M30, a brain permeable multitarget neurorestorative drug in post nigrostriatal dopamine neuron lesion of parkinsonism animal models

The anti-Parkinson iron chelator brain selective monoamine oxidase (MAO) AB inhibitor M30 [5-(N-methyl-N-propargylaminomethyl)-8-hydroxyquinoline] was shown to possess neuroprotective activities in vitro and in vivo, against several insults applicable to several neurodegenerative diseases, such as Alzheimer's disease, Parkinson's disease (PD) and ALS. We examined the effect of M30 on a pre-existing lesion induced by the parkinsonism-inducing toxin, MPTP (N-methyl-4-phenyl-1,2,3,6-tetrahydropyridine). In this neurorescue/neurorestorative paradigm, M30 was orally administered to mice for 14 days (2.5-5 mg/kg/day) following post MPTP or lactacystin lesion and was shown to significantly elevate striatal dopamine, serotonin and noradrenaline levels, reduce their metabolism, and elevate tyrosine-hydroxylase protein levels. Importantly, M30 elevated MPTP-reduced dopaminergic and transferrin receptor cell count in the substantia nigra pars compacta (SNpc). Finally, M30 was shown to decrease mitosis and elevate HIF (hypoxia induced factor) which regulates the neurotrophins BDNF, GDNF, VEGF and erythropoietin by elevating their brain levels, thus providing additional protection. These findings indicates that brain-permeable M30 has neurorestorative activity, which may clearly be of clinical importance for the treatment of PD.     

The Yeast Product Milmed Enhances the Effect of Physical Exercise on Motor Performance and Dopamine Neurochemistry Recovery in MPTP-Lesioned Mice

Both clinical and laboratory studies have demonstrated that different types of physical exercise may alleviate Parkinsonism yet evidence for complete restoration of motor function and biomarker integrity are difficult to identify. MPTP (1 × 30 mg/kg, s.c., 4 groups) or saline (vehicle 1 × 5 ml/kg, s.c., 1 group) were administered in a single dose regime over three consecutive weeks on Fridays. Three MPTP groups were given four 30-min periods/week (Mondays to Thursdays), of these two groups, MPTP + Exer + M(i) and MPTP + Exer + M(ii); the former were introduced to exercise and Milmed (oral injection) on the week following the 1st MPTP injection and the latter on the Monday prior to the 1st injection of MPTP onwards. One MPTP group, MPTP + Exer, was given access to exercise (running wheels) from the week following the 1st MPTP injection onwards. The fourth MPTP group, MPTP–NoEx, and the Vehicle group were only given access to exercise on a single day each week (Wednesdays, exercise test) from the week following the 1st MPTP injection onwards. The exercise/exercise + Milmed regime was maintained for a further 9 weeks. It was observed that exercise by itself ameliorated MPTP-induced deficits regarding motor function and dopamine loss only partially whereas in the groups combining exercise with twice weekly dosages of Milmed the MPTP-induced deficits were abolished by the 10th week of the intervention. The three main conclusions that were drawn from correlational analyses of individual mice were: (i) that DA integrity was observed to be a direct function of ability to express running exercise in a treadmill wheel-running arrangement, and (ii) that DA integrity was observed to be a direct function of the capacity for motor performance as measured by spontaneous motor activity and subthreshold l-Dopa (5 mg/kg) induced activity in the motor activity test chambers, and (iii) that the extent to which running exercise in a running wheel was predictive of later motor performance in the activity test chambers was highly convincing.     

Development and Validation of a Screening Assay for the Evaluation of Putative Neuroprotective Agents in the Treatment of Parkinson’s Disease

Following initial diagnosis of Parkinson’s disease, if it were possible to prescribe a treatment that could halt or prevent further neurodegeneration, disease progression could be prevented. The aim of this study was to generate a quick and reliable assay for assessing putative neuroprotective agents for parkinsonian patients. Abnormalities in mitochondria, proteasome and lysosome function, as well as oxidative stress cause cell death in Parkinson’s disease. Thus, we exposed neuroblastoma (SH-SY5Y) cells to EC₅₀ of toxins that mimic these cell death mechanisms (dopamine to induce oxidative stress; naphthazarin to inhibit lysosome function; proteasome inhibitor N-carbobenzyloxy-Ile-Glu(O-t-butyl)-Ala-leucinal (PSI) to inhibit the UPS (ubiquitin proteasome system) and rotenone to inhibit mitochondria function) in the presence of five compounds previously chosen as neuroprotective agents, and assessed cell viability. Coenzyme Q10 (117 μM) significantly protected against four toxins, dopamine: 16.3 ± 3.3%; naphthazarin: 10.8 ± 1.1%; PSI: 16.2 ± 2.9%; rotenone: 53.2 ± 4.2%; whereas caffeine (140 μM), creatine (25 mM), nicotine (1 μM) and deprenyl (10 μM) provided protection against some, but not all toxins. Interestingly, coenzyme Q10 is the only compound out of the five that showed neuroprotective potential in clinical trials. Thus, there is a direct correlation between the success of disease modifying agents in the clinic and their ability to protect against multiple cell death mechanisms in this assay. We propose that exposure of SH-SY5Y cells to different toxins that recapitulate cell death mechanisms in Parkinson’s disease serves as a rapid and reliable method to test neuroprotective agents that may succeed in clinical trials.     

Methylacridinium and its Cholinergic Properties

10-Methylacridinium iodide (methylacridinium; MA) is an inhibitor of cholinesterases. Inhibitors of acetylcholinesterase (AChE) are used in the treatment of myasthenia gravis, Alzheimer’s disease, and in the prophylaxis of poisoning with organophosphates. Using spectrophotometric Ellman’s method at 436 nm and commercial enzymes we found that MA inhibits AChE by binding with relatively high potency to the peripheral anionic site (IC₅₀ = 1.68 ± 0.14 μM; human recombinant AChE) and equally to its inhibition of butyrylcholinesterase (BuChE; IC₅₀ = 3.54 ± 0.27 μM; BuChE from human serum). MA also inhibits the binding of [³H]N-methylscopolamine to the muscarinic M2 receptor subtype, possibly in an allosteric manner (IC₅₀ = 1.90 μM). Functional effects on both the enzyme and the receptor could be observed in contractile studies on the isolated rat bladder. The ability of MA to cross the blood–brain barrier (log P = ?0.32; polar surface area 3.88) provides prerequisites for a potential use of the drug in the treatment of neural disorders.     

Evaluation of Nigrostriatal Neurodegeneration and Neuroinflammation Following Repeated Intranasal 1-Methyl-4-Phenyl-1,2,3,6-Tetrahydropyridine (MPTP) Administration in Mice, an Experimental Model of Parkinson’s Disease

Parkinson’s disease (PD) is the second most common neurodegenerative disorder affecting approximately 1 % of the population older than 60 years. The administration of the proneurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) in mice is the most widely used approach to elucidate the mechanisms of cell death involved in PD. However, the magnitude of the PD-like neurodegeneration induced by MPTP depends on many variables, including the regimen of its administration. It has been demonstrated that intranasal (i.n.) administration of MPTP constitutes a new route of toxin delivery to the brain that mimics environmental exposure to neurotoxins. Previous data showed that mice submitted to chronic and acute i.n. MPTP treatment displayed a robust (~80 %) and moderate (~55 %) loss of striatal dopamine, respectively. However, little is known about the neurodegenerative and neuroinflammatory processes following a subacute i.n. MPTP administration in mice. Here, the C57BL/6 mice were infused intranasally with MPTP (1 mg/nostril/day) during 4 consecutive days. At 7 and 28 days after the last administration, the subacute i.n. MPTP regime decreased the tyrosine hydroxylase (TH)-labeling in the striatum (40–50 %) and substantia nigra (25–30 %) and increased the astrogliosis in such brain areas at both time points. Taken together, our data showed that the subacute administration of MPTP into the nasal cavity of C57BL/6 mice induces long-lasting neurodegeneration and neuroinflammation in the nigrostriatal pathway, thus representing a valuable animal model for the investigation of neuroprotective strategies in PD.     

Doxycycline treatment reduces ischemic brain damage in transient middle cerebral artery occlusion in the rat

Agents that inhibit leukocyte adhesion including intercellular adhesion molecule-1 antibodies (anti-ICAM-1) have shown beneficial effects in experimental central nervous system (CNS) ischemia. Doxycycline inhibits leukocyte function in vitro by binding divalent cations and reduces spinal cord reperfusion injury. The authors used a clinically relevant model of focal CNS reperfusion injury to test whether treatment with doxycycline would reduce cerebral ischemic damage and improve functional outcome. Reversible middle cerebral artery occlusion was produced in adult Sprague-Dawley rats by advancing a filament into the internal carotid artery for 2 h. Animals received either IP doxycycline (10 mg/kg) (N=13) or saline (N=11) 30 min before ischemia, followed by 10mg/kg every 8 h×6. Both functional assessment (5 point neurologic scale) and infarct volume was evaluated at 48 h. Functional efficacy: doxycycline 0.5±0.2 (mean±SE) vs control 1.3±0.3 (p=0.03). Infarct volume: doxycycline 56±18 mm³ vs control 158±44 mm³ (p=0.03); This protective effect supports the role of doxycycline in reducing CNS reperfusion injury.     

Cardiac sympathetic denervation in Parkinson’s disease patients with SWEDDs

Dopamine transporter scans of some patients who have been clinically diagnosed with Parkinson’s disease (PD) fail to reveal abnormal dopaminergic functioning and are referred to as scans without evidence of dopaminergic deficits (SWEDDs). In this study, we investigated the differences between SWEDDs patients and PD patients using ¹²³I-metaiodobenzylguanidine (MIBG) scans. This study enrolled 20 patients with SWEDDs, 30 patients with early PD and 50 healthy controls. Cardiac ¹²³I-MIBG scans were performed on all subjects, and parameters including the early and delayed heart-to-mediastinum ratios (H/M) and the washout rate were compared among the three groups. The mean delayed H/M ratio in the PD group (mean ± standard deviation, 1.45 ± 0.23) was the lowest of the three groups, and the scans in the group without evidence of dopaminergic deficits exhibited a lower mean delayed H/M ratio (2.15 ± 0.48) than the control group (2.56 ± 0.55) (p < 0.05). The intermediate status of cardiac MIBG uptake in the SWEDDs patients in our study may have been due to the heterogeneity of the SWEDDs patients; some of these patients had Parkinsonism with unknown characteristics, some may have had early PD with false-negative dopamine transporter imaging, and some have had primary dystonia that was misdiagnosed as PD. These uncharacterised SWEDDs patients accounted for a larger proportion of the heterogeneous SWEDDs than observed in previous studies, but our results suggest that cardiac ¹²³I-MIBG scans may help to differentiate patients with SWEDDs from patients with PD.     

Ontogenetic Exposure of Rats to Pre- and Post-Natal Manganese Enhances Behavioral Impairments Produced by Perinatal 6-Hydroxydopamine

Rats lesioned shortly after birth with 6-hydroxydopamine (6-OHDA; 134 μg icv) represent a near-ideal model of severe Parkinson’s disease because of the near-total destruction of nigrostriatal dopaminergic fibers. The element manganese, an essential cofactor for many enzymatic reactions, itself in toxic amount, replicates some clinical features similar to those of Parkinson’s disease. The aim of this study was to examine the effect of neonatal manganese exposure on 6-OHDA modeling of Parkinson’s disease in rats. Manganese (MnCl₂·4H₂O) 10,000 ppm was included in the drinking water of pregnant Wistar rats from the time of conception until the 21st day after delivery, the age when neonatal rats were weaned. Control rats consumed tap water. Other groups of neonatal rat pups, on the 3rd day after birth, were pretreated with desipramine (20 mg/kg ip 1 h) prior to bilateral icv administration of 6-OHDA (30, 60, or 137 μg) or its vehicle saline-ascorbic (0.1%) (control). At 2 months after birth, in rats lesioned with 30, 60, or 134 μg 6-OHDA, endogenous striatal dopamine (DA) content was reduced, respectively, by 66, 92, and 98% (HPLC/ED), while co-exposure of these groups to perinatal manganese did not magnify the DA depletion. However, there was prominent enhancement of DA D₁ agonist (i.e., SKF 38393)-induced oral activity in the group of rats exposed perinatally to manganese and also treated neonatally with the 30 mg/kg dose of 6-OHDA. The 30 mg/kg 6-OHDA group, demonstrating cataleptogenic responses to SCH 23390 (0.5 mg/kg) and haloperidol (0.5 mg/kg ip), developed resistance if co-exposed to perinatal manganese. In the group exposed to manganese and lesioned with the 60 mg/kg dose of 6-OHDA, there was a reduction in D₂ agonist (i.e., quinpirole, 0.1 mg/kg)-induced yawning. The series of findings demonstrate that ontogenetic exposure to manganese results in an enhancement of behavioral toxicity to a moderate dose of 6-OHDA, despite the fact that there is no enhanced depletion of striatal DA depletion by the manganese treatment.     

MALDI Mass Spectrometry Imaging of 1-Methyl-4-phenylpyridinium (MPP+) in Mouse Brain

Parkinson’s disease (PD) is the second most common neurodegenerative disorder affecting ~1 % of the population older than 60 years. The administration of the proneurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) in mice is one of the most widely used approach to elucidate the mechanisms of cell death involved in PD. Its toxicity is attributed to its active metabolite 1-methyl-4-phenylpyridinium (MPP⁺). However, the magnitude of the PD-like neurodegeneration induced by MPTP depends on many variables, including the route of administration. Different groups, including us, demonstrated that intranasal (i.n.) administration of MPTP constitutes a new route of toxin delivery to the brain that mimics environmental exposure to neurotoxins. In particular, our previous data showed that mice submitted to acute i.n. MPTP administration displayed a significant decrease of striatal dopamine (DA) and a loss of dopaminergic (DA) neurons in the substantia nigra pars compacta. However, little is known about the timing and the anatomical distribution of MPP⁺ after i.n. MPTP administration in mice. In the present study, C57BL/6J mice received one dose of i.n. MPTP (1 mg/nostril) and were sacrificed at two different times after the administration. Using matrix-assisted laser desorption–ionization mass spectrometry imaging, a new technique for the detection of endogenous unlabeled molecules in tissue sections, we showed for the first time the MPP⁺ anatomical distribution in different brain regions. We demonstrated that the toxin first reached almost all the brain areas; however, in a second time MPP⁺ remained highly concentrated in the olfactory bulb, the basal ganglia, the ventral mesencephalon, and the locus coeruleus, regions differently affected in PD.     

Physical Exercise Attenuates MPTP-Induced Deficits in Mice

Two experiments were performed to investigate the effects of physical exercise upon the hypokinesia induced by two different types of MPTP administration to C57/BL6 mice. In the first, mice were administered either the standard MPTP dose (2 × 20 or 2 × 40 mg/kg, 24-h interval) or vehicle (saline, 5 ml/kg); and over the following 3 weeks were given daily 30-min period of wheel running exercise over five consecutive days/week or placed in a cage in close proximity to the running wheels. Spontaneous motor activity testing in motor activity test chambers indicated that exercise attenuated the hypokinesic effects of both doses of MPTP upon spontaneous activity or subthreshold l-Dopa-induced activity. In the second experiment, mice were either given wheel running activity on four consecutive days (30-min period) or placed in a cage nearby and on the fifth day, following motor activity testing over 60 min, injected with either MPTP (1 × 40 mg/kg) or vehicle. An identical procedure was maintained over the following 4 weeks with the exception that neither MPTP nor vehicle was injected after the fifth week. The animals were left alone (without either exercise or MPTP) and tested after 2- and 4-week intervals. Weekly exercise blocked, almost completely, the progressive development of severe hypokinesia in the MPTP mice and partially restored normal levels of activity after administration of subthreshold l-Dopa, despite the total absence of exercise following the fifth week. In both experiments, MPTP-induced loss of dopamine was attenuated by the respective regime of physical exercise with dopamine integrity more effectively preserved in the first experiment. The present findings are discussed in the context of physical exercise influences upon general plasticity and neuroreparative propensities as well as those specific for the nigrostriatal pathway.     

Molecular basis of discrepancies in neurotoxic properties among 1-methyl-4-aryl-1,2,3,6-tetrahydropyridines

The relationship between structural specificity of the main stages of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) action and the display of parkinsonogenic properties among homologous structures in a number of 4-tolyl derivatives of MPTP has been studied. All the compounds are better substrates for monoamine oxidase (MAO) than MPTP. MAO is inactivated during the reaction according to a mechanism of irreversible inhibition by 2,3-dihydropyridinium metabolite. All the tolyl derivatives are stronger inhibitors of MAO than 1-methyl-2,3-dihydropyridinium (MPDP). A significant contribution of enzyme inhibition to the catalytic conversion of the substrate leads to the fact that substrates having equal (para isomer) or even higher (meta isomer) values of catalytic parameters are oxidized by MAO to a lesser extent than MPTP. It has been found that all 4-arylpyridiniums (final products of MATP bioconversion) competitively and reversibly inhibit [¹⁴C]dopamine (DA) uptake in mouse brain synaptosomes. Affinity toward DA transporter characterized byK _I (μM) is 0.37±0.04, 0.7±0.1, 2.0±0.15, 2.0±0.35 for MPP, and its o-, m-, and p-tolyl derivatives, respectively. Joint calculation of specificity factors for the processes discussed define the following rank order for the biodelivery of MATP’s metabolic produces into DA nerve terminals: o-tolyl > MPTP ?> m-tolyl > p-tolyl. The regularity revealed is in good agreement with the observed relative potency of these compounds to cause dopaminergic neurodegeneration.     

Diffuse axonal injury in mild traumatic brain injury: a 3D multivoxel proton MR spectroscopy study

Since mild traumatic brain injury (mTBI) often leads to neurological symptoms even without clinical MRI findings, our goal was to test whether diffuse axonal injury is quantifiable with multivoxel proton MR spectroscopic imaging (¹H-MRSI). T1- and T2-weighted MRI images and three-dimensional ¹H-MRSI (480 voxels over 360 cm³, about 30 % of the brain) were acquired at 3 T from 26 mTBI patients (mean Glasgow Coma Scale score 14.7, 18–56 years old, 3–55 days after injury) and 13 healthy matched contemporaries as controls. The N-acetylaspartate (NAA), choline (Cho), creatine (Cr) and myo-inositol (mI) concentrations and gray-matter/white-matter (GM/WM) and cerebrospinal fluid fractions were obtained in each voxel. Global GM and WM absolute metabolic concentrations were estimated using linear regression, and patients were compared with controls using two-way analysis of variance. In patients, mean NAA, Cr, Cho and mI concentrations in GM (8.4 ± 0.7, 6.9 ± 0.6, 1.3 ± 0.2, 5.5 ± 0.6 mM) and Cr, Cho and mI in WM (4.8 ± 0.5, 1.4 ± 0.2, 4.6 ± 0.7 mM) were not different from the values in controls. The NAA concentrations in WM, however, were significantly lower in patients than in controls (7.2 ± 0.8 vs. 7.7 ± 0.6 mM, p = 0.0125). The Cho and Cr levels in WM of patients were positively correlated with time since mTBI. This ¹H-MRSI approach allowed us to ascertain that early mTBI sequelae are (1) diffuse (not merely local), (2) neuronal (not glial), and (3) in the global WM (not GM). These findings support the hypothesis that, similar to more severe head trauma, mTBI also results in diffuse axonal injury, but that dysfunction rather than cell death dominates shortly after injury.     

The complement and immunoglobulin levels in NMO patients

Since the discovery of aquaporin-4 (AQP4) antibody a decade ago, neuromyelitis optica (NMO) has been distinguished from multiple sclerosis (MS). MS mainly features T lymphocyte-oriented autoimmune responses while NMO is more precisely influenced by humoral immunity, among which the complement activation has always been reckoned as an important mechanism. The AQP4 antibody, namely NMO-IgG, adds to new evidence of how complement affects the severity of NMO. We compared the levels of complement (C3, C4, CH50) and immunoglobulins (IgG, IgM, IgA) between NMO patients and controls. Groups with AQP4 antibody positive and negative NMO patients were also compared with controls, respectively, aiming to elaborate on the relationship between complement activation and immunoglobulins. We also compared these indexes together with expanded disability status scale (EDSS) between two different groups in NMO patients and endeavored to figure out their correlations with each other. Complement and immunoglobulins were compared between NMO patients in acute phase and non-acute phase of the disease to find out the level fluctuation of CH50 and other indexes during different stages of NMO. We analyzed NMO patients (n = 88) and controls (n = 44) for IgG, IgM, IgA, other indexes like CH50, C3, C4 have also been explored between the two groups. Furthermore, we investigated whether these antibodies could mediate complement-dependent cytotoxicity. Thus, the NMO patients were split into two groups with or without AQP4 antibody to find out the status of NMO-IgG in the development and severity of the disease. EDSS was used as criteria for the evaluating the seriousness of NMO. Comparison between NMO patients in acute stage and non-acute stage of the disease was also made for a better understanding of the disease. Compared with controls, NMO patients had much higher IgG (13.984 ± 5.981 mg/ml, 11.430 ± 3.254 mg/ml, P < 0.01) but lower CH50 (respectively, 43.55 ± 12.172 U/L, 50.66 ± 12.523 U/L, P < 0.01). While IgG increased in Anti-AQP4 antibody-positive NMO patients, CH50 dropped in this group when compared with AQP4-negative patients. When compared with controls, both of the NMO groups had enhanced IgG and decreased CH50 though only AQP4-positive NMO patients showed significance (IgG 15.004 ± 6.613 mg/ml, 11.430 ± 3.254 mg/ml, P < 0.01) (CH50, respectively, 41.12 ± 12.581U/L, 50.66 ± 12.523 U/L, P < 0.01). C4 was also decreased though without evident significance (0.215 ± 0.118 mg/ml, 0.260 ± 0.133 mg/ml, P = 0.069). Those NMO patients in acute phase (with the course of newly attack of less than 1 month) had increased immunoglobulin (IgG 14.991 ± 6.639 mg/ml, 12.460 ± 4.490 mg/ml) but decreased complement (CH50 42.755 ± 12.403 U/L, 44.743 ± 11.890 U/L) than those who passed the acute phase. There was correlation between IgG and CH50 (R = ?0.402, P < 0.01) in NMO patients. Relationship was also found between IgG and EDSS (R = 0.609, P < 0.001), CH50 and EDSS (R = ?0.333, P < 0.01). These results indicate that NMO patients had enhanced immunoglobulin in acute phase but decreased complement. The complement was correlated with immunoglobulin. Among the two NMO groups, the complement system was only activated in NMO-IgG positive patients, which might indicate a potential different pathogenetic mechanism in NMO-IgG negative patients. Also, patients’ disability of the former group was more serious than their counterparts. Those patients in acute phase obviously had increased immunoglobulin but decreased complement. Thus, we have come to the conclusion that in AQP4-positive NMO patients, immunoglobulin activates complement system, which influences the functions of NMO patients.     

Effects of novel neuroprotective and neurorestorative multifunctional drugs on iron chelation and glucose metabolism

Iron accumulation and iron-related oxidative stress are involved in several pathological conditions and provide a rationale for the development of iron chelators as novel promising therapeutic strategies. Thus, we have recently synthesized multifunctional non-toxic, brain permeable iron chelating compounds, M30 and HLA20, possessing the neuroprotective N-propargyl moiety of the anti-Parkinsonian drug, monoamine oxidase (MAO)-B inhibitor, rasagiline and the antioxidant-iron chelating moiety of an 8-hydroxyquinoline derivative of the iron chelator, VK28. Here, we examined the hepatic regulatory effects of these novel compounds using two experimental approaches: chelation activity and glucose metabolism parameters. The present study demonstrated that M30 and HLA20 significantly decreased intracellular iron content and reduced ferritin expression levels in iron-loaded hepatoma Hep3B cells. In electron microscopy analysis, M30 was shown to reduce the electron-dense deposits of siderosomes by ~30 %, as well as down-regulate cytosolic ferritin particles observed in iron-overloaded cells. In vivo studies demonstrated that M30 administration (1 mg/kg, P.O. three times a week) reduced hepatic ferritin levels; increased hepatic insulin receptor and glucose transporter-1 levels and improved glucose tolerance in C57BL/6 mice and in a mouse model of type-2 diabetes, the ob/ob (leptin^?/?). The results clearly indicate that the novel multifunctional drugs, especially M30, display significant capacity of chelating intracellular iron and regulating glucose metabolism parameters. Such effects can have therapeutic significance in conditions with abnormal local or systemic iron metabolism, including neurological diseases.     

Periprocedural outcome for patients with carotid stenosis treated with endovascular therapy: a single center evaluation

Endovascular procedures are a less invasive revascularization strategies than endoarterectomy for carotid stenosis, but to date Guidelines recommend surgery for a major periprocedural safety. Evidences come from randomized studies where operator’s experience in endovascular group was not considered. We retrospectively evaluated 524 endovascular procedures (carotid angioplasty ± stenting, CAS) performed between 1996 and 2010 on 486 patients (mean age 71.3 ± 7.8 years) with symptomatic or asymptomatic carotid stenosis from a single center. We evaluated efficacy (residual stenosis ≤30 % after postprocedural angiography) and safety [minor (TIAs or myocardial infarcts) and major (stroke or death) complications in the first 30 days] of procedures and correlated them with the increasing experience of the operator. CAS was successful in 504/524 cases (96.2 %); unsuccessful procedures occurred more frequently in case of angioplasty alone rather than angioplasty and stenting (13/61, 21.3 % vs. 7/463, 1.5 %, OR 17.64, 95 % CI 6.69–46.06). 17/524 (3.2 %) CAS met the combined safety endpoint: stroke in 2.4 % and death in 0.8 %; the rate of disabling stroke/death was 1.6 %. Center experience was inversely related to the rate of stroke/death (R ² = 0.9375), passing from 5.0 % after 100 CAS to 2.8 % after 500 CAS; for disabling stroke/death (R ² = 0.9386), the rate was 4 % after 100 CAS and 1.6 % after 500 CAS. CAS is an effective and safe revascularization procedure in both symptomatic and asymptomatic patients, if effected in experienced centers. The use of carotid artery stenting than angioplasty alone and emboli protection devices can much more improve the previous considerations.     

Dose effects of lacosamide as add-on therapy for partial-onset seizure in adult

The objective of the study was to evaluate the dose effects of lacosamide on the efficacy and safety as adjunctive therapy for partial-onset seizure in adults. We searched online databases such as Pubmed, Embase, Cochrane Online Library, and Clinicaltrial.gov for randomized control trials. A meta-analysis was performed on RevMan 5.3 software. Four randomized control trials with 1855 patients out of 310 citations and 30 registered trials were identified. 400 mg/d was more effective than 200 mg/d [RR 1.23 (95 % CI 1.05–1.45), P = 0.01], but the 600 mg/d didn’t show more benefit than 400 mg/d [RR 1.01 (95 % CI 0.81–1.27), P = 0.90]. Increasing the dosage led to higher incidence of quitting the medication because of adverse events [400 vs. 200 mg/d RR 2.17 (95 % CI 1.15–4.11), P = 0.02; 600 vs. 400 mg/d RR 1.55 (95 % CI 1.12–2.15), P = 0.009]. Incidence of serious adverse events did not occur with the increase of dose [400 vs. 200 mg/d RR 1.26 (95 % CI 0.50–3.20), P = 0.62], [600 vs. 400 mg/d RR 0.52 (95 % CI 0.21–1.30), P = 0.16]. A dose of 400 mg/d resulted in a higher chance of dizziness [RR 1.50 (95 % CI 1.02–2.20), P = 0.04], vomiting [RR 1.73 (95 % CI 1.03–2.90), P = 0.04], and diplopia [RR 1.98 (95 % CI 1.19–3.30), P = 0.008] than that of 200 mg/d. 400 mg/d is the optimal dose for efficacy. The dose of 200 mg/d has the best safety for less occurrence of adverse events and less quitting. Current evidence suggests that a dose of 600 mg/d is unnecessary, except for particular reasons.     

URB597 and the Cannabinoid WIN55,212-2 Reduce Behavioral and Neurochemical Deficits Induced by MPTP in Mice: Possible Role of Redox Modulation and NMDA Receptors

Several physiological events in the brain are regulated by the endocannabinoid system (ECS). While synthetic cannabinoid receptor (CBr) agonists such as WIN55,212-2 act directly on CBr, agents like URB597, a fatty acid amide hydrolase (FAAH) inhibitor, induce a more “physiological” activation of CBr by increasing the endogenous levels of the endocannabinoid anandamide (AEA). Herein, we compared the pre- and post-treatment efficacy of URB597 and WIN55,212-2 on different endpoints evaluated in the toxic model produced by the mitochondrial toxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) in mice. MPTP (40 mg/kg, s.c., single injection) decreased locomotor activity, depleted the striatal and nigral levels of dopamine (DA), augmented the levels of lipid peroxidation and protein carbonylation in both regions, decreased the striatal protein levels of tyrosine hydroxylase, and increased the striatal protein content of the subunit 1 (NR1) of the N-methyl-d-aspartate receptor (NMDAr). Both URB597 (0.3 mg/kg, i.p., once a day) and WIN55,212-2 (10 μg/kg, i.p., twice a day), administered for five consecutive days, either before or after the MPTP injection, prevented the alterations elicited by MPTP and downregulated NMDAr. Our results support a modulatory role of the ECS on the toxic profile exerted by MPTP in mice via the stimulation of antioxidant activity and the induction of NMDAr downregulation and hypofunction, and favor the stimulation of CBr as an effective experimental therapeutic strategy.     

Intracortical EEG for the Detection of Vasospasm in Patients with Poor-Grade Subarachnoid Hemorrhage

Background

To study the feasibility of utilizing intracortical electroencephalography (ICE) including quantitative EEG (qEEG) analysis for the detection of vasospasm in five consecutive poor-grade SAH patients.

Methods

Intracortical electroencephalography (ICE) was obtained via a single miniature parenchymal 8-contact depth electrode placed at the bedside. Quantitative EEG parameters, calculated on surface EEG and ICE, included alpha/delta ratio (ADR), mean amplitude, suppression percent, and total power. Percent changes between averaged values over 4–6 h of baseline EEG and EEG prior to angiography were calculated. The entire continuous qEEG recording for each patient was then reviewed to determine optimal automated alarm criteria.

Results

ICE ADR was the most accurate for predicting angiographic vasospasm (5/5). ICE ADR decreased between baseline and follow-up by 42% (from 0.56 ± 0.07 to 0.32 ± 0.03) for those with vasospasm (N = 3) compared to 17% (0.62 ± 0.06 to 0.51 ± 0.03) for those without (N = 2). A sustained decrease in the ICE ADR from baseline (>25% for ≥4 h) occurred in all three patients with angiographically confirmed vasospasm and not in the two without; this decline occurred 1–3 days prior to angiographic confirmation.

Conclusions

Intracortical EEG is promising for detecting ischemia from vasospasm in poor-grade SAH patients, may be superior to scalp EEG, and allow automated detection, particularly using the ADR. Larger studies are needed to better define the effectiveness of this approach.     

Proanthocyanidin-rich fraction from Croton celtidifolius Baill confers neuroprotection in the intranasal 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine rat model of Parkinson’s disease

We have recently demonstrated that rodents treated intranasally with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) suffered impairments in olfactory, cognitive and motor functions associated with time-dependent disruption of dopaminergic neurotransmission in different brain structures conceivably analogous to those observed during different stages of Parkinson’s disease (PD). On the other hand, the proanthocyanidin-rich fraction (PRF) obtained from the bark of Croton celtidifolius Baill (Euphorbiaceae), a tree frequently found in the Atlantic forest in south Brazil, has been described to have several neurobiological activities including antioxidant and anti-inflammatory properties, which may be of interest in the treatment of PD. The present data indicated that the pretreatment with PRF (10 mg/kg, i.p.) during five consecutive days was able to prevent mitochondrial complex-I inhibition in the striatum and olfactory bulb, as well as a decrease of the enzyme tyrosine hydroxylase expression in the olfactory bulb and substantia nigra of rats infused with a single intranasal administration of MPTP (1 mg/nostril). Moreover, pretreatment with PRF was found to attenuate the short-term social memory deficits, depressive-like behavior and reduction of locomotor activity observed at different periods after intranasal MPTP administration in rats. Altogether, the present findings provide strong evidence that PRF from C. celtidifolius may represent a promising therapeutic tool in PD, thus being able to prevent both motor and non-motor early symptoms of PD, together with its neuroprotective potential.     

Dalfampridine in patients with downbeat nystagmus—an observational study

We investigated the effects of dalfampridine, the sustained-release form of 4-aminopyridine, on slow phase velocity (SPV) and visual acuity (VA) in patients with downbeat nystagmus (DBN) and the side effects of the drug. In this proof-of-principle observational study, ten patients received dalfampridine 10 mg bid for 2 weeks. Recordings were conducted at baseline, 180 min after first administration, after 2 weeks of treatment and after 4 weeks of wash-out. Mean SPV decreased from a baseline of 2.12 deg/s ± 1.72 (mean ± SD) to 0.51 deg/s ± 1.00 180 min after first administration of dalfampridine 10 mg and to 0.89 deg/s ± 0.75 after 2 weeks of treatment with dalfampridine (p < 0.05; post hoc both: p < 0.05). After a wash-out period of 1 week, mean SPV increased to 2.30 deg/s ± 1.6 (p < 0.05; post hoc both: p < 0.05). The VA significantly improved during treatment with dalfampridine. Also, 50 % of patients did not report any side effects. The most common reported side effects were abdominal discomfort and dizziness. Dalfampridine is an effective treatment for DBN in terms of SPV. It was well-tolerated in all patients.