Health Insurance Tax Credits and Health Insurance Coverage of Low-Earning Single Mothers

The Omnibus Budget Reconciliation Act of 1990 introduced a refundable tax credit for low-income working families who purchased health insurance coverage for their children. This health insurance tax credit (HITC) existed during tax years 1991, 1992, and 1993, and was then rescinded. We use Current Population Survey data and a difference-in-differences approach to estimate the HITC’s effect on private health insurance coverage of low-earning single mothers. The findings suggest that during 1991–1993, the health insurance coverage of single mothers was about 6 percentage points higher than it would have been in the absence of the HITC.Retirement; Health insurance; Low-wage workers; Tax credits and subsidies

Cosmological backreaction of a quantized massless scalar field

We consider the backreaction problem of a quantized minimally coupled massless scalar field in cosmology. The adiabatically regularized stress-energy tensor in a general Friedmann-Robertson-Walker background is approximately evaluated by using the fact that subhorizon modes evolve adiabatically and superhorizon modes are frozen. The vacuum energy density is verified to obey a new first order differential equation depending on a dimensionless parameter of order unity, which calibrates subhorizon/superhorizon division. We check the validity of the approximation by calculating the corresponding vacuum energy densities in fixed backgrounds, which are shown to agree with the known results in de Sitter space and space-times undergoing power law expansions. We then apply our findings to slow-roll inflationary models. Although backreaction effects are found to be negligible during the near exponential expansion, the vacuum energy density generated during this period might be important at later stages since it decreases slower than radiation or dust.Comment: 20 pages, 2 figures, v2: comments and a reference added, to appear in JCA

Venous infarction mimicking a neoplasm in spontaneous intracranial hypotension: an unusual cause of Parinaud's syndrome

We present a case of longstanding, undiagnosed spontaneous intracranial hypotension (SIH) with an acute presentation of Parinaud's syndrome, in whom serial imaging demonstrated development of a midbrain mass. The patient was ultimately diagnosed with tumefactive venous infarction secondary to SIH. However, this patient underwent a brainstem biopsy, which in retrospect may have been avoidable. This case demonstrates the imaging features of tumefactive venous infarction in SIH and highlights the risk of misinterpretation as a neoplasm with potentially catastrophic consequences

Progressive myoclonic epilepsy due to rare mitochondrial ND6 mutation, m.14487T>C

INTRODUCTION: Mitochondrial diseases exhibit wide phenotypic heterogeneity, and can present as progressive myoclonic epilepsy. SUMMARY: We report a case of adult-onset drug-resistant epilepsy, cortical myoclonus and bilateral optic neuropathies due to m.14487T>C, a rare mitochondrial gene mutation identified on whole-genome sequencing. This mutation, which affects the NADH dehydrogenase 6 (ND6) subunit of the mitochondrial respiratory chain, is most commonly implicated in cases of infantile-onset Leigh syndrome, although a broader phenotypic spectrum including migraine with aura and progressive myoclonic epilepsy have been described. Serial MRI scans over a 2-year period demonstrated the interval development of bihemispheric stroke-like lesions. Giant somatosensory evoked potentials and short-duration myoclonic jerks with craniocaudal spread on surface electromyography were consistent with cortical myoclonus. Optical coherence tomography showed bilateral symmetric thinning of the nerve fibre layer in the papillomacular bundles. CONCLUSION: Whole-genome sequencing can help to provide a definitive diagnosis for mitochondrial disease and should be considered in situations where clinical suspicion remains high despite normal genetic panels or muscle histopathology. Mitochondrial disease can present as adult-onset progressive myoclonic epilepsy, and bilateral optic neuropathies can be a striking feature of ND6 mitochondrial gene mutations. In our case, severe cortical myoclonus affecting speech and swallowing remained highly drug-resistant, however, symptomatic benefit was derived from targeted onabotulinum toxin A injections