New and Noteworthy Information—May 2015
Exploding head syndrome is relatively common in younger individuals, according to a study published online ahead of print March 13 in Journal of Sleep Research. Researchers assessed 211 undergraduate students for exploding head syndrome and isolated sleep paralysis using semistructured diagnostic interviews. A total of 18% of the sample population had exploding head syndrome during their lifetimes, and 16.60% of the population had recurrent cases of the syndrome. Exploding head syndrome affected both genders at equal rates, and investigators found it in 36.89% of participants who had been diagnosed with isolated sleep paralysis. Furthermore, exploding head syndrome episodes were accompanied by clinically significant levels of fear. For a minority of participants (2.80%), the fear was associated with clinically significant distress or impairment.
A distinctive pattern of abnormal protein deposits in the brain could help identify athletes with brain disorders, according to a study published online ahead of print April 6 in Proceedings of the National Academy of Science. Investigators used [F-18]FDDNP PET to detect brain patterns of neuropathology distribution in 14 retired professional football players with suspected chronic traumatic encephalopathy and compared results with those of 28 cognitively intact controls and 24 patients with Alzheimer’s dementia. The [F-18]FDDNP PET imaging results in retired players suggested the presence of the neuropathologic patterns consistent with models of concussion in which brainstem white matter tracts undergo early axonal damage and cumulative axonal injuries along subcortical, limbic, and cortical regions that support mood, emotions, and behavior. The pattern was distinct from that observed in Alzheimer’s disease.
A blood test could help identify women with fragile X syndrome who are at risk of dysexecutive and social anxiety symptoms, according to a study published online ahead of print March 25 in Neurology. Thirty-five women with FMR1 premutation between ages 22 and 55 and 35 age- and IQ-matched controls completed a range of executive function tests and self-reported symptoms of psychiatric disorders. The researchers found that FMR1 intron 1 methylation levels could help dichotomize women with the premutation into categories of greater and lesser risk. FMR1 intron 1 methylation and activation ratio were significantly correlated with the likelihood of probable dysexecutive or psychiatric symptoms. The significant relationships between methylation and social anxiety were mediated by executive function performance, but only in women with the premutation.
Targeted temperature management at 33 °C or 36 °C helps maintain good quality of life in patients with cardiac arrest, according to a study published online ahead of print April 6 in JAMA Neurology. Investigators studied 939 unconscious adults with cardiac arrest at 36 intensive care units. Patients were assigned to temperature management at 33 °C or 36 °C for 36 hours. Cognitive function was measured by Mini-Mental State Examination (MMSE). The median MMSE score was 14 for patients assigned to 33 °C and 17 for patients assigned to 36 °C. Approximately 19% of the 33 °C group and 18% of the 36 °C group reported needing help with everyday activities, and 66.5% in the 33 °C group versus 61.8% in the 36 °C group reported making a complete mental recovery.
Biracial population eligibility for r-tPA is similar by gender, according to a study published in the March issue of Stroke. The study included 1,837 patients with ischemic stroke who were age 18 or older and presented to 16 emergency departments in 2005. Eligibility for r-tPA and individual exclusion criteria were determined using 2013 American Heart Association and European Cooperative Acute Stroke Study III guidelines. The mean age was 72.2 for women and 66.1 for men. Eligibility for r-tPA was similar by sex, and adjusting the data for age did not alter this result. More women than men had severe hypertension, and the investigators found no gender differences in blood pressure treatment rates among patients with severe hypertension. More women were older than 80 and had an NIH Stroke Scale score greater than 25.
The brains of patients with traumatic brain injury (TBI) may appear to be older than their chronological age, according to a study published in the April issue of Annals of Neurology. A predictive model of normal aging was defined using machine learning in 1,537 healthy individuals, based on MRI-derived estimates of gray matter and white matter. Investigators used this aging model to estimate brain age for 99 patients with TBI and 113 healthy controls. Brains with TBI were estimated to be older, with a mean predicted age difference between chronological and estimated brain age of 4.66 years for gray matter and 5.97 years for white matter. The predicted age difference correlated strongly with the time since TBI, indicating that brain tissue loss increases throughout the chronic postinjury phase.
