Erythrocyte deformability correlates with systemic inflammation.

Recent evidence suggests that systemic conditions, particularly those associated with inflammation, can affect erythrocyte deformability in the absence of haematological conditions. In this exploratory study, we investigated the relationship between systemic inflammatory status and erythrocyte deformability (using osmotic gradient ektacytometry) in a heterogenous study population consisting of individuals with no medical concerns, chronic conditions, and acute illness, providing a wide range of systemic inflammation severity. 22 participants were included in a prospective observational study. Maximum Elongation Index (EImax) in ektacytometry served as the readout for erythrocyte deformability. Inflammatory status was assessed using C-reactive protein (CRP) and self-reported symptoms associated with inflammatory activation (Sickness Questionnaire Scores, SicknessQ). In a univariate linear regression, both CRP and SicknessQ scores significantly predicted EImax (CRP: F(1,20) = 7.751, p < 0.05 (0.011), R2 = 0.279; SicknessQ: F(1,18) = 4.831, p < 0.05 (0.041), R2 = 0.212). Sensitivity analyses with multivariable linear regression correcting for age showed concordant findings. Results suggest a linear relationship between erythrocyte deformability and biochemical and clinical markers of systemic inflammation. Replication of findings in a larger study, and mechanisms and clinical consequences need further in investigation.

Fewer COVID-19 Neurological Complications with Dexamethasone and Remdesivir.

OBJECTIVE: The objective of this study was to assess the impact of treatment with dexamethasone, remdesivir or both on neurological complications in acute coronavirus diease 2019 (COVID-19). METHODS: We used observational data from the International Severe Acute and emerging Respiratory Infection Consortium World Health Organization (WHO) Clinical Characterization Protocol, United Kingdom. Hospital inpatients aged ≥18 years with laboratory-confirmed severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2) infection admitted between January 31, 2020, and June 29, 2021, were included. Treatment allocation was non-blinded and performed by reporting clinicians. A propensity scoring methodology was used to minimize confounding. Treatment with remdesivir, dexamethasone, or both was assessed against the standard of care. The primary outcome was a neurological complication occurring at the point of death, discharge, or resolution of the COVID-19 clinical episode. RESULTS: Out of 89,297 hospital inpatients, 64,088 had severe COVID-19 and 25,209 had non-hypoxic COVID-19. Neurological complications developed in 4.8% and 4.5%, respectively. In both groups, neurological complications were associated with increased mortality, intensive care unit (ICU) admission, worse self-care on discharge, and time to recovery. In patients with severe COVID-19, treatment with dexamethasone (n = 21,129), remdesivir (n = 1,428), and both combined (n = 10,846) were associated with a lower frequency of neurological complications: OR = 0.76 (95% confidence interval [CI] = 0.69-0.83), OR = 0.69 (95% CI = 0.51-0.90), and OR = 0.54 (95% CI = 0.47-0.61), respectively. In patients with non-hypoxic COVID-19, dexamethasone (n = 2,580) was associated with less neurological complications (OR = 0.78, 95% CI = 0.62-0.97), whereas the dexamethasone/remdesivir combination (n = 460) showed a similar trend (OR = 0.63, 95% CI = 0.31-1.15). INTERPRETATION: Treatment with dexamethasone, remdesivir, or both in patients hospitalized with COVID-19 was associated with a lower frequency of neurological complications in an additive manner, such that the greatest benefit was observed in patients who received both drugs together. ANN NEUROL 2023;93:88-102.

Dehydration associates with lower urinary tract symptoms in progressive multiple sclerosis.

BACKGROUND: Lower urinary tract symptoms (LUTS) are common in persons with progressive multiple sclerosis (pwPMS), who may consequently limit their fluid intake. We aimed to investigate the hypothesis that LUTS associate with objective evidence of inadequate hydration status in pwPMS. METHODS: In this prospective study, 55 pwPMS were studied over 2 years. A 6-monthly first-morning urine specimen was analysed for urinary osmolality and sodium as hydration markers. LUTS symptom severity in three categories (urgency, voiding and discomfort) was assessed and quantified using a questionnaire. Correlation between LUTS severity and hydration was assessed within subjects and between subjects, controlling for age. RESULTS: Some 274 urine samples with accompanying LUTS data from 55 participants were analysed. Biochemical data showed the expected loss of urine-concentrating capacity with increasing age. Inadequate hydration was observed in 47% of participants. LUTS were very common (87% reported urgency and 89% voiding symptoms). Voiding and discomfort, but not urgency severity, were correlated with hydration markers, both within and between participants. CONCLUSIONS: LUTS are very common in pwPMS, and associate with inadequate hydration. The causes and consequences of inadequate hydration in MS need further study, since (i) this will focus greater attention on LUTS management in pwPMS and (ii) dehydration has been associated with reversible cognitive dysfunction and physical underperformance.

Risk of subarachnoid haemorrhage reduces with blood pressure values below hypertensive thresholds.

BACKGROUND: Hypertension is a known risk factor for subarachnoid haemorrhage (SAH). The aim of this study was to describe the relationship between blood pressure and SAH using a large cohort study and perform a meta-analysis of the published literature. METHODS: Participants in the UK Biobank were followed up via electronic records until 31 March 2017. Cox proportional hazards models were used to analyse the association between baseline blood pressure (systolic blood pressure [SBP], diastolic blood pressure [DBP] and MABP [mean arterial blood pressure]) and subsequent aneurysmal SAH. Linearity was assessed by comparing models including and excluding cubic splines. Electronic databases were searched from inception until 11 February 2022 for studies reporting on blood pressure and SAH. RESULTS: A total of 500,598 individuals were included with 539 (0.001%) suffering from aneurysmal SAH. Nonlinear models including cubic splines visually appeared linear between SBP of 110 and 180 mmHg and there was minimal difference in fit between linear and nonlinear models. When values were stratified, those with SBP 120-130 mmHg were at higher risk compared to those with SBP <120 mmHg (hazard ratio [HR] 1.41 [1.02, 1.95]). The meta-analysis demonstrated a similar increased risk of SAH in individuals with SBP 120-130 mmHg relative to those with <120 mmHg (HR 1.41 [1.17, 1.72]). A stepwise increase in risk was also seen at each subsequent threshold (130-140 mmHg: HR 1.85 [1.53, 2.24], 140-160 mmHg: HR 2.16 [1.57, 2.98], 160-180 mmHg: HR 2.81 [1.85, 4.29], >180 mmHg: HR 5.84 [1.94, 17.54]). CONCLUSIONS: The rate of SAH increases linearly with higher SBP in the general population and specifically appears lower in those with SBP <120 mmHg.

An assistive listening device improves hearing following aneurysmal subarachnoid haemorrhage.

BACKGROUND AND PURPOSE: Hearing impairment is common following aneurysmal subarachnoid haemorrhage (aSAH). Previous studies have demonstrated that auditory processing disorder (APD) is the primary underlying pathology. Assistive listening devices (ALDs) can be used to manage APD but have not been explored in aSAH. The aim of this study was to assess the benefit of an ALD for patients reporting hearing difficulty after aSAH. METHODS: This was a prospective pilot single-arm intervention study of an ALD for APD following aSAH. Patients who reported subjective hearing difficulty following aSAH were identified from the Wessex Neurological Centre aSAH database. Speech-in-noise was evaluated using the Bamford-Kowal-Bench (BKB) test under 60 and 65 dB noise conditions. BKB performance was compared with and without an ALD. Cognition was assessed using the Addenbrooke's Cognitive Examination-III. RESULTS: Fourteen aSAH patients with self-reported hearing loss were included in the analysis. Under both noise conditions the ALD significantly improved BKB performance (60 dB, Z = -3.30, p < 0.001; 65 dB, Z = -3.33, p < 0.001). There was no relationship between cognition and response to the ALD. CONCLUSIONS: This study demonstrates the marked benefit of ALDs to manage APD following aSAH, regardless of cognitive status. This finding has implications for the management of this common yet disabling deficit which impacts quality of life and employment. A further trial of ALDs in this patient group is needed to test whether these large, short-term benefits can be practically translated to the community for long-term benefit when used at home.

Real-world persistence of multiple sclerosis disease-modifying therapies.

BACKGROUND AND PURPOSE: Treatment persistence is the continuation of therapy over time. It reflects a combination of treatment efficacy and tolerability. We aimed to describe real-world rates of persistence on disease-modifying therapies (DMTs) for people with multiple sclerosis (pwMS) and reasons for DMT discontinuation. METHODS: Treatment data on 4366 consecutive people with relapse-onset multiple sclerosis (MS) were pooled from 13 UK specialist centres during 2021. Inclusion criteria were exposure to at least one MS DMT and a complete history of DMT prescribing. PwMS in blinded clinical trials were excluded. Data collected included sex, age at MS onset, age at DMT initiation, DMT treatment dates, and reasons for stopping or switching DMT. For pwMS who had received immune reconstituting therapies (cladribine/alemtuzumab), discontinuation date was defined as starting an alternative DMT. Kaplan-Meier survival analyses were used to express DMT persistence. RESULTS: In 6997 treatment events (1.6 per person with MS), median time spent on any single maintenance DMT was 4.3 years (95% confidence interval = 4.1-4.5 years). The commonest overall reasons for DMT discontinuation were adverse events (35.0%) and lack of efficacy (30.3%). After 10 years, 20% of people treated with alemtuzumab had received another subsequent DMT, compared to 82% of people treated with interferon or glatiramer acetate. CONCLUSIONS: Immune reconstituting DMTs may have the highest potential to offer a single treatment for relapsing MS. Comparative data on DMT persistence and reasons for discontinuation are valuable to inform treatment decisions and in personalizing treatment in MS.

Gadolinium enhancement of cranial nerves: Implications for interstitial fluid drainage from brainstem into cranial nerves in humans.

Drainage of interstitial fluid and solutes from the brainstem has not been well studied. To map one drainage pathway in the human brainstem, we took advantage of the focal blood-brain barrier disruption occurring in a multiple sclerosis brainstem lesion, coupled with intravenous injection of gadolinium, which simulates an intraparenchymal injection of gadolinium tracer within the restricted confines of this small brain region. Using high-resolution MRI, we show how it is possible for interstitial fluid to drain into the adjacent trigeminal and oculomotor nerves, in keeping with a pathway of communication between the extracellular spaces of the brainstem and cranial nerve parenchyma.

Mild Systemic Inflammation Increases Erythrocyte Fragility.

There is growing evidence that inflammation impairs erythrocyte structure and function. We assessed the impact of mild systemic inflammation on erythrocyte fragility in three different settings. In order to investigate causation, erythrocyte osmotic fragility was measured in mice challenged with a live attenuated bacterial strain to induce low-grade systemic inflammation; a significant increase in erythrocyte osmotic fragility was observed. To gather evidence that systemic inflammation is associated with erythrocyte fragility in humans, two observational studies were conducted. First, using a retrospective study design, the relationship between reticulocyte-based surrogate markers of haemolysis and high-sensitivity C-reactive protein was investigated in 9292 healthy participants of the UK Biobank project. Secondly, we prospectively assessed the relationship between systemic inflammation (measured by the urinary neopterin/creatinine ratio) and erythrocyte osmotic fragility in a mixed population (n = 54) of healthy volunteers and individuals with long-term medical conditions. Both human studies were in keeping with a relationship between inflammation and erythrocyte fragility. Taken together, we conclude that mild systemic inflammation increases erythrocyte fragility and may contribute to haemolysis. Further research is needed to assess the molecular underpinnings of this pathway and the clinical implications in inflammatory conditions.

A Systematic Review and Meta-Analysis of the Pathology Underlying Aneurysm Enhancement on Vessel Wall Imaging.

Intracranial aneurysms are common, but only a minority rupture and cause subarachnoid haemorrhage, presenting a dilemma regarding which to treat. Vessel wall imaging (VWI) is a contrast-enhanced magnetic resonance imaging (MRI) technique used to identify unstable aneurysms. The pathological basis of MR enhancement of aneurysms is the subject of debate. This review synthesises the literature to determine the pathological basis of VWI enhancement. PubMed and Embase searches were performed for studies reporting VWI of intracranial aneurysms and their correlated histological analysis. The risk of bias was assessed. Calculations of interdependence, univariate and multivariate analysis were performed. Of 228 publications identified, 7 met the eligibility criteria. Individual aneurysm data were extracted for 72 out of a total of 81 aneurysms. Univariate analysis showed macrophage markers (CD68 and MPO, p = 0.001 and p = 0.002), endothelial cell markers (CD34 and CD31, p = 0.007 and p = 0.003), glycans (Alcian blue, p = 0.003) and wall thickness (p = 0.030) were positively associated with enhancement. Aneurysm enhancement therefore appears to be associated with inflammatory infiltrate and neovascularisation. However, all these markers are correlated with each other, and the literature is limited in terms of the numbers of aneurysms analysed and the parameters considered. The data are therefore insufficient to determine if these associations are independent of each other or of aneurysm size, wall thickness and rupture status. Thus, the cause of aneurysm-wall enhancement currently remains unknown.

Haptoglobin Treatment for Aneurysmal Subarachnoid Hemorrhage: Review and Expert Consensus on Clinical Translation.

Aneurysmal subarachnoid hemorrhage (aSAH) is a devastating form of stroke frequently affecting young to middle-aged adults, with an unmet need to improve outcome. This special report focusses on the development of intrathecal haptoglobin supplementation as a treatment by reviewing current knowledge and progress, arriving at a Delphi-based global consensus regarding the pathophysiological role of extracellular hemoglobin and research priorities for clinical translation of hemoglobin-scavenging therapeutics. After aneurysmal subarachnoid hemorrhage, erythrocyte lysis generates cell-free hemoglobin in the cerebrospinal fluid, which is a strong determinant of secondary brain injury and long-term clinical outcome. Haptoglobin is the body's first-line defense against cell-free hemoglobin by binding it irreversibly, preventing translocation of hemoglobin into the brain parenchyma and nitric oxide-sensitive functional compartments of cerebral arteries. In mouse and sheep models, intraventricular administration of haptoglobin reversed hemoglobin-induced clinical, histological, and biochemical features of human aneurysmal subarachnoid hemorrhage. Clinical translation of this strategy imposes unique challenges set by the novel mode of action and the anticipated need for intrathecal drug administration, necessitating early input from stakeholders. Practising clinicians (n=72) and scientific experts (n=28) from 5 continents participated in the Delphi study. Inflammation, microvascular spasm, initial intracranial pressure increase, and disruption of nitric oxide signaling were deemed the most important pathophysiological pathways determining outcome. Cell-free hemoglobin was thought to play an important role mostly in pathways related to iron toxicity, oxidative stress, nitric oxide, and inflammation. While useful, there was consensus that further preclinical work was not a priority, with most believing the field was ready for an early phase trial. The highest research priorities were related to confirming haptoglobin's anticipated safety, individualized versus standard dosing, timing of treatment, pharmacokinetics, pharmacodynamics, and outcome measure selection. These results highlight the need for early phase trials of intracranial haptoglobin for aneurysmal subarachnoid hemorrhage, and the value of early input from clinical disciplines on a global scale during the early stages of clinical translation.

Functional effects of haemoglobin can be rescued by haptoglobin in an in vitro model of subarachnoid haemorrhage.

During subarachnoid haemorrhage, a blood clot forms in the subarachnoid space releasing extracellular haemoglobin (Hb), which causes oxidative damage and cell death in surrounding tissues. High rates of disability and cognitive decline in SAH survivors are attributed to loss of neurons and functional connections during secondary brain injury. Haptoglobin sequesters Hb for clearance, but this scavenging system is overwhelmed after a haemorrhage. Whilst exogenous haptoglobin application can attenuate cytotoxicity of Hb in vitro and in vivo, the functional effects of sub-lethal Hb concentrations on surviving neurons and whether cellular function can be protected with haptoglobin treatment remain unclear. Here we use cultured neurons to investigate neuronal health and function across a range of Hb concentrations to establish the thresholds for cellular damage and investigate synaptic function. Hb impairs ATP concentrations and cytoskeletal structure. At clinically relevant but sub-lethal Hb concentrations, we find that synaptic AMPAR-driven currents are reduced, accompanied by a reduction in GluA1 subunit expression. Haptoglobin co-application can prevent these deficits by scavenging free Hb to reduce it to sub-threshold concentrations and does not need to be present at stoichiometric amounts to achieve efficacy. Haptoglobin itself does not impair measures of neuronal health and function at any concentration tested. Our data highlight a role for Hb in modifying synaptic function in surviving neurons, which may link to impaired cognition or plasticity after SAH and support the development of haptoglobin as a therapy for subarachnoid haemorrhage.

Genetic variation in NFE2L2 is associated with outcome following aneurysmal subarachnoid haemorrhage.

BACKGROUND AND PURPOSE: Nuclear factor erythroid 2-related factor 2 (NRF2; encoded by the NFE2L2 gene) has been implicated in outcome following aneurysmal subarachnoid haemorrhage (aSAH) through its activity as a regulator of inflammation, oxidative injury and blood breakdown product clearance. The aim of this study was to identify whether genetic variation in NFE2L2 is associated with clinical outcome following aSAH. METHODS: Ten tagging single nucleotide polymorphisms (SNPs) in NFE2L2 were genotyped and tested for association with dichotomized clinical outcome, assessed by the modified Rankin scale, in both a discovery and a validation cohort. In silico functional analysis was performed using a range of bioinformatic tools. RESULTS: One SNP, rs10183914, was significantly associated with outcome following aSAH in both the discovery (n = 1007) and validation cohorts (n = 466). The risk of poor outcome was estimated to be 1.33-fold (95% confidence interval 1.12-1.58) higher in individuals with the T allele of rs10183914 (pmeta-analysis  = 0.001). In silico functional analysis identified rs10183914 as a potentially regulatory variant with effects on transcription factor binding in addition to alternative splicing with the T allele, associated with a significant reduction in the NFE2L2 intron excision ratio (psQTL  = 1.3 × 10-7 ). CONCLUSIONS: The NFE2L2 SNP, rs10183914, is significantly associated with outcome following aSAH. This is consistent with a clinically relevant pathophysiological role for oxidative and inflammatory brain injury due to blood and its breakdown products in aSAH. Furthermore, our findings support NRF2 as a potential therapeutic target following aSAH and other forms of intracranial haemorrhage.

The impact of smoking cessation on multiple sclerosis disease progression.

The negative impact of smoking in multiple sclerosis is well established; however, there is much less evidence as to whether smoking cessation is beneficial to progression in multiple sclerosis. Adults with multiple sclerosis registered on the United Kingdom Multiple Sclerosis Register (2011-20) formed this retrospective and prospective cohort study. Primary outcomes were changes in three patient-reported outcomes: normalized Multiple Sclerosis Physical Impact Scale (MSIS-29-Phys), normalized Multiple Sclerosis Walking Scale (MSWS-12) and the Hospital Anxiety and Depression Scale (HADS). Time to event outcomes were clinically significant increases in the patient-reported outcomes. The study included 7983 participants; 4130 (51.7%) of these had ever smoked, of whom 1315 (16.5%) were current smokers and 2815/4130 (68.2%) were former smokers. For all patient-reported outcomes, current smokers at the time of completing their first questionnaire had higher patient-reported outcomes scores indicating higher disability compared to those who had never smoked (∼10 points difference in MSIS-29-Phys and MSWS-12; 1.5-1.8 points for HADS-Anxiety and HADS-Depression). There was no improvement in patient-reported outcomes scores with increasing time since quitting in former smokers. Nine hundred and twenty-three participants formed the prospective parallel group, which demonstrated that MSIS-29-Phys [median (IQR) 5.03 (3.71, 6.34)], MSWS-12 [median (IQR) 5.28 (3.62, 6.94)] and HADS-Depression [median (IQR) 0.71 (0.47, 0.96)] scores worsened over a period of 4 years, whereas HADS-Anxiety remained stable. Smoking status was significant at Year 4; current smokers had higher MSIS-29-Phys and HADS-Anxiety scores [median (IQR) 3.05 (0.22, 5.88) and 1.14 (0.52, 1.76), respectively] while former smokers had a lower MSIS-29-Phys score of -2.91 (-5.03, -0.79). A total of 4642 participants comprised the time to event analysis. Still smoking was associated with a shorter time to worsening event in all patient-reported outcomes (MSIS-29-Phys: n = 4436, P = 0.0013; MSWS-12: n = 3902, P = 0.0061; HADS-Anxiety: n = 4511, P = 0.0017; HADS-Depression: n = 4511, P < 0.0001). Worsening in motor disability (MSIS-29-Phys and MSWS-12) was independent of baseline HADS-Anxiety and HADS-Depression scores. There was no statistically significant difference in the rate of worsening between never and former smokers. When smokers quit, there is a slowing in the rate of motor disability deterioration so that it matches the rate of motor decline in those who have never smoked. This suggests that smoking cessation is beneficial for people with multiple sclerosis.

The Haptoglobin Response after Aneurysmal Subarachnoid Haemorrhage.

Haptoglobin is the body's first line of defence against the toxicity of extracellular haemoglobin released following a subarachnoid haemorrhage (SAH). We investigated the haptoglobin response after SAH in cerebrospinal fluid (CSF) and serum. Paired CSF and serum samples from 19 controls and 92 SAH patients were assayed as follows: ultra-performance liquid chromatography for CSF haemoglobin and haptoglobin, immunoassay for serum haptoglobin and multiplexed CSF cytokines, and colorimetry for albumin. There was marked CSF haptoglobin deficiency: 99% of extracellular haemoglobin was unbound. The quotients for both CSF/serum albumin (qAlb) and haptoglobin (qHp) were used to compute the CSF haptoglobin index (qHp/qAlb). CSF from SAH patients had a significantly lower haptoglobin index compared to controls, especially in Haptoglobin-1 allele carriers. Serum haptoglobin levels increased after SAH and were correlated with CSF cytokine levels. Haptoglobin variables were not associated with long-term clinical outcomes post-SAH. We conclude that: (1) intrathecal haptoglobin consumption occurs after SAH, more so in haptoglobin-1 allele carriers; (2) serum haptoglobin is upregulated after SAH, in keeping with the liver acute phase response to central inflammation; (3) haptoglobin in the CSF is so low that any variation is too small for this to affect long-term outcomes, emphasising the potential for therapeutic haptoglobin supplementation.

Cryptococcal meningoencephalitis in multiple sclerosis treated with fingolimod.

A 21-year-old woman with multiple sclerosis (taking regular fingolimod) developed sudden-onset severe headache with nausea and malaise. Neurological examination was normal and she was afebrile. Blood results showed lymphocytes 0.53 x 109/L and C reactive protein 19 mg/L. CT scan of head and venogram were normal. CSF showed an opening pressure of 33 cm H2O and an incidental light growth of Cryptococcus neoformans, confirmed with positive India Ink stain and a positive cryptococcal antigen (1:100). She was treated for cryptococcal meningoencephalitis with amphotericin and flucytosine. Her presenting symptoms had closely mimicked subarachnoid haemorrhage. This atypical presentation of cryptococcal CNS infection highlights the need for vigilance in immunosuppressed patients.

Iron Deposition in the Brain After Aneurysmal Subarachnoid Hemorrhage.

BACKGROUND: After aneurysmal subarachnoid hemorrhage (SAH), thrombus forms over the cerebral cortex and releases hemoglobin. When extracellular, hemoglobin is toxic to neurones. High local hemoglobin concentration overwhelms the clearance capacity of macrophages expressing the hemoglobin-haptoglobin scavenger receptor CD163. We hypothesized that iron is deposited in the cortex after SAH and would associate with outcome. METHODS: Two complementary cross-sectional studies were conducted. Postmortem brain tissue from 39 SAH (mean postictal interval of 9 days) and 22 control cases was studied with Perls' staining for iron and immunolabeling for CD163, ADAM17 (a disintegrin and metallopeptidase domain 17), CD68, and Iba1 (ionized calcium binding adaptor molecule 1). In parallel, to study the persistence of cortical iron and its relationship to clinical outcome, we conducted a susceptibility-weighted imaging study of 21 SAH patients 6 months postictus and 10 control individuals. RESULTS: In brain tissue from patients dying soon after SAH, the distribution of iron deposition followed a gradient that diminished with distance from the brain surface. Iron was located intracellularly (mainly in macrophages, and occasionally in microglia, neurones, and glial cells) and extracellularly. Microglial activation and motility markers were increased after SAH, with a similar inward diminishing gradient. In controls, there was a positive correlation between CD163 and iron, which was lost after SAH. In SAH survivors, iron-sensitive imaging 6 months post-SAH confirmed persistence of cortical iron, related to the size and location of the blood clot immediately after SAH, and associated with cognitive outcome. CONCLUSIONS: After SAH, iron deposits in the cortical gray matter in a pattern that reflects proximity to the brain surface and thrombus and is related to cognitive outcome. These observations support therapeutic manoeuvres which prevent the permeation of hemoglobin into the cortex after SAH.

CD8 T-cell-mediated cerebellitis directed against Purkinje cell antigen after ipilimumab for small cell lung cancer.

We report a rapidly progressive and fatal CD8 T-cell-mediated cerebellitis after ipilimumab (cytotoxic T-lymphocyte-associated protein 4 inhibitor) for small cell lung cancer. Clinical features and histopathology were consistent with an accelerated form of paraneoplastic cerebellar degeneration. A patchy CD8 T-cell infiltrate spatially corresponded to areas of Purkinje cell loss, with occasional CD8 polarisation towards Purkinje cells. CD20-positive B cells were sparse. CD8 T-cell-mediated cerebellitis after immune checkpoint inhibitor treatment may recapitulate the early stages of paraneoplastic cerebellar degeneration.

Long-term fatigue following aneurysmal subarachnoid haemorrhage and the impact on employment.

BACKGROUND AND PURPOSE: Fatigue is common following aneurysmal subarachnoid haemorrhage (aSAH) but little is known about its frequency, prognosis and impact on employment. The aim of this study was to assess the frequency of fatigue, whether it changes over time and the relationship to employment in the long term. METHODS: This was a retrospective observational study of aSAH cases and matched controls from the UK Biobank. The presence of fatigue was compared between cases and controls using the chi-squared test. The change in frequency over time was assessed using Spearman's rank correlation coefficient. The effect of fatigue on employment was assessed using mediation analysis. RESULTS: Fatigue is more common following aSAH compared to matched controls (aSAH 18.7%; controls 13.7%; χ2  = 13.0, p < 0.001) at a mean follow-up of 123 months. Fatigue gradually improves over time with significant fatigue decreasing by 50% from ~20% in the first year to ~10% after a decade (p = 0.04). Fatigue significantly mediated 24.0% of the effect of aSAH status on employment. CONCLUSIONS: Fatigue is common following aSAH and persists in the long term. It gradually improves over time but has a major impact on aSAH survivors, significantly contributing to unemployment following haemorrhage. Further work is required to develop treatments and management strategies for fatigue with a view to improving this symptom and consequently employment following aSAH.

Duration and characteristics of persistent headache following aneurysmal subarachnoid hemorrhage.

OBJECTIVE: To assess the long-term frequency, prognosis, and phenotype of persistent headache following aneurysmal subarachnoid hemorrhage (aSAH). BACKGROUND: Very little is known about long-term headache following aSAH with no studies looking beyond 3 years. METHODS: Retrospective analysis comparing aSAH cases to matched controls in the UK Biobank, a prospective cohort study. Headache frequency and phenotype were compared using group comparison tests. The relationship between headache frequency and time was assessed using correlation analysis. RESULTS: Headache was more frequent following aSAH (aSAH: 258/864 [29.9%] vs. controls: 666/3456 [19.3%], χ2  = 45.5, p < 0.001) at a median follow-up of 7.5 years. Headache frequency decreased over time (RS  = -0.71, p = 0.028), affecting 29/58 (50%) patients in the first year and reducing to 13/47 (28%) patients 10 years later. Headache frequency was not related to aSAH severity (z = 0.249, p = 0.803), treatment (z = 0.583, p = 0.560), or hydrocephalus (z = -1.244, p = 0.214). There was a consistently higher frequency of migrainous features following aSAH compared to controls, although this did not reach statistical significance. CONCLUSIONS: Persistent headache is more frequent following aSAH compared to controls in the long term and the prevalence reduces gradually over time. The increased frequency of migrainous features suggests that selected patients with post-aSAH headache may benefit from migraine treatment.

Neurofilament light predicts neurological outcome after subarachnoid haemorrhage.

To improve outcome prediction following subarachnoid haemorrhage (SAH), we sought a biomarker integrating early brain injury and multiple secondary pathological processes in a prospective study of 42 non-traumatic SAH patients and 19 control individuals. Neurofilament light (NF-L) was elevated in CSF and serum following SAH. CSF and serum NF-L on Days 1-3 post-SAH strongly predicted modified Rankin score at 6 months, independent of World Federation of Neurosurgical Societies (WFNS) score. NF-L from Day 4 onwards also had a profound impact on outcome. To link NF-L to a SAH-specific pathological process, we investigated NF-L's relationship with extracellular haemoglobin. Most CSF haemoglobin was not complexed with haptoglobin, yet was able to be bound by exogenous haptoglobin i.e. haemoglobin was scavengeable. CSF scavengeable haemoglobin was strongly predictive of subsequent CSF NF-L. Next, we investigated NF-L efflux from the brain after SAH. Serum and CSF NF-L correlated positively. The serum/CSF NF-L ratio was lower in SAH versus control subjects, in keeping with glymphatic efflux dysfunction after SAH. CSF/serum albumin ratio was increased following SAH versus controls. The serum/CSF NF-L ratio correlated negatively with the CSF/serum albumin ratio, indicating that transfer of the two proteins across the blood-brain interface is dissociated. In summary, NF-L is a strong predictive marker for SAH clinical outcome, adding value to the WFNS score, and is a promising surrogate end point in clinical trials.