Electroencephalography in Orthostatic Tremor: A Prospective Study of 30 Patients.

Background: Orthostatic tremor (OT) is characterized by a sensation of instability while standing, associated with high frequency (1318 Hz) tremor in the legs. Small retrospective series have reported electroencephalography (EEG) findings in OT with discordant results.

Methods: We prospectively enrolled 30 OT subjects.

Ataxia Prevalence in Primary Orthostatic Tremor.

Background: The exact pathophysiology of primary Orthostatic Tremor (OT) is unknown. A central oscillator is assumed, and previous imaging studies show involvement of cerebellar pathways. However, the presence of ataxia on clinical exam is disputed.

Fractal auditory stimulation has greater benefit for people with Parkinson's disease showing more random gait pattern.

Background: Healthy gait dynamics are characterized by the presence of fractal, persistent stride-to-stride variations, which become more random with Parkinson's disease (PD). Rhythmic auditory stimulation with fractal beat-to-beat variations can change gait dynamics in people with PD toward more persistence.

Research Question: How does gait in people with PD change when synchronizing steps with fractal melodic metronomes with different step-to-beat ratios, and which stimulus do they prefer?

Methods: In this cross-sectional study, 15 people with PD and 15 healthy older adults walked over-ground in three conditions: self-paced, paced by a fractal auditory stimulus with a 1:1 step-to-beat ratio ('metronome'), and fractal auditory stimulus with a 1:2 step-to-beat ratio ('music').

Attending to Total Pain in Juvenile Huntington Disease: A Case Report Informed by Narrative Review of the Literature.

Objectives: To consider the impact of juvenile Huntington disease (JHD) from a biomedical, symptom burden, and total pain palliative care perspective.

Methods: This case report was informed by a narrative review of the literature with inclusion of expert opinion from pediatric palliative care, an adult and pediatric neurologist, and a child psychiatrist. Audio-recorded qualitative interview and coauthorship with the pediatric patient's primary caregiver (his mother).

Smartphone Apps Provide a Simple, Accurate Bedside Screening Tool for Orthostatic Tremor.

Background: Orthostatic Tremor (OT) is characterized by the presence of a sensation of instability while standing, associated with high frequency (13-18 Hz) lower extremity tremor. Diagnosis is confirmed with surface electromyography (EMG). An accurate screening tool that could be used in the routine clinical setting, without any specialized equipment, would be useful in earlier detection of OT and judicial use of additional testing.

Gait Dynamics in Parkinson's Disease: Short Gait Trials "Stitched" Together Provide Different Fractal Fluctuations Compared to Longer Trials.

The fractal analysis of stride-to-stride fluctuations in walking has become an integral part of human gait research. Fractal analysis of stride time intervals can provide insights into locomotor function and dysfunction, but its application requires a large number of strides, which can be difficult to collect from people with movement disorders such as Parkinson's disease. It has recently been suggested that "stitching" together short gait trials to create a longer time series could be a solution.

Comprehensive, blinded assessment of balance in orthostatic tremor.

Introduction: Orthostatic Tremor (OT) is a movement disorder characterized by a sensation of unsteadiness and tremors in the 13-18 Hz range present upon standing. The pathophysiology of OT is not well understood but there is a relationship between the sensation of instability and leg tremors. Despite the sensation of unsteadiness, OT patients do not fall often and balance in OT has not been formally assessed.

Continuous non-invasive monitoring to detect covert autonomic dysfunction in Parkinson's disease.

Background: Lightheadedness on standing is a disabling symptom in Parkinson's disease associated with orthostatic hypotension and is thought to represent cardiovascular autonomic dysfunction. Traditional orthostatic blood pressures are normal in some patients with lightheadedness and other measures of cardiovascular dysautonomia can be insensitive. In this study, we used continuous non-invasive arterial pressure monitoring to measure beat-to-beat changes in blood pressure and heart rate on standing and during Valsalva as a potential marker of autonomic dysfunction.

Botulinum toxin in the management of blepharospasm: current evidence and recent developments.

Blepharospasm is a focal (although usually bilateral) dystonia of the orbicularis oculi muscles, producing excessive eye closure. This produces significant disability through functional blindness. Botulinum neurotoxins (BoNT) have become the treatment of choice for blepharospasm; the impressive response rate and the tolerable safety profile have been proven through multiple clinical studies.

Hydrodynamic determinants of cell necrosis and molecular delivery produced by pulsed laser microbeam irradiation of adherent cells.

Time-resolved imaging, fluorescence microscopy, and hydrodynamic modeling were used to examine cell lysis and molecular delivery produced by picosecond and nanosecond pulsed laser microbeam irradiation in adherent cell cultures. Pulsed laser microbeam radiation at λ = 532 nm was delivered to confluent monolayers of PtK2 cells via a 40×, 0.8 NA microscope objective.

Examination of axonal injury and regeneration in micropatterned neuronal culture using pulsed laser microbeam dissection.

We describe the integrated use of pulsed laser microbeam irradiation and microfluidic cell culture methods to examine the dynamics of axonal injury and regeneration in vitro. Microfabrication methods are used to place high purity dissociated central nervous system neurons in specific regions that allow the axons to interact with permissive and inhibitory substrates. Acute injury to neuron bundles is produced via the delivery of single 180 ps duration, lambda = 532 nm laser pulses.

Biophysical response to pulsed laser microbeam-induced cell lysis and molecular delivery.

Cell lysis and molecular delivery in confluent monolayers of PtK(2) cells are achieved by the delivery of 6 ns, lambda = 532 nm laser pulses via a 40x, 0.8 NA microscope objective. With increasing distance from the point of laser focus we find regions of (a) immediate cell lysis; (b) necrotic cells that detach during the fluorescence assays; (c) permeabilized cells sufficient to facilitate the uptake of small (3 kDa) FITC-conjugated Dextran molecules in viable cells; and (d) unaffected, viable cells.

Laser-induced mixing in microfluidic channels.

We demonstrate a novel strategy for mixing solutions and initiating chemical reactions in microfluidic systems. This method utilizes highly focused nanosecond laser pulses from a Q-switched Nd:YAG laser at lambda = 532 nm to generate cavitation bubbles within 100- and 200-microm-wide microfluidic channels containing the parallel laminar flow of two fluids. The bubble expansion and subsequent collapse within the channel disrupts the laminar flow of the parallel fluid streams and produces a localized region of mixed fluid.

Pulsed laser microbeam-induced cell lysis: time-resolved imaging and analysis of hydrodynamic effects.

Time-resolved imaging was used to examine the use of pulsed laser microbeam irradiation to produce cell lysis. Lysis was accomplished through the delivery of 6 ns, lambda=532 nm laser pulses via a 40x, 0.8 NA objective to a location 10 microm above confluent monolayers of PtK2 cells.