The role of the MTHFR 677C>T polymorphism in methotrexate-induced liver toxicity: a meta-analysis in patients with cancer.

Methotrexate (MTX), one of the important pillars in the treatment of different forms of cancer, is associated with the development of hepatotoxicity. The 677C>T variant (rs1801133) in the methylenetetrahydrofolate reductase (MTHFR) gene might affect the development of hepatotoxicity. Results in literature are, however, contradictive. The aim of this study was to evaluate the role of the MTHFR 677C>T polymorphism in MTX-induced hepatotoxicity by analyzing a Dutch cohort of pediatric patients treated with high doses of MTX and subsequently performing a meta-analysis. Ninety-eight patients receiving 542 courses of high-dose MTX were genotyped for the MTHFR 677C>T variant. Hepatotoxicity was evaluated retrospectively according to common terminology criteria for adverse events-National Cancer Institute criteria. The influence of MTHFR 677C>T on hepatotoxicity was examined using a generalized estimating equation (GEE) analysis. A fixed-effect meta-analysis based on this and previous studies investigating the association between the MTHFR 677C>T polymorphism and uniformly coded hepatotoxicity was performed. The GEE analysis showed an increased risk of developing hepatotoxicity for T versus C allele (odds ratio (OR) 1.8; 95% confidence interval (CI) 1.0-3.2, P=0.04). This finding was not supported by the meta-analysis including seven studies and 1044 patients; the OR for the 677T versus C allele was 1.1 (95% CI 0.84-1.5, P=0.25). Heterogeneity between studies was observed, possibly related to differences in MTX dose and leucovorin rescue. In conclusion, in patients with cancer, the MTHFR 677T allele has only a minor role in the development of MTX-induced hepatotoxicity. Observed heterogeneity between studies warrants further study into (tailored) leucovorin rescue.

Electromagnetic fields (EMFs) and adenosine receptors modulate prostaglandin E(2) and cytokine release in human osteoarthritic synovial fibroblasts.

Synovial fibroblasts (SFs) contribute to the development of osteoarthritis (OA) by the secretion of a wide range of pro-inflammatory mediators, including cytokines and lipid mediators of inflammation. Previous studies suggest that electromagnetic fields (EMFs) may represent a potential therapeutic approach to limit cartilage degradation and control inflammation associated to OA, and that they may act through the adenosine pathway. Therefore, we investigated whether EMFs might modulate inflammatory activities of human SFs from OA patients (OASFs) treated with interleukin-1ß (IL-1ß), and the possible involvement of adenosine receptors (ARs) in mediating EMF effects. EMF exposure induced a selective increase in A(2A) and A(3) ARs. These increases were associated to changes in cAMP levels, indicating that ARs were functionally active also in EMF-exposed cells. Functional data obtained in the presence of selective A(2A) and A(3) adenosine agonists and antagonists showed that EMFs inhibit the release of prostaglandin E(2) (PGE(2)) and the proinflammatory cytokines interleukin-6 (IL-6) and interleukin-8 (IL-8), while stimulating the release of interleukin-10 (IL-10), an antinflammatory cytokine. These effects seem to be mediated by the EMF-induced upregulation of A(2A) and A(3) ARs. No effects of EMFs or ARs have been observed on matrix degrading enzyme production. In conclusion, this study shows that EMFs display anti-inflammatory effects in human OASFs, and that these EMF-induced effects are in part mediated by the adenosine pathway, specifically by the A(2A) and A(3) AR activation. Taken together, these results open new clinical perspectives to the control of inflammation associated to joint diseases.

Methylenetetrahydrofolate reductase gene promoter hypermethylation in semen samples of infertile couples correlates with recurrent spontaneous abortion.

STUDY QUESTION: Is the methylation status of the methylenetetrahydrofolate reductase (MTHFR) promoter region in semen samples associated with 'recurrent spontaneous abortion' (RSA)? SUMMARY ANSWER: MTHFR promoter hypermethylation is more frequent in semen samples from RSA couples than in semen samples from infertile couples with no history of RSA (NRSA) and affects the whole sperm population significantly more often. WHAT IS KNOWN ALREADY: Modifications to the MTHFR gene such as polymorphisms and promoter methylations are associated with male infertility. STUDY DESIGN, SIZE AND DURATION: Retrospective cohort study of semen samples from 20 RSA couples, 147 NRSA couples and 20 fertile men between 2011 and 2012. MATERIALS, SETTING AND METHODS: DNA from the semen samples of RSA, NRSA and fertile men were analyzed by methylation-specific PCR amplification using primers which anneal to the methylated or unmethylated cytosine-phosphodiester bond guanine (CpG) islands within the promoter region of MTHFR. The specificity of the PCR products was assessed by DNA sequencing. MAIN RESULTS AND THE ROLE OF CHANCE: The methylated MTHFR epigenotype (including samples where it co-existed with unmethylated MTHFR epigenotypes) was detected in 75% of RSA men, 54% of NRSA men and 15% of fertile men. MTHFR methylation was observed in the whole sperm population in semen samples from 55% of RSA men compared with 8% in NRSA men (P < 0.05) and 0% in fertile men (P < 0.05). DNA sequencing analysis was fully concordant with the PCR results and revealed that when MTHFR methylation occurred, CpG islands within the promoter region were 100% methylated (hypermethylation of MTHFR promoter). LIMITATIONS, REASONS FOR CAUTION: The relatively small sample size of RSA infertile couples. WIDER IMPLICATIONS OF THE FINDINGS: The hypermethylation of the MTHFR gene promoter should be taken into consideration as a novel putative risk factor in RSA etiology. STUDY FUNDING/COMPETING INTEREST(S): Our institution has received an FAR research grant from the University of Ferrara, Ferrara, Italy. No competing interests declared.

Adenosine analogs and electromagnetic fields inhibit prostaglandin E2 release in bovine synovial fibroblasts.

OBJECTIVE: To investigate the role of adenosine analogs and electromagnetic field (EMF) stimulation on prostaglandin E(2) (PGE(2)) release and cyclooxygenase-2 (COX-2) expression in bovine synovial fibroblasts (SFs). METHODS: SFs isolated from synovia were cultured in monolayer. Saturation and binding experiments were performed by using typical adenosine agonists: N6-cyclohexyladenosine (CHA, A(1)), 2-[p-(2-carboxyethyl)-phenetyl-amino]-5'-N-ethylcarboxamidoadenosine (CGS 21680, A(2A)), 5'-N-ethylcarboxamidoadenosine (NECA, non-selective), N6-(3-iodobenzyl)2-chloroadenosine-5'-N-methyluronamide (Cl-IB-MECA, A(3)). SFs were treated with TNF-alpha (10 ng/ml) and lipopolysaccharide (LPS) (1 microg/ml) to activate inflammatory response. Adenosine analogs were added to control and TNF-alpha- or LPS-treated cultures both in the absence and in the presence of adenosine deaminase (ADA) which is used to deplete endogenous adenosine. Parallel cultures were exposed to EMFs (75 Hz, 1.5 mT) during the period in culture (24h). PGE(2) release was measured by immunoassay. COX-2 expression was evaluated by RT-PCR. RESULTS: TNF-alpha and LPS stimulated PGE(2) release. All adenosine agonists, except for Cl-IB-MECA, significantly inhibited PGE(2) production. EMFs inhibited PGE(2) production in the absence of adenosine agonists and increased the effects of CHA, CGS 21680 and NECA. In ADA, the inhibition on PGE(2) release induced by CHA, CGS and NECA was stronger than in the absence of ADA and the EMF-inhibitory effect was lost. Changes in PGE(2) levels were associated to modification of COX-2 expression. CONCLUSIONS: This study supports anti-inflammatory activities of A(1) and A(2A) adenosine receptors and EMFs in bovine SFs. EMF activity appears mediated by an EMF-induced up-regulation of A(2A) receptors. Biophysical and/or pharmacological modulation of adenosine pathways may play an important role to control joint inflammation.

Pharmacological characterization of P2X1 and P2X3 purinergic receptors in bovine chondrocytes.

OBJECTIVE: The aim of the present study is that of characterizing, for the first time in a quantitative way, from a biochemical, physico chemical and functional point of view P2X(1) and P2X(3) purinergic receptors in bovine chondrocytes. The affinity and the potency of typical purinergic ligands were studied through competition binding experiments and their role in modulating chondrocyte actvities was investigated by analyzing nitric oxide (NO) and prostaglandin E2 (PGE(2)) release. METHODS: Saturation, competition binding experiments, western blotting and immunohistochemistry assays on the P2X(1) and P2X(3) purinergic receptors in bovine chondrocytes were performed. Thermodynamic analysis of the P2X(1) and P2X(3) purinergic binding was studied to investigate the forces driving drug-receptor coupling. In the functional assays (NO and PGE(2) release) the potency of purinergic agonists and antagonists was evaluated. RESULTS: Bovine chondrocytes expressed P2X(1) and P2X(3) purinergic receptors and thermodynamic parameters indicated that purinergic binding is enthalpy- and entropy-driven for agonists and totally entropy-driven for antagonists. Typical purinergic agonists such as adenosine 5'-triphosphate (ATP) and alpha,beta-methyleneATP were able to increase NO and PGE(2) release. A purinergic antagonist, A317491, was able to block the stimulatory effect on functional experiments mediated by the agonists. CONCLUSIONS: These data demonstrate for the first time the presence of functional P2X(1) and P2X(3) purinergic receptors in bovine chondrocytes. Agonists and antagonists are thermodynamically discriminated and are able to modulate functional responses such as NO and PGE(2) release. These results suggest the potential role of novel purinergic antagonists in the treatment of pathophysiological diseases linked to the inflammation and involved in articular cartilage resorption.

Evaluation of the Electroporation Efficiency of a Grid Electrode for Electrochemotherapy: From Numerical Model to In Vitro Tests.

Electrochemotherapy (ECT) is a local anticancer treatment based on the combination of chemotherapy and short, tumor-permeabilizing, voltage pulses delivered using needle electrodes or plate electrodes. The application of ECT to large skin surface tumors is time consuming due to technical limitations of currently available voltage applicators. The availability of large pulse applicators with few and more spaced needle electrodes could be useful in the clinic, since they could allow managing large and spread tumors while limiting the duration and the invasiveness of the procedure. In this article, a grid electrode with 2-cm spaced needles has been studied by means of numerical models. The electroporation efficiency has been assessed on human osteosarcoma cell line MG63 cultured in monolayer. The computational results show the distribution of the electric field in a model of the treated tissue. These results are helpful to evaluate the effect of the needle distance on the electric field distribution. Furthermore, the in vitro tests showed that the grid electrode proposed is suitable to electropore, by a single application, a cell culture covering an area of 55 cm(2). In conclusion, our data might represent substantial improvement in ECT in order to achieve a more homogeneous and time-saving treatment, with benefits for patients with cancer.

Modulation of gene expression in human osteoblasts by targeting a distal promoter region of human estrogen receptor-alpha gene.

Estrogen receptor (ER) alpha is expressed during osteoblast differentiation; however, both its functional role in bone metabolism and its involvement in osteoporotic pathogenesis caused by estrogen deficiency are not well understood. Loss of ER alpha gene expression could be one of the mechanisms leading to osteoporosis. Therefore, we investigated a possible modulation of ER alpha gene expression in a human osteoblastic cell line and in four primary osteoblast cultures by using a decoy strategy. Double stranded DNA molecules, mimicking a regulatory region of the ER alpha gene promoter (DNA-102) and acting as a 'silencer' in breast cancer cells, were introduced into osteoblasts as 'decoy' cis-elements to bind and functionally inactivate a putative negative transcription factor, and thus to induce ER alpha gene expression. We found that the DNA-102 molecule was able to specifically bind osteoblast nuclear proteins. Before decoy treatment, absence or variable low levels of ER alpha RNAs in the different cultures were detected. When the cells were transfected with the DNA-102 decoy, an increase in expression of ER alpha and osteoblastic markers, such as osteopontin, was observed, indicating a more differentiated osteoblastic phenotype both in the cell line and in primary cultures. These results showed that the DNA-102 sequence competes with endogenous specific negative transcription factors that may be critical for a decrease in or lack of ER alpha gene transcription. Therefore, osteoblastic transfection with the DNA-102 decoy molecule may be considered a tempting model in a putative therapeutic approach for those pathologies, such as osteoporosis, in which the decrease or loss of ER alpha expression plays a critical role in bone function.

Large T antigen coding sequences of two DNA tumor viruses, BK and SV40, and nonrandom chromosome changes in two glioblastoma cell lines.

The T antigen (TAg) coding sequences of two DNA tumor viruses, BKV and SV40, were detected by Polymerase Chain Reaction (PCR) amplification followed by Southern-blot hybridization in two human glioblastoma multiforme derived cell lines. RT-PCR analysis indicated that these two TAg coding sequences were expressed in both tumor cell lines carrying the viral early region DNAs. Moreover, analytical polyacrylamide gel electrophoresis (PAGE) and DNA sequence analyses showed that the amplified PCR products are indistinguishable from the TAg coding sequences of BKV and SV40 wildtype strains. Cytogenetic study performed in the two cell lines showed unbalanced changes, mainly gains of chromosomes 3p, 5, 6, 7, and 19 and losses of chromosomes 3, 3q, 16, 9p22-->pter, 18, and 20. Excess of chromosomes 6 and 7 are common to the two cell lines. The putative role of the TAg of the two DNA tumor viruses in transformation and karyotype changes is discussed.

The reduced sensitivity of the ProC Global test in protein S deficient subjects reflects a reduction in the associated thrombotic risk.

To investigate simultaneously a defect affecting the protein C/protein S (PC/PS) anticoagulant pathway is possible thanks to a methodological approach (ProC(R) Global; Dade Behring) based on the activation of endogenous plasma PC by a snake venom extract. Factor V (FV) Leiden, the most frequent cause of hereditary thrombosis, is well detected by the test with sensitivity of 100% irrespective of the presence/absence of thrombosis in the subjects investigated. The test is also suited to detect PC or PS defect, but in this case the in vitro impairment of the PC/PS pathway is less pronounced particularly for PS defects (sensitivity for PC and PS defect, 85-100 and 30-90%, respectively). In this study, we hypothesized that the lower sensitivity described for PS defect, compared with those of PC and FV Leiden defects, could also be related to the clinical condition of the subject investigated (symptomatic/asymptomatic) rather than solely to the PS plasma activity/level. Therefore, we analyzed 126 subjects with single congenital defects in the PC/PS pathway: 46 subjects with PS deficiency (26 thrombotic cases and 20 asymptomatic relatives), 40 subjects with PC deficiency (25 thrombotic cases and 15 asymptomatic relatives), and 40 heterozygous FV Leiden subjects (25 thrombotic cases and 15 asymptomatic relatives). By a cut-off of normalized Agkistrodon contortix snake venom ratio of 0.84, the sensitivity in the whole group of cases (sensitivity a) was 76.1, 95.0 and 100%, respectively, for PS, PC and FV Leiden defects. The test failed to detect 11 (23.9%) among the 46 PS-deficient subjects, and all these cases except two belonged to the asymptomatic subgroup (9/20; 45%). Excluding the 20 asymptomatic relatives, the new sensitivity (sensitivity b) for the PS defect was 92.3%. The comparison of the sensitivity in the symptomatic PS cases and in the asymptomatic ones was significantly different (P = 0.010). Among the 40 PC-deficient subjects, only two (5.0%) were not detected by the test and they belonged indifferently to the two subgroups. Finally, none of the 40 FV Leiden heterozygotes were misdiagnosed by the test. These results suggest that in symptomatic PS-deficient cases the test could reflect a post-thrombotic effect and/or reveal potential unidentified prothrombotic influences assessing a prothrombotic risk condition.

Mitochondrial abnormalities in nigral neurons of the marmoset and Macaca fascicularis treated with MPTP.

In a previous study we observed the processes determining the cellular death in nigral neurons of Macaca fascicularis and common Marmoset treated with MPTP. The purpose of this study is to consider, in substantia nigra neurons of the same animals, mitochondrial abnormalities caused by neurotoxin. Three Macaca fascicularis and 5 common Marmosets, respectively treated with 3 and 4 mg/kg of MPTP dissolved in saline + 10% ethanol, were suppressed by means of an i.v. injection phenobarbital. The substantia nigra, isolated from the mesencephalon, has been examined under Electron Microscope. Different mitochondrial abnormalities have been observed in nigral neurons: crystal abnormalities occur more frequently than other alterations. They are correlated with various degrees of mitochondrial enlargement. Dissolution of the matrix induces formation of spherical highly electron-dense inclusions of various volume and in different number; they are probably lipoprotein. Laminar bodies and myelin-like figures are determined by alterations of the external membrane. Particular roundish organules, placed near normal mitochondria, are limited by fragments of membrane with a granular material, occasionally flowing in the cytoplasm. The biochemical hypothesis concerning the genesis of the observed abnormalities is discussed in the present study.

Preliminary experiences with "real-time" intraoperative ultrasonography associated to the laser and the ultrasonic aspirator in neurosurgery.

Twelve cerebral lesions were operated upon with various laser sources (carbon dioxide, neodymium-yttrium-argon-garnet, and argon) and with an ultrasonic aspirator utilizing the intraoperative "real-time" ultrasonography. With the last method, the tumor was imaged just as well through the intact dura mater as on the brain surface itself, allowing a precise localization of deep intracranial lesions. A sharp selectivity on the healthy tissues is, in this way, achievable to reach the tumor, which is successively removed with the laser and ultrasonic aspirator checking the surgical maneuvers on the visual control of the ultrasonograph.

Coordinate effects of Concanavalin A on cytoskeletal organization, cell shape, glycosaminoglycan accumulation and exoglycosidase activity in chick embryonic cultured fibroblasts.

The effects of Concanavalin A on cell morphology, cytoskeleton arrangement and some metabolic activities of 11-day chick embryo fibroblasts were examined. In fibroblasts, Con A caused a dose-dependent round morphology and a change in tubulin, actin and alpha-actinin arrangement, whereas it did not modify 3H-thymidine incorporation. In addition, lectin stimulated more hyaluronic acid than sulphated glycosaminoglycan synthesis, affected glycosaminoglycan sulphation, and also reduced beta-N-acetyl-D-glucosaminidase, beta-N-acetyl-D-galactosaminidase and beta-glucuronidase activities.

Preliminary spectroscopic studies on the neuromelanic pigment of human substantia nigra nucleus.

The neuromelanic pigment obtained from human mid-brain Substantia Nigra Nucleus was studied by I.R. spectroscopy and compared with synthetic dopamine melanin. Natural neuromelanin and synthetic dopamine melanin show very similar features in two characteristic I.R. absorption regions: 1400 cm-1, typical of phenolic OH groups, and 3200 cm-1 band, typical of aminic groups. Natural mid-brain neuromelanin shows a different absorption in the I.R. region at 3000 cm-1 and in the 1300-900 cm-1 range probably due to the presence of lipidic residues bound to the molecule. The results of the U.V. spectroscopic analysis suggest a correlation between the optical density of human neuromelanic pigment and the different ages of the subjects providing the specimens.

[Neuroendocrine correlations in the pathogenesis and pathology of Parkinson disease]. / Correlati neuroendocrini nella patogenesi e nella patologia del morbo di Parkinson.

In Parkinson's disease the decrease of dopamine in the nigro-striatal pathway is allied to modifications of other neuromodulation systems. The biochemical disorder of cholinergic, gabaergic and epinephrinergic pathways is present. Moreover the alteration of certain neuropeptides such as endorphins or enkefalins have been found. The Authors analyse the functional repercussions of these important biochemical modifications in the T.I.D.A. tract. In particular the variation of PRL synthesis and secretion due to dopamine deficiency during basal conditions and after pharmacological treatment is discussed.

[An unusual case of focal symptomatology, monoparalysis of the abducent nerve and vertebrobasilar ectasia]. / Raro caso di sintomatologia focale, monoparesi del nervo abducente in ectasia vertebro basilare.

Ectasia of the basilar artery is a well-defined form with a complicated clinical symptomatology. Angiography has made it possible to show that its pathogenesis springs from marked changes in the diameter and length of the artery. A case is presented in which the usual array of symptoms was replaced by homonymous diplopia only. It showed that CT can on its own provide information both for diagnosis of the specific lesion, and for assessment of changes in the bone structures, the cerebral parenchima, and the ventricular system.

[Tardive dyskinesia]. / La discinesia tardiva.

Neuroleptic drug treatment can produce tardive dyskinesia of which the incidence, risk factors, clinical characteristics and problems of differential diagnosis are described. Possible therapeutic approaches are then considered in the light of the hypothesis that the condition may derive from a physiopathological hypersensitivity of the dopamine receptors.

Tissue expander: histological and histochemical study 6 months after transplant--our experience.

Implanting an expander in the subcutaneous layer causes gradual expansion and provides additional tissue for reconstruction of tissular defects. The force applied remodels the connective tissue and modifies dermis contractibility in additional tissue. Other authors confirm that parameters such as mitosis and hyaluronan influence the system in the tissue regeneration processes. We studied histochemical and morphological variations of tissue expanders before and 6 months after transplant. Our histochemical data do not show any changes in dermis glycosaminoglycans of the expanded and transplant-expanded skin when compared to controls. Morphological data demonstrate reorganization of connective fibers and disappearance of the papillar layer. The latter is not yet formed in the expanded skin 6 months after transplant. This suggests that a long time is required for biological reconstruction of epidermal-dermal interactions after transplant.

Inadequacy of transcranial magnetic stimulation in the neurophysiologic assessment of Bell's palsy.

Transcranial magnetic stimulation is a non-invasive procedure which to stimulate the brain cortex and the peripheral nerve pathways. A new technique was recently introduced to record the muscle action potential of facial muscles by means of transcranial magnetic stimulation of the facial nerve. The experimental data that was obtained indicate that this technique allows to stimulate the facial nerve above the stylomastoid foramen: a greater tract of the nerve can therefore be explored than what was possible with the traditional electrical stimulation at the mastoid. Until now no comparison data was available on the clinical usefulness of the two methods. We decided to study 14 normal controls and 26 patients suffering from unilateral idiopathic facial palsy (Bell's palsy) and to submit these two groups to magnetic transcranial stimulation and electrical stimulation of the facial nerve in the mastoid region, to the purpose of observing where the nerve is stimulated by the magnetic impulse and which of the two techniques can be of accurate prognostic value in the study of the evolution of the clinical lesion. The electromyographic responses were elicited by the electrical stimulation at the mastoid and by transcranial stimulation after positioning the coil on the parieto-occipital scalp. A recording was taken from the ipsilateral orhicularis oculi muscle utilising two cupped electrodes. The latency and the amplitude of the compound muscle action potential were measured bilaterally in order to compare the results obtained on both the affected and the healthy sides. The patients were scheduled to two neurophysiological and clinical evaluations at about 30 days interval one from the other: the first test was not carried out before 20 days from the onset of the deficit; further clinical examination was carried out only 6 months later. The analysis of the results obtained in the normal controls submitted to transcranial magnetic stimulation indicate that the nerve is activated at the point where it originates from the brainstem. The study carried out showed that transcranial magnetic stimulation of the facial nerve, does not provide data which can be correlated to the clinical situation observed at the time of the study; furthermore, transcranial magnetic stimulation does not supply any prognostic data on the clinical evolution of the lesion.

Usefulness of motor evoked potentials in compressive myelopathy.

Motor Evoked Potentials elicited by transcranial magnetic stimulation were recorded from 1 degree Dorsal Interosseus for the upper limbs and from Extensor Digitorum Brevis for the lower limbs in 42 subjects with compressive myelopathy (36 in the cervical region and 6 in the dorsal region), radiologically defined by Nuclear Magnetic Resonance (NMR) imaging, with no clinical and radiological signs of radiculopathy. Central motor conduction abnormalities in the cortex-C8 and cortex-L5 tract were compared with clinical signs of motor impairment and with NMR findings. The subjects with medullar hyperintensity of NMR signal at the compression site level, showed a central conduction time (C.C.T.) prolongation in at least one side in the 70% of cases in the cortex-C8 tract and in the 95% of cases in the cortex-L5 tract, while in the cases with no compression site alterations of signal, C.C.T. abnormalities were observed only in 25% in the cortex-C8 tract and in 42% in the cortex-L5 tract. In 12 subjects (10 with cervical compression and 2 with dorsal compression) we compared Motor Evoked Potentials before, two weeks and two months after surgical decompression. The C.C.T. cortex-C8 and cortex-L5 improved at least in one side in 11 out of the 12 subjects, showing a good correlation with clinical recovery. In the examined patients we found a latency reduction statistically significant between the first and second investigation, with a trend to stabilization in the following controls.

[Transcranial magnetic stimulation of the facial nerve: evaluation of a new method in neurophysiological study of Bell's palsy]. / Stimolazione magnetica transcranica del nervo facciale: valutazione di una nuova metodica nello studio neurofisiologico della paralisi di Bell.

Transcranial magnetic stimulation is a new technique used to stimulate brain areas as well as peripheral nerves in healthy, waking persons. To date this technique has appeared safe. The aim of the present study was to assess the clinical application of this method in patients with Bell's palsy. Electromyographic responses were elicited by electrical and magnetic transcranial stimulation of the facial nerve in 26 patients affected by Bell's palsy. Electrical stimulation: stimuli of 0.1 ms duration, and up to 15 V, were delivered through surface electrodes set 2.5 cm apart over the facial nerve at the stylomastoid foramen. Magnetic stimulation: the coil was placed tangent to the parieto-occipital surface of the scalp. The stimulus intensity was then increased stepwise until a supramaximal response was obtained. Recording: the focal recording electrode was placed ipsilateral to the side stimulated over the superior orbicularis oculi; the reference electrode was placed over the nasal bone. The patients were tested with two neurophysiological determinations: the first 15-30 days from the onset of the palsy; the second 30-60 days after the first. A clinical follow-up was performed six months after the second determination. The results indicate that, contrary to traditional electroneurography, transcranial magnetic stimulation is not able to supply useful neurophysiological indications in patients with Bell's palsy. Although the absence of compound muscle action potential upon stimulation of the side with the lesion did demonstrate some impediment to conduction, it did not have any prognostic value since it was also present in patients who were clinically well at the time of the second check-up.