RESUMO
BACKGROUND: Sensory impairment is associated with reduced functional recovery in stroke survivors. Invasive vagus nerve stimulation (VNS) paired with rehabilitative interventions improves motor recovery in chronic stroke. Noninvasive approaches, for example, transcutaneous auricular VNS (taVNS) are safe, well-tolerated and may also improve motor function in those with residual weakness. We report the impact of taVNS paired with a motor intervention, repetitive task practice, on sensory recovery in a cohort of patients with chronic stroke. METHODS: Twelve participants who were more than 3 months postischemic stroke with residual upper limb weakness received 18â¯×â¯1 hour sessions over 6 weeks with an average of at least 300 repetitions of functional arm movements per session concurrently with taVNS at maximum tolerated intensity. Light touch and proprioception were scored as part of the Upper Limb Fugl-Meyer (UFM) assessment at baseline and postintervention (score range for sensation 0-12). RESULTS: Eleven participants (92%) had sensory impairment at baseline of whom 7 (64%) regained some sensation (proprioception nâ¯=â¯6 participants, light touch nâ¯=â¯2, both modalities n =â¯1) postintervention. The maximal increase in UFM sensation score (3 points) was seen in the patient with the greatest improvement in motor function. CONCLUSIONS: taVNS paired with motor rehabilitation may improve sensory recovery in chronic stroke patients. The relative contribution of motor and sensory rehabilitation to overall functional recovery in chronic stroke needs further characterization in a larger, phase 2 study.
Assuntos
Terapia por Exercício , Atividade Motora , Sensação , Reabilitação do Acidente Vascular Cerebral/métodos , Acidente Vascular Cerebral/terapia , Estimulação Elétrica Nervosa Transcutânea , Extremidade Superior/inervação , Estimulação do Nervo Vago , Idoso , Doença Crônica , Orelha , Estudos de Viabilidade , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Plasticidade Neuronal , Propriocepção , Recuperação de Função Fisiológica , Acidente Vascular Cerebral/diagnóstico , Acidente Vascular Cerebral/fisiopatologia , Fatores de Tempo , Tato , Percepção do Tato , Resultado do TratamentoRESUMO
BACKGROUND: Invasive vagus nerve stimulation (VNS) has the potential to enhance the effects of physiotherapy for upper limb motor recovery after stroke. Noninvasive, transcutaneous auricular branch VNS (taVNS) may have similar benefits, but this has not been evaluated in stroke recovery. We sought to determine the feasibility of taVNS delivered alongside upper limb repetitive task-specific practice after stroke and its effects on a range of outcome measures evaluating limb function. MATERIALS AND METHODS: Thirteen participants at more than 3 months postischemic stroke with residual upper limb dysfunction were recruited from the community of Sheffield, United Kingdom (October-December 2016). Participants underwent 18 × 1-hour sessions over 6 weeks in which they made 30-50 repetitions of 8-10 arm movements concurrently with taVNS (NEMOS; Cerbomed, Erlangen, Germany, 25 Hz, .1-millisecond pulse width) at maximum tolerated intensity (mA). An electrocardiogram and rehabilitation outcome scores were obtained at each visit. Qualitative interviews determined the acceptability of taVNS to participants. RESULTS: Median time after stroke was 1.16 years, and baseline median/interquartile range upper limb Fugl-Meyer (UFM) score was 63 (54.5-99.5). Participants attended 92% of the planned treatment sessions. Three participants reported side effects, mainly fatigue, but all performed mean of more than 300 arm repetitions per session with no serious adverse events. There was a significant change in the UFM score with a mean increase per participant of 17.1 points (standard deviation 7.8). CONCLUSION: taVNS is feasible and well-tolerated alongside upper limb repetitive movements in poststroke rehabilitation. The motor improvements observed justify a phase 2 trial in patients with residual arm weakness.
Assuntos
Reabilitação do Acidente Vascular Cerebral , Extremidade Superior , Estimulação do Nervo Vago , Idoso , Terapia Combinada , Orelha , Estudos de Viabilidade , Feminino , Humanos , Entrevistas como Assunto , Masculino , Pessoa de Meia-Idade , Paresia/etiologia , Paresia/fisiopatologia , Paresia/terapia , Satisfação do Paciente , Projetos Piloto , Pesquisa Qualitativa , Recuperação de Função Fisiológica , Acidente Vascular Cerebral/complicações , Acidente Vascular Cerebral/fisiopatologia , Acidente Vascular Cerebral/terapia , Reabilitação do Acidente Vascular Cerebral/efeitos adversos , Resultado do Tratamento , Extremidade Superior/fisiopatologia , Estimulação do Nervo Vago/efeitos adversos , Estimulação do Nervo Vago/métodosRESUMO
Embedded three-dimensional (3-D) metal-insulator-metal (MIM) decoupling capacitors with high-κ dielectric films of high capacitance and long-life time are increasingly needed on integrated chips. Towards achieving better electrical performance, there is a need for investigation into the influence of the variation in atomic layer deposition (ALD) parameters used for thin high-κ dielectric films (10 nm) made of Al2O3-doped ZrO2. This variation should always be related to the structural uniformity, the electrical characteristics, and the electrical reliability of the capacitors. This paper discusses the influence of different Zr precursor pulse times per ALD cycle and deposition temperatures (283 °C/556 K and 303 °C/576 K) with respect to the capacitance density (C-V), voltage linearity and leakage current density (I-V). Moreover, the dielectric breakdown and TDDB characteristics are evaluated under a wide range of temperatures (223-423 K).