Aspartame use and Parkinson's disease: review of associated effects on neurotransmitters, oxidative stress, and cognition.

Objective: The purpose of this review was to assess the current evidence regarding the associated physiological and cognitive effects of aspartame (APM) consumption and Parkinson's Disease (PD). METHODS: A total of 32 studies demonstrating effects of APM on monoamine deficiencies, oxidative stress, and cognitive changes were reviewed. RESULTS: Multiple studies demonstrated decreased brain dopamine, decreased brain norepinephrine, increased oxidative stress, increased lipid peroxidation, and decreased memory function in rodents after APM use. In addition, PD animal models have been found to be more sensitive to the effects of APM. DISCUSSION: Overall, studies of APM use over time yielded more consistent results; however, no study has examined long-term effects on APM in human PD patients. Based on the current evidence, long-term human based observational research is needed to further investigate the potential effect of APM on PD.

Performance of the Dreem 2 EEG headband, relative to polysomnography, for assessing sleep in Parkinson's disease.

GOAL AND AIMS: To pilot the feasibility and evaluate the performance of an EEG wearable for measuring sleep in individuals with Parkinson's disease. FOCUS TECHNOLOGY: Dreem Headband, Version 2. REFERENCE TECHNOLOGY: Polysomnography. SAMPLE: Ten individuals with Parkinson's disease. DESIGN: Individuals wore Dreem Headband during a single night of polysomnography. CORE ANALYTICS: Comparison of summary metrics, bias, and epoch-by-epoch analysis. ADDITIONAL ANALYTICS AND EXPLORATORY ANALYSES: Correlation of summary metrics with demographic and Parkinson's disease characteristics. CORE OUTCOMES: Summary statistics showed Dreem Headband overestimated several sleep metrics, including total sleep, efficiency, deep sleep, and rapid eye movement sleep, with an exception in light sleep. Epoch-by-epoch analysis showed greater specificity than sensitivity, with adequate accuracy across sleep stages (0.55-0.82). IMPORTANT SUPPLEMENTAL OUTCOMES: Greater Parkinson's disease duration and rapid eye movement behavior were associated with more wakefulness, and worse Parkinson's disease motor symptoms were associated with less deep sleep. CORE CONCLUSION: The Dreem Headband performs similarly in Parkinson's disease as it did in non-Parkinson's disease samples and shows promise for improving access to sleep assessment in people with Parkinson's disease.

Dynamic networks of cortico-muscular interactions in sleep and neurodegenerative disorders.

The brain plays central role in regulating physiological systems, including the skeleto-muscular and locomotor system. Studies of cortico-muscular coordination have primarily focused on associations between movement tasks and dynamics of specific brain waves. However, the brain-muscle functional networks of synchronous coordination among brain waves and muscle activity rhythms that underlie locomotor control remain unknown. Here we address the following fundamental questions: what are the structure and dynamics of cortico-muscular networks; whether specific brain waves are main network mediators in locomotor control; how the hierarchical network organization relates to distinct physiological states under autonomic regulation such as wake, sleep, sleep stages; and how network dynamics are altered with neurodegenerative disorders. We study the interactions between all physiologically relevant brain waves across cortical locations with distinct rhythms in leg and chin muscle activity in healthy and Parkinson's disease (PD) subjects. Utilizing Network Physiology framework and time delay stability approach, we find that 1) each physiological state is characterized by a unique network of cortico-muscular interactions with specific hierarchical organization and profile of links strength; 2) particular brain waves play role as main mediators in cortico-muscular interactions during each state; 3) PD leads to muscle-specific breakdown of cortico-muscular networks, altering the sleep-stage stratification pattern in network connectivity and links strength. In healthy subjects cortico-muscular networks exhibit a pronounced stratification with stronger links during wake and light sleep, and weaker links during REM and deep sleep. In contrast, network interactions reorganize in PD with decline in connectivity and links strength during wake and non-REM sleep, and increase during REM, leading to markedly different stratification with gradual decline in network links strength from wake to REM, light and deep sleep. Further, we find that wake and sleep stages are characterized by specific links strength profiles, which are altered with PD, indicating disruption in the synchronous activity and network communication among brain waves and muscle rhythms. Our findings demonstrate the presence of previously unrecognized functional networks and basic principles of brain control of locomotion, with potential clinical implications for novel network-based biomarkers for early detection of Parkinson's and neurodegenerative disorders, movement, and sleep disorders.

Dry Eye Syndrome and Sicca Complex are Commonly Found in Patients with Postural Orthostatic Tachycardia Syndrome.

PURPOSE: Patients with postural orthostatic tachycardia syndrome (POTS) present to outpatient dysautonomia clinics endorsing a wide range of symptoms. Dry eyes and mouth, or sicca complex are frequently reported. This retrospective study investigates the incidence and quantifies the severity of dry eye syndrome (DES) in patients with POTS. PATIENTS AND METHODS: This retrospective study compiles survey results, and dry eye clinical data from twenty-three POTS patients (22 females, average age 34.9 and st dev 14.0 years) surveyed during their initial or follow-up appointments. Patient's medication lists were documented to account for anticholinergics, antihistamines, and anticholinesterase use. Patients endorsing dry eye symptoms were tested with Schirmer's test strips to identify clinically dry eyes and stratified for severity. RESULTS: Sixty-five percent of patients endorsed dry eye symptoms (15/23). Seventy-four percent of patients endorsed dry mouth symptoms (17/23). Among patients endorsing dry eyes, 81% of eyes had decreased tear production with Schirmer's strip wetting less than 10 mm/5 min (13/16). CONCLUSION: DES is an additional and significant disease burden for the POTS patient population. Dry eye and exocrine gland function should be evaluated as part of the dysautonomia work up with referral to ophthalmology as appropriate. Patients with clinically dry eyes who report additional autonomic dysfunction should be further evaluated for widespread autonomic dysfunction.

Electroencephalographic patterns during sleep in children with chromosome 15q11.2-13.1 duplications (Dup15q).

Our objective was to define the EEG features during sleep of children with neurodevelopmental disorders due to copy number gains of 15q11-q13 (Dup15q). We retrospectively reviewed continuous EEG recordings of 42 children with Dup15q (mean age: eight years, 32 with idic15), and data collected included background activity, interictal epileptiform discharges, sleep organization, and ictal activity. Three patterns were recognized: Pattern 1: Alpha­delta sleep was noted in 14 children (33%), not associated with any clinical changes. Pattern 2: Electrical status epilepticus in sleep was noted in 15 children (35%), all diagnosed with treatmentresistant epilepsy. Thirteen of the 15 children had clinical seizures. Pattern 3: Frequent bursts of high amplitude bifrontal predominant, paroxysmal fast activity (12­15 Hz) during non-REM sleep was noted in 15 children (35%). All 15 children had treatment-resistant epilepsy. This is the first report of electroencephalographic patterns during sleep of children with Dup15q reporting alpha-delta rhythms, CSWS, and high amplitude fast frequencies. Alpha-delta rhythms are described in children with dysautonomia and/or mood disorders and CSWS in children with developmental regression. The significance of these findings in cognitive function and epilepsy for the children in our cohort needs to be determined with follow-up studies.

Visual hallucinations in photographs in Parkinson's disease.

Visual hallucinations are reported in 16-37% of drug-treated patients with Parkinson's disease (PD) and are the most common hallucinations in PD. We report two patients with PD with symptoms that uniquely integrate visual hallucinations and delusions. We report two cases of patients with PD with visual hallucinations who saw the persistence of these hallucinations in photographs. These pictures were taken to prove the absence of these hallucinations. We believe this is the first description of this peculiar phenomenon, in which hallucinations or illusions could be replicated in photographs. Both patients had delusions associated with the images and we speculate that the images they saw in the photographs represent a further delusion, hence a 'delusional hallucination' or 'delusional illusion.' We believe that delusions fostering hallucinations are rare.