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2.
Ther Adv Neurol Disord ; 15: 17562864221101687, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35706844

RESUMO

Women with epilepsy (WWE) wishing for a child represent a highly relevant subgroup of epilepsy patients. The treating epileptologist needs to delineate the epilepsy syndrome and choose the appropriate anti-seizure medication (ASM) considering the main goal of seizure freedom, teratogenic risks, changes in drug metabolism during pregnancy and postpartum, demanding for up-titration during and down-titration after pregnancy. Folic acid or vitamin K supplements and breastfeeding are also discussed in this review. Lamotrigine and levetiracetam have the lowest teratogenic potential. Data on teratogenic risks are also favorable for oxcarbazepine, whereas topiramate tends to have an unfavorable profile. Valproate needs special emphasis. It is most effective in generalized seizures but should be avoided whenever possible due to its teratogenic effects and the negative impact on neuropsychological development of in utero-exposed children. Valproate still has its justification in patients not achieving seizure freedom with other ASMs or if a woman decides to or cannot become pregnant for any reason. When valproate is the most appropriate treatment option, the patient and caregiver must be fully informed of the risks associated with its use during pregnancies. Folate supplementation is recommended to reduce the risk of major congenital malformations. However, there is insufficient information to address the optimal dose and it is unclear whether higher doses offer greater protection. There is currently no general recommendation for a peripartum vitamin K prophylaxis. During pregnancy most ASMs (e.g. lamotrigine, oxcarbazepine, and levetiracetam) need to be increased to compensate for the decline in serum levels; exceptions are valproate and carbamazepine. Postpartum, baseline levels are reached relatively fast, and down-titration is performed empirically. Many ASMs in monotherapy are (moderately) safe for breastfeeding and women should be encouraged to do so. This review provides a practically oriented overview of the complex management of WWE before, during, and after pregnancy.

3.
Psychiatry Res ; 310: 114431, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35219263

RESUMO

The knowledge about the effects of cannabis on human cortical brain processes is increasing. In this regard, transcranial magnetic stimulation (TMS) enables the evaluation of central nervous system function, including drug effects. Moreover, repetitive TMS (rTMS) has been used therapeutically in several substance use disorders. In this scoping review, we summarize and discuss studies that have employed TMS and rTMS techniques in users of cannabis for recreational purposes. In subjects with a history of persistent cannabis use, TMS studies showed reduced short-interval cortical inhibition (SICI). This observation points more at neurobiological changes of chronic cannabis use than to a direct effect of cannabis on gamma-aminobutyric acid (GABA) A receptors. Moreover, individuals vulnerable to becoming long-term users of cannabis may also have underlying pre-existing abnormalities in SICI. Of note, the use of cannabis is associated with an increased risk of schizophrenia, and the down-regulation of GABAergic function may play a role. Less frequent cannabis use and spontaneous craving were observed following rTMS applied to the dorsolateral prefrontal cortex (DLPFC). There is emerging evidence that the posterior cingulate cortex and the precuneus are potential targets for rTMS intervention in cannabis use disorder. However, larger and randomized trials should corroborate these encouraging findings.


Assuntos
Cannabis , Transtornos Relacionados ao Uso de Substâncias , Encéfalo , Fissura/fisiologia , Humanos , Córtex Pré-Frontal , Estimulação Magnética Transcraniana/métodos
4.
Brain Res ; 1772: 147673, 2021 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-34597651

RESUMO

In patients with restless legs syndrome (RLS) a motor cortical disinhibition has been reported in transcranial magnetic stimulation (TMS) studies, but the neuronal excitability in other cortical areas has been poorly explored. The aim of this study was the functional evaluation of thalamo-cortical circuits and inhibitory cortical responses in the sensory cortex in RLS. We assessed the high-frequency somatosensory evoked potentials (HF-SEP) in sixteen subjects suffering from RLS of different degrees of severity. In patients with severe or very severe RLS we found a significant desynchronization with amplitude reduction of both pre- and post-synaptic HF-SEP bursts, which suggest an impairment in the thalamo-cortical projections and in the cortical inhibitory interneurons activity, respectively. The assessment of the central sensory pathways by means of HF-SEP may shed light on the pathophysiological mechanisms of RLS.


Assuntos
Vias Aferentes/fisiopatologia , Sistema Nervoso Central/fisiopatologia , Síndrome das Pernas Inquietas/fisiopatologia , Adulto , Idoso , Córtex Cerebral/fisiopatologia , Sincronização Cortical , Potenciais Somatossensoriais Evocados , Feminino , Humanos , Interneurônios , Masculino , Pessoa de Meia-Idade , Córtex Motor/fisiopatologia , Tálamo/fisiopatologia , Estimulação Magnética Transcraniana
5.
CNS Drugs ; 35(3): 265-281, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33754312

RESUMO

BACKGROUND: Cannabidiol (CBD), which is one major constituent of the Cannabis sativa plant, has anti-seizure properties and does not produce euphoric or intrusive side effects. A plant-derived, highly purified CBD formulation with a known and constant composition has been approved by the US Food and Drug Administration for the treatment of seizures associated with Dravet syndrome, Lennox-Gastaut syndrome, and tuberous sclerosis complex. In the European Union, the drug has been authorized by the European Medicines Agency for the treatment of seizures associated with Dravet syndrome and Lennox-Gastaut syndrome, in conjunction with clobazam, and is under regulatory review for the treatment of seizures in patients with tuberous sclerosis complex. OBJECTIVES: This systematic review aimed to summarize the currently available body of knowledge about the use of this US Food and Drug Administration/European Medicines Agency-approved oral formulation of pharmaceutical-grade CBD in patients with epileptic conditions, especially developmental and epileptic encephalopathies other than Dravet syndrome and Lennox-Gastaut syndrome. METHODS: The relevant studies were identified through MEDLINE and the US National Institutes of Health Clinical Trials Registry in October 2020. There were no date limitations or language restrictions. The following types of studies were included: clinical trials, cohorts, case-control, cross-sectional, clinical series, and case reports. Participants had to meet the following criteria: any sex, any ethnicity, any age, diagnosis of epilepsy, receiving plant-derived, highly purified (> 98% w/w) CBD in a sesame oil-based oral solution for the treatment of seizures. Data extracted from selected records included efficacy, tolerability, and safety outcomes. RESULTS: Five hundred and seventy records were identified by database and trial register searching. Fifty-seven studies were retrieved for detailed assessment, of which 42 were eventually included for the review. The participants of the studies included patients of both pediatric and adult age. Across the trials, purified CBD was administered at dosages up to 50 mg/kg/day. In a randomized double-blind controlled trial in patients with tuberous sclerosis complex, CBD was associated with a significantly greater percent reduction in seizure frequency than placebo over the treatment period. Open-label studies suggested the effectiveness of CBD in the treatment of children and adults presenting with other epilepsy syndromes than those addressed by regulatory trials, including CDKL5 deficiency disorder and Aicardi, Dup15q, and Doose syndromes, SYNGAP1 encephalopathy, and epilepsy with myoclonic absences. The most common adverse events observed during treatment with CBD included somnolence, decreased appetite, diarrhea, and increased serum aminotransferases. CONCLUSIONS: The currently available data suggest that response to treatment with a highly purified, plant-derived CBD oil-based solution can be seen in patients across a broad range of epilepsy disorders and etiologies. The existing evidence can provide preliminary support for additional research.


Assuntos
Canabidiol/farmacologia , Epilepsias Mioclônicas/tratamento farmacológico , Epilepsia/tratamento farmacológico , Síndromes Epilépticas/tratamento farmacológico , Síndrome de Lennox-Gastaut/tratamento farmacológico , Anticonvulsivantes/farmacologia , Estudos de Casos e Controles , Estudos Transversais , Método Duplo-Cego , Humanos , Convulsões/tratamento farmacológico
6.
Epilepsy Behav ; 117: 107835, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33611098

RESUMO

PURPOSE: To investigate the opinions of physicians on the use of complementary and alternative medicine (CAM) in patients with epilepsy (PWE) worldwide. METHODS: Online survey addressed to neurologists and psychiatrists from different countries. RESULTS: Totally, 1112 physicians from 25 countries (different world region: Europe, North America, South America, Middle-East, Africa, Former Soviet Union Republics) participated; 804 (72.3%) believed that CAM might be helpful in PWE. The most commonly endorsed CAM included meditation (41%) and yoga (39%). Female sex, psychiatry specialization, and working in North and South America were associated with the belief that CAM is helpful in PWE. Two-hundred and forty five out of 1098 participants (22.3%) used/prescribed CAM to PWE; among them, 174 (71%) people perceived CAM to be less effective and 114 (46.5%) people found CAM to be safer than conventional antiseizure medications (ASMs). The most common reasons to prescribe CAM for PWE were: to satisfy the patient (49.9%), dissatisfaction with the efficacy (35.6%), and dissatisfaction with the adverse effects (31.2%) of conventional therapies. CONCLUSION: Although the evidence supporting the use of CAM for the treatment of epilepsy is extremely sparse, most physicians worldwide believe that it could be integrated with the use of conventional ASMs, at least in some patients. High-quality controlled trials are warranted to provide robust evidence on the usefulness of CAM options in PWE.


Assuntos
Terapias Complementares , Epilepsia , Médicos , África , Epilepsia/terapia , Europa (Continente) , Feminino , Humanos , Oriente Médio , América do Norte , América do Sul , Inquéritos e Questionários
7.
Epilepsy Behav ; 101(Pt B): 106551, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31676239

RESUMO

Status epilepticus (SE) is a life-threatening condition with a mortality of up to 60% in the advanced and comatose forms of SE. In one out of five adults, first and second line fails to control epileptic activity, leading to refractory status epilepticus (RSE) and in around 3% to super-refractory status epilepticus (SRSE), where SE continues despite anesthetic treatment for 24 h or more. In this rare but devastating condition, innovative and safe treatments are needed. In a recent review on the use of vagal nerve stimulation in RSE and SRSE, a 74% response rate for abrogation of SE was reported. Here, we review the currently available evidence supporting the use of neurostimulation, including vagal nerve stimulation, direct cortical stimulation, transcranial magnetic stimulation, electroconvulsive therapy, and deep brain stimulation in RSE and SRSE. This article is part of the Special Issue "Proceedings of the 7th London-Innsbruck Colloquium on Status Epilepticus and Acute Seizures".


Assuntos
Epilepsia Resistente a Medicamentos/terapia , Terapia por Estimulação Elétrica/métodos , Estado Epiléptico/terapia , Estimulação Encefálica Profunda , Humanos , Estimulação Magnética Transcraniana , Estimulação do Nervo Vago
8.
Epilepsy Behav ; 88: 5-14, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30212726

RESUMO

BACKGROUND: Admission to the epilepsy monitoring unit (EMU) for long-term video-electroencephalography (EEG) monitoring (VEEG) constitutes the gold standard for seizure diagnosis and presurgical evaluation. This study applied the concept of a high-frequency systematic monitoring of psychological states and tested patients' compliance in order to evaluate if its integration in the EMU is feasible and if patients benefit from the graphically underpinned discussion of their EMU stay-related cognitions and emotions. METHODS: The process-monitoring is technically realized by an internet-based device for data collection and data analysis, the Synergetic Navigation System (SNS). A convenient sample was enrolled: All eligible patients who were admitted to the EMU of the Department of Neurology, Christian Doppler Medical Center, Salzburg, Austria, between November 6th 2017 and January 26th 2018 were approached and recruited upon consent. After a short resource-oriented interview, each enrolled patient was provided with a tablet. The daily questionnaire included eight standardized and up to three personalized items. Self-assessments were collected every 5 h prior to meal times (6:30 am, 11:30 am, and 4:30 pm) and at 9:30 pm. The detailed visualizations of the patients' replies were discussed with the participants during a feedback session at the end of the EMU stay. RESULTS: Twenty-one patients (12 women/9 men, median age 29 years [range 18-74 years]) were consecutively recruited (72% of all eligible patients). Compliance rates were high (median: 82%, range 60%-100%) among the respondents. Mood correlated strongly with hopefulness (r = 0.71) and moderately with energy (r = 0.63) in all patients. When correlating the intraindividual medians of the process questionnaire time series with the pretest total scores, energy correlated moderately and negatively with the Perceived Stress Scale (PSS) (r = -0.45), while self-efficacy correlated moderately and negatively with the Neurological Disorders Depression Inventory for Epilepsy (NDDI-E) total scores in all patients (r = -0.5). Nine patients (43%) reported that they learned something meaningful about themselves after the feedback discussion of their individual time series. CONCLUSION: The results support the feasibility of high-frequency monitoring of psychological states and processes in routine EMU settings. Repeated daily collections four times per day of psychological surveys allow for the assessment of highly resolved, equidistant time series data, which gives insight into psychological states and processes during EMU admission.


Assuntos
Prestação Integrada de Cuidados de Saúde/organização & administração , Epilepsia/psicologia , Monitorização Fisiológica , Convulsões/psicologia , Adolescente , Adulto , Idoso , Áustria , Eletroencefalografia , Epilepsia/fisiopatologia , Feminino , Unidades Hospitalares/estatística & dados numéricos , Humanos , Masculino , Pessoa de Meia-Idade , Cooperação do Paciente/estatística & dados numéricos , Projetos Piloto , Inquéritos e Questionários , Adulto Jovem
9.
CNS Drugs ; 32(10): 905-916, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-30132269

RESUMO

BACKGROUND: Lennox-Gastaut syndrome (LGS) is a severe developmental epileptic encephalopathy, and available interventions fail to control seizures in most patients. Cannabidiol (CBD) is a major chemical of marijuana, which has anti-seizure properties and different mechanisms of action compared with other approved antiepileptic drugs (AEDs). OBJECTIVE: The aim was to evaluate the efficacy and safety of CBD as adjunctive treatment for seizures in patients with LGS using meta-analytical techniques. METHODS: Randomized, placebo-controlled, single- or double-blinded trials were identified. Main outcomes included the ≥ 50% reduction in baseline drop and non-drop seizure frequency, and the incidence of treatment withdrawal and adverse events (AEs). Risk ratios (RRs) with 95% confidence intervals (CIs) were estimated through the inverse variance method. RESULTS: Two trials were included involving 396 participants. Patients presenting ≥ 50% reduction in drop seizure frequency during the treatment were 40.0% with CBD and 19.3% with placebo [RR 2.12 (95% CI 1.48-3.03); p < 0.001]. The rate of non-drop seizure frequency was reduced by 50% or more in 49.4% of patients in the CBD and 30.4% in the placebo arms [RR 1.62 (95% CI 1.09-2.43); p = 0.018]. The RR for CBD withdrawal was 4.93 (95% CI 1.50-16.22; p = 0.009). The RR to develop any AE during CBD treatment was 1.24 (95% CI 1.11-1.38; p < 0.001). AEs significantly associated with CBD were somnolence, decreased appetite, diarrhea and increased serum aminotransferases. CONCLUSIONS: Adjunctive CBD resulted in a greater reduction in seizure frequency and a higher rate of AEs than placebo in patients with LGS presenting seizures uncontrolled by concomitant AEDs.


Assuntos
Anticonvulsivantes/uso terapêutico , Canabidiol/efeitos adversos , Canabidiol/uso terapêutico , Síndrome de Lennox-Gastaut/tratamento farmacológico , Método Duplo-Cego , Humanos , Síndrome de Lennox-Gastaut/metabolismo , Razão de Chances , Ensaios Clínicos Controlados Aleatórios como Assunto , Convulsões/tratamento farmacológico , Convulsões/metabolismo , Transaminases/metabolismo
10.
Curr Opin Neurol ; 31(2): 198-210, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29493559

RESUMO

PURPOSE OF REVIEW: Neurostimulation is becoming an increasingly accepted treatment alternative for patients with drug-resistant epilepsy (DRE) who are unsuitable surgery candidates. Standardized guidelines on when or how to use the various neurostimulation modalities are lacking. We conducted a systematic review on the currently available neurostimulation modalities primarily with regard to effectiveness and safety. RECENT FINDINGS: For vagus nerve stimulation (VNS), there is moderate-quality evidence for its effectiveness in adults with drug-resistant partial epilepsies. Moderate-to-low-quality evidence supports the efficacy and safety of deep brain stimulation (DBS) and responsive neurostimulation (RNS) in patients with DRE. There is moderate-to-very low-quality evidence that transcranial direct current stimulation (tDCS) is effective or well tolerated. For transcutaneous vagus nerve stimulation (tVNS), transcranial magnetic stimulation (TMS) and trigeminal nerve stimulation (TNS), there are insufficient data to support the efficacy of any of these modalities for DRE. These treatment modalities, nevertheless, appear well tolerated, with no severe adverse events reported. SUMMARY: Head-to-head comparison of treatment modalities such as VNS, DBS and RNS across different epileptic syndromes are required to decide which treatment modality is the most effective for a given patient scenario. Such studies are challenging and it is unlikely that data will be available in the near future. Additional data collection on potentially promising noninvasive neurostimulation modalities like tVNS, TMS, TNS and tDCS is warranted to get a more precise estimate of their therapeutic benefit and long-term safety.


Assuntos
Estimulação Encefálica Profunda , Epilepsia Resistente a Medicamentos/terapia , Estimulação Transcraniana por Corrente Contínua , Estimulação Magnética Transcraniana , Estimulação do Nervo Vago , Tomada de Decisão Clínica , Contraindicações de Procedimentos , Terapia por Estimulação Elétrica , Epilepsia/terapia , Humanos , Resultado do Tratamento , Nervo Trigêmeo
11.
Front Neurosci ; 11: 689, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29311771

RESUMO

In rehabilitation of patients with spinal cord injury (SCI), imagination of movement is a candidate tool to promote long-term recovery or to control futuristic neuroprostheses. However, little is known about the ability of patients with spinal cord injury to perform this task. It is likely that without the ability to effectively perform the movement, the imagination of movement is also problematic. We therefore examined, whether patients with SCI experience increased difficulties in motor imagery (MI) compared to healthy controls. We examined 7 male patients with traumatic spinal cord injury (aged 23-70 years, median 53) and 20 healthy controls (aged 21-54 years, median 30). All patients had incomplete SCI, with AIS (ASIA Impairment Scale) grades of C or D. All had cervical lesions, except one who had a thoracic injury level. Duration after injury ranged from 3 to 314 months. We performed the Movement Imagery Questionnaire Revised as well as the Beck Depression Inventory in all participants. The self-assessed ability of patients to visually imagine movements ranged from 7 to 36 (Md = 30) and tended to be decreased in comparison to healthy controls (ranged 16-49, Md = 42.5; W = 326.5, p = 0.055). Also, the self-assessed ability of patients to kinesthetically imagine movements (range = 7-35, Md = 31) differed significantly from the control group (range = 23-49, Md = 41; W = 337.5, p = 0.0047). Two patients yielded tendencies for depressive mood and they also reported most problems with movement imagination. Statistical analysis however did not confirm a general relationship between depressive mood and increased difficulty in MI across both groups. Patients with spinal cord injury seem to experience difficulties in imagining movements compared to healthy controls. This result might not only have implications for training and rehabilitation programs, but also for applications like brain-computer interfaces used to control neuroprostheses, which are often based on the brain signals exhibited during the imagination of movements.

12.
Neuromodulation ; 18(7): 580-91; discussion 590-1, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26245458

RESUMO

BACKGROUND: Electrical and magnetic trans-spinal stimulation can be used to increase the motor output of multiple spinal segments and modulate cortico-spinal excitability. The application of direct current through the scalp as well as repetitive transcranial magnetic stimulation are known to influence brain excitability, and hence can also modulate other central nervous system structures, including spinal cord. OBJECTIVE: This study aimed to evaluate the effects and the therapeutic usefulness of these noninvasive neuromodulatory techniques in healthy subjects and in the neurorehabilitation of patients with spinal cord disorders, as well as to discuss the possible mechanisms of action. A comprehensive review that summarizes previous studies using noninvasive spinal cord stimulation is lacking. METHODS: PubMed (MEDLINE) and EMBASE were systematically searched to identify the most relevant published studies. We performed here an extensive review in this field. RESULTS: By decreasing the spinal reflex excitability, electrical and magnetic trans-spinal stimulation could be helpful in normalizing reflex hyperexcitability and treating hypertonia in subjects with lesions to upper motor neurons. Transcutaneous spinal direct current stimulation, based on applying direct current through the skin, influences the ascending and descending spinal pathways as well as spinal reflex excitability, and there is increasing evidence that it also can induce prolonged functional neuroplastic changes. When delivered repetitively, magnetic stimulation could also modulate spinal cord functions; however, at present only a few studies have documented spastic-reducing effects induced by repetitive spinal magnetic stimulation. Moreover, paired peripheral and transcranial stimulation can be used to target the spinal cord and may have potential for neuromodulation in spinal cord-injured subjects. CONCLUSIONS: Noninvasive electrical and magnetic spinal stimulation may provide reliable means to characterize important neurophysiologic and pathophysiologic aspects of spinal cord function. Moreover, transcutaneous direct current stimulation and repetitive magnetic stimulation may hold therapeutic promise in patients with spinal cord disorders, although future well-controlled studies are needed to corroborate and extend the preliminary findings.


Assuntos
Traumatismos da Medula Espinal/terapia , Estimulação da Medula Espinal/instrumentação , Estimulação da Medula Espinal/métodos , Bases de Dados Bibliográficas/estatística & dados numéricos , Humanos , Magnetoterapia , Estimulação Elétrica Nervosa Transcutânea
13.
Brain Res Bull ; 116: 93-7, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-26151771

RESUMO

Transcranial magnetic stimulation (TMS) is a useful non-invasive approach for studying cortical physiology. To further clarify the mechanisms of cortical reorganization after spinal cord injury (SCI), we used a non-invasive paired TMS protocol for the investigation of the corticospinal I-waves, the so-called I-wave facilitation, in eight patients with cervical SCI. We found that the pattern of I-wave facilitation significantly differs between SCI patients with normal and abnormal central motor conduction (CMCT), and healthy controls. The group with normal CMCT showed increased I-wave facilitation, while the group with abnormal CMCT showed lower I-wave facilitation compared to a control group. The facilitatory I-wave interaction occurs at the level of the motor cortex, and the mechanisms responsible for the production of I-waves are under control of GABA-related inhibition. Therefore, the findings of our small sample preliminary study provide further physiological evidence of increased motor cortical excitability in patients with preserved corticospinal projections. This is possibly due to decreased GABAergic intracortical inhibition. The excitability of networks producing short-interval intracortical facilitation could increase after SCI as a mechanism to enhance activation of residual corticospinal tract pathways and thus compensate for the impaired ability of the motor cortex to generate appropriate voluntary movements. Finally, the I-wave facilitation technique could be used in clinical neurorehabilitation as an additional method of assessing and monitoring function in SCI.


Assuntos
Córtex Motor/fisiopatologia , Tratos Piramidais/fisiopatologia , Traumatismos da Medula Espinal/fisiopatologia , Adulto , Eletromiografia , Potencial Evocado Motor , Feminino , Humanos , Extremidade Inferior/fisiopatologia , Masculino , Pessoa de Meia-Idade , Músculo Esquelético/fisiopatologia , Inibição Neural/fisiologia , Estimulação Magnética Transcraniana , Extremidade Superior/fisiopatologia , Ácido gama-Aminobutírico/metabolismo
14.
Neurol Sci ; 36(5): 689-700, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25721941

RESUMO

The development of different methods of brain stimulation provides a promising therapeutic tool with potentially beneficial effects on subjects with impaired cognitive functions. We performed a systematic review of the studies published in the field of neurostimulation in Alzheimer's disease (AD), from basic research to clinical applications. The main methods of non-invasive brain stimulation are repetitive transcranial magnetic stimulation and transcranial direct current stimulation. Preliminary findings have suggested that both techniques can enhance performances on several cognitive functions impaired in AD. Another non-invasive emerging neuromodulatory approach, the transcranial electromagnetic treatment, was found to reverse cognitive impairment in AD transgenic mice and even improves cognitive performance in normal mice. Experimental studies suggest that high-frequency electromagnetic fields may be critically important in AD prevention and treatment through their action at mitochondrial level. Finally, the application of a widely known invasive technique, the deep brain stimulation (DBS), has increasingly been considered as a therapeutic option also for patients with AD; it has been demonstrated that DBS of fornix/hypothalamus and nucleus basalis of Meynert might improve or at least stabilize cognitive functioning in AD. Initial encouraging results provide support for continuing to investigate non-invasive and invasive brain stimulation approaches as an adjuvant treatment for AD patients.


Assuntos
Doença de Alzheimer/terapia , Ensaios Clínicos como Assunto , Terapia por Estimulação Elétrica/métodos , Pesquisa Translacional Biomédica , Doença de Alzheimer/genética , Animais , Humanos , Camundongos , Camundongos Transgênicos
15.
Neuroimage Clin ; 4: 240-8, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24455474

RESUMO

Recovery of consciousness has been associated with connectivity in the frontal cortex and parietal regions modulated by the thalamus. To examine this model and to relate alterations to deficits in cognitive functioning and conscious processing, we investigated topological network properties in patients with chronic disorders of consciousness recovered from coma. Resting state fMRI data of 34 patients with unresponsive wakefulness syndrome and 25 in minimally conscious state were compared to 28 healthy controls. We investigated global and local network characteristics. Additionally, behavioral measures were correlated with the local metrics of 28 regions within the fronto-parietal network and the thalamus. In chronic disorders of consciousness, modularity at the global level was reduced suggesting a disturbance in the optimal balance between segregation and integration. Moreover, network properties were altered in several regions which are associated with conscious processing (particularly, in medial parietal, and frontal regions, as well as in the thalamus). Between minimally conscious and unconscious patients the local efficiency of medial parietal regions differed. Alterations in the thalamus were particularly evident in non-conscious patients. Most of the regions affected in patients with impaired consciousness belong to the so-called 'rich club' of highly interconnected central nodes. Disturbances in their topological characteristics have severe impact on information integration and are reflected in deficits in cognitive functioning probably leading to a total breakdown of consciousness.


Assuntos
Transtornos da Consciência/patologia , Lobo Frontal/patologia , Rede Nervosa/patologia , Lobo Parietal/patologia , Tálamo/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Análise de Variância , Estudos de Casos e Controles , Feminino , Lateralidade Funcional , Humanos , Imageamento Tridimensional , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade
16.
J Spinal Cord Med ; 37(1): 19-31, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24090372

RESUMO

CONTEXT: Past evidence has shown that invasive and non-invasive brain stimulation may be effective for relieving central pain. OBJECTIVE: To perform a topical review of the literature on brain neurostimulation techniques in patients with chronic neuropathic pain due to traumatic spinal cord injury (SCI) and to assess the current evidence for their therapeutic efficacy. METHODS: A MEDLINE search was performed using following terms: "Spinal cord injury", "Neuropathic pain", "Brain stimulation", "Deep brain stimulation" (DBS), "Motor cortex stimulation" (MCS), "Transcranial magnetic stimulation" (TMS), "Transcranial direct current stimulation" (tDCS), "Cranial electrotherapy stimulation" (CES). RESULTS: Invasive neurostimulation therapies, in particular DBS and epidural MCS, have shown promise as treatments for neuropathic and phantom limb pain. However, the long-term efficacy of DBS is low, while MCS has a relatively higher potential with lesser complications that DBS. Among the non-invasive techniques, there is accumulating evidence that repetitive TMS can produce analgesic effects in healthy subjects undergoing laboratory-induced pain and in chronic pain conditions of various etiologies, at least partially and transiently. Another very safe technique of non-invasive brain stimulation - tDCS - applied over the sensory-motor cortex has been reported to decrease pain sensation and increase pain threshold in healthy subjects. CES has also proved to be effective in managing some types of pain, including neuropathic pain in subjects with SCI. CONCLUSION: A number of studies have begun to use non-invasive neuromodulatory techniques therapeutically to relieve neuropathic pain and phantom phenomena in patients with SCI. However, further studies are warranted to corroborate the early findings and confirm different targets and stimulation paradigms. The utility of these protocols in combination with pharmacological approaches should also be explored.


Assuntos
Estimulação Encefálica Profunda/métodos , Neuralgia/etiologia , Neuralgia/terapia , Traumatismos da Medula Espinal/complicações , Encéfalo/anatomia & histologia , Encéfalo/fisiologia , Humanos
17.
Handb Clin Neurol ; 116: 599-611, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24112927

RESUMO

Transcranial magnetic stimulation (TMS) has been used extensively to characterize motor system pathophysiology in Alzheimer's disease (AD) and other forms of dementia, as well to monitor the effects of certain pharmacological agents. Among the studies focusing on motor cortical excitability measures, the most consistent finding is a significant reduction of short-latency afferent inhibition (SAI) in AD and other forms of dementia in which the cholinergic system is affected, such as dementia with Lewy bodies. SAI evaluation may thus provide a reliable biomarker of cortical cholinergic dysfunction in dementias. Moreover, most TMS studies have demonstrated cortical hyperexcitability and asymptomatic motor cortex functional reorganization in the early stages of the disease. Integrated approaches utilizing TMS together with high-density EEG have indicated impaired cortical plasticity and functional connectivity across different neural networks in AD. Paired associative stimulation-induced plasticity has also been found to be abnormal in patients with AD. The development of novel noninvasive methods of brain stimulation, in particular repetitive TMS (rTMS) and transcranial direct current stimulation (tDCS), has increased the interest in neuromodulatory techniques as potential therapeutic tools for cognitive rehabilitation in AD. Preliminary studies have revealed that rTMS and tDCS can induce beneficial effects on specific cognitive functions in AD. Future studies are warranted to replicate and extend the initial findings.


Assuntos
Encéfalo/fisiologia , Demência/terapia , Terapia por Estimulação Elétrica/métodos , Estimulação Magnética Transcraniana/métodos , Humanos , Inibição Neural/fisiologia
18.
PLoS One ; 8(9): e74572, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24073216

RESUMO

The active oddball paradigm is a candidate task for voluntary brain activation. Previous research has focused on group effects, and has largely overlooked the potential problem of interindividual differences. Interindividual variance causes problems with the interpretation of group-level results. In this study we want to demonstrate the degree of consistency in the active oddball task across subjects, in order to answer the question of whether this task is able to reliably detect conscious target processing in unresponsive patients. We asked 18 subjects to count rare targets and to ignore frequent standards and rare distractors in an auditory active oddball task. Event-related-potentials (ERPs) and time-frequency data were analyzed with permutation-t-tests on a single subject level. We plotted the group-average ERPs and time-frequency data, and evaluated the numbers of subjects showing significant differences between targets and distractors in certain time-ranges. The distinction between targets/distractors and standards was found to be significant in the time-range of the P300 in all participants. In contrast, significant differences between targets and distractors in the time-range of the P3a/b were found in 8 subjects, only. By including effects in the N1 and in a late negative component there remained 2 subjects who did not show a distinction between targets and distractors in the ERP. While time-frequency data showed prominent effects for target/distractor vs. standard, significant differences between targets and distractors were found in 2 subjects, only. The results suggest that time-frequency- and ERP-analysis of the active oddball task may not be sensitive enough to detect voluntary brain activation in unresponsive patients. In addition, we found that time-frequency analysis was even less informative than ERPs about the subject's task performance. Despite suggesting the use of more sensitive paradigms and/or analysis techniques, the present results give further evidence that electroencephalographic research should rely more strongly on single-subject analysis because interpretations of group-effects may be misleading.


Assuntos
Estimulação Acústica , Encéfalo/fisiologia , Eletroencefalografia , Potenciais Evocados/fisiologia , Tempo de Reação/fisiologia , Análise e Desempenho de Tarefas , Adulto , Mapeamento Encefálico , Feminino , Humanos , Masculino , Adulto Jovem
19.
Epilepsia ; 54 Suppl 4: 3-12, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23909849

RESUMO

A working group was created to address clinical "gaps to care" as well as opportunities for development of new treatment approaches for epilepsy. The working group primarily comprised clinicians, trialists, and pharmacologists. The group identified a need for better animal models for both efficacy and tolerability, and noted that animal models for potential disease-modifying or antiepileptogenic effect should mirror conditions in human trials. For antiseizure drugs (ASDs), current animal models have not been validated with respect to their relationship to efficacy in common epilepsy syndromes. The group performed an "expert opinion" survey of perceived efficacy of the available ASDs, and identified a specific unmet need for ASDs to treat tonic-atonic and myoclonic seizures. No correlation has as yet been demonstrated between animal models of tolerability and adverse effects (AEs), versus tolerability in humans. There is a clear opportunity for improved therapies in relation to dose-related AEs. The group identified common and rare epilepsy syndromes that could represent opportunities for clinical trials. They identified opportunities for antiepileptogenic (AEG) therapies in both adults and children, acknowledging that the presence of a biomarker would substantially improve the chances of a successful trial. However, the group acknowledged that disease-modifying therapies (given after the first seizure or after the development of epilepsy) would be easier to study than AEG therapies.


Assuntos
Anticonvulsivantes/uso terapêutico , Descoberta de Drogas , Avaliação Pré-Clínica de Medicamentos , Drogas em Investigação/uso terapêutico , Epilepsia/tratamento farmacológico , Necessidades e Demandas de Serviços de Saúde , Animais , Ensaios Clínicos como Assunto , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Epilepsias Mioclônicas/tratamento farmacológico , Epilepsia Generalizada/tratamento farmacológico , Epilepsia Tônico-Clônica/tratamento farmacológico , Humanos
20.
Int J Psychophysiol ; 87(1): 35-41, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23123181

RESUMO

Motor imagery tasks are well established procedures in brain computer interfaces, but are also used in the assessment of patients with disorders of consciousness. For testing awareness in unresponsive patients it is necessary to know the natural variance of brain responses to motor imagery in healthy subjects. We examined 22 healthy subjects using EEG in three conditions: movement of both hands, imagery of the same movement, and an instruction to hold both hands still. Single-subject non-parametric statistics were applied to the fast-Fourier transformed data. Most effects were found in the α- and ß-frequency ranges over central electrodes, that is, in the µ-rhythm. We found significant power changes in 18 subjects during movement and in 11 subjects during motor imagery. In 8 subjects these changes were consistent over both conditions. The significant power changes during movement were a decrease of µ-rhythm. There were 2 subjects with an increase and 9 subjects with a decrease of µ-rhythm during imagery. α and ß are the most responsive frequency ranges, but there is a minor number of subjects who show a synchronization instead of the more common desynchronization during motor imagery. A (de)synchronization of µ-rhythm can be considered to be a normal response.


Assuntos
Imaginação/fisiologia , Percepção de Movimento/fisiologia , Movimento/fisiologia , Desempenho Psicomotor/fisiologia , Estimulação Acústica/métodos , Adulto , Eletroencefalografia/métodos , Feminino , Humanos , Masculino , Adulto Jovem
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