Effects of deep brain stimulation on the kinematics of gait and balance in patients with idiopathic Parkinson's disease.

BACKGROUND: Advanced stages of idiopathic Parkinson's disease are often characterised by gait alterations and postural instability. Despite improvements in patients' motor symptoms after deep brain stimulation of the subthalamic nucleus, its effects on gait and balance remain a matter of debate. This study investigated the effects of deep brain stimulation on balance and kinematic parameters of gait. METHODS: The gait of 26 patients with advanced idiopathic Parkinson's disease was analysed before and after (between 3 and 6 months) after bilateral deep brain stimulation of the subthalamic nucleus. Computerised analysis was used to study cadence, number of cycles with the correct support sequence, number of cycles, duration of the cycle stages, and knee and ankle goniometry. Balance, postural instability, and mobility were assessed using the Tinetti and Timed Up and Go test. FINDINGS: After stimulation, the following changes were significant (p < 0.01): number of cycles with the correct support sequence, number of total cycles, and foot contact. Patients improved significantly (p < 0.01) in the Tinetti and Timed Up and Go tests, the risk factors for falls changed from high (median 17) to low (median 25), and they improved from minor dependence (statistical median 14) to normality (statistical median 8.70). INTERPRETATION: Deep brain stimulation to inhibit hyperactivity of the subthalamic nucleus was associated with an improvement in the space-time variables of gait and balance in patients with Parkinson's disease for up to 3-6 months. These results highlight the major role of the subthalamic nucleus in motor control mechanisms during locomotion and balance.

Combined Stimulation of the Substantia Nigra and the Subthalamic Nucleus for the Treatment of Refractory Gait Disturbances in Parkinson's Disease: A Preliminary Study.

Deep brain stimulation of the subthalamic nucleus is efficient for the treatment of motor symptoms (i.e., tremors) in patients with Parkinson's disease. Gait disorders usually appear during advanced stages of idiopathic Parkinson's disease in up to 80% of patients and have an important impact on their quality of life. The effects of deep brain stimulation of the subthalamic nucleus on gait and balance are still controversial. For this reason, alternative targets have been considered, such as stimulation of the pedunculopontine nucleus and the pars reticulata of substantia nigra, involved in the integration of the functional connections for gait. Due to the proximity of the subthalamic nucleus to the substantia nigra, their combined stimulation is feasible and may lead to better outcomes, improving axial symptoms. Our objective was to prospectively compare simultaneous stimulation of both structures versus conventional subthalamic stimulation in improving gait disorders. In ten patients with advanced Parkinson's disease, deep brain stimulation leads (eight linear contacts) were implanted, and gait analysis was performed 6 months after surgery in off-stimulation and after 4 weeks of dual or single subthalamic stimulation. An improvement in gait parameters was confirmed with both stimulation conditions, with better results with combined substantia nigra and subthalamic stimulation compared with conventional subthalamic stimulation. Further studies are needed to determine if this effect remains after long-term dual-target stimulation.

Neuromuscular involvement in COVID-19 critically ill patients.

OBJECTIVE: Coronavirus disease 2019 (COVID-19) has a high incidence of intensive care admittance due to the severe acute respiratory syndrome (SARS). Intensive care unit (ICU)-acquired weakness (ICUAW) is a common complication of ICU patients consisting of symmetric and generalised weakness. The aim of this study was to determine the presence of myopathy, neuropathy or both in ICU patients affected by COVID-19 and whether ICUAW associated with COVID-19 differs from other aetiologies. METHODS: Twelve SARS CoV-2 positive patients referred with the suspicion of critical illness myopathy (CIM) or polyneuropathy (CIP) were included between March and May 2020. Nerve conduction and concentric needle electromyography were performed in all patients while admitted to the hospital. Muscle biopsies were obtained in three patients. RESULTS: Four patients presented signs of a sensory-motor axonal polyneuropathy and seven patients showed signs of myopathy. One muscle biopsy showed scattered necrotic and regenerative fibres without inflammatory signs. The other two biopsies showed non-specific myopathic findings. CONCLUSIONS: We have not found any distinctive features in the studies of the ICU patients affected by SARS-CoV-2 infection. SIGNIFICANCE: Further studies are needed to determine whether COVID-19-related CIM/CIP has different features from other aetiologies. Neurophysiological studies are essential in the diagnosis of these patients.

Análisis cuantitativo de la marcha en pacientes con enfermedad de Parkinson avanzada / Quantitative gait analysis in patients with advanced Parkinson’s disease

Objetivo. Describir las alteraciones de la marcha e inestabilidad postural en un grupo de pacientes con enfermedad de Parkinson (EP) avanzada. Pacientes y métodos. Se analizó la marcha de pacientes con EP en estadio avanzado on medicación. Por medio de un sistema de análisis computarizado del movimiento, se estudiaron las variables cinemáticas: cadencia, número de ciclos con apoyo correcto (ciclos HFPS), número de ciclos totales, duración de las fases del ciclo, electromiografía, y goniometría de rodilla y tobillo. La valoración clínica del equilibrio y la inestabilidad postural se completó con los tests Tinetti y Timed Up & Go. Resultados. El análisis mostró alteraciones en los parámetros espaciotemporales con respecto a los rangos de normalidad: disminución de los ciclos HFPS, aumento del número total de ciclos y alteración de la cadencia en muchos pacientes, y conservación de la cadencia media dentro de los límites de la normalidad, aumento de la duración de la fase de apoyo, disminución del apoyo monopodal y alteración del rango articular de la rodilla y el tobillo. Asimismo, se observó una alteración en las puntuaciones obtenidas en las escalas clínicas, que mostraban un aumento del factor de riesgo de caídas y dependencia leve. Conclusión. La cuantificación mediante análisis objetivo de las variables cinéticas y cinemáticas en los pacientes con EP puede emplearse como herramienta para establecer la influencia de las distintas alternativas terapéuticas en el trastorno de la marcha (AU)

Aim. To describe the gait disorders and postural instability in a group of patients with advanced Parkinson’s disease (PD). Patients and Methods. Gait was analysed in patients in advanced stages of PD on medication. Using a computerised analysis system, we studied the kinematic variables: cadence, number of correct gait cycles (HFPS cycles), total number of cycles, duration of the phases of the cycle, electromyography and a goniometric study of the knee and the ankle. The clinical appraisal of balance and postural instability was completed with the Tinetti and Timed Up & Go tests. Results. The analysis showed alterations in the spatio-temporal parameters with respect to the ranges considered to be normal: reduction of the HFPS cycles, increase in the total number of cycles and alteration of the cadence in many patients. It also revealed that the mean cadence was kept within the limits of normal values, an increase in the duration of the contact phase, reduction of monopodal support and alteration of the joint range of motion of the knee and the ankle. Likewise, changes are also observed in the scores obtained on the clinical scales, which show an increase in the risk factor for falls and mild dependence. Conclusion. Quantification by objective analysis of the kinetic and kinematic variables in patients with PD can be used as a tool to establish the influence of the different therapeutic alternatives in gait disorders (AU)