Diagnostic Value of Brain Calcifications in Adult-Onset Leukoencephalopathy with Axonal Spheroids and Pigmented Glia

Adult-onset leukoencephalopathy with axonal spheroids and pigmented glia is a rare neurodegenerative disease resulting from mutations in the colony stimulating factor 1 receptor gene. Accurate diagnosis can be difficult because the associated clinical and MR imaging findings are nonspecific. We present 9 cases with intracranial calcifications distributed in 2 brain regions: the frontal white matter adjacent to the anterior horns of the lateral ventricles and the parietal subcortical white matter. Thin-section (1-mm) CT scans are particularly helpful in detection due to the small size of the calcifications. These calcifications had a symmetric "stepping stone appearance" in the frontal pericallosal regions, which was clearly visible on reconstructed sagittal CT images. Intrafamilial variability was seen in 2 of the families, and calcifications were seen at birth in a single individual. These characteristic calcification patterns may assist in making a correct diagnosis and may contribute to understanding of the pathogenesis of leukoencephalopathy.

Longitudinal modeling of frontal cognition in APOE ε4 homozygotes, heterozygotes, and noncarriers

BACKGROUND

Fibrillar amyloid deposition preferentially affects the frontal lobes, temporal pole/neocortex, and posterior cingulate by age 65 years in APOE ε4 carriers prior to the diagnosis of mild cognitive impairment (MCI) and Alzheimer disease (AD), but is it impairing frontally mediated neuropsychological performance?

METHODS

A total of 71 ε4 homozygotes (HMZ), 194 ε4 heterozygotes (HTZ), and 356 ε4 noncarriers (NC) who did not differ significantly in mean age (56.6 years), years of education (15.6), gender (70% women), or follow-up duration (6.3 years) had neuropsychological testing every 2 years including the Auditory Verbal Learning Test (AVLT) and frontal/executive tasks sensitive to psychomotor speed, working memory, problem solving, and activity. A subset also received the Iowa Gambling Task (IGT). Findings were then tested in a clinical sample of 27 patients with incident MCI and AD.

RESULTS

APOE ε4 carriers had greater acceleration of decline (quadratic effect) than NC on the AVLT (p = 0.04) but not on any frontal test. APOE ε4 HMZ had greater velocity of decline (linear effects) than NC on all mental arithmetic tests: paced auditory serial attention task (PASAT) 3 second (p = 0.01) and 2 second (p = 0.004) versions; and Wechsler Adult Intelligence Scale-Revised arithmetic (p = 0.048). IGT performance did not differ between 12 ε4 HMZ, 27 ε4 HTZ, and 44 NC. Among 27 patients with incident MCI and AD, the PASAT showed progressive decline preceding diagnosis in 50%.

CONCLUSIONS

No frontal cognitive effects were as robust as memory decline. APOE ε4 HMZ declined more quickly than NC on mental arithmetic tests related to frontal lobe-mediated working memory ability.

Cerebrovascular risk factors and preclinical memory decline in healthy APOE ε4 homozygotes

OBJECTIVE

To characterize the effects of cerebrovascular (CV) risk factors on preclinical memory decline in cognitively normal individuals at 3 levels of genetic risk for Alzheimer disease (AD) based on APOE genotype.

METHODS

We performed longitudinal neuropsychological testing on an APOE ε4 enriched cohort, ages 21-97. The long-term memory (LTM) score of the Auditory Verbal Learning Test (AVLT) was the primary outcome measure. Any of 4 CV risk factors (CVany), including hypercholesterolemia (CHOL), prior cigarette use (CIG), diabetes mellitus (DM), and hypertension (HTN), was treated as a dichotomized variable. We estimated the longitudinal effect of age using statistical models that simultaneously modeled the cross-sectional and longitudinal effects of age on AVLT LTM by APOE genotype, CVany, and the interaction between the two.

RESULTS

A total of 74 APOE ε4 homozygotes (HMZ), 239 ε4 heterozygotes (HTZ), and 494 ε4 noncarriers were included. APOE ε4 carrier status showed a significant quadratic effect with age-related LTM decline in all models as previously reported. CVany was associated with further longitudinal AVLT LTM decline in APOE ε4 carriers (p=0.02), but had no effect in noncarriers. When ε4 HTZ and HMZ were considered separately, there was a striking effect in HMZ (p<0.001) but not in HTZ. In exploratory analyses, significant deleterious effects were found for CIG (p=0.001), DM (p=0.03), and HTN (p=0.05) in APOE ε4 carriers only that remained significant only for CIG after correction for multiple comparisons.

CONCLUSION

CV risk factors influence age-related memory decline in APOE ε4 HMZ.

Family history of dementia is a risk factor for Lewy body disease

Genetic factors are important in Alzheimer disease (AD) and Parkinson disease but have not been well characterized in Lewy body dementia (LBD). The authors obtained family history in patients from an autopsy series of AD and LBD and in living healthy controls. A family history of dementia was more common in both LBD and AD compared with controls, suggesting that genetic factors are as important in LBD as they are in AD.

Cardiac troponin levels following monitored epileptic seizures

Cardiac arrhythmia associated with myocardial injury is a proposed mechanism for sudden unexplained death in epilepsy. The authors measured serial cardiac troponin levels in 11 patients after monitored seizures. Using highly sensitive assays and criteria, no troponin elevations were seen, indicating that myocardial injury does not occur during uncomplicated seizures. An elevation in postictal troponin elevations should suggest the presence of cardiac injury secondary to neurocardiogenic mechanisms or primary cardiac factors, prompting further evaluation.