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1.
J Sex Med ; 19(9): 1479-1487, 2022 09.
Article in English | MEDLINE | ID: mdl-35811288

ABSTRACT

BACKGROUND: The integrity of the neural pathways that link genital sensitive areas to the brain and the correlation with subjective sensations in transgender women with gender dysphoria after gender affirming surgery (GAS) have not been explored in detail and remain controversial, so far. AIM: To test with electrophysiology the integrity of the nervous paths after GAS, and to explore the relationship between genital sensitivity and self-perceived orgasmic intensity in transgender women after GAS. METHODS: Six patients who underwent GAS between 2016 and 2019 were enrolled in the study, and the evaluation of genital and pelvic neural pathways was performed. OUTCOMES: Genital sensory thresholds (at clitoral, vaginal, and anal sites) investigated by Somatosensory Evoked Potentials (SEP) and the intensity of orgasm (measured by a psychometric tool, the Orgasmometer) were combined to obtain an objective and subjective evaluation. RESULTS: SSEPs confirmed the integrity of the large diameter, dorsal column-lemniscus pathway subserving the genital area after GAS. Perceptual Threshold (PT) values were much lower at the neoclitoris compared to neovagina and anal sites. There was no correlation between Orgasmometer and SEP at anal and neovaginal level, while a trend was found at clitoral level. CLINICAL IMPLICATION: These findings could lead clinicians to a better understanding of postsurgical sexual life in transgender women in order to develop surgical techniques that could focus more on functional aspects of neovagina and neoclitoris. STRENGTHS & LIMITATIONS: Limitations: study very preliminary/exploratory; small number of patients; no long-term follow-up. Strengths: first assessment of sensory pelvic floor innervation in transgender women after GAS; use of objective methods; first attempt at correlating objectives findings to subjective experience of the sexual orgasm. CONCLUSIONS: Our evaluation showed that SSEPs is a good indicator of neural sensitivity, especially in neoclitoris, and that these measurements were consistent with the analysis of self-perceived orgasmic intensity. Canale D, Molinaro A, Marcocci C, et al. Genital Sensitivity and Perceived Orgasmic Intensity in Transgender Women With Gender Dysphoria After Gender-Affirming Surgery: A Pilot Study Comparing Pelvic Floor Evoked Somatosensory Potentials and Patient Subjective Experience. J Sex Med 2022;19:1479-1487.


Subject(s)
Gender Dysphoria , Transgender Persons , Clitoris , Female , Humans , Orgasm , Pelvic Floor , Pilot Projects
2.
Clin EEG Neurosci ; 53(5): 460-466, 2022 Sep.
Article in English | MEDLINE | ID: mdl-32938220

ABSTRACT

BACKGROUND AND RATIONALE: Hyperkinetic movement disorders represent a heterogeneous group of diseases, different from a genetic and clinical perspective. In the past, neurophysiological approaches provided different, sometimes contradictory findings, pointing to an impaired cortical inhibition as a common electrophysiological marker. Our aim was to evaluate changes in interhemispheric communication in patients with idiopathic cervical dystonia (ICD) and spinocerebellar ataxias (SCAs). MATERIALS AND METHODS: Eleven patients with ICD, 7 with genetically confirmed SCA2 or SCA3, and 10 healthy volunteers were enrolled. The onset latency and duration of the ipsilateral silent period (iSPOL and iSPD, respectively), as well as the so-called transcallosal conduction time (TCT), were then recorded from the abductor pollicis brevis of the right side using an 8-shaped focal coil with wing diameters of 70 mm; all these parameters were evaluated and compared among groups. In SCAs, changes in neurophysiological measures were also correlated to the mutational load. RESULTS: iSPD was significantly shorter in patients with SCA2 and SCA3, when compared both to control and ICD (P < .0001); iSPOL and TCT were prolonged in SCAs patients (P < .001). Changes in iSPD, iSPOL, and TCT in SCAs are significantly correlated with the mutational load (P = .01, P = .02, and P = .002, respectively). DISCUSSION: This is the first study to assess changes in interhemispheric communication in patients with SCAs and ICD, using a transcranial magnetic stimulation protocol. Together with previous data in Huntington's disease, we suggest that these changes may underlie, at least in part, a common disease mechanism of polyglutamine disorders.


Subject(s)
Spinocerebellar Ataxias , Torticollis , Electroencephalography , Humans , Spinocerebellar Ataxias/genetics , Transcranial Magnetic Stimulation
3.
Physiol Rep ; 9(18): e14992, 2021 09.
Article in English | MEDLINE | ID: mdl-34536067

ABSTRACT

COVID-19 is a public health emergency with cases increasing globally. Its clinical manifestations range from asymptomatic and acute respiratory disease to multiple organ dysfunction syndromes and effects of COVID-19 in the long term. Interestingly, regardless of variant, all COVID-19 share impairment of the sense of smell and taste. We would like to report, as far as we know, the first comprehensive neurophysiological evaluation of the long-term effects of SARS-CoV-2 on the olfactory system with potential-related neurological damage. The case report concerns a military doctor, with a monitored health history, infected in April 2020 by the first wave of the epidemic expansion while on military duty in Codogno (Milan). In this subject, we find the electrophysiological signal in the periphery, while its correlate is absent in the olfactory bulb region than in whole brain recordings. In agreement with this result is the lack of metabolic signs of brain activation under olfactory stimulation. Consequently, quantitative and qualitative diagnoses of anosmia were made by means of olfactometric tests. We strongly suggest a comprehensive series of olfactometric tests from the first sign of COVID-19 and subsequent patient assessments. In conclusion, electrophysiological and metabolic tests of olfactory function have made it possible to study the long-term effects and the establishment of neurological consequences.


Subject(s)
Anosmia/physiopathology , Anosmia/virology , COVID-19/complications , Adult , COVID-19/physiopathology , Electrophysiology/methods , Evoked Potentials/physiology , Humans , Male , Olfactory Bulb/physiopathology , Olfactory Nerve/physiopathology , SARS-CoV-2 , Sensory Thresholds/physiology , Post-Acute COVID-19 Syndrome
4.
Front Neurol ; 11: 614717, 2020.
Article in English | MEDLINE | ID: mdl-33343504

ABSTRACT

Introduction: In recent years, a growing body of literature has investigated the use of non-invasive brain stimulation (NIBS) techniques as a putative treatment in Huntington's Disease (HD). Our aim was to evaluate the effects of cerebellar transcranial Direct Current Simulation (ctDCS) on the motor outcome in patients affected by HD, encompassing at the same time the current knowledge about the effects of NIBS both on motor and non-motor dysfunctions in HD. Materials and Methods: Four patients (two females) were enrolled and underwent ctDCS (both anodal or sham, elapsed by at least 3 months: 2.0 mA, 20 min per day, 5 days a week). Clinical scores were assessed by using the Unified Huntington's Disease Rating Scale - part I (UHDRS-I), immediately before ctDCS (T0), at the end of the 5-days treatment (T1) and 4 weeks later (T2). Results: Anodal ctDCS improved motor scores compared to baseline (p = 0.0046), whereas sham stimulation left them unchanged (p = 0.33, Friedman test). In particular, following anodal ctDCS, UHDRS-I score significantly improved, especially regarding the subitem "dystonia," both at T1 and T2 compared to sham condition (p < 0.05; Wilcoxon matched-pairs signed test). Conclusions: ctDCS improved motor scores in HD, with effects lasting for about 4 weeks after tDCS completion. This is the first study discussing the putative role of cerebellar non-invasive simulation for the treatment of HD.

5.
BMC Neurol ; 20(1): 408, 2020 Nov 07.
Article in English | MEDLINE | ID: mdl-33160304

ABSTRACT

BACKGROUND: Mutations in TGM6 gene, encoding for transglutaminase 6 (TG6), have been implicated in the pathogenesis of spinocerebellar ataxia type 35 (SCA35), a rare autosomal dominant disease marked by cerebellar degeneration and characterized by postural instability, incoordination of gait, features of cerebellar dysfunction and pyramidal signs. CASE PRESENTATION: Here we report the case of an Italian patient with late-onset, slowly progressive cerebellar features, including gait ataxia, scanning speech and ocular dysmetria and pyramidal tract signs. Whole exome sequencing revealed the rare heterozygous c.1024C > T (p.R342W) variant of TGM6, located at a highly evolutionary conserved position and predicted as pathogenic by in silico tools. Expression of TG6-R342W mutant in HEK293T cells led to a significant reduction of transamidase activity compared to wild-type TG6. CONCLUSION: This finding extends SCA35 genetic landscape, highlighting the importance of TGM6 screening in undiagnosed late-onset and slowly progressive cerebellar ataxias.


Subject(s)
Spinocerebellar Ataxias/genetics , Spinocerebellar Degenerations/diagnosis , HEK293 Cells , Humans , Male , Middle Aged , Mutation , Transglutaminases/genetics , Transglutaminases/metabolism
6.
Neurol Sci ; 41(12): 3503-3515, 2020 Dec.
Article in English | MEDLINE | ID: mdl-32683566

ABSTRACT

This review focuses on new and/or less standardized event-related potentials methods, in order to improve their knowledge for future clinical applications. The olfactory event-related potentials (OERPs) assess the olfactory functions in time domain, with potential utility in anosmia and degenerative diseases. The transcranial magnetic stimulation-electroencephalography (TMS-EEG) could support the investigation of the intracerebral connections with very high temporal discrimination. Its application in the diagnosis of disorders of consciousness has achieved recent confirmation. Magnetoencephalography (MEG) and event-related fields (ERF) could improve spatial accuracy of scalp signals, with potential large application in pre-surgical study of epileptic patients. Although these techniques have methodological limits, such as high inter- and intraindividual variability and high costs, their diffusion among researchers and clinicians is hopeful, pending their standardization.


Subject(s)
Cognitive Neuroscience , Brain , Electroencephalography , Evoked Potentials , Humans , Italy , Magnetoencephalography , Psychophysiology , Reproducibility of Results
7.
Neurol Sci ; 41(11): 3075-3084, 2020 Nov.
Article in English | MEDLINE | ID: mdl-32524324

ABSTRACT

BACKGROUND: Vagal nerve stimulation (VNS) is an effective palliative therapy in drug-resistant epileptic patients and is also approved as a therapy for treatment-resistant depression. Depression is a frequent comorbidity in epilepsy and it affects the quality of life of patients more than the seizure frequency itself. The aim of this systematic review is to analyze the available literature about the VNS effect on depressive symptoms in epileptic patients. MATERIAL AND METHODS: A comprehensive search of PubMed, Medline, Scopus, and Google Scholar was performed, and results were included up to January 2020. All studies concerning depressive symptom assessment in epileptic patients treated with VNS were included. RESULTS: Nine studies were included because they fulfilled inclusion criteria. Six out of nine papers reported a positive effect of VNS on depressive symptoms. Eight out of nine studies did not find any correlation between seizure reduction and depressive symptom amelioration, as induced by VNS. Clinical scales for depression, drug regimens, and age of patients were broadly different among the examined studies. CONCLUSIONS: Reviewed studies strongly suggest that VNS ameliorates depressive symptoms in drug-resistant epileptic patients and that the VNS effect on depression is uncorrelated to seizure response. However, more rigorous studies addressing this issue are encouraged.


Subject(s)
Epilepsy , Vagus Nerve Stimulation , Antidepressive Agents , Epilepsy/therapy , Humans , Quality of Life , Treatment Outcome
8.
Neurol Sci ; 41(10): 2711-2735, 2020 Oct.
Article in English | MEDLINE | ID: mdl-32388645

ABSTRACT

Event-related potentials (ERPs) are obtained from the electroencephalogram (EEG) or the magnetoencephalogram (MEG, event-related fields (ERF)), extracting the activity that is time-locked to an event. Despite the potential utility of ERP/ERF in cognitive domain, the clinical standardization of their use is presently undefined for most of procedures. The aim of the present review is to establish limits and reliability of ERP medical application, summarize main methodological issues, and present evidence of clinical application and future improvement. The present section of the review focuses on well-standardized ERP methods, including P300, Contingent Negative Variation (CNV), Mismatch Negativity (MMN), and N400, with a chapter dedicated to laser-evoked potentials (LEPs). One section is dedicated to proactive preparatory brain activity as the Bereitschaftspotential and the prefrontal negativity (BP and pN). The P300 and the MMN potentials have a limited but recognized role in the diagnosis of cognitive impairment and consciousness disorders. LEPs have a well-documented usefulness in the diagnosis of neuropathic pain, with low application in clinical assessment of psychophysiological basis of pain. The other ERP components mentioned here, though largely applied in normal and pathological cases and well standardized, are still confined to the research field. CNV, BP, and pN deserve to be largely tested in movement disorders, just to explain possible functional changes in motor preparation circuits subtending different clinical pictures and responses to treatments.


Subject(s)
Cognitive Neuroscience , Electroencephalography , Brain , Evoked Potentials , Female , Humans , Italy , Male , Psychophysiology , Reproducibility of Results
9.
Ann Vasc Surg ; 62: 275-286, 2020 Jan.
Article in English | MEDLINE | ID: mdl-31445091

ABSTRACT

BACKGROUND: Venous percutaneous transluminal angioplasty (vPTA) in patients with multiple sclerosis (MS) and chronic cerebrospinal venous insufficiency (CCSVI) have shown contradictory results. The aim of the study is to evaluate the efficacy of the procedure in a randomized wait list control study. METHODS: 66 adults with neurologist-confirmed diagnosis of MS and sonographic diagnosis of CCSVI were allocated into vPTA-yes group (n = 31) or vPTA-not group (n = 35, control group). vPTA was performed immediately 15 days after randomization in the PTA-yes group and 6 months later in the control group. Evoked potentials (EPs), clinical-functional measures (CFMs), and upper limb kinematic measures (ULKMs) were measured at baseline (T0) and six months after in both groups, just before the venous angioplasty in the vPTA-not group (T1). RESULTS: Comparing the vPTA-yes and vPTA-not group, the CFM-derived composite functional outcome showed 11 (37%) versus 7 (20%) improved, 1 (3%) versus 3 (8%) stable, 0 versus 7 (20%) worsened, and 19 (61%) versus 18 (51%) mixed patients (χ2 = 8.71, df = 3, P = 0.03). Unadjusted and adjusted (for baseline confounding variables) odds ratio at 95% confidence interval were, respectively, 1.93 (1.3-2.8), P value 0.0007, and 1.85 (1.2-1.7), P value 0.002. EP- and ULKM-derived composite functional outcome showed no significant difference between the two groups. CONCLUSIONS: Venous angioplasty can positively impact a few CFMs especially for the quality of life but achieving disability improvement is unlikely.


Subject(s)
Angioplasty , Cerebral Veins , Cerebrovascular Disorders/therapy , Multiple Sclerosis, Chronic Progressive/therapy , Multiple Sclerosis, Relapsing-Remitting/therapy , Upper Extremity/innervation , Venous Insufficiency/therapy , Adolescent , Adult , Aged , Angioplasty/adverse effects , Biomechanical Phenomena , Cerebral Veins/diagnostic imaging , Cerebral Veins/physiopathology , Cerebrovascular Disorders/diagnostic imaging , Cerebrovascular Disorders/physiopathology , Chronic Disease , Evoked Potentials, Motor , Humans , Italy , Middle Aged , Multiple Sclerosis, Chronic Progressive/diagnosis , Multiple Sclerosis, Chronic Progressive/physiopathology , Multiple Sclerosis, Relapsing-Remitting/diagnosis , Multiple Sclerosis, Relapsing-Remitting/physiopathology , Quality of Life , Recovery of Function , Time Factors , Treatment Outcome , Venous Insufficiency/diagnostic imaging , Venous Insufficiency/physiopathology , Young Adult
10.
Neurol Sci ; 40(9): 1775-1783, 2019 Sep.
Article in English | MEDLINE | ID: mdl-31055731

ABSTRACT

BACKGROUND: Epilepsy and hypertension are common chronic conditions, both showing high prevalence in older age groups. This review outlines current experimental and clinical evidence on both direct and indirect role of hypertension in epileptogenesis and discusses the principles of drug treatment in patients with hypertension and epilepsy. METHODS: We selected English-written articles on epilepsy, hypertension, stroke, and cerebrovascular disease until December, 2018. RESULTS: Renin-angiotensin system might play a central role in the direct interaction between hypertension and epilepsy, but other mechanisms may be contemplated. Large-artery stroke, small vessel disease and posterior reversible leukoencephalopathy syndrome are hypertension-related brain lesions able to determine epilepsy by indirect mechanisms. The role of hypertension as an independent risk factor for post-stroke epilepsy has not been demonstrated. The role of hypertension-related small vessel disease in adult-onset epilepsy has been demonstrated. Posterior reversible encephalopathy syndrome is an acute condition, often caused by a hypertensive crisis, associated with the occurrence of acute symptomatic seizures. Chronic antiepileptic treatment should consider the risk of drug-drug interactions with antihypertensives. CONCLUSIONS: Current evidence from preclinical and clinical studies supports the vision that hypertension may be a cause of seizures and epilepsy through direct or indirect mechanisms. In both post-stroke epilepsy and small vessel disease-associated epilepsy, chronic antiepileptic treatment is recommended. In posterior reversible encephalopathy syndrome blood pressure must be rapidly lowered and prompt antiepileptic treatment should be initiated.


Subject(s)
Cerebral Small Vessel Diseases/complications , Epilepsy/etiology , Hypertension/complications , Seizures/etiology , Stroke/complications , Humans
11.
Neurol Sci ; 40(10): 2065-2071, 2019 Oct.
Article in English | MEDLINE | ID: mdl-31129772

ABSTRACT

BACKGROUND: Respiratory failure represents an unavoidable step in patients with amyotrophic lateral sclerosis (ALS) and other motor neuron diseases (MND). The development of diaphragm ultrasonography (DUS) provides an alternative useful and risk-free tool to supply clinical, functional, and neurophysiological assessment of respiratory muscle weakness. Our aim was to evaluate if sonographic changes (thickness and echogenicity in the costal portion of the diaphragm, at rest and during respiratory movements) may be used in ALS patients to assess disease severity over time, to rule out any risk or discomfort due to traditional neurophysiological investigations. METHODS: Twenty ALS patients (mean age, 64.6 ± 10.5 years) were enrolled and data were compared with age-matched healthy volunteers; DUS data were correlated with respiratory function and disease severity scale. Examinations were performed using Telemed Echo-wave II or Esaote MyLabGamma devices in conventional B-Mode. RESULTS: Mean resting thickness was reduced in all cases; changes in thickness during inspiration and expiration were also reduced (p < 0.0001) and lost in severe cases (n = 3). In bulbar-onset disease, respiratory scores were strictly correlated with the difference in diaphragm thickness between full inspiration-and expiration-as well as on the diaphragm thickness in expiration (p < 0.001). CONCLUSIONS: DUS represents a simple, painless, and risk-free tool; moreover, it provides useful functional and structural insights to the understanding of diaphragm function and the degree of respiratory failure in ALS.


Subject(s)
Amyotrophic Lateral Sclerosis/complications , Diaphragm/diagnostic imaging , Respiratory Insufficiency/diagnostic imaging , Ultrasonography/methods , Aged , Aged, 80 and over , Female , Humans , Male , Middle Aged , Respiratory Insufficiency/etiology
12.
Sci Rep ; 9(1): 3684, 2019 03 06.
Article in English | MEDLINE | ID: mdl-30842443

ABSTRACT

Event-Related Potentials (ERPs) occurring independently from any stimulus are purely endogenous (emitted potentials) and their neural generators can be unequivocally linked with cognitive processes. In the present study, the subjects performed two similar visual counting tasks: a standard two-stimulus oddball, and an omitted-target oddball task, characterized by the physical absence of the target stimulus. Our investigation aimed at localizing the neural sources of the scalp-recorded endogenous/emitted ERPs. To optimize the source localization, the high temporal resolution of electrophysiology was combined with the fine spatial information provided by the simultaneous recording of functional magnetic resonance (fMRI). Both tasks identified two endogenous ERP components in the 300 to 520 ms interval. An earlier component, pP2, showed a bilateral generator in the anterior Insula. A later P3 component (P3b) was generated bilaterally in the temporal-parietal junction, the premotor and motor area and the anterior intraparietal sulcus (this latter one only in the standard oddball). Anticipatory slow waves (beginning 900 to 500 ms pre-stimulus), also of endogenous nature, were produced by the inferior and middle frontal gyrus and the supplementary and cingulate motor areas. Our protocol disentangled pre- from post-stimulus fMRI activations and provided original clues to the psychophysiological interpretation of emitted/endogenous ERPs.


Subject(s)
Electroencephalography , Evoked Potentials/physiology , Magnetic Resonance Imaging , Adult , Brain Mapping/methods , Event-Related Potentials, P300/physiology , Female , Humans , Male , Photic Stimulation , Young Adult
14.
Cerebellum ; 18(3): 527-535, 2019 Jun.
Article in English | MEDLINE | ID: mdl-30830672

ABSTRACT

Phantom limb pain (PLP) is a disabling and intractable sensation arising in about 80% of patients after amputation. The aim of this study was to evaluate the possibility to modulate nociceptive processing and pain perception with cerebellar transcranial direct current stimulation (ctDCS) in patients suffering from painful and non-painful phantom limb sensations. Fourteen upper limb amputees underwent ctDCS (anodal or sham, 2.0 mA, 20 min per day, 5 days a week). Clinical scores and electrophysiological parameters were assessed before tDCS, at the end of the 5-day treatment, 2 and 4 weeks later. Laser-evoked potentials (LEPs) were obtained from the stump using a Nd:YAP laser by pulses with short duration (5 ms) and small diameter spots (5 mm). Changes in visual analogue scores (VAS) were evaluated (chronic pain, paroxysmal pain, stump pain, phantom movements, phantom sensations). Anodal polarization significantly dampened LEP amplitudes (N1, p = 0.021 and N2/P2, p = 0.0034), whereas sham intervention left them unchanged. Anodal ctDCS significantly reduced paroxysmal pain (p < 0.0001), non-painful phantom limb sensations (p < 0.0001) and phantom limb movements (p = 0.0003), whereas phantom limb and stump pain did not change compared to the sham condition. Anodal ctDCS significantly improves both paroxysmal pain and non-painful phantom limb sensations, which are likely induced by maladaptive changes in the sensorimotor network and posterior parietal cortex respectively.


Subject(s)
Cerebellum/physiopathology , Phantom Limb/therapy , Transcranial Direct Current Stimulation/methods , Adult , Cross-Over Studies , Double-Blind Method , Female , Humans , Male , Middle Aged
15.
Clin Neurophysiol Pract ; 3: 104-106, 2018.
Article in English | MEDLINE | ID: mdl-30215018

ABSTRACT

OBJECTIVE: Holmes tremor is a rare kind of hyperkinetic movement disorder, clinically characterized by irregular, monolateral, high-amplitude jerks, sharing a quite similar frequency with those observed in Parkinson's disease; its generation likely relies on a combined involvement of cerebello-thalamic and nigrostriatal pathways. METHODS: We report the case of a man with a combined resting-postural-kinetic tremor. Neuroimaging revealed an intracranial dermoid cyst at the right pontocerebellar angle with brainstem dislocation. We performed an extensive electrophysiological assessment from the extensor digitorum communis (EDC) and flexor carpi radialis (FCR) muscles. RESULTS: Both the spontaneous variability of tremor frequency and frequency entrainment argued against an organic aetiology. Polymyography revealed: 1) a paradoxical increase of tremor amplitude with mass loading; 2) jerks' synchronization between antagonistic muscles during voluntary contralateral motor performances; 3) tremor inhibition while asking the patient to make a ballistic movement. CONCLUSIONS: We suggest a complete psychogenic genesis or, at least in part, a possible co-existence of a rubral tremor with functional traits. SIGNIFICANCE: Here, we propose a simple and fast test battery for an early diagnosis of functional tremor. Our results prompt further studies to re-define electrodiagnostic criteria in hyperkinetic movement disorders, possibly updating the floating border between organic and psychogenic disease.

16.
Front Behav Neurosci ; 12: 109, 2018.
Article in English | MEDLINE | ID: mdl-29896093

ABSTRACT

Objective: Amblyopia is a neurodevelopmental disorder characterized by visual acuity and contrast sensitivity loss, refractory to pharmacological and optical treatments in adulthood. In animals, the corpus callosum (CC) contributes to suppression of visual responses of the amblyopic eye. To investigate the role of interhemispheric pathways in amblyopic patients, we studied the response of the visual cortex to transcranial Direct Current Stimulation (tDCS) applied over the primary visual area (V1) contralateral to the "lazy eye." Methods: Visual acuity (logMAR) was assessed before (T0), immediately after (T1) and 60' following the application of cathodal tDCS (2.0 mA, 20') in 12 amblyopic patients. At each time point, Visual Evoked Potentials (VEPs) triggered by grating stimuli of different contrasts (K90%, K20%) were recorded in both hemispheres and compared to those obtained in healthy volunteers. Results: Cathodal tDCS improved visual acuity respect to baseline (p < 0.0001), whereas sham polarization had no significant effect. At T1, tDCS induced an inhibitory effect on VEPs amplitudes at all contrasts in the targeted side and a facilitation of responses in the hemisphere ipsilateral to the amblyopic eye; compared with controls, the facilitation persisted at T2 for high contrasts (K90%; Holm-Sidak post hoc method, p < 0.001), while the stimulated hemisphere recovered more quickly from inhibition (Holm-Sidak post hoc method, p < 0.001). Conclusions: tDCS is a promising treatment for amblyopia in adults. The rapid recovery of excitability and the concurrent transcallosal disinhibition following perturbation of cortical activity may support a critical role of interhemispheric balance in the pathophysiology of amblyopia.

17.
Physiol Rep ; 6(10): e13471, 2018 05.
Article in English | MEDLINE | ID: mdl-29845771

ABSTRACT

The cerebellum is involved in a wide number of integrative functions. We evaluated the role of cerebellum in peripersonal defensive behavior, as assessed by the so-called hand blink reflex (HBR), modulating cerebellar activity with transcranial direct current stimulation (tDCS). Healthy subjects underwent cerebellar (sham, anodal, and cathodal tcDCS) and motor cortex tDCS (anodal or cathodal; 20', 2 mA). For the recording of HBR, electrical stimuli were delivered using a surface bipolar electrode placed on the median nerve at the wrist and EMG activity recorded from the orbicularis oculi muscle bilaterally. Depending on the hand position respective to the face, HBR was assessed in four different conditions: "hand-far," "hand-near" (eyes open), "side hand," and "hand-patched" (eyes closed). While sham and cathodal cerebellar stimulation had no significant effect, anodal tcDCS dramatically dampened the magnitude of the HBR, as measured by the area under the curve (AUC), in the "hand-patched" and "side hand" conditions only, for ipsilateral (F(4,171)  = 15.08, P < 0.0001; F(4,171)  = 8.95, P < 0.0001) as well as contralateral recordings (F(4,171)  = 17.96, P < 0.0001); F4,171)  = 5.35, P = 0.0004). Cerebellar polarization did not modify AUC in the "hand-far" and "hand-near" sessions. tDCS applied over the motor area did not affect HBR. These results seem to support a role of the cerebellum in the defensive responses within the peripersonal space surrounding the face, thus suggesting a possible cerebellar involvement in visual-independent defensive behavior.


Subject(s)
Blinking , Cerebellum/physiology , Hand/physiology , Transcranial Direct Current Stimulation , Adult , Electric Stimulation , Female , Humans , Male , Median Nerve/physiology , Motor Cortex/physiology , Personal Space , Young Adult
18.
Neuromodulation ; 21(5): 480-488, 2018 Jul.
Article in English | MEDLINE | ID: mdl-29314454

ABSTRACT

RATIONALE: Spinal cord stimulation (SCS) is an effective option for neuropathic pain treatment. New technological developments, as high-frequency (HF) and theta burst stimulation (TBS), have shown promising results, although putative mechanisms of action still remain debated. METHODS: thirty patients with lower back pain were enrolled and underwent LF, HF, and TBS. Laser evoked potentials (LEPs) were recorded by using a Nd:YAG laser. Amplitudes and latencies of the main two components (N1, N2/P2) were compared among different experimental sessions. Changes in resting motor threshold (RMT), cortical silent period (cSP), short intracortical inhibition (SICI), and intracortical facilitation (ICF) were also evaluated. RESULTS: TBS dampened LEP amplitudes compared with LF (N1: p = 0.032; N2/P2: p < 0.0001) and HF stimulation (N1: p = 0.029; N2/P2: p < 0.0001, Holm-Sidak post-hoc test). Concurrently, TBS increased N1 latency, when compared with baseline and LF stimulation (p = 0.009 and 0.0033). Whereas RMT and SICI did not change among experimental conditions, TBS significantly prolonged cSP duration compared with baseline (p = 0.002), LF (p = 0.048), and HF-SCS (p = 0.016); finally, both HF (p = 0.004) and TBS (p = 0.0039) increased ICF. CONCLUSION: TBS modulates medial and lateral pain pathways through distinct mechanisms, possibly involving both GABA(a)ergic and Glutamatergic networks at an intracortical level. These results may have implications for therapy and for the choice of best stimulation protocol.


Subject(s)
Brain/physiology , Electric Stimulation/methods , Evoked Potentials/physiology , Low Back Pain/therapy , Spinal Cord/physiology , Transcranial Magnetic Stimulation/methods , Adult , Aged , Analysis of Variance , Biophysics , Electrodes, Implanted , Electromyography , Evoked Potentials, Motor/physiology , Female , Humans , Male , Middle Aged , Reaction Time/physiology , Visual Analog Scale
19.
J Cardiovasc Echogr ; 28(4): 218-227, 2018.
Article in English | MEDLINE | ID: mdl-30746325

ABSTRACT

The introduction of three-dimensional echography (3D echo) in vascular field is not recent, but it still remains a seldom-used technique because of the costs of ultrasound probe and the need of dedicated laboratories. Therefore, despite significant prognostic implications, the high diagnostic accuracy in plaque definition, and the relative ease of use, 3D echo in vascular field is a niche technique. The purpose of this review is mainly clinical and intends to demonstrate the potential strength of a 3D approach, including technical aspects, in order to present to clinicians and imagers the appealing aspects of a noninvasive and radiation-free methodology with relevant diagnostic and prognostic correlates in the assessment of carotid atherosclerosis. A comprehensive literature search (since 1990s to date) using the PubMed, MEDLINE, and Cochrane libraries databases has been conducted. Articles written in English have been assessed, including reviews, clinical trials, meta-analyses, and interventional/observational studies. Manual cross-referencing was also performed, and relevant references from selected articles were reviewed. The search was limited to studies conducted in humans. Search terms, retrieved also with PubMed Advanced search and AND/OR Boolean operators (mainly in title and abstract), included three-dimensional, echo, stroke/transient ischemic attack, predictors, carotid, imaging, and biomarkers.

20.
Cerebellum ; 16(1): 55-61, 2017 02.
Article in English | MEDLINE | ID: mdl-26846218

ABSTRACT

In the general population, transcranial anodal direct current stimulation of the cerebellum (ctDCS) reduces pain intensity and the amplitude of nociceptive laser evoked potentials (LEPs), whereas cathodal ctDCS elicits opposite effects. Since behavioral findings suggest that the cerebellar activity of highly hypnotizable individuals (highs) differs from the general population, we investigated whether hypnotizability-related differences occur in the modulation of pain by ctDCS. Sixteen healthy highs (according to the Stanford Hypnotic Susceptibility Scale, form A) and 16 participants not selected according to hypnotizability (controls) volunteered to undergo laser nociceptive stimulation of the dorsum of the left hand before and after anodal or cathodal ctDCS. LEPs amplitudes and latencies and the subjective pain experience (Numerical Rating Scale) were analyzed. Smaller LEP amplitudes and longer latencies were observed in highs with respect to controls independently of stimulation. After anodal and cathodal cerebellar stimulation, controls reported lower and higher pain than before it, respectively. In contrast, highs did not report significant changes in the perceived pain after both stimulations. They increased significantly their N2/P2 amplitude after anodal ctDCS and did not exhibit any significant change after cathodal tDCS, whereas controls decreased the N1 and N2P2 amplitude and increased their latency after anodal cerebellar stimulation and did the opposite after cathodal ctDCS. In conclusion, the study showed impaired cerebellar pain modulation and suggested altered cerebral cortical representation of pain in subjects with high hypnotizability scores.


Subject(s)
Cerebellum/physiopathology , Hypnosis , Pain Perception/physiology , Pain/physiopathology , Adult , Analysis of Variance , Evoked Potentials , Female , Humans , Individuality , Lasers , Male , Physical Stimulation , Random Allocation , Transcranial Direct Current Stimulation , Young Adult
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