Long-Term Task- and Dopamine-Dependent Dynamics of Subthalamic Local Field Potentials in Parkinson's Disease.

Subthalamic nucleus (STN) local field potentials (LFP) are neural signals that have been shown to reveal motor and language behavior, as well as pathological parkinsonian states. We use a research-grade implantable neurostimulator (INS) with data collection capabilities to record STN-LFP outside the operating room to determine the reliability of the signals over time and assess their dynamics with respect to behavior and dopaminergic medication. Seven subjects were implanted with the recording augmented deep brain stimulation (DBS) system, and bilateral STN-LFP recordings were collected in the clinic over twelve months. Subjects were cued to perform voluntary motor and language behaviors in on and off medication states. The STN-LFP recorded with the INS demonstrated behavior-modulated desynchronization of beta frequency (13-30 Hz) and synchronization of low gamma frequency (35-70 Hz) oscillations. Dopaminergic medication did not diminish the relative beta frequency oscillatory desynchronization with movement. However, movement-related gamma frequency oscillatory synchronization was only observed in the medication on state. We observed significant inter-subject variability, but observed consistent STN-LFP activity across recording systems and over a one-year period for each subject. These findings demonstrate that an INS system can provide robust STN-LFP recordings in ambulatory patients, allowing for these signals to be recorded in settings that better represent natural environments in which patients are in a variety of medication states.

Recurrent polymorphonuclear pleocytosis with increased red blood cells caused by varicella zoster virus infection of the central nervous system: Case report and review of the literature.

We describe an immunocompetent 45-year-old woman who had four episodes of neurological disease (meningoencephalitis, multifocal vasculopathy, myelitis and inflammatory brain stem disease) produced by varicella zoster virus (VZV) over an 11-month period, all in the absence of rash. The cerebrospinal fluid (CSF) contained anti-VZV IgG antibody, but not VZV DNA throughout her illness, reaffirming the superiority of detection of anti-VZV IgG in CSF compared to VZV DNA in diagnosing VZV infection of the nervous system. Moreover, 3 of 7 CSF samples examined during the 11 months showed a VZV-induced pleocytosis consisting predominantly of polymorphonuclear cells (PMNs), and 4 of 7 samples also contained increased numbers of red blood cells (RBCs). Because increased PMNs and RBCs in CSF can also occur in patients with central and peripheral nervous system disease produced by cytomegalovirus (CMV), the differential diagnosis of chronic nervous system infection with increased PMNs and RBCs in CSF should include analyses for both VZV and CMV.

Exercise and epilepsy: a survey of Midwest epilepsy patients.

Obesity and lack of physical activity are an increasing problem. In addition to common barriers to physical activity, people with epilepsy also face fear of exercise-induced seizures, medication side effects, and, often, confusing advice regarding the safety of exercise. To explore barriers faced by people with epilepsy, we mailed a survey to 412 adult patients with epilepsy from an epilepsy center in Kansas. Survey items assessed patients' exercise habits, attitudes regarding exercise, and barriers to exercise. Forty-seven percent completed the survey. Most respondents reported that they did exercise, though most did so 3 or fewer days per week and at light intensity. Respondents who reported seizures as a barrier to exercise did not exercise with less frequency or intensity than those who did not report seizures as a barrier, but these respondents reported greater fear of seizures. Patient-specific education about the benefits of exercise needs to be initiated by physicians.