise assessment from the early stages, in order to reduce discontinuity between the hospital and rehabilitation phases. While clinical observation remains the "gold standard" for the diagnostic assessment of patients with DOC, neurophysiological investigations (electroencephalography, short latency evoked potentials and event-related potentials) could help to further understanding of the pathophysiology underlying the state of unresponsiveness, differentiate coma from other apparently similar conditions (i.e., locked-in and locked-in-like syndromes), and potentially integrate prognostic evaluation with monitoring of the evolution of the clinical state. Moreover, these techniques have the considerable advantage of being available at the bedside. Discontinuity between the hospital and rehabilitation phases is rightly considered to be one of the critical points in the assessment of patients with DOC. In our view, a continuum of expert neurological assessment that begins with monitoring of the acute phase (focusing on evolution of primary brain damage and secondary complications) and follows through to the patient's discharge from the intensive care unit (focusing on the pathophysiology of brain damage and prognostication based on clinical, neuroimaging and neurophysiological tests) could help to: i) optimise the rehabilitation programme according to the expectations of recovery; ii) provide a basis for comparison with subsequent periodic re-evaluations; iii) ensure uniformity of assessment regardless of the heterogeneity of care facilities; and iv) characterise a subset of patients who, showing discrepancies between neurophysiological tests and clinical status, are more likely to undergo unexpected recovery.

Are neurophysiologic tests reliable, ultra-early prognostic indices after cardiac arrest?

OBJECTIVES: Determining early and reliable prognosis in comatose subjects after cardiac arrest is a central component of post-cardiac arrest care both for developing realistic prognostic expectations for families, and for better determining which resources are mobilized or withheld for individual patients. The aim of the study was to evaluate the prognostic accuracy of EEG and SEP patterns during the very early period (within the first 6 h) after cardiac arrest. METHODS: We retrospectively analysed comatose patients after CA, either inside or outside the hospital, in which prognostic evaluation was made during the first 6 h from CA. Prognostic evaluation comprised clinical evaluation (GCS and pupillary light reflex) and neurophysiological (electroencephalography (EEG) and somatosensory evoked potentials (SEP)) studies. Prognosis was evaluated with regards to likelihood of recovery of consciousness and also likelihood of failure to regain consciousness. RESULTS: Forty-one comatose patients after cardiac arrest were included. All patients with continuous and nearly continuous EEG recovered consciousness. Isoelectric EEG was always associated with poor outcome. Burst-suppression, suppression and discontinuous patterns were usually associated with poor outcome although some consciousness recovery was observed. Bilaterally absent SEP responses were always associated with poor outcome. Continuous and nearly continuous EEG patterns were never associated with bilaterally absent SEP. CONCLUSIONS: During the very early period following cardiac arrest (first 6 h), EEG and SEP maintain their high predictive value to predict respectively recovery and failure of recovery of consciousness. A very early EEG exam allows identification of patients with very high probability of a good outcome, allowing rapid use of the most appropriate therapeutic procedures.

Does a combination of ≥2 abnormal tests vs. the ERC-ESICM stepwise algorithm improve prediction of poor neurological outcome after cardiac arrest? A post-hoc analysis of the ProNeCA multicentre study.

BACKGROUND: Bilaterally absent pupillary light reflexes (PLR) or N20 waves of short-latency evoked potentials (SSEPs) are recommended by the 2015 ERC-ESICM guidelines as robust, first-line predictors of poor neurological outcome after cardiac arrest. However, recent evidence shows that the false positive rates (FPRs) of these tests may be higher than previously reported. We investigated if testing accuracy is improved when combining PLR/SSEPs with malignant electroencephalogram (EEG), oedema on brain computed tomography (CT), or early status myoclonus (SM). METHODS: Post-hoc analysis of ProNeCA multicentre prognostication study. We compared the prognostic accuracy of the ERC-ESICM prognostication strategy vs. that of a new strategy combining ≥2 abnormal results from any of PLR, SSEPs, EEG, CT and SM. We also investigated if using alternative classifications for abnormal SSEPs (absent-pathological vs. bilaterally-absent N20) or malignant EEG (ACNS-defined suppression or burst-suppression vs. unreactive burst-suppression or status epilepticus) improved test sensitivity. RESULTS: We assessed 210 adult comatose resuscitated patients of whom 164 (78%) had poor neurological outcome (CPC 3-5) at six months. FPRs and sensitivities of the ≥2 abnormal test strategy vs. the ERC-ESICM algorithm were 0[0-8]% vs. 7 [1-18]% and 49[41-57]% vs. 63[56-71]%, respectively (p < .0001). Using alternative SSEP/EEG definitions increased the number of patients with ≥2 concordant test results and the sensitivity of both strategies (67[59-74]% and 54[46-61]% respectively), with no loss of specificity. CONCLUSIONS: In comatose resuscitated patients, a prognostication strategy combining ≥2 among PLR, SSEPs, EEG, CT and SM was more specific than the 2015 ERC-ESICM prognostication algorithm for predicting 6-month poor neurological outcome.

SSEP amplitude accurately predicts both good and poor neurological outcome early after cardiac arrest; a post-hoc analysis of the ProNeCA multicentre study.

AIM: To assess if, in comatose resuscitated patients, the amplitude of the N20 wave (N20amp) of somatosensory evoked potentials (SSEP) can predict 6-months neurological outcome. SETTING: Multicentre study in 13 Italian intensive care units. METHODS: The N20amp in microvolts (µV) was measured at 12 h, 24 h, and 72 h from cardiac arrest, along with pupillary reflex (PLR) and a 30-min EEG classified according to the ACNS terminology. Sensitivity and false positive rate (FPR) of N20amp alone or in combination were calculated. RESULTS: 403 patients (age 69[58-68] years) were included. At 12 h, an N20amp >3 µV predicted good neurological outcome (Cerebral Performance Categories [CPC] 1-2) with 61[50-72]% sensitivity and 11[6-18]% FPR. Combining it with a benign (continuous or nearly continuous) EEG increased sensitivity to 91[82-96]%. For poor outcome (CPC 3-5), an N20Amp ≤0.38 µV, ≤0.73 µV and ≤1.01 µV at 12 h, 24 h, and 72 h, respectively, had 0% FPR with sensitivity ranging from 61[51-69]% and 82[76-88]%. Sensitivity was higher than that of a bilaterally absent N20 at all time points. At 12 h and 24 h, a highly malignant (suppression or burst-suppression) EEG and bilaterally absent PLR achieved 0% FPR only when combined with SSEP. A combination of all three predictors yielded a 0[0-4]% FPR, with maximum sensitivity of 44[36-53]%. CONCLUSION: At 12 h from arrest, a high N20Amp predicts good outcome with high sensitivity, especially when combined with benign EEG. At 12 h and 24 h from arrest a low-voltage N20amp has a high sensitivity and is more specific than EEG or PLR for predicting poor outcome.

A multimodal diagnostic approach for lateralised rhythmic delta activity in the ictal-interictal continuum.

The ictal-interictal continuum represents a diagnostic challenge even for expert neurrophysiologists, often requiring an additional multimodal diagnostic workup to understand its clinical significance. Lateralised rhythmic delta activity (LRDA) is an ictal-interictal continuum pattern that has only recently been investigated and recognised as potentially ictogenic or sometimes even ictal. We describe a patient who presented with acute-onset aphasia, initially suspected of having a stroke; advanced brain imaging with CT-perfusion showed features suggesting regional left temporo-parietal hyperperfusion and an EEG revealed LRDA with fluctuations and intermixed sharp waves in the same areas. Treatment with lacosamide caused both clinical and EEG improvement after a few hours, supporting the hypothesis that the EEG pattern represented an ictal/interictal phenomenon. In the literature, a correlation between metabolic/perfusion imaging and ictal-interictal continuum patterns is described regarding lateralised periodic discharges but less studied for LRDA. In this case, we adopted a multimodal approach, integrating advanced imaging, EEG, clinical features, and response to therapy, to consider the overall clinical presentation as focal NCSE.