Quantitative noninvasive measurement of cerebrospinal fluid flow in shunted hydrocephalus.

OBJECTIVE: Standard MRI protocols lack a quantitative sequence that can be used to evaluate shunt-treated patients with a history of hydrocephalus. The objective of this study was to investigate the use of phase-contrast MRI (PC-MRI), a quantitative MR sequence, to measure CSF flow through the shunt and demonstrate PC-MRI as a useful adjunct in the clinical monitoring of shunt-treated patients. METHODS: The rapid (96 seconds) PC-MRI sequence was calibrated using a flow phantom with known flow rates ranging from 0 to 24 mL/hr. Following phantom calibration, 21 patients were scanned with the PC-MRI sequence. Multiple, successive proximal and distal measurements were gathered in 5 patients to test for measurement error in different portions of the shunt system and to determine intrapatient CSF flow variability. The study also includes the first in vivo validations of PC-MRI for CSF shunt flow by comparing phase-contrast-measured flow rate with CSF accumulation in a collection burette obtained in patients with externalized distal shunts. RESULTS: The PC-MRI sequence successfully measured CSF flow rates ranging from 6 to 54 mL/hr in 21 consecutive pediatric patients. Comparison of PC-MRI flow measurement and CSF volume collected in a bedside burette showed good agreement in a patient with an externalized distal shunt. Notably, the distal portion of the shunt demonstrated lower measurement error when compared with PC-MRI measurements acquired in the proximal catheter. CONCLUSIONS: The PC-MRI sequence provided accurate and reliable clinical measurements of CSF flow in shunt-treated patients. This work provides the necessary framework to include PC-MRI as an immediate addition to the clinical setting in the noninvasive evaluation of shunt function and in future clinical investigations of CSF physiology.

Gaps in the wall of a perivascular space act as valves to produce a directed flow of cerebrospinal fluid: a hoop-stress model.

The flow of cerebrospinal fluid (CSF) along perivascular spaces (PVSs) is an important part of the brain's system for clearing metabolic waste. Astrocyte endfeet bound the PVSs of penetrating arteries, separating them from brain extracellular space. Gaps between astrocyte endfeet might provide a low-resistance pathway for fluid transport across the wall. Recent studies suggest that the astrocyte endfeet function as valves that rectify the CSF flow, producing the net flow observed in pial PVSs by changing the size of the gaps in response to pressure changes. In this study, we quantify this rectification based on three features of the PVSs: the quasi-circular geometry, the deformable endfoot wall, and the pressure oscillation inside. We provide an analytical model, based on the thin-shell hoop-stress approximation, and predict a pumping efficiency of about 0.4, which would contribute significantly to the observed flow. When we add the flow resistance of the extracellular space (ECS) to the model, we find an increased net flow during sleep, due to the known increase in ECS porosity (decreased flow resistance) compared to that in the awake state. We corroborate our analytical model with three-dimensional fluid-solid interaction simulations.

TOPMed imputed genomics enhances genomic atlas of the human proteome in brain, cerebrospinal fluid, and plasma.

Comprehensive expression quantitative trait loci studies have been instrumental for understanding tissue-specific gene regulation and pinpointing functional genes for disease-associated loci in a tissue-specific manner. Compared to gene expressions, proteins more directly affect various biological processes, often dysregulated in disease, and are important drug targets. We previously performed and identified tissue-specific protein quantitative trait loci in brain, cerebrospinal fluid, and plasma. We now enhance this work by analyzing more proteins (1,300 versus 1,079) and an almost twofold increase in high quality imputed genetic variants (8.4 million versus 4.4 million) by using TOPMed reference panel. We identified 38 genomic regions associated with 43 proteins in brain, 150 regions associated with 247 proteins in cerebrospinal fluid, and 95 regions associated with 145 proteins in plasma. Compared to our previous study, this study newly identified 12 loci in brain, 30 loci in cerebrospinal fluid, and 22 loci in plasma. Our improved genomic atlas uncovers the genetic control of protein regulation across multiple tissues. These resources are accessible through the Online Neurodegenerative Trait Integrative Multi-Omics Explorer for use by the scientific community.

NIR-II nanoprobes for investigating the glymphatic system function under anesthesia and stroke injury.

The glymphatic system plays an important role in the transportation of cerebrospinal fluid (CSF) and the clearance of metabolite waste in brain. However, current imaging modalities for studying the glymphatic system are limited. Herein, we apply NIR-II nanoprobes with non-invasive and high-contrast advantages to comprehensively explore the function of glymphatic system in mice under anesthesia and cerebral ischemia-reperfusion injury conditions. Our results show that the supplement drug dexmedetomidine (Dex) enhances CSF influx in the brain, decreases its outflow to mandibular lymph nodes, and leads to significant differences in CSF accumulation pattern in the spine compared to isoflurane (ISO) alone, while both ISO and Dex do not affect the clearance of tracer-filled CSF into blood circulation. Notably, we confirm the compromised glymphatic function after cerebral ischemia-reperfusion injury, leading to impaired glymphatic influx and reduced glymphatic efflux. This technique has great potential to elucidate the underlying mechanisms between the glymphatic system and central nervous system diseases.

Anestesia neuroaxial en pacientes portadores de dispositivos de derivación de líquido cefalorraquídeo: revisión descriptiva / Neuraxial anaesthesia in patients with cerebrospinal fluid shunts: A descriptive review

La anestesia neuroaxial en pacientes portadores de dispositivos de derivación de líquido cefalorraquídeo (LCR) se ha asociado clásicamente a un alto riesgo de complicaciones. Con el fin de recabar toda la evidencia disponible, se realizó una búsqueda estructurada de los trabajos publicados en usuarios portadores de estos dispositivos, sometidos a algún tipo de técnica neuroaxial para procedimientos obstétricos o quirúrgicos no relacionados con el mismo, valorando la eficacia de la técnica y las complicaciones perioperatorias. Solo se encontraron series de casos y casos clínicos (n = 72). Se identificó uno de insuficiente cobertura anestésica, que precisó una modificación de la técnica, así como una complicación intraoperatoria con compromiso de seguridad para el sujeto. No se describió ningún caso de infección ni disfunciones posoperatorias del dispositivo relacionadas con el método anestésico. La evidencia hallada es escasa y de baja calidad, lo que no permite establecer conclusiones significativas, aunque los pacientes podrían beneficiarse de una valoración individualizada. (AU)

Neuraxial anesthesia in patients with cerebrospinal fluid (CSF) shunt devices has traditionally been associated with a high risk of complications. In order to gather all available evidence, a structured search was conducted to include published studies involving users of these devices, undergoing any form of neuraxial technique for obstetric or surgical procedures unrelated to them. Effectiveness of the technique and perioperative complications were assessed. Only case series and case reports (n = 72) were identified. One patient was found to have insufficient anesthetic coverage, necessitating a modification of the technique, and another one had an intraoperative complication which compromised the subject's safety. No infection events or postoperative device dysfunction related to the anesthetic method were described. The evidence found is scarce and of low quality, preventing the establishment of significant conclusions. Nevertheless, patients may obtain benefit from an individualized evaluation. (AU)

Fistula espontánea de LCR como manifestación de la hipertensión intracraneal idiopática / Spontaneous CSF fistula as manifestation of idiopathic intracranial hypertension

Introducción: La fistula espontanea de líquido cefalorraquídeo (LCR) de origen desconocido, es una afección poco frecuente cuya etiología se relaciona cada vez más con la hipertensión intracraneal idiopática (HII). Este estudio trata de concienciar que no deben considerase como 2 procesos distintos, sino que las fistulas pueden ser una forma de inicio, requiriendo un estudio y tratamiento posterior. Se describen las técnicas de reparación, así como el estudio de la HII. Resultados: Se trataron 8 pacientes, 5 mujeres y 3 varones, con edades comprendidas entre 46 y 72 años, con diagnóstico de fistula espontánea de LCR, 4 nasales y 4 óticas a los que se le sometió a tratamiento quirúrgico. Tras la reparación se realizó un estudio diagnóstico para la HII mediante RMN y angio-RM, presentando en todos los casos una estenosis de seno venoso transverso. Los valores de presión intracraneal obtenidos mediante punción lumbar mostraron valores de 20mmHg o superiores. Todos los pacientes fueron diagnosticados de HII. El seguimiento a un año no reveló ninguna recidiva de las fistulas, manteniendo un control de la HII. Conclusión: A pesar de su escasa frecuencia tanto de las fistulas craneales de LCR como de la HII, debe considerarse una asociación de ambas afecciones continuando el estudio y vigilancia de estos pacientes tras el cierre de la fístula.(AU)

Introduction: Spontaneous cerebrospinal fluid (CSF) fistula, of unknown origin, is a rare condition whose etiology is increasingly related to idiopathic intracranial hypertension (IIH). This study tries to raise awareness that they should not be considered as two different processes, but that fistulas can be a form of debut, requiring a study and subsequent treatment. Repair techniques are described, as well as the study of IIH. Results: We treated eight patients, five women and three men, aged between 46 and 72 years, with a diagnosis of spontaneous CSF fistula, four nasal and four otics who underwent surgical treatment. After repair, a diagnostic study was performed for IIH by MRI and angio-MRI, presenting in all cases a transverse venous sinus stenosis. The intracranial pressure values obtained by lumbar puncture showed values of 20mmHg or higher. All patients were diagnosed with IIH. The one-year follow-up did not reveal any recurrence of the fistulas, maintaining a control of the IIH. Conclusion: Despite their low frequency of both cranial CSF fistula and IIH, an association of both conditions should be considered by continuing the study and surveillance of these patients after fistula closure.(AU)

Modelos experimentales murinos en la esclerosis lateral amiotrófica. Puesta al día / Murine experimental models of amyotrophic lateral sclerosis: An update

Introducción: La esclerosis lateral amiotrófica (ELA) es una enfermedad neurodegenerativa, progresiva y de etiología desconocida caracterizada por la degeneración de motoneuronas superiores e inferiores. Aproximadamente el 90% de los casos de ELA son esporádicos, mientras que el 10% restante se consideran familiares. Independientemente de si son familiares o esporádicas, los pacientes desarrollan una debilidad progresiva, atrofia muscular con espasticidad y contracturas. Por lo general, la esperanza de vida en los pacientes de ELA es de 2 a 5 años. Desarrollo: Los modelos in vivo han ayudado a explicar la etiología y la patogénesis, así como los mecanismos de la ELA. Sin embargo, estos mecanismos no están del todo esclarecidos aún, por lo que los modelos experimentales son fundamentales para continuar con el estudio de los mismos, así como para la búsqueda de posibles dianas terapéuticas. A pesar de que el 90% de los casos son esporádicos, la mayoría de los modelos utilizados hasta la actualidad para estudiar la patogénesis están basados en las mutaciones genéticas asociadas a la enfermedad familiar, lo que provoca que la patogénesis de la ELA esporádica no sea aún conocida. Por tanto, sería fundamental el estudio de la enfermedad en modelos basados en la enfermedad esporádica. Conclusión: En el presente artículo se han revisado los principales modelos experimentales, tanto genéticos como esporádicos, utilizados en el estudio de esta enfermedad, enfocándonos en los que se han desarrollado utilizando el roedor como plataforma experimental.(AU)

Introduction: Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disease whose aetiology is unknown. It is characterised by upper and lower motor neuron degeneration. Approximately 90% of cases of ALS are sporadic, whereas the other 10% are familial. Regardless of whether the case is familial or sporadic, patients will develop progressive weakness, muscle atrophy with spasticity, and muscle contractures. Life expectancy of these patients is generally 2–5 years after diagnosis. Development: In vivo models have helped to clarify the aetiology and pathogenesis of ALS, as well as the mechanisms of the disease. However, as these mechanisms are not yet fully understood, experimental models are essential to the continued study of the pathogenesis of ALS, as well as in the search for possible therapeutic targets. Although 90% of cases are sporadic, most of the models used to study ALS pathogenesis are based on genetic mutations associated with the familial form of the disease; the pathogenesis of sporadic ALS remains unknown. Therefore, it would be critical to establish models based on the sporadic form. Conclusion: This article reviews the main genetic and sporadic experimental models used in the study of this disease, focusing on those that have been developed using rodents.(AU)

Diversity of enteroviruses in cerebrospinal fluid specimens collected from hospitalised patients in the private and public sector in South Africa.

Enteroviruses cause a wide range of neurological illnesses such as encephalitis, meningitis, and acute flaccid paralysis. Two types of enteroviruses, echovirus E4 and E9, have recently been detected in South Africa and are known to be associated with meningitis and encephalitis. The objective of this study was to characterize enterovirus strains detected in cerebrospinal fluid specimens of hospitalized patients in the private and public sector to identify genotypes associated with meningitis and encephalitis. From January 2019 to June 2021 enterovirus positive nucleic acid samples were obtained from a private (n = 116) and a public sector (n = 101) laboratory. These enteroviruses were typed using a nested set of primers targeting the VP1 region of the enterovirus genome, followed by Sanger sequencing and BLASTn analysis. Forty-two percent (91/217) of the strains could be genotyped. Enterovirus B species was the major species detected in 95% (86/91) of the specimens, followed by species C in 3% (3/91) and species A in 2% (2/91) of the specimens. Echovirus E4 and E9 were the two major types identified in this study and were detected in 70% (64/91) and in 10% (9/91) of specimens, respectively. Echovirus E11 has previously been identified in sewage samples from South Africa, but this study is the first to report Echovirus E11 in cerebrospinal fluid specimens from South African patients. The genotypes identified during this study are known to be associated with encephalitis and meningitis. The predominant detection of echovirus E4 followed by E9 corresponds with other studies conducted in South Africa.

Detection of Glymphatic Outflow of Tau from Brain to Cerebrospinal Fluid in Mice.

Glymphatic system denotes a brain-wide pathway that eliminates extracellular solutes from brain. It is driven by the flow of brain interstitial fluid (ISF) and cerebrospinal fluid (CSF) via perivascular spaces. Glymphatic convective flow is driven by cerebral arterial pulsation, which is facilitated by a water channel, aquaporin-4 (AQP4) expressed in astrocytic end-foot processes. Since its discovery, the glymphatic system receives a considerable scientific attention due to its pivotal role in clearing metabolic waste as well as neurotoxic substances such as amyloid b peptide. Tau is a microtubule binding protein, however it is also physiologically released into extracellular fluids. The presence of tau in the blood stream indicates that it is eventually cleared from the brain to the periphery, however, the detailed mechanisms that eliminate extracellular tau from the central nervous system remained to be elucidated. Recently, we and others have reported that extracellular tau is eliminated from the brain to CSF by an AQP4 dependent mechanism, suggesting the involvement of the glymphatic system. In this chapter, we describe the detailed protocol of how we can assess glymphatic outflow of tau protein from brain to CSF in mice.

Targeted sequencing from cerebrospinal fluid for rapid identification of drug-resistant tuberculous meningitis.

Mortality from tuberculous meningitis (TBM) remains around 30%, with most deaths occurring within 2 months of starting treatment. Mortality from drug-resistant strains is higher still, making early detection of drug resistance (DR) essential. Targeted next-generation sequencing (tNGS) produces high read depths, allowing the detection of DR-associated alleles with low frequencies. We applied Deeplex Myc-TB-a tNGS assay-to cerebrospinal fluid (CSF) samples from 72 adults with microbiologically confirmed TBM and compared its genomic drug susceptibility predictions to a composite reference standard of phenotypic susceptibility testing (pDST) and whole genome sequencing, as well as to clinical outcomes. Deeplex detected Mycobacterium tuberculosis complex DNA in 24/72 (33.3%) CSF samples and generated full DR reports for 22/24 (91.7%). The read depth generated by Deeplex correlated with semi-quantitative results from MTB/RIF Xpert. Alleles with <20% frequency were seen at canonical loci associated with first-line DR. Disregarding these low-frequency alleles, Deeplex had 100% concordance with the composite reference standard for all drugs except pyrazinamide and streptomycin. Three patients had positive CSF cultures after 30 days of treatment; reference tests and Deeplex identified isoniazid resistance in two, and Deeplex alone identified low-frequency rifampin resistance alleles in one. Five patients died, of whom one had pDST-identified pyrazinamide resistance. tNGS on CSF can rapidly and accurately detect drug-resistant TBM, but its application is limited to those with higher bacterial loads. In those with lower bacterial burdens, alternative approaches need to be developed for both diagnosis and resistance detection.

Validating the accuracy of real-time phase-contrast MRI and quantifying the effects of free breathing on cerebrospinal fluid dynamics.

BACKGROUND: Understanding of the cerebrospinal fluid (CSF) circulation is essential for physiological studies and clinical diagnosis. Real-time phase contrast sequences (RT-PC) can quantify beat-to-beat CSF flow signals. However, the detailed effects of free-breathing on CSF parameters are not fully understood. This study aims to validate RT-PC's accuracy by comparing it with the conventional phase-contrast sequence (CINE-PC) and quantify the effect of free-breathing on CSF parameters at the intracranial and extracranial levels using a time-domain multiparametric analysis method. METHODS: Thirty-six healthy participants underwent MRI in a 3T scanner for CSF oscillations quantification at the cervical spine (C2-C3) and Sylvian aqueduct, using CINE-PC and RT-PC. CINE-PC uses 32 velocity maps to represent dynamic CSF flow over an average cardiac cycle, while RT-PC continuously quantifies CSF flow over 45-seconds. Free-breathing signals were recorded from 25 participants. RT-PC signal was segmented into independent cardiac cycle flow curves (Qt) and reconstructed into an averaged Qt. To assess RT-PC's accuracy, parameters such as segmented area, flow amplitude, and stroke volume (SV) of the reconstructed Qt from RT-PC were compared with those derived from the averaged Qt generated by CINE-PC. The breathing signal was used to categorize the Qt into expiratory or inspiratory phases, enabling the reconstruction of two Qt for inspiration and expiration. The breathing effects on various CSF parameters can be quantified by comparing these two reconstructed Qt. RESULTS: RT-PC overestimated CSF area (82.7% at aqueduct, 11.5% at C2-C3) compared to CINE-PC. Stroke volumes for CINE-PC were 615 mm³ (aqueduct) and 43 mm³ (spinal), and 581 mm³ (aqueduct) and 46 mm³ (spinal) for RT-PC. During thoracic pressure increase, spinal CSF net flow, flow amplitude, SV, and cardiac period increased by 6.3%, 6.8%, 14%, and 6%, respectively. Breathing effects on net flow showed a significant phase difference compared to the other parameters. Aqueduct-CSF flows were more affected by breathing than spinal-CSF. CONCLUSIONS: RT-PC accurately quantifies CSF oscillations in real-time and eliminates the need for cardiac synchronization, enabling the quantification of the cardiac and breathing components of CSF flow. This study quantifies the impact of free-breathing on CSF parameters, offering valuable physiological references for understanding the effects of breathing on CSF dynamics.

A technique for repeated blood and cerebrospinal fluid sampling from individual rats over time without the need for repeated anesthesia.

Ethical animal use follows the 3R's: Replacement, Reduction and Refinement. Here, we present the use of simultaneous jugular vein and cisterna magna catheterization via a port system in rats for repeated fluid sampling for 14 consecutive days without loss of catheter patency. This technique allows repeated intra-animal sampling without anesthesia and, if used with pooling samples from a cohort of animals, replaces the need for terminal collections for sufficient sample volumes.

[Possibilities of dynamic phase contrast MRI of cerebrospinal fluid for performing a tap test in a patient with idiopathic normotensive hydrocephalus]. / Vozmozhnosti dinamicheskoi fazovo-kontrastnoi MR-likvorografii pri vypolnenii tap-testa u patsienta s idiopaticheskoi normotenzivnoi gidrotsefaliei.

Idiopathic normotensive hydrocephalus (iNH) is a widespread disease in elderly patients. The effectiveness of iNG treatment and the subsequent quality of patients' lives directly depends on timely and early diagnosis. The criteria for diagnosing iNG that are used in neuroimaging can also be found in patients without clinical manifestations of this disease, and the widely used tap-test is an invasive technique with a rather low sensitivity. The need for early diagnosis and initiation of treatment before the development of irreversible damage to brain structures determines the relevance of the search for an accessible, minimally invasive, accurate and safe diagnostic method. The article presents a clinical observation of the use of phase-contrast MRI of cerebrospinal fluid (CSF) in a female patient with a positive response to the tap test with a quantitative analysis of changes in CSF flow parameters and ALVI and Evans indices depending on the time after CSF evacuation. Phase-contrast MRI of CSF with a quantitative assessment of CSF flow parameters in combination with an assessment of the ALVI index has the potential to increase the accuracy of diagnosing iNH and is of scientific interest for further research.

Don't rash it! The clinical significance of positive Varicella zoster virus PCR in cerebrospinal fluid of patients with neurological symptoms.

BACKGROUND: Varicella zoster virus (VZV) is among the leading pathogens causing meningitis and encephalitis. While VZV-PCR-positive CSF is considered a gold-standard for diagnosis, it is not-uncommon to detect VZV-DNA in CSF of patients with other acute or chronic illness. Our goal was to determine the clinical relevance of VZV-PCR-positive CSF when investigating patients with neurological symptoms. METHODS: In this retrospective cohort from the largest hospital in Israel, we collected demographic, clinical and laboratory data of patients with VZV-PCR-positive CSF, analyzing the significance of various parameters. RESULTS: During a 5-years study, 125 patient-unique VZV-PCR-positive CSFs were recorded, in which only 9 alternative diagnoses were noted. The commonest symptoms were headache (N = 104, 83 %) and rash (N = 96, 76 %). PCR-cycle-threshold (Ct), a surrogate of viral burden, did not significantly vary across the clinical manifestations; however, patients with rash and Ct<35 were prone to develop stroke in the following year (N = 6, 7 %). Empiric nucleoside-analogue treatment was not associated with a better outcome compared to treatment administered upon a positive-PCR result. DISCUSSION: Our findings suggest that in patients with neurological symptoms, detection of VZV-DNA in CSF renders VZV the probable culprit. Nevertheless, a systematic evaluation of treatment and follow-up algorithms of patients with suspected or proved VZV meningitis and encephalitis is needed. The benefits of a prompt treatment should be weighed against the potential complications of nucleoside-analogue. Conversely, the propensity for stroke in patients with higher viral-burden, necessitates further studies assessing VZV causal role, directing additional workup, treatment and monitoring policy.

Radiological Analysis of Cerebrospinal Fluid Dynamics at the Craniovertebral Junction Using Time-Spatial Labeling Inversion Pulse Magnetic Resonance Imaging in Patients with Cervical Spinal Canal Stenosis.

OBJECTIVE: Spondylotic changes in the cervical spine cause degeneration, leading to cervical spinal canal stenosis. This stenotic change can affect cerebrospinal fluid (CSF) dynamics by compressing the dural sac and reducing space in the subarachnoid space. We examined CSF dynamics at the craniovertebral junction (CVJ) using time-spatial labeling inversion pulse magnetic resonance imaging (Time-SLIP MRI) in patients with cervical spinal canal stenosis. METHODS: The maximum longitudinal movement of the CSF at the CVJ was measured as length of motion (LOM) in the Time-SLIP MRI of 56 patients. The sum of ventral and dorsal LOM was defined as the total LOM. Patients were classified into 3 groups depending on their spinal sagittal magnetic resonance imaging findings: control (n = 27, Kang classification grades 0 and 1), stenosis (n = 14, Kang classification grade 2), and severe stenosis (n = 15, Kang classification grade 3). RESULTS: Time-SLIP MRI revealed pulsatile movement of the CSF at the CVJ. The mean total, ventral, and dorsal LOM was 14.2 ± 9, 8.1 ± 5.7, and 3.8 ± 2.9 mm, respectively. The ventral LOM was significantly larger than the dorsal LOM. The total LOM was significantly smaller in the severe stenosis group (6.1 ± 3.4 mm) than in the control (16.0 ± 8.4 mm) or stenosis (11 ± 5.4 mm) groups (P < 0.001, Kruskal-Wallis H-test). In 5 patients, postoperative total LOM was improved after adequate decompression surgery. CONCLUSIONS: This study demonstrates that CSF dynamics at the CVJ are influenced by cervical spinal canal stenosis. Time-SLIP MRI is useful for evaluating CSF dynamics at the CVJ in patients with spinal canal stenosis.

Elevated levels of ß2-microglobulin in cerebrospinal fluid in adult patients with viral encephalitis/meningitis.

BACKGROUND: Increased cerebrospinal fluid (CSF) ß2-microglobulin (ß2-MG) values are attributed to immune activation, lymphoid cell turnover and release of tissue destruction in the central nervous system (CNS). We investigated plasma and CSF ß2-MG levels in adult patients with viral encephalitis/meningitis and their correlations with clinical parameters. METHOD: CSF samples from 26 patients with viral encephalitis/meningitis were collected. Moreover, 24 CSF samples from patients with non-inflammatory neurological disorders (NIND) as controls were collected. Plasma samples from 22 enrolled patients and 20 healthy individuals were collected. The ß2-MG levels were measured by immunoturbidimetry on an automatic biochemical analyzer. Clinical data were extracted from an electronic patient documentation system. RESULT: CSF levels of ß2-MG, adenosine deaminase (ADA), white blood cell (WBC), lactate dehydrogenase (LDH), protein and lactate were significantly increased in patients with viral encephalitis/meningitis respectively (p < 0.001, p < 0.001, p < 0.001, p = 0.001, p < 0.001, p = 0.013). In contrast, no statistically significant difference was found in plasma levels of ß2-MG. Furthermore, CSF levels of ß2-MG were weakly correlated with WBC (r = 0.426, p = 0.030), lymphocyte percentage (r = 0.599, p = 0.018), ADA (r = 0.545, p = 0.004) and LDH (r = 0.414, p = 0.036), but not with lactate (r = 0.381, p = 0.055), protein (r = 0.179, p = 0.381) and plasma levels of ß2-MG (r = -0.156, p = 0.537) in viral encephalitis/meningitis patients. CONCLUSION: CSF ß2-MG may be a potential inflammatory marker for viral encephalitis/meningitis in adult patients diagnosed with viral encephalitis/meningitis.