Long Loop Reflex 2 in Patients with Cortical Dementias: A Pilot Study.

INTRODUCTION: Dementia is a major public health problem and it appears to be a global epidemic. The prevalence is doubling every 5 years and it is expected that 70% of persons above 60 years will live in developing countries by 2020 and 15% of them are likely to suffer from dementia. Disease modifying treatments work only if initiated very early; however, diagnostic tools are not always able to clearly differentiate the different types in very early stage. Therefore, inexpensive and easily available biomarkers are needed to know if collectively they will improve the sensitivity of specific diagnosis. Therefore, in this pilot study, we have tried to analyze if long loop reflex (LLR2) is differentially affected in these two conditions early in the course of Alzheimer's dementia (AD) and frontotemporal dementia (FTD) based on hypothesis taking into account the anatomical substrates involved. PATIENTS AND METHODS: Mild cases of clinically probable AD and FTD after appropriate inclusion criteria were subjected for LLR testing in the upper limb at median nerve. The presence or absence of LLR was assessed and also the latency, amplitude, and duration assessed. RESULTS AND CONCLUSION: LLR 2 is differentially affected in both these conditions. Absence of LLR2 was consistently seen in FTD which can be explained by early break down of frontal subcortical circuits in this condition as against AD. This is likely to serve as a very cheap and very early biomarker to differentiate the two common types of cortical dementias.

Self-ignited high temperature synthesis and enhanced super-exchange interactions of Ho(3+)-Mn(2+)-Fe(3+)-O(2-) ferromagnetic nanoparticles.

The present work is focused on the effect of Fe(3+) replacement by rare earth-Ho(3+) ions and their influence on the properties of MnFe2O4 ferrite. The Ho(3+) substituted MnFe2O4 ferrite samples with chemical formula MnHoxFe2-xO4 were synthesized where substitution concentration of Ho(3+) was 0.0, 0.05, 0.1 and 0.15. The samples were synthesized by the self-ignited sol-gel method using the nitrates of the respective elements. Powder X-ray diffraction, transmission electron microscopy, infrared spectroscopy, vibrating sample magnetometer (VSM) and electrical measurements were employed to characterize the structural, magnetic and electrical properties of these ferrite nanoparticles. The cations distribution between the tetrahedral (A-site) and octahedral sites (B-site) has been estimated by XRD analysis. It is found that substitution of Ho(3+) ions favorably influenced the magnetic and electrical properties. Magnetic measurements were carried out at 77 and 300 K. Saturation magnetization and coercivity increased from 54.57 to 71.6 emu g(-1) and 172 to 766 Oe, respectively, with increasing the Ho(3+) substitution. The change in magnetic properties may be explained with the increase of A-O-B (FeA(3+)-O(2-)-HoB(3+)) super exchange interactions and the anisotropy constant. The electrical properties show that the pure sample has lower resistivity with respect to any Ho(3+) doped one. The conduction mechanism is used to interpret electrical measurements. Results of the presently investigated samples with enhanced saturation magnetization, coercivity and remanence ratio indicate that the Ho(3+) doped MnFe2O4 nanoparticles can be a useful candidate for the application in high density recording media.