Kappa free light chains is a valid tool in the diagnostics of MS: A large multicenter study.

OBJECTIVE: To validate kappa free light chain (KFLC) and lambda free light chain (LFLC) indices as a diagnostic biomarker in multiple sclerosis (MS). METHODS: We performed a multicenter study including 745 patients from 18 centers (219 controls and 526 clinically isolated syndrome (CIS)/MS patients) with a known oligoclonal IgG band (OCB) status. KFLC and LFLC were measured in paired cerebrospinal fluid (CSF) and serum samples. Gaussian mixture modeling was used to define a cut-off for KFLC and LFLC indexes. RESULTS: The cut-off for the KFLC index was 6.6 (95% confidence interval (CI) = 5.2-138.1). The cut-off for the LFLC index was 6.9 (95% CI = 4.5-22.2). For CIS/MS patients, sensitivity of the KFLC index (0.88; 95% CI = 0.85-0.90) was higher than OCB (0.82; 95%CI = 0.79-0.85; p < 0.001), but specificity (0.83; 95% CI = 0.78-0.88) was lower (OCB = 0.92; 95% CI = 0.89-0.96; p < 0.001). Both sensitivity and specificity for the LFLC index were lower than OCB. CONCLUSION: Compared with OCB, the KFLC index is more sensitive but less specific for diagnosing CIS/MS. Lacking an elevated KFLC index is more powerful for excluding MS compared with OCB but the latter is more important for ruling in a diagnosis of CIS/MS.

A population-based epidemiological study of neuromyelitis optica spectrum disorder in Hungary.

BACKGROUND AND PURPOSE: The goal of this study was to determine the prevalence and incidence of neuromyelitis optica spectrum disorder (NMOSD) in Hungary based on the 2015 International Panel of NMO Diagnosis (IPND) criteria. METHODS: A retrospective population-based cohort study was conducted of 6.4 million Hungarians (age ≥ 16 years) between 1 January 2006 and 31 December 2016. Possible NMOSD patients were selected via multistage re-evaluation from multiple sources. Crude and sex- and serostatus-specific prevalence (per 100 000 persons) and incidence rates (per 1 000 000 person-years) from 2006 to 2015 were estimated and age-adjusted rates were determined. RESULTS: Of 2262 study candidates, 154 NMOSD patients (age ≥ 16 years) with onset until 31 December 2016 were identified based on 2015 IPND criteria. The prevalence analysis on 1 January 2016 included 123 NMOSD living cases, resulting in a prevalence of 1.91 [95% confidence interval (CI) 1.52-2.28] per 100 000 persons. The 101 incident cases emerging from the observed 76 394 288 person-years provided an incidence rate of 1.32 (95% CI 1.08-1.61) per 1 000 000 person-years. Age-adjusted prevalence was 1.87 (95% CI 1.56-2.23) per 100 000 persons and incidence was 1.20 (95% CI 0.98-1.46) per 1 000 000 person-years. CONCLUSIONS: In this first report of a large population-based epidemiological study from an Eastern European Caucasian population using robust case validation, a greater prevalence and incidence of NMOSD was found compared to previous large studies in Caucasian populations.

Topical dura mater application of CFA induces enhanced expression of c-fos and glutamate in rat trigeminal nucleus caudalis: attenuated by KYNA derivate (SZR72).

BACKGROUND: Migraine is a debilitating neurological disorder where trigeminovascular activation plays a key role. We have previously reported that local application of Complete Freund's Adjuvant (CFA) onto the dura mater caused activation in rat trigeminal ganglion (TG) which was abolished by a systemic administration of kynurenic acid (KYNA) derivate (SZR72). Here, we hypothesize that this activation may extend to the trigeminal complex in the brainstem and is attenuated by treatment with SZR72. METHODS: Activation in the trigeminal nucleus caudalis (TNC) and the trigeminal tract (Sp5) was achieved by application of CFA onto the dural parietal surface. SZR72 was given intraperitoneally (i.p.), one dose prior CFA deposition and repeatedly daily for 7 days. Immunohistochemical studies were performed for mapping glutamate, c-fos, PACAP, substance P, IL-6, IL-1ß and TNFα in the TNC/Sp5 and other regions of the brainstem and at the C1-C2 regions of the spinal cord. RESULTS: We found that CFA increased c-fos and glutamate immunoreactivity in TNC and C1-C2 neurons. This effect was mitigated by SZR72. PACAP positive fibers were detected in the fasciculus cuneatus and gracilis. Substance P, TNFα, IL-6 and IL-1ß immunopositivity were detected in fibers of Sp5 and neither of these molecules showed any change in immunoreactivity following CFA administration. CONCLUSION: This is the first study demonstrating that dural application of CFA increases the expression of c-fos and glutamate in TNC neurons. Treatment with the KYNA analogue prevented this expression.

Investigation of vitamin D receptor polymorphisms in amyotrophic lateral sclerosis.

BACKGROUND: Amyotrophic lateral sclerosis (ALS) patients manifest aberrations in the vitamin D endocrine system, with a vitamin D deficiency. Genetic investigations have identified those proteins which link vitamin D to ALS pathology: major histocompatibility complex class II molecules, toll-like receptors, poly(ADP ribose) polymerase-1, haeme oxygenase-1, the reduced form of nicotinamide adenine dinucleotide phosphate and calcium-binding proteins. Vitamin D additionally impacts ALS through cell-signalling mechanisms: glutamate, matrix metalloproteinases, the Wnt/ß-catenin signalling pathway, mitogen-activated protein kinase pathways, prostaglandins, reactive oxygen species and nitric oxide synthase, but its role has been only poorly investigated. OBJECTIVE: Our aim was to investigate vitamin D receptor (VDR) gene single nucleotide polymorphisms (SNPs) in an ALS population. This gene encodes the nuclear hormone receptor for vitamin D3. MATERIALS AND METHODS: A total of 75 consecutive sporadic ALS patients (~20% of the Hungarian ALS population) and 97 healthy controls were enrolled to investigate the possible effects of the different VDR alleles. A restriction fragment length polymorphism technique was utilized for allele discrimination. RESULTS: One of the four investigated SNPs was associated with the disease, but none of the alleles of these SNPs influenced the age at disease onset. The ApaI A allele was more frequent in the ALS group than in the control group and may be an ALS risk factor. CONCLUSIONS: This is the first verification of the genetic link between ALS and VDR. However, further studies are needed to confirm these findings.

KYNA analogue SZR72 modifies CFA-induced dural inflammation- regarding expression of pERK1/2 and IL-1ß in the rat trigeminal ganglion.

BACKGROUND: Neurogenic inflammation has for decades been considered an important part of migraine pathophysiology. In the present study, we asked the question if administration of a novel kynurenic acid analogue (SZR72), precursor of an excitotoxin antagonist and anti-inflammatory substance, can modify the neurogenic inflammatory response in the trigeminal ganglion. METHODS: Inflammation in the trigeminal ganglion was induced by local dural application of Complete Freunds Adjuvant (CFA). Levels of phosphorylated MAP kinase pERK1/2 and IL-1ß expression in V1 region of the trigeminal ganglion were investigated using immunohistochemistry and Western blot. FINDINGS: Pretreatment with one dose of SZR72 abolished the CFA-induced pERK1/2 and IL-1ß activation in the trigeminal ganglion. No significant change was noted in case of repeated treatment with SZR72 as compared to a single dose. CONCLUSIONS: This is the first study that demonstrates that one dose of KYNA analog before application of CFA can give anti-inflammatory response in a model of trigeminal activation, opening a new line for further investigations regarding possible effects of KYNA derivates.

Neuroprotective effect of oxaloacetate in a focal brain ischemic model in the rat.

During an ischemic event, the well-regulated glutamate (Glu) homeostasis is disturbed, which gives rise to extremely high levels of this excitatory neurotransmitter in the brain tissues. It was earlier reported that the administration of oxaloacetate (OxAc) as a Glu scavenger reduces the Glu level in the brain by enhancing the brain-to-blood Glu efflux. Here, we studied the neuroprotective effect of OxAc administration in a new focal ischemic model in rats. Occlusion of the middle cerebral artery resulted in immediate reduction of the somatosensory-evoked responses (SERs), and the amplitudes remained at the reduced level throughout the whole ischemic period. On reperfusion, the SERs started to increase, but never reached the control level. OxAc proved to be protective, since the amplitudes started to recover even during the ischemia, and finally fully regained the control level. The findings of the histological measurements were in accordance with the electrophysiological data. After Fluoro Jade C staining, significantly fewer labeled cells were detected in the OxAc-treated group relative to the control. These results provide new evidence of the neuroprotective effect of OxAc against ischemic injury, which strengthens the likelihood of its future applicability as a novel neuroprotective agent for the treatment of ischemic stroke patients.

Acetyl-L-carnitine and oxaloacetate in post-treatment against LTP impairment in a rat ischemia model. An in vitro electrophysiological study.

A high proportion of research relating to cerebral ischemia focuses on neuroprotection. The application of compounds normally present in the organism is popular, because they do not greatly influence the synaptic activity by receptor modulation, and can be administered without serious side effects. Oxaloacetate (OxAc) and acetyl-L-carnitine (ALC) are such favorable endogenous molecules. ALC can exert a protective effect by improving the energy state of the neurons under ischemic conditions. A promising neuroprotective strategy is glutamate scavenging, which can be achieved by the intravenous administration of OxAc. This study involved the possible protective effects of ALC and OxAc in different post-treatment protocols against long-term potentiation (LTP) impairment. Ischemia was induced in rats by 2-vessel occlusion, which led to a decreased LTP relative to the control group. High-dose (200 mg/kg) ALC or OxAc post-treatment resulted in a higher potentiation relative to the 2VO group, but it did not reach the control level, whereas low-dose ALC (100 mg/kg) in combination with OxAc completely restored the LTP function. Many previous studies have concluded that ALC can be protective only as pretreatment. The strategy described here reveals that ALC can also be neuroprotective when utilized as post-treatment against ischemia.

Kynurenic acid modulates experimentally induced inflammation in the trigeminal ganglion.

BACKGROUND: The trigeminal ganglion (TG) plays a central role in cranial pain. Administration of complete Freund's adjuvant (CFA) into the temporomandibular joint (TMJ) elicits activation of TG. Kynurenic acid (KYNA) is an endogenous excitatory amino acid receptor blocker, which may have an anti-inflammatory effect. We hypothesize that KYNA may reduce CFA-induced activation within the TG. METHODS: A local inflammation was induced by administration of CFA into the TMJ in rats. KYNA and kynurenic acid amide 2 (KYNAA2) were intraperitoneally administered. We investigated changes of mitogen-activated protein kinases (MAPKs as ERK1/2, p38 and SAPK/JNK), NF-κB, CaMKII and DREAM, in addition to calcitonin gene-related peptide (CGRP) and its receptor components calcitonin receptor-like receptor (CLR) and receptor activity-modifying protein 1 (RAMP1) in the TG, with immunohistochemistry and Western blot at 2 and 10 days post-CFA injection. RESULTS: We showed CFA-induces increases in pERK1/2, pp38, CaMKII, NF-κB and DREAM immunohistochemistry after 2 and 10 days. KYNAA2 displayed stronger effects on MAPKs than KYNA. Increased expression of CaMKII, NF-κB and DREAM were found in the neurons. Western blot showed significantly increase in pERK expression at 10 days post-CFA, which decreased after 10 days of KYNA treatment. Two days post-CFA, a significantly increase in pp38 expression was found, which decreased after 2 days of KYNA and KYNAA2 treatment. CONCLUSIONS: The CFA-induced inflammatory model for the TG activation provided a time-related expression of MAPK (pERK1/2, pp38) and NF-κB. It involves both the neuronal and glial activation, which points to possible neuron-glia interactions during this process. The administration of the endogenous NMDA-receptor antagonists, KYNA and its derivative KYNAA2, resulted in the inhibition of the induced signaling system of the TG, which further points the importance of the glutamate receptors in this mechanism.

Dural administration of inflammatory soup or Complete Freund's Adjuvant induces activation and inflammatory response in the rat trigeminal ganglion.

BACKGROUND: Migraine is a painful disorder with a huge impact on individual and public health. We hypothesize that migraine pain originates from a central mechanism that results secondarily in hypersensitivity in peripheral afferents associated with the cerebral and cranial blood vessels. It has previously been shown that application of inflammatory or algesic substances onto the dura mater or chemical stimulation of the dural receptive fields causes hypersensitivity to mechanical and thermal stimulation together with direct activation of the TG. We asked whether local inflammation of dura mater induces inflammatory activation in the trigeminal ganglion. METHODS: We performed topical administration of inflammatory soup (IS) or Complete Freund's Adjuvant (CFA) onto an exposed area of the rat dura mater in vivo for 20 min. The window was closed and the rats were sacrificed after 4 h and up to 7 days. Myography was performed on middle meningeal arteries. The trigeminal ganglia were removed and processed for immunohistochemistry or Western blot. RESULTS: Both CFA and IS induced enhanced expression of pERK1/2, IL-1ß and CGRP in the trigeminal ganglia. The pERK1/2 immunoreactivity was mainly seen in the satellite glial cells, while IL-1ß reactivity was observed in the neuronal cytoplasm, close to the cell membrane, seemingly as sign of neuro-glial interaction. The CGRP expression in the neurons and nerve fibres was enhanced after the application of either inflammatory agent. Myography resulted in a strong vasoconstrictor response to IS, but not to CFA. CONCLUSIONS: These results suggest that the application of IS or CFA onto the dura mater causes long-term activation of the TG and demonstrate the importance of the neuro-glial interaction in the activation of the trigeminovascular system.

Prevalence of multiple sclerosis in Csongrád County, Hungary.

OBJECTIVE: Recent epidemiological studies were mainly based on the Poser or other diagnostic criteria. There have been no previous data from Hungary, which were assessed with the more up-to-date McDonald criteria and which give comparable standardized data from the region. MATERIALS AND METHODS: Data were collected from the MS Register of the Department of Neurology at the University of Szeged. All possible and definitive patients with MS living in the county on the prevalence day were included in the study. Direct standardization was based on the European standard population. RESULTS: On 1 January 2013, 379 registered patients with MS were alive in the county, that is, a crude MS prevalence of 89.8/100,000, 46.6/100,000 in males and 128.6/100,000 in females; standardized prevalence: 83.7/100,000 (42.3/100,000 for males, 122.6/100,000 for females). The distribution of the clinical forms: 11% clinically isolated syndrome, 69% relapsing-remitting form, 14% secondary progressive form, 6% primary progressive form. Patients with no or only mild symptoms comprised 91.9% of the relapsing-remitting population. CONCLUSIONS: This is the first standardized epidemiological study based on the McDonald criteria in Central Europe. Hungary is a medium-risk country as concerns the prevalence of MS. The crude prevalence appears to have increased relative to previous reports from the county.

Where does a migraine attack originate? In the brainstem.

Migraine is a common, paroxysmal, highly disabling primary headache disorder. The origin of migraine attacks is enigmatic. Numerous clinical and experimental results suggest that the activation of distinct brainstem nuclei is crucial in its pathogenesis, but the primary cause of this activation is not fully understood. We conclude that the initialization of a migraine attack can be explained as an altered function of the neuronal elements of the brainstem nuclei. In light of our findings and the literature data, we can assume that migraine is a subcortical disorder of a specific brainstem area.

Preparation and properties of nanoscale containers for biomedical application in drug delivery: preliminary studies with kynurenic acid.

The main purpose of this study was to facilitate the delivery of kynurenic acid (KYNA) across the blood-brain barrier (BBB) by applying micelles as nanoscale containers. Non-ionic amphiphilic molecules were used for preparation of spherical micelles for delivery of kynurenic acid in aqueous solution in physiological condition. It was established that Triton X 100 and Lutensol AP 20 non-ionic surfactants are able to produce stable nanocontainers for delivery of kynurenic acid molecules. The incorporation of KYNA molecules was investigated by dynamic light scattering and the size of micelles were calculated between 5 and 10 nm in 150 mM NaCl and pH 7.5-7.6 solutions. Encapsulated kynurenic acid showed a significantly higher blood-brain barrier permeability compared with non-encapsulated kynurenic acid. The in vivo experiments showed that the encapsulated kynurenic acid is able to display effects within the central nervous system, even after its peripheral administration.

Mild traumatic brain injury.

Traumatic Brain Injury (TBI) is among the most frequent neurological disorders. Of all TBIs 90% are considered mild with an annual incidence of 100­300/100.000. Intracranial complications of Mild Traumatic Brain Injury (MTBI) are infrequent (10%), requiring neurosurgical intervention in a minority of cases (1%), but potentially life-threatening (case fatality rate 0,1%). Hence, a true health management problem exists because of the need to exclude the small chance of a life threatening complication in large numbers of individual patients. The 2002 EFNS guidelines used a best evidence approach based on the literature until 2001 to guide initial management with respect to indications for CT, hospital admission, observation and follow up of MTBI patients. This updated EFNS guideline version for initial management inMTBI proposes a more selectively strategy for CT when major (dangerous mechanism, GCS<15, 2 points deterioration on the GCS, clinical signs of (basal) skull fracture, vomiting, anticoagulation therapy, post traumatic seizure) or minor (age, loss of consciousness, persistent anterograde amnesia, focal deficit, skull contusion, deterioration on the GCS) risk factors are present based on published decision rules with a high level of evidence. In addition clinical decision rules for CT now exist for children as well. Since 2001 recommendations, although with a lower level of evidence, have been published for clinical in hospital observation to prevent and treat other potential threads to the patient including behavioral disturbances (amnesia, confusion and agitation) and infection.

Genetic polymorphisms of human ß-defensins in patients with ischemic stroke.

OBJECTIVES AND METHODS: Genetic predisposition of the inflammatory host response may affect the development of stroke. On the basis of the theory of infectious burden and risk of stroke, we considered it of interest to investigate the relevance of the single-nucleotide polymorphisms (SNPs) in the DEFB1 gene and the copy number variant (CNV) of the DEFB4 genes in ischemic stroke. RESULTS: There were no significant differences in the genotype frequencies of the three SNPs of the DEFB1 gene between the patients with stroke (n = 312) and the healthy blood donors (n = 221). However, a higher frequency of a lower (<4) copy number of the DEFB4 gene was observed in the patients with ischemic stroke as compared with the healthy controls (40% vs 24%, respectively). Additionally, low plasma concentrations of hBD-2 (187 ± 20 pg/ml) were characteristic of the patients with fewer than four copy numbers relative to those with more than four copy numbers (385 ± 35 pg/ml). CONCLUSIONS: The low copy number of the DEFB4 gene, involving a weakened antimicrobial defense of the host, might be important in the pathogenesis of stroke.

Lesion probability mapping to explain clinical deficits and cognitive performance in multiple sclerosis.

BACKGROUND: Lesion dissemination in time and space represents a key feature and diagnostic marker of multiple sclerosis (MS). The correlation between magnetic resonance imaging (MRI) lesion load and disability is only modest, however. Strategic lesion location might at least partially account for this 'clinico-radiologic paradox'. OBJECTIVES: Here we used a non-parametric permutation-based approach to map lesion location probability based on MS lesions identified on T2-weighted MRI. We studied 121 patients with clinically isolated syndrome, relapsing-remitting or secondary progressive MS and correlated these maps to assessments of neurologic and cognitive functions. RESULTS: The Expanded Disability Status Scale correlated with bilateral periventricular lesion location (LL), and sensory and coordination functional system deficits correlated with lesion accumulation in distinct anatomically plausible regions, i.e. thalamus and middle cerebellar peduncule. Regarding cognitive performance, decreased verbal fluency correlated with left parietal LL comprising the putative superior longitudinal fascicle. Delayed spatial recall correlated with _amygdalar, _left frontal and parietal LL. Delayed selective reminding correlated with bilateral frontal and temporal LL. However, only part of the spectrum of cognitive and neurological problems encountered in our cohort could be explained by specific lesion location. CONCLUSIONS: Lesion probability mapping supports the association of specific lesion locations with symptom development in MS, but only to limited extent.

Migraine is a neuronal disease.

Migraine is a common, paroxysmal, highly disabling primary headache disorder with a genetic background. The primary cause and the origin of migraine attacks are enigmatic. Numerous clinical and experimental results suggest that activation of the trigeminal system (TS) is crucial in its pathogenesis, but the primary cause of this activation is not fully understood. Since activation of the peripheral and central arms of the TS might be related to cortical spreading depression and to the activity of distinct brainstem nuclei (e.g. the periaqueductal grey), we conclude that migraine can be explained as an altered function of the neuronal elements of the TS, the brainstem, and the cortex, the centre of this process comprising activation of the TS. In light of our findings and the literature data, therefore, we can assume that migraine is mainly a neuronal disease.

The L-kynurenine signalling pathway in trigeminal pain processing: a potential therapeutic target in migraine?

INTRODUCTION: In recent years the kynurenine family of compounds, metabolites of tryptophan, has become an area of intensive research because of its neuroactive properties. Two metabolites of this family have become of interest in relation to migraine and pain processing. DISCUSSION: Experimental studies have shown that kynurenic acid (KYNA) plays an important role in the transmission of sensory impulses in the trigeminovascular system and that increased levels of KYNA decrease the sensitivity of the cerebral cortex to cortical spreading depression. Furthermore, another metabolite of the kynurenine family, L-kynurenine, exerts vasodilating effects similar to nitric oxide by increasing cyclic guanosine monophosphate. CONCLUSION: This review summarizes current knowledge of the role of kynurenine signalling in trigeminal and central pain processing, including its therapeutic prospects in migraine treatment.

Neurology residency training in Europe--the current situation.

INTRODUCTION: Little is known about neurological training curricula in Europe. A joint approach by the European Federation of Neurological Societies (EFNS), the Union of European Medical Specialists/European Board of Neurology and the European Association of Young Neurologist and Trainees was established to explore the spectrum of neurology training in Europe. METHODS: In 2006, a questionnaire-based survey on neurology curricula as well as demographic data was designed by WS and WG and distributed by the EFNS to the national delegates of the EFNS, which comprises all European countries and Israel. RESULTS: By 2009, delegates from 31 of 41 countries (representing 76% of 505 million) had returned the questionnaire. A total of 24,165 specialists (46% women) were registered in the 31 countries. This corresponds to an average of 6.6 neurologists per 100,000 inhabitants (range 0.9-17.4/100,000 inhabitants). Duration of training in Europe was on average 4.9,years, ranging from 3 to 6,years. The number of residents interested in neurological training exceeded the amount of available training positions. Performance of neurological trainees was regularly assessed in 26 countries (84%), usually by recurrent clinical evaluation. Board examinations were held in 23 countries (74%). Interim examinations were performed in three countries, exit examinations in 14 and both interim and exit examination in 6. Considerable differences were also found in manpower (0.9-17.4 neurologists/100,000 inhabitants) and working conditions (e.g. average weekly working hours ranging from 30-80 h/month). We found a significant positive correlation between manpower and theoretical training hours. CONCLUSION: Considerable differences exist in training curricula of European countries. These data might provide the basis for European training and quality assurance initiatives.

Synthesis and biological effects of some kynurenic acid analogs.

The overactivation of excitatory amino acid receptors plays a key role in the pathomechanism of several neurodegenerative disorders and in ischemic and post-ischemic events. Kynurenic acid (KYNA) is an endogenous product of the tryptophan metabolism and, as a broad-spectrum antagonist of excitatory amino acid receptors, may serve as a protective agent in neurological disorders. The use of KYNA is excluded, however, because it hardly crosses the blood-brain barrier. Accordingly, new KYNA analogs which can readily cross this barrier and exert their complex anti-excitatory activity are generally needed. During the past 6 years, we have developed several KYNA derivatives, among others KYNA amides. These new analogs included one, N-(2-N,N-dimethylaminoethyl)-4-oxo-1H-quinoline-2-carboxamide hydrochloride (KYNA-1), that has proved to be neuroprotective in several models. This paper reports on the synthesis of 10 new KYNA amides (KYNA-1-KYNA-10) and on the effectiveness of these molecules as inhibitors of excitatory synaptic transmission in the CA1 region of the hippocampus. The molecular structure and functional effects of KYNA-1 are compared with those of other KYNA amides. Behavioral studies with these KYNA amides demonstrated that they do not exert significant nonspecific general side-effects. KYNA-1 may therefore be considered a promising candidate for clinical studies.