Thalamic atrophy in patients with clinically isolated syndrome (CIS) is associated with the development of clinically definite multiple sclerosis (MS), according to a study published online ahead of print April 23 in Radiology. Using MRI, researchers assessed 216 patients with CIS at baseline, six months, one year, and two years. MRI measures of progression included new and enlarged T2 lesions and changes in whole-brain, tissue-specific global, and regional gray matter volumes. In mixed-effect model analysis, the lateral ventricle volume, accumulation of new total T2 and new enlarging T2 lesions increase, and thalamic and whole-brain volume decrease were associated with development of clinically definite MS. In multivariate regression analysis, decrease in thalamic volumes and increase in lateral ventricle volumes were associated with the development of clinically definite MS.
Functional MRI (fMRI) can identify pain caused by heat in healthy persons, according to research published in the April 11 New England Journal of Medicine. In four studies of 114 participants, investigators developed an fMRI-based measure that predicts pain intensity, tested its sensitivity and specificity to pain versus warmth, assessed its specificity relative to social pain, and assessed the responsiveness of the measure to the analgesic remifentanil. The neurologic signature distinguished painful heat from nonpainful warmth, pain anticipation, and pain recall with sensitivity and specificity of 94% or more. The signature discriminated between painful heat and nonpainful warmth with 93% sensitivity and specificity. It also distinguished between physical pain and social pain with 85% sensitivity and 73% specificity. The strength of the signature response was substantially reduced after remifentanil administration.
Family history of late-onset Alzheimer’s disease is associated with an increased prevalence of an abnormal cerebral beta-amyloid and tau protein phenotype in patients with mild cognitive impairment (MCI), according to a study published on April 17 in PLOS One. Investigators studied 257 participants (ages 55 to 89) in the Alzheimer’s Disease Neuroimaging Initiative. Subjects were categorized as cognitively normal, having MCI, or having Alzheimer’s disease. Among patients with MCI, CSF Ab42 was lower, t-tau was higher, and t-tau–Ab42 ratio was higher in patients with a family history of Alzheimer’s disease than in patients without. A significant residual effect of family history on pathologic markers in MCI remained after adjusting for APOE e4. The effect of family history was not significant in patients with Alzheimer’s disease.
Most potential migraine triggers are so variable that it may not be possible to identify them without formal experimentation, according to a study published in the April issue of Headache. Investigators examined the similarity of day-to-day weather conditions over four years, as well as the similarity of ovarian hormones and perceived stress over a median of 89 days in nine patients with headache and regular menstrual cycles. A threshold of 90% similarity using Gower’s index identified similar days for comparison. The day-to-day variability in the three headache triggers was substantial enough that finding two naturally similar days for which to contrast the effect of a fourth trigger (eg, drinking wine) occurred infrequently. Fluctuations in weather patterns resulted in a median of 2.3 similar days each year.
Elevated low-density lipoprotein (LDL) cholesterol and altered cholesterol homeostasis may promote neurodegeneration, atherosclerosis, and Alzheimer’s disease by disrupting chromosome segregation, according to research published on April 12 in PLOS One. In a study of mice, investigators observed that high dietary cholesterol induced aneuploidy. In a separate study, the accumulation of intracellular cholesterol was associated with the accumulation of aneuploid fibroblasts, neurons, and glia in patients with Niemann-Pick C1. The researchers also observed that oxidized LDL, LDL, and cholesterol, but not high-density lipoprotein (HDL), induced chromosome mis-segregation and aneuploidy in cultured cells, including neuronal precursors. LDL-induced aneuploidy required the LDL receptor, but not Ab. Cholesterol treatment disrupted the structure of the mitotic spindle, providing a cell biologic mechanism for its aneugenic activity, and ethanol or calcium chelation attenuated lipoprotein-induced chromosome mis-segregation.
The incidence of dementia in central Stockholm may have decreased from the late 1980s to the early 2000s, according to research published online ahead of print April 17 in Neurology. Investigators analyzed data from two cross-sectional surveys of people ages 75 or older. One study was conducted from 1987 to 1989 and included 1,700 participants; the other was conducted from 2001 to 2004 and included 1,575 subjects. The team inferred the incidence of dementia according to its relationship with prevalence and survival. The adjusted odds ratio of dementia in the later study versus the earlier study was 1.17. The multiadjusted hazard ratio of death in the later study versus the earlier study was 0.71 in subjects with dementia, 0.68 in those without dementia, and 0.66 in all participants.