Transient smartphone blindness (TSB) was recently described in 2 women who experienced recurrent episodes of monocular vision impairment immediately after viewing a smartphone.1 This physiologic phenomenon is caused by temporarily discrepant light adaptation levels between the 2 retinae. We confirm the phenomenon of TSB and its relevance to neurologic practice, including the potential for misdiagnosis as cerebrovascular disease or multiple sclerosis (MS).
A 39-year-old woman with longstanding asymmetric facial flushing noticed episodic deformation of her left pupil (figure 1), which 2 months later became miotic. Despite no ptosis, a left Horner syndrome was pharmacologically confirmed (figure 2). She also had left cheek pain, present only at mealtime. Radiologic investigations were normal.
To investigate systemic levels of acetylcholinesterase in early Parkinson disease (PD) with 11C-donepezil PET, a potential marker of parasympathetic innervation.
This was a cross-sectional study with 19 patients with early-stage PD (disease duration 1.5 ± 0.6 years) and 16 age-matched controls who had clinical assessments, olfaction tests, and 11C-donepezil PET to measure acetylcholinesterase density in peripheral organs.
The patients with PD showed significantly reduced 11C-donepezil uptake in the small intestine (–14%, p = 0.018), colon (–22%, p < 0.001), and kidneys (–14%, p = 0.028). No difference in myocardial or pancreatic acetylcholinesterase levels was seen.
We found significantly decreased 11C-donepezil signal in the intestine and kidneys of patients with early PD, suggesting that parasympathetic denervation is present early in the disease course.
Kern et al.1 conducted a small, observational, retrospective, longitudinal, population-based cohort study of calcium supplementation and increased dementia risk in elderly women. Women who took calcium supplementation had higher odds of dementia. However, the number of individuals taking calcium supplements without vitamin D was low and compromised the reliability of the results. The sample size (n = 98) in the calcium supplements group included women taking calcium supplements with 85.7% (84 of 98) also taking vitamin D.1 The authors, recognizing vitamin D as a confounding variable, included it in regression models and stated that vitamin D did not affect the «main results.»1 However, controlling for vitamin D would not improve statistical power. Women taking calcium supplements with vitamin D should have been excluded at baseline because the dependent variable in the hypothesis was calcium supplementation alone.1 The calcium supplement group was described as «women treated with calcium supplements,»1 but they were actually women treated with calcium supplements, most of whom took vitamin D. Thus, the study hypothesis of calcium supplementation association with an increased risk of dementia was tested with a small sample size of 98 where only 14 individuals were relevant to the research question.
Women with epilepsy (WWE) have increased risk of adverse pregnancy outcomes for both the mother and child.1,2 Some of these risks can be reduced by planning prior to pregnancy. Risks of major congenital malformations and adverse cognitive/behavioral outcomes are higher for certain antiepileptic drugs (AEDs). For example, guidelines recommend avoiding the use of valproate during pregnancy.1 However, waiting until a woman knows she is pregnant and contacts her physician creates a risk of fetal exposure during early pregnancy. Further, changing AED during pregnancy risks precipitating seizures. Waiting until a woman is planning pregnancy does not work as many pregnancies are unplanned. Even in the general population, unintended pregnancies may increase the risk of unfavorable outcomes and of abortions (42% in 2011 excluding miscarriages).3,4 Thus, understanding the rates of unintended pregnancy in WWE is important. No prior large-scale studies have examined the rate and predictors of unintended pregnancies in WWE, despite the fact that some AEDs with enzyme-inducing properties can lower hormonal contraceptive levels.
To characterize the temporal and spatial pattern of cerebral microbleeds (CMBs) after cranial irradiation in patients with medulloblastoma.
We retrospectively identified patients with medulloblastoma treated with craniospinal irradiation at the Massachusetts General Hospital between 1999 and 2015. Longitudinal MRI including T2*-weighted gradient-recalled echo (GRE) sequences were reviewed, and the prevalence, spatial pattern, and risk factors associated with CMBs were characterized.
We identified a total of 27 patients; 5 patients were children (median age 6.3 years) and 22 patients were adults (median age 28.8 years). CMBs were found in 67% (18/27) of patients, who were followed for a median of 4.1 years. Patients with CMBs had longer GRE follow-up time compared to those without CMBs (4.9 vs 1.7 years, p = 0.035). The median latency of the appearance of CMBs was 2.79 years (interquartile range 1.76–4.26). The prevalence of CMBs increased with each year from time of radiation therapy, and the cumulative prevalence was highest in patients age <20 years (100% cumulative prevalence, vs 59% in adult patients treated at age ≥20 years). CMBs were mostly found in lobar distribution and predominately in bilateral occipital lobes. Patients using antithrombotic medications developed CMBs at a significantly higher rate (p = 0.041).
Our data demonstrate a high prevalence of CMBs following cranial irradiation, progressively increasing with each year from time of radiation therapy.