Selective Cerebrospinal Fluid Hypothermia: Bioengineering Development and In Vivo Study of an Intraventricular Cooling Device (V-COOL).

Hypothermia is a promising therapeutic strategy for severe vasospasm and other types of non-thrombotic cerebral ischemia, but its clinical application is limited by significant systemic side effects. We aimed to develop an intraventricular device for the controlled cooling of the cerebrospinal fluid, to produce a targeted hypothermia in the affected cerebral hemisphere with a minimal effect on systemic temperature. An intraventricular cooling device (acronym: V-COOL) was developed by in silico modelling, in vitro testing, and in vivo proof-of-concept application in healthy Wistar rats (n = 42). Cerebral cortical temperature, rectal temperature, and intracranial pressure were monitored at increasing flow rate (0.2 to 0.8 mL/min) and duration of application (10 to 60 min). Survival, neurological outcome, and MRI volumetric analysis of the ventricular system were assessed during the first 24 h. The V-COOL prototyping was designed to minimize extra-cranial heat transfer and intra-cranial pressure load. In vivo application of the V-COOL device produced a flow rate-dependent decrease in cerebral cortical temperature, without affecting systemic temperature. The target degree of cerebral cooling (- 3.0 °C) was obtained in 4.48 min at the flow rate of 0.4 mL/min, without significant changes in intracranial pressure. Survival and neurological outcome at 24 h showed no significant difference compared to sham-treated rats. MRI study showed a transient dilation of the ventricular system (+ 38%) in a subset of animals. The V-COOL technology provides an effective, rapid, selective, and safe cerebral cooling to a clinically relevant degree of - 3.0 °C.

Comorbidities in patients with epilepsy: Frequency, mechanisms and effects on long-term outcome.

OBJECTIVE: To assess frequency, types, and mechanisms of comorbidities in people with epilepsy and verify their association with disease features and outcome. METHODS: This cohort study was performed in 13 Italian epilepsy centers with nationwide distribution and accurate records. Eligible patients were children and adults diagnosed before December 31, 2005, and followed for a minimum of 10 years. Two pairs of raters independently reviewed patients' records and classified each comorbidity. In case of disagreement, a third reviewer made the final decision. Comorbidities were classified according to type (organ/system) and underlying mechanism (causal, shared risk factors, chance association). Comorbidity types and mechanisms were described in the entire sample and according to epilepsy prognostic patterns (sustained remission, relapsing-remitting course, no remission). RESULTS: Of 1006 included patients, 266 (26.4%) had at least one comorbidity. The most common were developmental/perinatal (7.5% of cases), psychiatric (6.2%), cardiovascular (5.3%), and endocrine/metabolic (3.8%). Among 408 reported comorbidities, the underlying mechanisms were, in decreasing order, chance association (42.2%), shared risk factors (31.1%), and causal (26.7%). Psychiatric diseases were present in 13.3% of patients with no remission, 5.9% of patients with relapsing-remitting course, and 4.8% of patients with sustained remission (p = .016). The corresponding numbers for endocrine/metabolic diseases were respectively, 9.6%, 3.4%, and 2.9% (p = .013); for respiratory diseases were 3.6%, .3%, and .3% (p = .001), and for urogenital diseases were 3.6%, .7%, and 1.6% (p = .048). The association of endocrine/metabolic, psychiatric, and respiratory comorbidities with epilepsy prognosis was confirmed by multivariable analysis adjusted for the main demographic and clinical variables, with patients with these comorbidities showing a lower probability of achieving remission. SIGNIFICANCE: Comorbidities in epilepsy are not uncommon and reflect differing underlying mechanisms. Psychiatric, endocrine/metabolic, and respiratory disorders are associated with a worse long-term epileptological outcome.

Discontinuation of antiseizure medications in seizure-free patients with long-term follow-up: Patients' profile, seizure recurrence, and risk factors.

OBJECTIVE: To compare withdrawal of antiseizure medications (ASM) to continued treatment in newly diagnosed individuals achieving seizure freedom, and assess the risk of relapse and factors associated with relapse. METHODS: This is a multicenter retrospective cohort study with long-term follow-up. Patients with newly diagnosed epilepsy were identified from the medical records of 13 Italian epilepsy centers and followed up until the most recent visit or death. Seizure-free patients discontinuing treatment were compared to patients who maintained treatment for baseline characteristics. Treatment was stopped upon clinical judgment. The probability of relapse was calculated with the Kaplan-Meier method. Demographic, clinical, and instrumental variables associated with relapse were assessed with Cox proportional hazards models. RESULTS: One thousand and six patients aged 1 month to 72 years at diagnosis were enrolled and followed up for 17,892 person-years (median follow-up, 9.9 years). Three hundred and twenty patients (31.8%) underwent one or more treatment discontinuations. Factors associated with ASM withdrawal were younger age at remission and normal psychiatric examination. The probability of relapse after the first withdrawal was 16% at six months, 24% at 12 months, and 36%, 45%, and 53% at three, five, and ten years, respectively. The probability of remission after the first relapse was 59% at one month, 67%, 72, and 76% at three, six, and 12 months, respectively. Variables associated with relapse were age 14+ years, structural etiology, abnormal neuroimaging, ASM initiation after a single seizure, and symptomatic/cryptogenic epilepsy. CONCLUSIONS: About one half of seizure-free patients stopping ASM relapse in 10 years. However, the possibility of remission after relapse is high, particularly in children and patients with idiopathic/cryptogenic epilepsy. Treatment deprescription might be encouraged at least in these patients.

Neurological outcome of postanoxic refractory status epilepticus after aggressive treatment.

Refractory status epilepticus (RSE) occurs in up to 30% of patients following resuscitation after cardiac arrest. The impact of aggressive treatment of postanoxic RSE on long-term neurological outcome remains uncertain. We investigated neurological outcome of cardiac arrest patients with RSE treated with a standardized aggressive protocol with antiepileptic drugs and anesthetics, compared with patients with other electroencephalographic (EEG) patterns. A prospective cohort of 166 consecutive patients with cardiac arrest in coma was stratified according to four independent EEG patterns (benign; RSE; generalized periodic discharges (GPDs); malignant nonepileptiform) and multimodal prognostic indicators. Primary outcomes were survival and cerebral performance category (CPC) at 6 months. Refractory status epilepticus occurred in 36 patients (21.7%) and was treated with an aggressive standardized protocol as long as multimodal prognostic indicators were not unfavorable. Refractory status epilepticus started after 3 ±â€¯2.3 days after cardiac arrest and lasted 4.7 ±â€¯4.3 days. A benign electroencephalographic patterns was recorded in 76 patients (45.8%), a periodic pattern (GPDs) in 13 patients (7.8%), and a malignant nonepileptiform EEG pattern in 41 patients (24.7%). The four EEG patterns were highly associated with different prognostic indicators (low flow time, clinical motor seizures, N20 responses, neuron-specific enolase (NSE), neuroimaging). Survival and good neurological outcome (CPC 1 or 2) at 6 months were 72.4% and 71.1% for benign EEG pattern, 54.3% and 44.4% for RSE, 15.4% and 0% for GPDs, and 2.4% and 0% for malignant nonepileptiform EEG pattern, respectively. Aggressive and prolonged treatment of RSE may be justified in cardiac arrest patients with favorable multimodal prognostic indicators. This article is part of the Special Issue "Proceedings of the 7th London-Innsbruck Colloquium on Status Epilepticus and Acute Seizures".

Prognostic patterns and predictors in epilepsy: a multicentre study (PRO-LONG).

OBJECTIVES: To describe the long-term prognosis of epilepsy and prognostic patterns in a large cohort of newly diagnosed patients and identify prognostic factors. METHODS: Study participants were 13 Italian epilepsy centres with accessible records dating back to 2005 or earlier, complete data on seizure outcome and treatments, precise epilepsy diagnosis, and follow-up of at least 10 years. Records were examined by trained neurology residents for demographics, seizure characteristics, neurological signs, psychiatric comorbidity, first electroencephalogram (EEG) and MRI/CT, epilepsy type and aetiology, antiepileptic drugs (AEDs), and 1-year, 2-year, 5-year and 10-year seizure remissions. Five predefined prognostic patterns were identified: early remission, late remission, relapsing-remitting course, worsening course and no remission. Prognostic factors were assessed using multinomial logistic regression models. RESULTS: 1006 children and adults were followed for 17 892 person-years (median 16 years; range 10-57). During follow-up, 923 patients (91.7%) experienced 1-year remission. 2-year, 5-year and 10-year remissions were present in 89.5%, 77.1% and 44.4% of cases. 5-year remission was associated with one to two seizures at diagnosis, generalised epilepsy, no psychiatric comorbidity, and treatment with one or two AEDs during follow-up. 10-year remission was associated with one or two AEDs. The most common prognostic pattern was relapsing-remitting (52.2%), followed by early remission (24.5%). 8.3% of cases experienced no remission. Predictors of a relapsing-remitting course were <6 seizures at diagnosis, (presumed) genetic aetiology and no psychiatric comorbidity. CONCLUSIONS: Few seizures at diagnosis, generalised epilepsy and no psychiatric comorbidity predict early or late seizure freedom in epilepsy. Achieving remission at any time after the diagnosis does not exclude further relapses.

Neurologic outcome of postanoxic refractory status epilepticus after aggressive treatment.

OBJECTIVE: To investigate neurologic outcome of patients with cardiac arrest with refractory status epilepticus (RSE) treated with a standardized aggressive protocol with antiepileptic drugs and anesthetics compared to patients with other EEG patterns. METHODS: In the prospective cohort study, 166 consecutive patients with cardiac arrest in coma were stratified according to 4 independent EEG patterns (benign, RSE, generalized periodic discharges [GPDs], malignant nonepileptiform) and multimodal prognostic indicators. Primary outcomes were survival and cerebral performance category (CPC) at 6 months. RESULTS: RSE occurred in 36 patients (21.7%) and was treated with an aggressive standardized protocol as long as multimodal prognostic indicators were not unfavorable. RSE started after 3 ± 2.3 days after cardiac arrest and lasted 4.7 ± 4.3 days. A benign EEG pattern was recorded in 76 patients (45.8%); a periodic pattern (GPDs) was seen in 13 patients (7.8%); and a malignant nonepileptiform EEG pattern was recorded in 41 patients (24.7%). The 4 EEG patterns were highly associated with different prognostic indicators (low-flow time, clinical motor seizures, N20 responses, neuron-specific enolase, neuroimaging). Survival and good neurologic outcome (CPC 1 or 2) at 6 months were 72.4% and 71.1% for benign EEG pattern, 54.3% and 44.4% for RSE, 15.4% and 0% for GPDs, and 2.4% and 0% for malignant nonepileptiform EEG pattern, respectively. CONCLUSIONS: Aggressive and prolonged treatment of RSE may be justified in patients with cardiac arrest with favorable multimodal prognostic indicators.

Efficacy and safety of perampanel oral loading in postanoxic super-refractory status epilepticus: A pilot study.

Refractory nonconvulsive status epilepticus (NCSE) occurs in 10%-30% of patients following resuscitation after cardiac arrest. Both the optimal treatment and prognosis of postanoxic status epilepticus remain uncertain. We analyzed acute electroencephalographic changes, neurological outcome at 3 months, and adverse effects in consecutive postanoxic patients with super-refractory NCSE treated with add-on oral loading of perampanel. Eight postanoxic patients with super-refractory NCSE were treated with perampanel (dose range = 6-12 mg). All patients had continuous electroencephalographic monitoring showing definite generalized NCSE and favorable multimodal prognostic indicators (presence of brainstem reflexes, presence of bilateral N20 responses, absence of periodic discharges/generalized epileptic periodic discharges). In six patients (75%), status epilepticus resolved within 72 hours after administration of perampanel, without changing the comedication. Neurological outcomes at 3 months were return to normal or minimal disability in four patients (50%). A mild cholestatic liver injury, which required no specific treatment, was observed in five patients (62.5%). Perampanel 6-12 mg oral loading appeared to be an effective option in selected patients with postanoxic super-refractory NCSE with good prognostic indicators. In this patient population, our safety data indicate a risk of cholestasis.

Long-term applicability of the new ILAE definition of epilepsy. Results from the PRO-LONG study.

OBJECTIVE: The new epilepsy definition adopted by the International League Against Epilepsy (ILAE) includes patients with one unprovoked seizure with a probability of further seizures, similar to the general recurrence risk after two unprovoked seizures, occurring in a 10-year period. Long-term follow-up of patients diagnosed after a single seizure is needed to assess the applicability of the new epilepsy definition in clinical practice. METHODS: Patients with newly diagnosed epilepsy were recruited retrospectively with a minimum follow-up of 10 years. Patients were stratified in two groups depending on the occurrence of one (new definition, ND) or two or more unprovoked seizures (traditional definition, TD) at the time of epilepsy diagnosis and compared for disease characteristics and factors predicting seizure recurrence. The primary outcome was the occurrence of a new unprovoked seizure during follow-up in the ND group. The secondary outcome was the achievement of an early remission in both groups. RESULTS: Among 1,006 patients with newly diagnosed epilepsy, 152 (15.1%) were diagnosed after a single seizure. Compared to patients diagnosed using the TD, patients diagnosed according to the ND showed a higher proportion of subjects with an abnormal neurologic examination (19.9% vs. 13.7%, p = 0.0504) and with focal seizures (69.3% vs. 60.4%, p = 0.0021). The two samples differed in the presence of at least one of the factors predicting seizure recurrence (focal seizures or abnormal findings in at least one among the following: neurologic examination, electroencephalography [EEG], and neuroimaging) (94.6% vs. 89.1%, p = 0.0376). Long-term recurrence in patients diagnosed with the new definition was 83.6% at 10 years and 89.1% at 15 years. The probability of early remission did not differ between the two groups. SIGNIFICANCE: Our results support the applicability of the new epilepsy definition in clinical practice. Individual patient characteristics and a personalized diagnostic approach can justify treatment after a single unprovoked seizure.

Cerebral collateral therapeutics in acute ischemic stroke: A randomized preclinical trial of four modulation strategies.

Cerebral collaterals are dynamically recruited after arterial occlusion and highly affect tissue outcome in acute ischemic stroke. We investigated the efficacy and safety of four pathophysiologically distinct strategies for acute modulation of collateral flow (collateral therapeutics) in the rat stroke model of transient middle cerebral artery (MCA) occlusion. A composed randomization design was used to assign rats (n = 118) to receive phenylephrine (induced hypertension), polygeline (intravascular volume load), acetazolamide (cerebral arteriolar vasodilation), head down tilt (HDT) 15° (cerebral blood flow diversion), or no treatment, starting 30 min after MCA occlusion. Compared to untreated animals, treatment with collateral therapeutics was associated with lower infarct volumes (62% relative mean difference; 51.57 mm3 absolute mean difference; p < 0.001) and higher chance of good functional outcome (OR 4.58, p < 0.001). Collateral therapeutics acutely increased cerebral perfusion in the medial (+40.8%; p < 0.001) and lateral (+19.2%; p = 0.016) MCA territory compared to pretreatment during MCA occlusion. Safety indicators were treatment-related mortality and cardiorespiratory effects. The highest efficacy and safety profile was observed for HDT. Our findings suggest that acute modulation of cerebral collaterals is feasible and provides a tissue-saving effect in the hyperacute phase of ischemic stroke prior to recanalization therapy.

Cerebral collateral circulation in experimental ischemic stroke.

Cerebral collateral circulation is a subsidiary vascular network, which is dynamically recruited after arterial occlusion, and represents a powerful determinant of ischemic stroke outcome. Although several methods may be used for assessing cerebral collaterals in the acute phase of ischemic stroke in humans and rodents, they are generally underutilized. Experimental stroke models may play a unique role in understanding the adaptive response of cerebral collaterals during ischemia and their potential for therapeutic modulation. The systematic assessment of collateral perfusion in experimental stroke models may be used as a "stratification factor" in multiple regression analysis of neuroprotection studies, in order to control the within-group variability. Exploring the modulatory mechanisms of cerebral collaterals in stroke models may promote the translational development of therapeutic strategies for increasing collateral flow and directly compare them in term of efficacy, safety and feasibility. Collateral therapeutics may have a role in the hyperacute (even pre-hospital) phase of ischemic stroke, prior to recanalization therapies.

Cerebral collateral flow defines topography and evolution of molecular penumbra in experimental ischemic stroke.

Intracranial collaterals are dynamically recruited after arterial occlusion and are emerging as a strong determinant of tissue outcome in both human and experimental ischemic stroke. The relationship between collateral flow and ischemic penumbra remains largely unexplored in pre-clinical studies. The aim of the present study was to investigate the pattern of collateral flow with regard to penumbral tissue after transient middle cerebral artery (MCA) occlusion in rats. MCA was transiently occluded (90min) by intraluminal filament in adult male Wistar rats (n=25). Intracranial collateral flow was studied in terms of perfusion deficit and biosignal fluctuation analyses using multi-site laser Doppler monitoring. Molecular penumbra was defined by topographical mapping and quantitative signal analysis of Heat Shock Protein 70kDa (HSP70) immunohistochemistry. Functional deficit and infarct volume were assessed 24h after ischemia induction. The results show that functional performance of intracranial collaterals during MCA occlusion inversely correlated with HSP70 immunoreactive areas in both the cortex and the striatum, as well as with infarct size and functional deficit. Intracranial collateral flow was associated with reduced areas of both molecular penumbra and ischemic core and increased areas of intact tissue in rats subjected to MCA occlusion followed by reperfusion. Our findings prompt the development of collateral therapeutics to provide tissue-saving strategies in the hyper-acute phase of ischemic stroke prior to recanalization therapy.

Optimized system for cerebral perfusion monitoring in the rat stroke model of intraluminal middle cerebral artery occlusion.

The translational potential of pre-clinical stroke research depends on the accuracy of experimental modeling. Cerebral perfusion monitoring in animal models of acute ischemic stroke allows to confirm successful arterial occlusion and exclude subarachnoid hemorrhage. Cerebral perfusion monitoring can also be used to study intracranial collateral circulation, which is emerging as a powerful determinant of stroke outcome and a possible therapeutic target. Despite a recognized role of Laser Doppler perfusion monitoring as part of the current guidelines for experimental cerebral ischemia, a number of technical difficulties exist that limit its widespread use. One of the major issues is obtaining a secure and prolonged attachment of a deep-penetration Laser Doppler probe to the animal skull. In this video, we show our optimized system for cerebral perfusion monitoring during transient middle cerebral artery occlusion by intraluminal filament in the rat. We developed in-house a simple method to obtain a custom made holder for twin-fibre (deep-penetration) Laser Doppler probes, which allow multi-site monitoring if needed. A continuous and prolonged monitoring of cerebral perfusion could easily be obtained over the intact skull.