Monoclonal antibodies against CGRP (R): non-responders and switchers: real world data from an austrian case series

OBJECTIVE

Assessement of the responder and non-responder rate to consecutive monoclonal CGRP-antibody (CGRP-mAb) treatment, the presence of side effects, analysis of predictors of response and loss-of-effectiveness evaluation over time.

METHODS

We conducted a retrospective analysis including 171 patients with episodic (EM) or chronic migraine (CM), who received one, two or three different CGRP-mAbs. Non-response was defined as ≤ 50% reduction of monthly migraine days (MMDs) in EM and ≤ 30% reduction of MMDs in CM after 3 months of treatment.

RESULTS

123 (71.9%) responded to the first mAb. Side effects led to treatment discontinuation in 9 (5.3%) patients. Of the 26 patients who did not respond to the first mAb or experienced a loss of efficacy over time, 11 (42.3%) responded to the second and two (28.6%) of 7 to the third monoclonal antibody. Poor response to therapy was associated with a higher monthly migraine frequency (p = 0.028), a higher number of prior preventive migraine therapies (p = 0.011) and medication overuse (p = 0.022).

CONCLUSION

Our findings support mAb-class switch in non-responders or in patients experiencing a loss of effectiveness. The use of a third CGRP-mAb could be beneficial for some patients.

Brain microdialysate tau dynamics predict functional and neurocognitive recovery after poor-grade subarachnoid haemorrhage

Subarachnoid haemorrhage is a devastating disease that results in neurocognitive deficits and a poor functional outcome in a considerable proportion of patients. In this study, we investigated the prognostic value of microtubule-associated tau protein measured in the cerebral microdialysate for long-term functional and neuropsychological outcomes in poor-grade subarachnoid haemorrhage patients. We recruited 55 consecutive non-traumatic subarachnoid haemorrhage patients who underwent multimodal neuromonitoring, including cerebral microdialysis. Mitochondrial dysfunction was defined as lactate-to-pyruvate ratio >30 together with pyruvate >70 mmol/L and metabolic distress as lactate-to-pyruvate ratio >40. The multidimensional 12-month outcome was assessed by means of the modified Rankin scale (poor outcome: modified Rankin scale ≥4) and a standardized neuropsychological test battery. We used multivariable generalized estimating equation models to assess associations between total microdialysate-tau levels of the first 10 days after admission and hospital complications and outcomes. Patients were 56 ± 12 years old and presented with a median Hunt & Hess score of 5 (interquartile range: 3-5). Overall mean total microdialysate-tau concentrations were highest within the first 24 h (5585 ± 6291 pg/mL), decreased to a minimum of 2347 ± 4175 pg/mL on Day 4 (P < 0.001) and remained stable thereafter (P = 0.613). Higher total microdialysate-tau levels were associated with the occurrence of delayed cerebral ischaemia (P = 0.001), episodes of metabolic distress (P = 0.002) and mitochondrial dysfunction (P = 0.034). Patients with higher tau levels had higher odds for a poor 12-month functional outcome (adjusted odds ratio: 2.61; 95% confidence interval: 1.32-5.17; P = 0.006) and impaired results in the trail making test-B (adjusted odds ratio: 3.35; 95% confidence interval: 1.16-9.68; P = 0.026) indicative of cognitive flexibility. Total microdialysate-tau levels significantly decreased over the first 10 days (P < 0.05) in patients without delayed cerebral ischaemia or good functional outcomes and remained high in those with delayed cerebral ischaemia and poor 12-month outcomes, respectively. Dynamic changes of total tau in the cerebral microdialysate may be a useful biomarker for axonal damage associated with functional and neurocognitive recovery in poor-grade subarachnoid haemorrhage patients. In contrast, ongoing axonal damage beyond Day 3 after bleeding indicates a higher risk for delayed cerebral ischaemia as well as a poor functional outcome.

Management of Refractory Status Epilepticus: An International Cohort Study (MORSE CODe) Analysis of Patients Managed in the ICU

BACKGROUND AND OBJECTIVES

Status epilepticus that continues after the initial benzodiazepine and a second anticonvulsant medication is known as refractory status epilepticus (RSE). Management is highly variable because adequately powered clinical trials are missing. We aimed to determine whether propofol and midazolam were equally effective in controlling RSE in the intensive care unit, focusing on management in resource-limited settings.

METHODS

Patients with RSE treated with midazolam or propofol between January 2015 and December 2018 were retrospectively identified among 9 centers across 4 continents from upper-middle-income economies in Latin America and high-income economies in North America, Europe, and Asia. Demographics, Status Epilepticus Severity Score, etiology, treatment details, and discharge modified Rankin Scale (mRS) were collected. The primary outcome measure was good functional outcome defined as a mRS score of 0-2 at hospital discharge.

RESULTS

Three hundred eighty-seven episodes of RSE (386 patients) were included, with 162 (42%) from upper-middle-income and 225 (58%) from high-income economies. Three hundred six (79%) had acute and 79 (21%) remote etiologies. Initial RSE management included midazolam in 266 (69%) and propofol in 121 episodes (31%). Seventy episodes (26%) that were initially treated with midazolam and 42 (35%) with propofol required the addition of a second anesthetic to treat RSE. Baseline characteristics and outcomes of patients treated with midazolam or propofol were similar. Breakthrough (odds ratio [OR] 1.6, 95% CI 1.3-2.0) and withdrawal seizures (OR 2.0, 95% CI 1.7-2.5) were associated with an increased number of days requiring continuous intravenous anticonvulsant medications (cIV-ACMs). Prolonged EEG monitoring was associated with fewer days of cIV-ACMs (1-24 hours OR 0.5, 95% CI 0.2-0.9, and >24 hours OR 0.7, 95% CI 0.5-1.0; reference EEG <1 hour). This association was seen in both, high-income and upper-middle-income economies, but was particularly prominent in high-income countries. One hundred ten patients (28%) were dead, and 80 (21%) had good functional outcomes at hospital discharge.

DISCUSSION

Outcomes of patients with RSE managed in the intensive care unit with propofol or midazolam infusions are comparable. Prolonged EEG monitoring may allow physicians to decrease the duration of anesthetic infusions safely, but this will depend on the implementation of RSE management protocols. Goal-directed management approaches including EEG targets may hold promise for patients with RSE.

CLASSIFICATION OF EVIDENCE

This study provides Class III data that propofol and midazolam are equivalently efficacious for RSE.

Caspr2 antibodies in herpes simplex encephalitis: an extension of the spectrum of virus induced autoimmunity? - A case report

BACKGROUND

Post herpes simplex virus (HSV) autoimmune encephalitis has been reported mainly in association with NMDA receptor antibodies, however, never with Caspr2 antibodies.

CASE PRESENTATION

We report an 82-year old female patient with encephalitis who presented with aphasia, left temporo-mesial hyperintense lesion on MRI, epileptiform discharges on spot electroencephalography, cerebrospinal fluid (CSF) lymphocytic pleocytosis and who showed positive HSV polymerase chain reaction in CSF as well as antibodies against contactin-associated protein-like 2 (Caspr2).

CONCLUSION

This is the first report of a patient with encephalitis who tested positive for HSV as well as for Caspr2 antibodies.

Intracerebral Iron Accumulation may be Associated with Secondary Brain Injury in Patients with Poor Grade Subarachnoid Hemorrhage

BACKGROUND

The amount of intracranial blood is a strong predictor of poor outcome after subarachnoid hemorrhage (SAH). Here, we aimed to measure iron concentrations in the cerebral white matter, using the cerebral microdialysis (CMD) technique, and to associate iron levels with the local metabolic profile, complications, and functional outcome.

METHODS

For the observational cohort study, 36 patients with consecutive poor grade SAH (Hunt & Hess grade of 4 or 5, Glasgow Coma Scale Score ≤ 8) undergoing multimodal neuromonitoring were analyzed for brain metabolic changes, including CMD iron levels quantified by graphite furnace atomic absorption spectrometry. The study time encompassed 14 days after admission. Statistical analysis was performed using generalized estimating equations.

RESULTS

Patients were admitted in a poor clinical grade (n = 26, 72%) or deteriorated within 24 h (n = 10, 28%). The median blood volume in the subarachnoid space was high (SAH sum score = 26, interquartile range 20-28). Initial CMD iron was 44 µg/L (25-65 µg/L), which significantly decreased to a level of 25 µg/L (14-30 µg/L) at day 4 and then constantly increased over the remaining neuromonitoring days (p < 0.01). A higher intraventricular hemorrhage sum score (≥ 5) was associated with higher CMD iron levels (Wald-statistic = 4.1, df  = 1, p = 0.04) but not with the hemorrhage load in the subarachnoid space (p = 0.8). In patients developing vasospasm, the CMD iron load was higher, compared with patients without vasospasm (Wald-statistic = 4.1, degree of freedom = 1, p = 0.04), which was not true for delayed cerebral infarction (p = 0.4). Higher iron concentrations in the brain extracellular fluid (34 µg/L, 36-56 µg/L vs. 23 µg/L, 15-37 µg/L) were associated with mitochondrial dysfunction (CMD lactate to pyruvate ratio > 30 and CMD-pyruvate > 70 µM/L, p < 0.001). Brain extracellular iron load was not associated with functional outcome after 3 months (p > 0.5).

CONCLUSIONS

This study suggests that iron accumulates in the cerebral white matter in patients with poor grade SAH. These findings may support trials aiming to scavenger brain extracellular iron based on the hypothesis that iron-mediated neurotoxicity may contribute to acute and secondary brain injury following SAH.

What Should a Clinician Do When Spreading Depolarizations are Observed in a Patient?

The International Conference on Spreading Depolarizations (iCSD) held in Boca Raton, Florida, in the September of 2018 devoted a section to address the question, "What should a clinician do when spreading depolarizations are observed in a patient?" Discussants represented a wide range of expertise, including neurologists, neurointensivists, neuroradiologists, neurosurgeons, and pre-clinical neuroscientists, to provide both clinical and basic pathophysiology perspectives. A draft summary of viewpoints offered was then written by a multidisciplinary writing group of iCSD members, based on a transcript of the session. Feedback of all discussants was formally collated, reviewed, and incorporated into the final document which was subsequently approved by all authors.

Migraine and aura triggered by normobaric hypoxia

BACKGROUND

For future experimental studies or the development of targeted pharmaceutical agents, a deeper insight into the pathophysiology of migraine is of utmost interest. Reliable methods to trigger migraine attacks including aura are desirable to study this complex disease in vivo.

METHODS

To investigate hypoxia as a trigger for migraine and aura, we exposed volunteers diagnosed with migraine, with (n = 16) and without aura (n = 14), to hypoxia utilizing a hypoxic chamber adjusted to a FiO₂ of 12.6%. The occurrence of headache, migraine, aura, and accompanying symptoms were registered and vital signs were collected for 6 hours under hypoxia and 2 hours of follow-up. A binary logistic regression analysis examined the probability of triggering headaches, migraines, aura, photo- and phonophobia.

FINDINGS

Of 30 participants, 24 (80.0%) developed headaches and 19 (63.3%) migraine, five (16.7%) reported aura. Two patients that developed aura never experienced aura symptoms before in their life. The increase of mean heart frequency was higher in patients developing headaches or migraine. Mean SpO₂ during hypoxia was 83.39%.

CONCLUSION

Hypoxia was able to trigger migraine attacks and aura independently of any pharmacological agent.

Autoantibodies against neuronal surface proteins in spontaneous subarachnoid and intracerebral haemorrhage

Background

Brain autoimmunity has been reported in patients with preceding infection of the central nervous system by herpesviridae. It has been hypothesized that neuronal damage releasing antigens might trigger secondary immune response. The objective of the study was to investigate whether brain damage due to spontaneous subarachnoid haemorrhage (SAH) or intracerebral haemorrhage (ICH) induces reactivity against neuronal surface proteins.

Methods

Patients with spontaneous SAH and ICH, who had cerebrospinal fluid (CSF) and serum sampling within 2 weeks after disease onset (baseline) and afterwards at least 10 days later (follow-up), were included. Antibodies against NMDA, GABA-B, AMPA-1/− 2 receptor, LGI1 and CASPR2 were determined by indirect immunofluorescence.

Results

A total of 43 SAH and 11 ICH patients aged 62 (±12) years (65% females) had simultaneous CSF/ serum sampling median 5 and 26.5 days after disease onset. At baseline, all CSF samples were collected via ventricular drainage, at follow-up 20 (37.0%) patients had CSF collection by lumbar puncture because ventricular drain had been already removed. All CSF and serum samples at baseline and follow-up tested negative for antibodies against NMDA, GABA-B, AMPA-1/− 2 receptor, LGI1 and CASPR2.

Conclusions

Immunoreactivity against common neuronal surface proteins was not observed within the early disease course of spontaneous SAH and ICH.

Nosocomial Infections and Antimicrobial Treatment in Coiled Patients with Aneurysmal Subarachnoid Hemorrhage

BACKGROUND

Nosocomial infections are common in patients with spontaneous subarachnoid hemorrhage (SAH). The aim of this retrospective cohort study was to determine the incidence of infections during SAH and to evaluate the course of inflammation parameters and its implications for long term outcome.

OBJECTIVE

Ninety-nine consecutive coiled SAH patients were included. Laboratory and clinical parameters as well as culture positive infections were followed over the disease course. Long-term outcome was assessed at 6-month by the Glasgow Outcome score (GOS) and dichotomized in favorable (GOS&gt;3) and unfavorable outcome (GOS≤3).

RESULTS

The most frequent infections were pulmonary (30.3%) urinary tract (25.3%), blood stream infections (20.2%) and ventriculitis (5.1%). The incidence of infections did not significantly differ between outcome groups. In contrast, patients with unfavorable outcome had a higher incidence of sepsis (46.7% versus 24.6%). C-reactive protein (CRP) and leukocytes were significantly higher in patients with unfavorable outcome. A CRP increase of 6 mg/dl or more in the first 3 days after SAH was independently associated with unfavorable outcome (OR 7.19 CI 1.7-30.52; p=0.008). Patients with an early CRP increase were more frequently treated with antimicrobial therapy in the first 3 days after admission which led to a significantly lower incidence of culture positive infections in the later course.

CONCLUSION

A sharp CRP-increase in the acute phase of SAH could potentially aid the intensivist in the early identification of patients at high risk for neurological morbidity. Early antimicrobial treatment reduces the rate of patients showing culture positive infections in the course of the disease.

Targeted Temperature Management in Spontaneous Intracerebral Hemorrhage: A Systematic Review

BACKGROUND

Fever is common in neurocritical care patients and is associated with poor outcome. Targeted temperature management (TTM), i.e. therapeutic hypothermia or controlled normothermia, after acute brain injury has been studied as a neuroprotectant for several decades. In contrast to pharmacological agents with specific targets TTM affects multiple pathophysiological mechanisms and is primarily thought to attenuate secondary brain injury. Most promising results have been obtained from experimental studies on cerebral ischemia or traumatic brain injury showing beneficial effects of hypothermia on structural and functional outcome.

OBJECTIVE

The aim of this systematic review of the literature is to provide an overview on preclinical and clinical data on the use of TTM for intracerebral hemorrhage (ICH). The impact of TTM on structural changes and functional outcome after induced and spontaneous ICH will be summarized.

RESULTS AND DISCUSSION

A positive influence of hypothermia has been observed in animal models of spontaneous ICH improving, among others, perihematomal edema, blood-brain barrier integrity, inflammation and thrombin-induced injury. However, results regarding functional outcome are conflicting. Little data is available on the effect of TTM after spontaneous ICH in humans. Single-center observational studies have shown reduced perihematomal edema under mild hypothermia and an association with favorable outcome. However, these beneficial effects on mortality and functional outcome have not been confirmed in randomized studies so far. Thus, results from ongoing, prospective randomized-controlled trials are highly anticipated.

Neuroglucopenia and Metabolic Distress in Two Patients with Viral Meningoencephalitis: A Microdialysis Study

Introduction

Viral encephalitis is an emerging disease requiring intensive care management in severe cases. Underlying pathophysiologic mechanisms are incompletely understood and may be elucidated using invasive multimodal neuromonitoring techniques in humans.

Methods

Two otherwise healthy patients were admitted to our neurological intensive care unit with altered level of consciousness necessitating mechanical ventilation. Brain imaging and laboratory workup suggested viral encephalitis in both patients. Invasive neuromonitoring was initiated when head computed tomography revealed generalized brain edema, including monitoring of intracranial pressure, brain metabolism (cerebral microdialysis; CMD), brain tissue oxygen tension (in one patient), and cerebral blood flow (in one patient).

Results

Brain metabolism revealed episodes of severe neuroglucopenia (brain glucose <0.7 mM/l) in both patients, which were not attributable to decreased cerebral perfusion or hypoglycemia. CMD-glucose levels changed depending on variations in insulin therapy, nutrition, and systemic glucose administration. The metabolic profile, moreover, showed a pattern of non-ischemic metabolic distress suggestive for mitochondrial dysfunction. Both patients had a prolonged but favorable clinical course and improved to a modified Rankin Scale Score of 1 and 0 three months later.

Conclusion

Invasive multimodal neuromonitoring is feasible in poor-grade patients with viral meningoencephalitis and may help understand pathophysiologic mechanisms associated with secondary brain injury. The detection of neuroglucopenia and mitochondrial dysfunction may serve as treatment targets in the future.

Cerebral tau is elevated after aneurysmal subarachnoid haemorrhage and associated with brain metabolic distress and poor functional and cognitive long-term outcome

BACKGROUND

Recent evidence suggests axonal injury after aneurysmal subarachnoid haemorrhage (aSAH). The microtubule-associated protein, tau, has been shown to be elevated in the cerebrospinal fluid after aSAH, however, brain extracellular tau levels and their relation to long-term neurological and cognitive outcomes have not been investigated.

METHODS

Serial cerebral microdialysis (CMD) samples were collected from 22 consecutive aSAH patients with multimodal neuromonitoring to determine CMD-total-tau by ELISA. CMD-total-tau was analysed considering other brain metabolic parameters, brain tissue oxygen tension (PbtO2), and functional and neuropsychological outcome at 12 months. All outcome models were analysed using generalised estimating equations with an autoregressive working correlation matrix to account for multiple measurements of brain extracellular proteins per subject.

RESULTS

CMD-total-tau levels positively correlated with brain extracellular fluid levels of lactate (r=0.40, p<0.001), glutamate (r=0.45, p<0.001), pyruvate (r=0.26, p<0.001), and the lactate-pyruvate ratio (r=0.26, p<0.001), and were higher in episodes of hypoxic (PbtO2<20 mm Hg) brain extracellular lactate elevation (>4 mmol/L) (p<0.01). More importantly, high CMD-total-tau levels were associated with poor functional outcome (modified Rankin Scale ≥4) 12 months after aSAH even after adjusting for disease severity and age (p=0.001). A similar association was found with 3/5 neuropsychological tests indicative of impairments in cognition, psychomotor speed, visual conceptualisation and frontal executive functions at 1 year after aSAH (p<0.01).

CONCLUSIONS

These results suggest that CMD-total tau may be an important biomarker for predicting long-term outcome in patients with severe aSAH. The value of axonal injury needs further confirmation in a larger patient cohort, preferably combined with advanced imaging techniques.