Differential role of dopamine in emotional attention and memory: evidence from Parkinson's disease.

Consistent with the hypothesis that dopamine is implicated in the processing of salient stimuli relevant to the modification of various behavioral responses, Parkinson's disease is associated with emotional blunting. To address the hypothesis that emotional attention and memory are modulated by dopaminergic neurotransmission in Parkinson's disease, we assessed 15 nondemented patients with Parkinson's disease while on and off dopaminergic medication and 15 age-matched healthy controls. Visual stimuli were presented, and recognition was used to assess emotional memory.

Preserved emotional modulation of motor response time despite psychomotor slowing in young-old adults.

Whereas aging affects cognitive and psychomotor processes negatively, the impact of aging on emotional processing is less clear. Using an "old-new" binary decision task, we ascertained the modulation of response latencies after presentation of neutral and emotional pictures in "young" (M = 27.1 years) and "young-old" adults with a mean age below 60 (M = 57.

Emotional processing affects movement speed.

Emotions can affect various aspects of human behavior. The impact of emotions on behavior is traditionally thought to occur at central, cognitive and motor preparation stages. Using EMG to measure the effects of emotion on movement, we found that emotional stimuli differing in valence and arousal elicited highly specific effects on peripheral movement time.

Do A-waves help predict intravenous immunoglobulin response in multifocal motor neuropathy without block?

Introduction: Are there electrophysiological findings that predict response to intravenous immunoglobulin (IVIg) in patients with lower motor neuron (LMN) syndromes without multifocal conduction block (MCB)?

Methods: We enrolled 9 patients with LMN syndromes without MCB to receive 18 weeks of IVIg therapy. Response was measured at weeks 2 and 18 using the Appel Amyotrophic Lateral Sclerosis (AALS) score (includes grip and pincer strength measures), ALS Functional Rating Scale (ALSFRS), and electrophysiological measures, including motor unit estimates (MUNEs).

Results: No change occurred in AALS or ALSFRS scores posttreatment.

Usefulness of tilt-induced heart rate changes in the differential diagnosis of vasovagal syncope and chronic autonomic failure.

Objective: To determine whether the heart rate changes during tilt table testing could be used in the differential diagnosis between vasovagal syncope and chronic autonomic failure.

Methods: We compared the relationship between electrocardiographic R-R intervals and beat-to-beat blood pressure in 43 patients with typical vasovagal responses and 30 patients with chronic autonomic failure (6 pure autonomic failure, 23 multiple system atrophy, and 1 Parkinson's disease).

Results: In every patient with vasovagal syncope, at the time when the blood pressure was falling, it was possible to identify at least 12 successive heart beats (mean 33 +/- 2 heart beat, range 12-57) when blood pressure and heart rate fell in parallel, i.

Effect of medication and psychotherapy on heart rate variability in panic disorder.

Background: Panic disorder (PD) patients have been shown to have reduced heart rate variability (HRV). Low HRV has been associated with elevated risk for cardiovascular disease. Our aim was to investigate the effects of treatment on heart rate (HR) in patients with PD through a hyperventilation challenge.

ALSFRS and appel ALS scores: discordance with disease progression.

Progression of disease and effectiveness of therapy in patients with amyotrophic lateral sclerosis (ALS) are determined by both questionnaire- and examination-based measures. To determine whether both types of measurement tools are equally predictive at all stages of disease, we compared questionnaire-based ALS Functional Rating Scale (ALSFRS) scores to the examination-based Appel ALS (AALS) scores at different stages of disease. Same-day scores were obtained during 174 visits in 62 patients with definite or probable ALS.

A ketogenic diet as a potential novel therapeutic intervention in amyotrophic lateral sclerosis.

Background: The cause of neuronal death in amyotrophic lateral sclerosis (ALS) is uncertain but mitochondrial dysfunction may play an important role. Ketones promote mitochondrial energy production and membrane stabilization.

Results: SOD1-G93A transgenic ALS mice were fed a ketogenic diet (KD) based on known formulations for humans.

Electrical activation of the human vestibulo-sympathetic reflex.

Muscle sympathetic nerve activity (MSNA) is modulated on a beat-to-beat basis by the baroreflex. Vestibular input from the otolith organs also modulates MSNA, but characteristics of the vestibulo-sympathetic reflex (VSR) are largely unknown. The purpose of this study was to elicit the VSR with electrical stimulation to estimate its latency in generating MSNA.

Norepinephrine precursor therapy in neurogenic orthostatic hypotension.

Background: In patients with neurogenic orthostatic hypotension (NOH), the availability of the sympathetic neurotransmitter norepinephrine (NE) in the synaptic cleft is insufficient to maintain blood pressure while in the standing posture.

Methods And Results: We determined the effect of oral administration of the synthetic amino acid L-threo-3,4-dihydroxyphenylserine (L-DOPS), which is decarboxylated to NE by the enzyme L-aromatic amino acid decarboxylase (L-AADC) in neural and nonneural tissue, on blood pressure and orthostatic tolerance in 19 patients with severe NOH (8 with pure autonomic failure and 11 with multiple-system atrophy). A single-blind dose-titration study determined the most appropriate dose for each patient.

Midodrine in neurally mediated syncope: a double-blind, randomized, crossover study.

Neurally mediated syncope is the most frequent cause of syncope in patients without structural heart disease. Its most common trigger is a reduction in venous return to the heart due to excessive venous pooling in the legs. We conducted a double-blind, randomized, crossover trial to investigate the efficacy of midodrine, a selective alpha-1 adrenergic agonist that decreases venous capacitance, in preventing neurally mediated syncope triggered by passive head-up tilt.