News Roundup

New and Noteworthy Information—December 2017


 

Brain Glucose Level Is Associated With Alzheimer’s Disease Severity

Impaired glucose metabolism due to reduced glycolytic flux may be intrinsic to Alzheimer’s disease pathogenesis, according to a study published online ahead of print October 19 in Alzheimer’s & Dementia. Within the autopsy cohort of the Baltimore Longitudinal Study of Aging, researchers measured brain glucose concentration and assessed the ratios of serine, glycine, and alanine to glucose. Investigators also quantified protein levels of the neuronal and astrocytic glucose transporters. In addition, study authors assessed the relationships between plasma glucose measured before death and brain tissue glucose. Higher brain tissue glucose concentration, reduced glycolytic flux, and lower neuronal glucose transporters were related to severity of Alzheimer’s disease pathology and the expression of Alzheimer’s disease symptoms. Longitudinal increases in fasting plasma glucose levels were associated with higher brain tissue glucose concentrations.

An Y, Varma VR, Varma S, et al. Evidence for brain glucose dysregulation in Alzheimer’s disease. Alzheimers Dement. 2017 Oct 19 [Epub ahead of print].

Is it Better to Be Asleep or Awake for DBS Implantation?

Patients with Parkinson’s disease who undergo deep brain stimulation (DBS) device implantation while asleep have better communication, cognition, and speech outcomes, according to a study published November 7 in Neurology. Thirty DBS candidates with Parkinson’s disease underwent imaging-guided implantation while asleep. Their six-month outcomes were compared to those of 39 patients who previously had undergone implantation while awake. Assessments included an off-levodopa Unified Parkinson’s Disease Rating Scale (UPDRS) II and III, the 39-item Parkinson’s Disease Questionnaire, motor diaries, and speech fluency. No difference was observed in improvement of UPDRS III or UPDRS II. Improvement in on time without dyskinesia was superior in asleep implantation. Quality of life scores improved in both groups. Improvement in summary index and subscores for cognition and communication were superior in implantation while asleep.

Brodsky MA, Anderson S, Murchison C, et al. Clinical outcomes of asleep vs awake deep brain stimulation for Parkinson disease. Neurology. 2017;89(19):1944-1950.

Is Inflammation During Middle Age Linked to Brain Shrinkage Later On?

People with blood biomarkers of inflammation during midlife may have more brain shrinkage decades later than people without these biomarkers, according to a study published online ahead of print November 1 in Neurology. Plasma levels of fibrinogen, albumin, white blood cells, von Willebrand factor, and Factor VIII were assessed at baseline in 1,633 participants in the Atherosclerosis Risk in Communities Study. Each standard deviation increase in midlife inflammation composite score was associated with 1,788 mm3 greater ventricular volume, 110 mm3 smaller hippocampal volume, 519 mm3 smaller occipital volume, and 532 mm3 smaller Alzheimer disease signature region volumes and reduced episodic memory 24 years later. Compared with participants with no elevated midlife inflammatory markers, participants with elevations in three or more markers had 5% smaller hippocampal and Alzheimer’s disease signature region volumes.

Walker KA, Hoogeveen RC, Folsom AR, et al. Midlife systemic inflammatory markers are associated with late-life brain volume: The ARIC study. Neurology. 2017 Nov 1 [Epub ahead of print].

Novel Wristbands Improve Seizure Detection

Wrist-worn convulsive seizure detectors provide more accurate seizure counts than previous automated detectors do, while maintaining tolerable false alarm rates (FAR) for ambulatory monitoring, according to a study published in the November issue of Epilepsia. Hand-annotated video-EEG seizure events were collected from 69 patients at six clinical sites. Two novel wristbands and one current wristband were used to record electrodermal activity and accelerometer signals, obtaining 5,928 hours of data, including 55 convulsive epileptic seizures in 22 patients. The novel wristbands consistently outperformed the current wristband. The best wristband had a sensitivity of 94.55% and an FAR of 0.2 events per day. When increasing the sensitivity to 100%, the FAR was as much as 13 times lower than with the current detector. Automatically estimated seizure durations were correlated with true durations.

Onorati F, Regalia G, Caborni C, et al. Multicenter clinical assessment of improved wearable multimodal convulsive seizure detectors. Epilepsia. 2017;58(11):1870-1879.

Focused Ultrasound Reduces Parkinson’s Disease Tremor

Focused ultrasound thalamotomy for patients with tremor-dominant Parkinson’s disease demonstrates improvement in medication-refractory tremor by Clinical Rating Scale for Tremor assessments, even in the setting of a placebo response, according to a study published online ahead of print October 30 in JAMA Neurology. Researchers randomized 20 patients to unilateral focused ultrasound thalamotomy and seven to a sham procedure. Twenty-six participants were male, and the median age was 67.8. The predefined primary outcomes were safety and difference in improvement between groups at three months in the on-medication treated hand tremor subscore from the Clinical Rating Scale for Tremor. On-medication median tremor scores improved 62% from a baseline of 17 points following focused ultrasound thalamotomy, and 22% from a baseline of 23 points after sham procedures.

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