Automatic detection of F waves and F-MUNE in two types of motor neuron diseases.

INTRODUCTION/AIMS: Motor unit number estimation by F waves (F-MUNE) is an uncommonly used MUNE technique. Our aim in this study was to assess the sensitivity of F-MUNE values elicited with newly developed software in motor neuron diseases. METHODS: F waves were recorded by 300 submaximal stimuli from abductor digiti minimi and abductor pollicis brevis muscles of 35 patients with amyotrophic lateral sclerosis, 18 with previous poliomyelitis, and 20 controls. The software determined the surface motor unit action potentials (sMUAPs) and calculated the F-MUNE values. Compound muscle action potential scans were also recorded to obtain MScanFit. RESULTS: The sMUAP amplitudes were higher and F-MUNE values were lower in both muscles of the patients when compared with controls. F-MUNE values could distinguish patients from controls. Significant correlations were found between F-MUNE and MScanFit in the patient groups. DISCUSSION: The new F-MUNE software offered promising results in revealing motor unit loss caused by motor neuron diseases.

Corticomotor Excitability in Two Kinds of Motor Neuron Diseases: A Study on the Patients With Amyotrophic Lateral Sclerosis and Poliomyelitis Survivors.

PURPOSE: To examine upper motor neuron functions comparatively in patients with amyotrophic lateral sclerosis (ALS) and poliomyelitis survivors using transcranial magnetic stimulation (TMS) methods. METHODS: Single- and paired-pulse TMS with conventional methods and the triple-stimulation technique were performed by recording from the abductor digiti minimi and abductor pollicis brevis muscles in 31 patients with ALS, 18 patients with poliomyelitis survivors, and 21 controls. Nine patients were diagnosed as having postpoliomyelitis syndrome after a 6-month follow-up. RESULTS: Triple-stimulation technique and some of conventional TMS studies were able to distinguish ALS from both poliomyelitis survivors and controls. A reduced ipsilateral silent period in abductor pollicis brevis muscles was the only parameter to show a significant difference when comparing thenar and hypothenar muscles in ALS. No significant difference was present in any TMS parameters between the postpoliomyelitis syndrome and non-postpoliomyelitis syndrome groups. CONCLUSIONS: Conventional TMS and particularly triple-stimulation technique studies are helpful in disclosing upper motor neuron dysfunction in ALS. The results of this study might favor the cortical hypothesis for split hand in ALS, but they revealed no significant indication for upper motor neuron dysfunction in postpoliomyelitis syndrome.

Compound muscle action potential scan and MScanFit motor unit number estimation during Wallerian degeneration after nerve transections.

BACKGROUND: Compound muscle action potential (CMAP) scan and MScanFit have been used to understand the consequences of denervation and reinnervation. This study aimed to monitor these parameters during Wallerian degeneration (WD) after acute nerve transections (ANT). METHODS: Beginning after urgent surgery, CMAP scans were recorded at 1-2 day intervals in 12 patients with ANT of the ulnar or median nerves, by stimulating the distal stump (DS). Stimulus intensities (SI), steps, returners, and MScanFit were calculated. Studies were grouped according to the examination time after ANT. Results were compared with those of 27 controls. RESULTS: CMAP amplitudes and MScanFit progressively declined, revealing a positive correlation with one another. SIs were higher in WD groups than controls. Steps appeared or disappeared in follow-up scans. The late WD group had higher returner% than the early WD and control groups. CONCLUSIONS: MScanFit can monitor neuromuscular dysfunction during WD. SIs revealed excitability changes in DS.

Cerebral Amyloid Angiopathy Related Inflammation Presenting as Steroid Responsive Brain Mass.

Cerebral amyloid angiopathy (CAA) is a common but often asymptomatic disease, characterized by the deposition of amyloid proteins within brain parenchyma and leptomeningeal-cortical vessels. It can occur as a sporadic disorder or accompany Alzheimer disease (AD). The usual presentation of CAA is spontaneous lobar hemorrhage, Unlike CAA, cerebral amyloid angiopathy-related inflammation (CAA-ri), a subtype of CAA, can show various presentations and responds to steroid (or immuno suppressive) treatment. We report a patient with mixed dementia who showed subacute progression in cognitive impairment and had a mass lesion on brain magnetic resonance imaging (MRI). The lesion was identified as CAA related inflammation and the cognitive status of the patient improved significantly after steroid treatment. In this case report, we aimed to emphasize that CAA-ri is one of the possible diagnoses that should be considered in demented patients with rapid cognitive deterioration and showing brain lesions resembling neoplasms on the MRI. Therefore, steroids or other immunosuppresive treatments, which may lead to a dramatic clinical improvement, could be administered without delay.

Repeater F-waves in amyotrophic lateral sclerosis: Electrophysiologic indicators of upper or lower motor neuron involvement?

OBJECTIVE: To extract insight about the mechanism of repeater F-waves (Frep) by exploring their correlation with electrophysiologic markers of upper and lower motor neuron dysfunction in amyotrophic lateral sclerosis (ALS). METHODS: The correlations of Frep parameters with clinical scores and the results of neurophysiological index (NI), MScanfit MUNE, F/M amplitude ratio (F/M%), single and paired-pulse transcranial magnetic stimulation (TMS), and triple stimulation technique (TST) studies, recorded from abductor digiti minimi (ADM) and abductor pollicis brevis (APB) muscles of 35 patients with ALS were investigated. RESULTS: Frep parameters were correlated with NI and MScanfit MUNE in ADM muscle and F/M% in both muscles. None of the Frep parameters were correlated with clinical scores or TST and TMS measures. While the CMAP amplitudes were similar in the two recording muscles, there was a more pronounced decrease of F-wave persistence in APB, probably heralding the subsequent split hand phenomenon. CONCLUSION: Our findings suggest that the presence and density of Freps are primarily related to the degree of lower motor neuron loss and show no correlation with any of the relatively extensive set of parameters for upper motor neuron dysfunction. SIGNIFICANCE: Freps are primarily related to lower motor neuron loss in ALS.

Parameters derived from compound muscle action potential scan for discriminating amyotrophic lateral sclerosis-related denervation.

INTRODUCTION: The objective of this study was to determine compound muscle action potential (CMAP) scan parameters and MScanFit motor unit number estimation (MUNE) in patients with amyotrophic lateral sclerosis (ALS) and to compare the results in the abductor pollicis brevis (APB) to those in the abductor digiti minimi (ADM). METHODS: CMAP scans were recorded from the APB and ADM in 35 patients with ALS and 21 controls. MScanFit MUNE, neurophysiological index (NI), step%, returner%, and D50 were calculated. RESULTS: CMAP scan parameters including the returner%, MScanFit MUNE, and NI can distinguish ALS with high sensitivity and specificity. The electrophysiological parameters, with the exception of D50 (the number of largest consecutive differences of recorded responses generating 50% of maximum CMAP), showed more pronounced changes in the APB than in the ADM, even though most of the patients had normal APB/ADM amplitude ratios. DISCUSSION: CMAP scan parameters and MScanFit MUNE can be used in the evaluation of denervation and reinnervation and may herald the "split hand" in ALS.

An economic valuation of a biotechnology R&D project in a developing economy

Background: Biotechnology complements technological developments in main sectors of economies, such as health, energy, and agriculture, and thus contributes to economic development. It provides solutions to the problems that are frequently faced in developing economies, such as resource constraints, lower productivity and environmental concerns. In order to benefit from biotechnology, its associated markets need to develop and function well to support the developments and transactions of intangible assets, such as technology transfers, license agreements and research and development joint ventures. Economic valuation of the intangible assets is necessary for the development and functioning of these markets. It provides better understanding of value creation at micro scales and its economic and financial dynamics. The literature lacks valuation studies in biotechnology sectors in developing economies. This study performs economic valuation analysis of a research and development project of a Turkish biotechnology company operating in health sector. Turkey, as a developing economy, has slow progress in biotechnology despite its wealth of biological resources and genetic variety. Thus, the study provides an excellent case to analyze valuation issues in developing economies. It uses data from in-depth interviews from the company and employs real options and discounted cash flow (DCF) methods. Results: Developing countries and biotechnology sector introduce additional risks that need to be accounted for in valuation. These risks reduce the value of the project under real options and discounted cash flow methods. Since real options method permits the valuation of options that might arise during the R&D process and provides flexibility to managers to act, it results in higher values compared to discounted cash flow method...

Effects of valsartan on stress-induced changes of serum vascular endothelial growth factor and nitric oxide in mice.

This study investigated the effects of renin-angiotensin system (RAS) blockade on stress-induced changes of serum vascular endothelial growth factor (VEGF) and nitric oxide (NO) in mice. Chronic stress increased the serum NO levels significantly compared to control group (p = .0172). Valsartan, an angiotensin II receptor antagonist, alone, did not make significant difference versus control group. In chronic stress + valsartan group, serum NO levels decreased nonsignificantly compared to chronic stress group. There was a nonsignificant increase in serum VEGF levels after chronic stress. Valsartan alone or with chronic stress did not significantly affect the serum VEGF levels. In conclusion, there was no correlation between NO and VEGF changes during the stress response. In this respect, there may be other mechanisms to explain the stress-induced NO increase.

Losartan may prevent the elevation of plasma glucose, corticosterone and catecholamine levels induced by chronic stress.

INTRODUCTION: Stress is a stimulus that activates the hypothalamic pituitary adrenal (HPA) axis and sympathetic nervous system (SNS). Increased activity of the SNS causes to increment or impairment in blood pressure, heart rate, body temperature and plasma glucose and adreno- corticotrophic hormone (ACTH) levels. Angiotensin II (Ang II), which is a product of the renin-angiotensin system (RAS), is an important factor affecting the activity of the SNS and responses to stress. We suggest that the blockade of Ang II may be worthwhile in the prevention and treatment of diabetes mellitus and cardiovascular diseases affected by stress. Therefore, we investigated the effects of immobilisation stress on blood glucose, norepinephrine (NE), epinephrine (E) and corticosterone levels and the effects of an Ang II receptor antagonist, losartan, on these parameters. MATERIALS AND METHODS: The rats were kept in small cylindrical cages for 60 min/day for 10 consecutive days to perform chronic immobilisation stress. Losartan (10 mg/kg) was given daily by gavage to Losartan (L) and Losartan + Chronic Stress (L+CS) groups. Control (C) and Chronic Stress (CS) groups received an equal volume of saline daily by gavage for 10 days. After the last stress regimen, blood samples were collected for plasma glucose, NE, E and corticosteroid measurements. RESULTS: Plasma glucose, NE, E and corticosterone levels in the CS Group increased significantly compared with the C group. In Group L+CS, the plasma glucose, NE, E and corticosterone levels decreased significantly vs. Group CS. In Group L there was no significant difference vs. Group C. CONCLUSION: It can be speculated that chronic blockade of RAS may decrease the excess sympathetic responses to stress in cardiovascular diseases and prevent the likely development of Type II diabetes mellitus.

Losartan may prevent the elevation of plasma glucose levels induced by chronic stress.

The effect of angiotensin II antagonist, losartan, on chronic stress-induced elevation of blood glucose levels was investigated in rats. Chronic immobilization stress caused an increase in blood glucose levels in rats. Administration of losartan (3 mg/kg, po) before stress exposure significantly prevented this increment. We suggest that losartan showed this effect by decreasing the excessive sympathetic response to stress. In conclusion, there is a relationship between stress, sympathetic nervous system, and renin-angiotensin system.