Predictive Model for Estimating the Risk of Epilepsy After Aneurysmal Subarachnoid Hemorrhage: The RISE Score

BACKGROUND AND OBJECTIVES

The occurrence of seizures after aneurysmal subarachnoid hemorrhage (aSAH) is associated with a poorer functional and cognitive prognosis and less favorable quality of life. It would be of value to promptly identify patients at risk of epilepsy to optimize follow-up protocols and design preventive strategies. Our aim was to develop a predictive score to help stratify epilepsy risk in patients with aSAH.

METHODS

This is a retrospective, longitudinal study of all adults with aSAH admitted to our center (2012-2021). We collected demographic data, clinical and radiologic variables, data on early-onset seizures (EOSs), and data on development of epilepsy. Exclusion criteria were previous structural brain lesion, epilepsy, and ≤7 days' follow-up. Multiple Cox regression was used to evaluate factors independently associated with unprovoked remote seizures (i.e., epilepsy). The best fitting regression model was used to develop a predictive score. Performance was evaluated in an external validation cohort of 308 patients using receiver-operating characteristic curve analysis.

RESULTS

From an initial database of 743 patients, 419 met the inclusion criteria and were included in the analysis. The mean age was 60 ± 14 years, 269 patients (64%) were women, and 50 (11.9%) developed epilepsy within a median follow-up of 4.2 years. Premorbid modified Rankin Score (mRS) (hazard ratio [HR] 4.74 [1.8-12.4], p = 0.001), VASOGRADE score (HR 2.45 [1.4-4.2], p = 0.001), surgical treatment (HR 2.77 [1.6-4.9], p = 0.001), and presence of EOSs (HR 1.84 [1.0-3.4], p = 0.05) were independently associated with epilepsy. The proposed scale, designated RISE, scores 1 point for premorbid mRS ≥ 2 (R), VASOGRADE-Yellow (I, Ischemia), surgical intervention (S), and history of EOSs (E) and 2 points for VASOGRADE-Red. RISE stratifies patients into 3 groups: low (0-1), moderate (2-3), and high (4-5) risk (2.9%, 20.8%, and 75.7% developed epilepsy, respectively). On validation in a cohort from a different tertiary care center (N = 308), the new scale yielded a similar risk distribution and good predictive power for epilepsy within 5 years after aSAH (area under the curve [AUC] 0.82; 95% CI 0.74-0.90).

DISCUSSION

The RISE scale is a robust predictor of post-SAH epilepsy with immediate clinical applicability. In addition to facilitating personalized diagnosis and treatment, RISE may be of value for exploring future antiepileptogenesis strategies.

Use of thoracic ultrasound in acute respiratory distress syndrome

Acute respiratory distress syndrome (ARDS) is a significant cause of morbidity and mortality in critically ill patients, yet it is often underrecognized. Current imaging techniques, such as CT scan and X-ray, have several limitations, including inter-observer reliability, limited accessibility, radiation and the need for transportation. Ultrasound has become an essential bedside tool in the critical care setting and the emergency room, offering several advantages over traditional imaging techniques. It is nowadays widely used for diagnosis and early management of acute respiratory and circulatory failure. Lung ultrasound (LUS) provides non-invasively valuable information regarding lung aeration, ventilation distribution and respiratory complications in ARDS patients at the bedside. Moreover, a holistic ultrasound approach, combining LUS, echocardiography, and diaphragm ultrasound offers physiological information that could help the clinician to personalize ventilator settings and guide fluid resuscitation in these patients. Ultrasound techniques could also inform about possible causes of weaning failure in difficult-to-wean patients. However, it is uncertain whether clinical decisions based on ultrasound assessment can improve outcomes in ARDS patients and this clinical approach requires further investigation. In this article, we review the use of thoracic ultrasound, including lung and diaphragm examination, for the clinical assessment of patients with ARDS, and discuss its limitations and future perspectives.

Closed-loop oxygen control improves oxygen therapy in acute hypoxemic respiratory failure patients under high flow nasal oxygen: a randomized cross-over study (the HILOOP study)

Background

We aimed to assess the efficacy of a closed-loop oxygen control in critically ill patients with moderate to severe acute hypoxemic respiratory failure (AHRF) treated with high flow nasal oxygen (HFNO).

Methods

In this single-centre, single-blinded, randomized crossover study, adult patients with moderate to severe AHRF who were treated with HFNO (flow rate ≥ 40 L/min with FiO₂ ≥ 0.30) were randomly assigned to start with a 4-h period of closed-loop oxygen control or 4-h period of manual oxygen titration, after which each patient was switched to the alternate therapy. The primary outcome was the percentage of time spent in the individualized optimal SpO₂ range.

Results

Forty-five patients were included. Patients spent more time in the optimal SpO₂ range with closed-loop oxygen control compared with manual titrations of oxygen (96.5 [93.5 to 98.9] % vs. 89 [77.4 to 95.9] %; p < 0.0001) (difference estimate, 10.4 (95% confidence interval 5.2 to 17.2). Patients spent less time in the suboptimal range during closed-loop oxygen control, both above and below the cut-offs of the optimal SpO₂ range, and less time above the suboptimal range. Fewer number of manual adjustments per hour were needed with closed-loop oxygen control. The number of events of SpO₂ < 88% and < 85% were not significantly different between groups.

Conclusions

Closed-loop oxygen control improves oxygen administration in patients with moderate-to-severe AHRF treated with HFNO, increasing the percentage of time in the optimal oxygenation range and decreasing the workload of healthcare personnel. These results are especially relevant in a context of limited oxygen supply and high medical demand, such as the COVID-19 pandemic.

Trial registration The HILOOP study was registered at www.clinicaltrials.gov under the identifier NCT04965844.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13054-022-03970-w.

Pleth variability index may predict preload responsiveness in patients treated with nasal high flow: a physiological study

The purpose of this study was to determine whether the plethysmographic variability index ("PVi") can predict preload responsiveness in patients with nasal high flow (NHF) (≥30 L/min) with any sign of hypoperfusion. "Preload responsiveness" was defined as a ≥10% increase in stroke volume (SV), measured by transthoracic echocardiography, after passive leg raising. SV and PVi were reassessed in preload responders after receiving a 250-mL fluid challenge. Twenty patients were included and 12 patients (60%) were preload responders. Responders showed higher baseline mean PVi (24% vs. 13%; P = 0.001) and higher mean PVi variation (ΔPVi) after passive leg raising (6.8% vs. -1.7%; P < 0.001). No differences between mean ΔPVi after passive leg raising and mean ΔPVi after fluid challenge were observed (6.8% vs. 7.4%; P = 0.24); and both values were strongly correlated (r = 0.84; P < 0.001). Baseline PVi and ΔPVi after passive leg raising showed excellent diagnostic accuracy identifying preload responders (AUROC 0.92 and 1.00, respectively). Baseline PVi ≥ 16% had a sensitivity of 91.7% and a specificity of 87.5% for detecting preload responders. Similarly, ΔPVi after passive leg raising ≥2% had a 100% of both sensitivity and specificity. Thus, PVi might predict "preload responsiveness" in patients treated with NHF, suggesting that it may guide fluid administration in these patients.NEW & NOTEWORTHY This is the first study that analyzes the use of noninvasive plethysmographic variability index (PVi) for preload assessment in patients treated with nasal high flow (NHF). Its results showed that PVi might identify preload responders. Therefore, PVi may be used in the day-to-day clinical decision-making process in critically ill patients treated with NHF, helping to provide adequate resuscitation volume.

Long-term prognosis related to deep sedation in refractory status Epilepticus

OBJECTIVE

To evaluate long-term prognosis in patients with refractory status epilepticus according to the level of sedation reached during drug-induced coma.

MATERIALS AND METHODS

Longitudinal study of patients with status epilepticus who received anesthetics to induce therapeutic coma. Demographic data, clinical, and electroencephalographic characteristics were collected, as well as variables related to sedation. We considered as deep sedation the EEG burst-suppression patterns (suppression ratio > 50%). A GOSE (Glasgow Outcome Scale Extended) score of 7 or 8 was considered as good prognosis. A comparative study was carried out to identify predictors of good or poor prognosis at discharge, at 1 and 2 years of follow-up.

RESULTS

We included 61 patients: 63.9% were men; mean age 53.5 ± 16.8 years (range 16-86 years), 39.3% reached deep sedation; 62.3% had > 48 h induced coma. The median hospital stay was 21 days, while 10 days in the intensive care unit (ICU). In the multiple regression analysis, an ICU length of stay ≥ 7 days was associated with poor prognosis at discharge and at long-term (P < .05), while deep sedation was associated only with poor long-term prognosis (1 and 2 years, P < .05). The Kaplan-Meier curve showed higher survival in the group that did not undergo deep sedation (P < .05).

CONCLUSIONS

In refractory status epilepticus, deep sedation is associated with poor prognosis at long-term.

Extracorporeal Membrane Oxygenation Retrieval in Coronavirus Disease 2019: A Case-Series of 19 Patients Supported at a High-Volume Extracorporeal Membrane Oxygenation Center

OBJECTIVE

To evaluate the performance of the extracorporeal membrane oxygenation retrieval team at a high-volume extracorporeal membrane oxygenation center during the coronavirus disease 2019 pandemic.

DESIGN

Observational study including all adult patients with confirmed infection due to severe acute respiratory syndrome coronavirus-2 cannulated at other centers and transported on extracorporeal membrane oxygenation to the ICU of the Vall d'Hebron University Hospital between 15 March and 10 June 2020.

SETTING

The ICU (capacity expanded to 200 during the pandemic) of the Vall d'Hebron University Hospital (a 1,100-bed public university hospital in Barcelona), the referral center for extracorporeal respiratory support in Catalonia (7.5 million inhabitants).

PATIENTS

Extracorporeal membrane oxygenation was considered if the Pao2/Fio2 ratio less than 80 mm Hg (refractory to prone position) and/or Paco2 greater than 80 mm Hg and pH less than 7.25 for more than 6 hours, and no contraindications for extracorporeal support were present.

INTERVENTIONS

Venovenous extracorporeal membrane oxygenation was initiated in the primary center. Then, patients were transferred to the ICU of the Vall d'Hebron University Hospital where they received support until respiratory improvement. After decannulation, patients were discharged for rehabilitation at the primary center.

MEASUREMENTS AND MAIN RESULTS

Nineteen patients with severe acute respiratory syndrome coronavirus-2 infection and with a mean Pao2/Fio2 ratio of 71 mm Hg (57-118 mm Hg) despite prone positioning and a mean Paco2 of 70 mm Hg (47-110 mm Hg) were transferred to our center from their primary hospital after cannulation and received venovenous extracorporeal membrane oxygenation support. Prior to cannulation, six patients (31.5%) presented vascular thrombosis, and nine (47.4%) were already receiving anticoagulant therapy. Eighteen transfers were carried out with no significant complications. While on extracorporeal membrane oxygenation, thrombotic events were recorded in nine patients (47.4%) and hemorrhagic events in 13 (68.4%). Thirteen patients (68.4%) were successfully weaned, and 12 (63.1%) were discharged home.

CONCLUSIONS

Extracorporeal membrane oxygenation retrieval can rescue young, previously healthy patients with severe coronavirus disease 2019 in whom all the conventional respiratory measures have failed. Thrombotic and hemorrhagic complications are frequent in this cohort.

Presynaptic muscarinic acetylcholine autoreceptors (M1, M2 and M4 subtypes), adenosine receptors (A1 and A2A) and tropomyosin-related kinase B receptor (TrkB) modulate the developmental synapse elimination process at the neuromuscular junction

Background

The development of the nervous system involves an initially exuberant production of neurons that make an excessive number of synaptic contacts. The initial overproduction of synapses promotes connectivity. Hebbian competition between axons with different activities (the least active are punished) leads to the loss of roughly half of the overproduced elements and this refines connectivity and increases specificity. The neuromuscular junction is innervated by a single axon at the end of the synapse elimination process and, because of its relative simplicity, has long been used as a model for studying the general principles of synapse development. The involvement of the presynaptic muscarinic ACh autoreceptors may allow for the direct competitive interaction between nerve endings through differential activity-dependent acetylcholine release in the synaptic cleft. Then, the most active ending may directly punish the less active ones. Our previous results indicate the existence in the weakest axons on the polyinnervated neonatal NMJ of an ACh release inhibition mechanism based on mAChR coupled to protein kinase C and voltage-dependent calcium channels. We suggest that this mechanism plays a role in the elimination of redundant neonatal synapses.

Results

Here we used confocal microscopy and quantitative morphological analysis to count the number of brightly fluorescent axons per endplate in P7, P9 and P15 transgenic B6.Cg-Tg (Thy1-YFP)16 Jrs/J mice. We investigate the involvement of individual mAChR M₁-, M₂- and M₄-subtypes in the control of axonal elimination after the Levator auris longus muscle had been exposed to agonist and antagonist in vivo. We also analysed the role of adenosine receptor subtypes (A₁ and A_2A) and the tropomyosin-related kinase B receptor. The data show that postnatal axonal elimination is a regulated multireceptor mechanism that guaranteed the monoinnervation of the neuromuscular synapses.

Conclusion

The three receptor sets considered (mAChR, AR and TrkB receptors) intervene in modulating the conditions of the competition between nerve endings, possibly helping to determine the winner or the lossers but, thereafter, the final elimination would occur with some autonomy and independently of postsynaptic maturation.

Pre- and postsynaptic maturation of the neuromuscular junction during neonatal synapse elimination depends on protein kinase C

The distribution of acetylcholine receptors (AChRs) within and around the neuromuscular junction changes dramatically during the first postnatal weeks, a period during which polyneuronal innervation is eliminated. We reported previously that protein kinase C (PKC) activation accelerates postnatal synapse loss. Because of the close relationship between axonal retraction and AChR cluster dispersal, we hypothesize that PKC can modulate morphological maturation changes of the AChR clusters in the postsynaptic membrane during neonatal axonal reduction. We applied substances affecting PKC activity to the neonatal rat levator auris longus muscle in vivo. Muscles were then stained immunohistochemically to detect both AChRs and axons. We found that, during the first postnatal days of normal development, substantial axonal loss preceded the formation of areas in synaptic sites that were free of AChRs, implying that axonal loss could occur independently of changes in AChR cluster organization. Nevertheless, there was a close relationship between axonal loss and AChR organization; PKC modulates both, although differently. Block of PKC activity with calphostin C prevented both AChR loss and axonal loss between postnatal days 4 and 6. PKC may act primarily to influence AChR clusters and not axons, insofar as phorbol ester activation of PKC accelerated changes in receptor aggregates but produced relatively little axon loss.

IgM monoclonal antibody against terminal moiety of GM2, GalNAc-GD1a and GalNAc-GM1b from a pure motor chronic demyelinating polyneuropathy patient: effects on neurotransmitter release

We describe a patient with a pure motor chronic demyelinating polyneuropathy with an IgM monoclonal component showing anti-GM2, GalNAc-GD1a and GalNAc-GM1b reactivity whose common epitope appears to be -[GalNAcbeta1-4Gal(3-2alphaNeuAc)beta1]. We used intracellular recording to study how IgM from this patient affected neurotransmitter release in the mouse diaphragm in vitro. Adding serum (and specifically, the purified monoclonal IgM component) blocked the nerve-evoked response in both quantal content and evoked endplate potential (EPP) amplitude in a complement-independent and reversible manner. The IgM increased the frequency of spontaneous miniature endplate potentials (MEPPs) in a complement-dependent and reversible manner but had no effect on MEPP amplitude.

Topological differences along mammalian motor nerve terminals for spontaneous and alpha-bungarotoxin-induced sprouting

Spontaneous sproutings can be observed in end plates from normal adult vertebrate muscles and motor end plates develop increased growth signs and sprouts when target muscle cells become less active or paralysed. Nevertheless, very little is known about where in the motor nerve terminal arborization spontaneous and experimentally induced sprouts originate, their similarities and differences and also about their final maturation or elimination. In this study we investigate the topological properties of both spontaneous and alpha-bungarotoxin-induced sprouts (during different periods of intoxication and after recovery) along the motor nerve terminal branches of the Levator auris longus muscle of Swiss mice (between 48-169 day old). Muscles were processed for immunocytochemistry to simultaneously detect postsynaptic AChRs and axons. This procedure permits us to make an accurate identification of the fine sprouts and a morphometric study of the presynaptic branching pattern profile in control muscles, during the toxin action and after recovery from paralysis. The results show that in normal muscles, the initial and trunk segments (those between branch points) of the terminal arborization sprouted proportionally more branches when taking their relative lengths into account than the distal free-end segments. In contrast, every micrometer of alpha-bungarotoxin-treated muscles throughout the full terminal arborization have the same probability of generating a sprout. Moreover, the toxin-induced sprouts can consolidate as new branches once recovered from the paralysis without changing the total length of the nerve terminal arborization.

Physiological activity-dependent ultrastructural plasticity in normal adult rat neuromuscular junctions

The major finding of the present study is that the ultrastructural organization of the neuromuscular synapse can be modified by a small, 4-week-long, physiological increase in the locomotor activity of the extensor digitorum longus muscle of normal adult rats trained to walk. This study measures these plastic adaptations using several synaptic morphological parameters. The observed changes in neuromuscular junctions affect both pre- and postsynaptic membranes. In particular, the presynaptic membrane densities in the active zones and the postsynaptic adaxonal membrane densities become larger, which shows that in the normal adult mammal neuromuscular junction, there is an activity-dependent modulation of the neurotransmission-related structures in response to slight physiologic functional demands. The nature and magnitude of these changes are discussed.

p53 in breast cancer. Its relation to histological grade, lymph-node status, hormone receptors, cell-proliferation fraction (ki-67) and c-erbB-2. Immunohistochemical study of 153 cases

The mutation of the p53 gene is a common phenomenon in numerous human tumors, leading to the accumulation of nonfunctioning p53 protein in the cell nucleus, which can be detected by immunohistochemistry. In breast cancer, it has been suggested that the overexpression of p53 protein in the nucleus is an indicator of poor prognosis, which must be borne in mind in selecting coadjuvant treatment for each patient. This study is an immunohistochemical analysis of p53 expression in 153 cases of mammary carcinoma, correlating it with histological grade, axillary node status, hormone receptors, cell-proliferation fraction and expression of the c-erbB-2 oncoprotein. Of all the breast-cancer tissue analyzed, 43.79% was positive for p53. The overexpression of this protein bears a direct statistically significant relationship to histological grade, cell-proliferation fraction and c-erbB-2, and an inverse relationship to estrogen and progesterone receptors. No statistically significant relationship was found with axillary node status. The expression of p53 in poorly differentiated tumors-commonly receptor negative and with a high proliferation fraction-may indicate greater tumor aggressiveness and a high risk of relapse.

Hormonal receptors, cell proliferation fraction (Ki-67) and c-erbB-2 amplification in breast cancer. Relationship between differentiation degree and axillary lymph node metastases

In view of the limitations of conventional prognostic factors such as differentiation degree, metastatic lymph nodes, hormonal receptors and others, especially when early lesions are found, additional new markers have been studied, such as gene amplification and cell proliferation index, in order to choose the appropriate treatment. Primary breast carcinoma tumors from 97 patients were examined for differentiation degree, metastatic lymph nodes, hormonal receptors, c-erbB-2 amplification and cell proliferation index (Ki-67). A negative relationship with hormonal receptors and c-erbB-2 amplification, Ki-67 and differentiation degree was found, whereas the relationship between c-erbB-2, Ki-67 and differentiation degree was positive. No relationship was found between these factors and metastatic lymph nodes. The concurrence of high cell proliferation index, c-erbB-2 amplification and negative hormonal receptor presence would indicate a subpopulation with a high risk of recurrence. But a larger survival study is necessary to correlate these factors with clinical outcome.

Activity-dependent plastic changes in the motor nerve terminals of the adult rat

Small and short-lasting physiologic variations in the locomotor activity of normal adult rats can induce remodelling in the motor nerve endings of the fast extensor digitorum longus muscle. The specificity and relative importance of the different plastic adaptations occurring in the presynaptic axonal tree have been studied, in silver impregnated nerve endings, by using an automatic image analysis treatment of the nerve terminals' geometric properties and a discriminant analysis of the morphometric parameters. Changes observed, like selective length variations in certain terminal segments and positional rearrangements, agree with a mechanism of neural connectivity regulation in the adult that arises as a consequence of normal neuromuscular activity.

Pattern of arborization of the motor nerve terminals in the fast and slow mammalian muscles

A silver impregnation method and a morphometric approach were used to define differences existing in the motor nerve terminal branching pattern between a fast-twitch muscle (extensor digitorum longus) and a slow-twitch one (soleus) of the normal adult rat. Because no single measure can describe precisely all geometrical properties (ie both topology and metrics) of the nerve terminals, we evaluated morphologic parameters defining length and angular characteristics in the different terminal segments classified according to their centrifugal order. The main results indicate that the distal free-end segments in the extensor digitorum longus muscle are shorter and less divergent than in the soleus nerve terminals. The endings in the two muscles have different fractal dimensions. Findings are discussed in the context of the hypothetical mechanisms governing motor nerve terminal size and complexity.

Branching pattern of the motor nerve endings in a skeletal muscle of the adult rat

We have performed a morphometric analysis of the branching pattern of the rat sternomastoid motor nerve terminals in normal and regenerated singly-innervated synaptic areas, in junctions with an accessory ending and also in dually-innervated synaptic areas. We tried to seek measurable differences related to the terminal complexity and size in these different situations. The number of sole-plate nuclei is always significantly correlated with the nerve terminal parameters and unrelated to the muscle cell diameter. A significant correlation between the terminal complexity and the postsynaptic size is found only in the smallest endings whereas correlation is lost with the increase in nerve terminal complexity. In normal singly-innervated areas, the mean length of the distal free-end segments of the terminal arborisation becomes reduced with the increase in complexity of the terminals, whereas the mean length of the segments between branching points and the mean angle of branch emergence is, on average, constant. Whereas the accessory endings show the same branching pattern as the endings during the initial days of regeneration, the parent ending can be considered as a miniature version of the endings in normal singly-innervated junctions. In dually-innervated areas, the smallest endings show a similar branching pattern to the accessory endings and the endings during the initial process of reinnervation, whereas the larger endings show a significant reduction in the length of the distally placed segments compared to the normal endings in singly-innervated areas. Results indicate that the terminal branching pattern is not haphazard but, on the contrary, general rules and tendencies can be measured.

Motor nerve terminal morphologic plasticity induced by small changes in the locomotor activity of the adult rat

The possible existence of plastic changes in the branching pattern and the complexity of silver-impregnated motor nerve terminals was studied in the extensor digitorum longus muscle of adult rats housed in metabolic cages or trained to walk. Results indicate a precise inverse relation between the amount of locomotor activity and the complexity finally attained by the motor nerve terminals.

Changes in motor nerve terminals during bupivacaine-induced postsynaptic deprivation

The local anaesthetic agent bupivacaine induces a rapid degeneration of muscle cells when injected in the sternocleidomastoid muscle of the adult rat with no damage to intramuscular nerves. Nevertheless, silver impregnation and electron microscopy reveal a sequence of retraction and sprouting of the motor nerve endings during the period of the bupivacaine-induced muscle cell deprivation by necrosis. These morphological changes seem to be qualitatively similar to the retraction and growth phenomena described as forming part of the remodelling process affecting normal untreated neuromuscular junctions of the adult amphibia and mammals. The results are discussed in the context of the regulatory mechanisms governing the maintenance of motor nerve terminals.