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.

A case of parasympathetic hyperactivity and associated Parry-Romberg syndrome.

This case report describes a 46-year-old female with a history of multiple endocrine neoplasia type 1 syndrome status post-parathyroidectomy, thymectomy via robotic video-assisted thoracoscopic surgery, and pituitary adenoma resection presenting with parasympathetic hyperactivity and Parry-Romberg syndrome. Parry-Romberg syndrome is a rare disorder that manifests as facial hemiatrophy. Reported symptoms include cognitive dysfunction, olfactory hallucinations, and parasympathetic hyperactivity: miosis of the right eye, anhidrosis, diarrhea, urinary incontinence, bowel incontinence, and orthostatic hypotension. Previous reports have noted associations between Parry-Romberg syndrome and sympathetic hyperactivity and dysregulation. This case report focuses on an association between Parry-Romberg syndrome and unopposed parasympathetic activity.

Self-Reported Exercise Trends in Parkinson's Disease Patients.

OBJECTIVE: To examine trends in type, frequency, and effectiveness of different modes of exercise in patients with Parkinson's Disease (PD). BACKGROUND: Exercise has been shown to improve symptoms in PD patients. Recent studies suggest that dance may be a particularly helpful exercise option. However, it remains unclear how the benefits of various forms of exercise compare to dance and to each other. Information on these trends can help inform future exercise programs for PD patients. METHOD: 55 PD patients completed a survey on their exercise frequency, the impact of exercise on their symptoms, and whether they exercise alone or in groups. 9 PD patients who attend dance therapy classes completed an extended survey with additional questions comparing the benefit of dance therapy to traditional forms of exercise. RESULTS: Of the 64 patients surveyed, 67% of patients exercised at least twice a week for at least 30 minutes at a time, and 28% of patients exercised alone only. Walking was most commonly reported (77%), followed by stretching (52%), and weights (28%). 97% of patients who exercised noted mitigation of their PD symptoms. Additionally, a significantly greater percentage of patients who exercised in groups reported symptomatic improvements compared to patients who only exercised alone (p = 0.03). CONCLUSION: More patients who participated in group exercise reported symptomatic improvement compared to those who exercised strictly alone. This suggests that the psychosocial and cognitive component of group therapy, such as dance, may confer additional benefits to PD patients.

Education Research: A framework for global health curricula for neurology trainees.

As the global burden of neurologic disease increases, educating future neurologists about the principles of global health through global health curricula is of utmost importance. However, few neurology residency training programs have developed and implemented comprehensive global health curricula. This report outlines the design, implementation, and evaluation of the University of Massachusetts Medical School neurology residency global health curriculum. Using accepted curriculum development methods and incorporating an innovative use of technology, we created a global health curriculum focused on neurology to engage trainees. The implementation of curricula and organization of elective opportunities also incorporates learning objectives and an evaluation process. The University of Massachusetts Medical School neurology global health curriculum can be used as a framework for other residency programs developing global health programs. Global health education increases young neurologists' awareness of the growing burden of neurologic disease and, subsequently, may motivate them to address the need for neurologic expertise around the world.

Dermatological Manifestations of Postural Tachycardia Syndrome Are Common and Diverse.

BACKGROUND AND PURPOSE: Postural tachycardia syndrome (POTS) is a syndrome of orthostatic intolerance in the setting of excessive tachycardia with orthostatic challenge, and these symptoms are relieved when recumbent. Apart from symptoms of orthostatic intolerance, there are many other comorbid conditions such as chronic headache, fibromyalgia, gastrointestinal disorders, and sleep disturbances. Dermatological manifestations of POTS are also common and range widely from livedo reticularis to Raynaud's phenomenon. METHODS: Questionnaires were distributed to 26 patients with POTS who presented to the neurology clinic. They were asked to report on various characteristics of dermatological symptoms, with their answers recorded on a Likert rating scale. Symptoms were considered positive if patients answered with "strongly agree" or "agree", and negative if they answered with "neutral", "strongly disagree", or "disagree". RESULTS: The most commonly reported symptom was rash (77%). Raynaud's phenomenon was reported by over half of the patients, and about a quarter of patients reported livedo reticularis. The rash was most commonly found on the arms, legs, and trunk. Some patients reported that the rash could spread, and was likely to be pruritic or painful. Very few reported worsening of symptoms on standing. CONCLUSIONS: The results suggest that dermatological manifestations in POTS vary but are highly prevalent, and are therefore of important diagnostic and therapeutic significance for physicians and patients alike to gain a better understanding thereof. Further research exploring the underlying pathophysiology, incidence, and treatment strategies is necessary.

The youngest reported case of corticobasal degeneration.

Corticobasal degeneration (CBD) is a movement disorder characterized by early apraxia and asymmetric parkinsonism that responds poorly to anti-Parkinson medications. There are clinical manifestations reflecting dysfunction in both the cerebral cortex and the basal ganglia. Patients typically present between the sixth and seventh decades. Previously, the youngest clinically diagnosed individual was 40 years old. Here we describe a 34-year-old woman who meets the clinical diagnostic criteria for CBD with onset of symptoms at age 28. In this patient, the first symptom was an 'uncooperative' right hand. This was soon followed by right hand dystonia. Symptoms progressed rapidly, and she developed generalized bradykinesia, rigidity, and corticospinal tract signs with preservation of the initial asymmetry. Her symptoms did not respond to a daily dose of 1200 mg of immediate release levodopa. Extensive laboratory workup and brain imaging were normal. Neuropsychological evaluation revealed mild deficits consistent with frontal-subcortical dysfunction. The chronic, progressive course, asymmetric limb rigidity, apraxia, focal dystonia, and lack of response to levodopa suggest CBD. To our knowledge, this is the youngest reported case of clinically probable CBD.