481 research outputs found
Anti-MAG negative distal acquired demyelinating symmetric neuropathy in association with a neuroendocrine tumor.
Potential risks of iatrogenic complications of nerve conduction studies (NCS) and electromyography (EMG)
AbstractNerve conduction and electromyography studies are generally well tolerated and pose little risk to patients of serious adverse events in the hands of a well-trained competent practitioner. However, some patients and certain examinations do carry a higher risk of potential complications. It is good medical practice to inform patients of any risks, their potential severity and relative frequency. In order to obtain informed consent a dialogue should take place about the nature, purpose and effects of the studies, so patients can decide if they wish to undergo the proposed investigation. In this educational review we identify those procedures and patients at risk, and provide pragmatic practice recommendations for managing these material risks
Upper limb entrapment neuropathies in multiple sclerosis
Introduction
Entrapment neuropathies of upper limbs such as carpal tunnel and cubital tunnel syndromes are common in the general population. Identification of entrapment neuropathies of upper limbs in patients with multiple sclerosis can be clinically challenging as signs and symptoms could be attributed to multiple sclerosis. People at later stages of multiple sclerosis use mobility aids and wheelchairs. Weakness of hands in this cohort due to entrapment neuropathies could adversely affect their mobility and independence.
Methods
This was a retrospective review of records of patients with multiple sclerosis referred for clinical neurophysiological studies with clinical suspicion of upper limb entrapment neuropathies over a 10-year period. We collected demographic details, clinical features, clinical neurophysiological data and details of aids and appliances used for mobility.
Results
Among 71 patients, 38 (53.5%) patients had at least one entrapment neuropathy of upper limb confirmed by clinical neurophysiological studies. Twelve (31%) patients had median nerve entrapment, 20 (53%) had ulnar nerve entrapment and six (16%) had both. Risk of ulnar nerve entrapment was significantly higher in patients using a powered wheelchair (odds ratio 5.7, 95% confidence interval (1.7–18.7, p = 0.0037).
Discussion
Entrapment neuropathies should be considered in patients with multiple sclerosis reporting sensory and motor symptoms of hands
Neurological Dysfunction in Coeliac Disease and Non-Coeliac Gluten Sensitivity
OBJECTIVES: Non-coeliac gluten sensitivity (NCGS) refers to patients with primarily gastrointestinal symptoms
without enteropathy that symptomatically benefi t from gluten-free diet (GFD). Little is known about
its pathophysiology, propensity to neurological manifestations, and if these differ from patients with
coeliac disease (CD). We investigated the clinical and immunological characteristics of patients
presenting with neurological manifestations with CD and those with NCGS.
METHODS: We compared clinical, neurophysiological, and imaging data of patients with CD and NCGS
presenting with neurological dysfunction assessed and followed up regularly over a period of
20 years.
RESULTS: Out of 700 patients, 562 were included. Exclusion criteria included no bowel biopsy to confi rm
CD, no HLA type available, and failure to adhere to GFD. All patients presented with neurological
dysfunction and had circulating anti-gliadin antibodies. Out of 562 patients, 228 (41%) had
evidence of enteropathy (Group 1, CD) and 334 (59%) did not (Group 2, NCGS). The most common
neurological manifestations were cerebellar ataxia, peripheral neuropathy, and encephalopathy. There
was a greater proportion of patients with encephalopathy in Group 1 and with a greater proportion
of neuropathy in Group 2. The severity of ataxia did not differ between the two groups. Patients in
Group 1 had more severe neuropathy. All patients from both groups responded to gluten-free diet.
Anti-tissue transglutaminase (TG2) antibodies were found in 91% of patients in Group 1 and in
29% of patients in Group 2. Comparison between those patients in Group 2 with HLA-DQ2/DQ8 and
those without as well as those with positive TG2 compared with those with negative TG2 antibodies
identifi ed no differences within these subgroups. Serological positivity for TG6 antibodies was similar
in the two groups (67 and 60%).
CONCLUSIONS: The neurological manifestations of CD and NCGS are similar and equally responsive to a GFD
suggestive of common pathophysiological mechanisms
Chronic idiopathic axonal polyneuropathy: Prevalence of pain and impact on quality of life
BACKGROUND AND AIM: Chronic idiopathic axonal polyneuropathy (CIAP) is a term describing axonal neuropathies of insidious onset, with slow or no progression of the disease over at least 6 months and with no etiology being identified despite appropriate investigations. We aimed to establish the prevalence of pain in patients with CIAP and investigate the impact of pain on quality of life (QoL). METHODS: All consecutive patients with CIAP attending a specialist neuropathy clinic were invited to participate. Pain was assessed via the DN4 questionnaire and the visual analogue scale (VAS). Overall Neuropathy Limitations Scale (ONLS) was used to assess the severity of neuropathy. The SF-36 questionnaire was used to measure participants' quality of life. RESULTS: Fifty-five patients with CIAP were recruited (63.6% male, mean age 73.4 ± 8.7 years). Based on the DN4 questionnaire, peripheral neuropathic pain was present in 33 patients (60.0%). After having adjusted for age, gender and disease severity pain showed significant negative correlations with the energy/fatigue domain of QoL (β = -0.259, p = 0.049), with the emotional well-being domain (β = -0.368, p = 0.007) and the general health perception domain (β = -0.356, p = 0.007). CONCLUSION: Pain is very prevalent in CIAP and is associated with poorer emotional well-being, worse general health perception, and increased fatigue
Eimeria species occurrence varies between geographic regions and poultry production systems and may influence parasite genetic diversity
Coccidiosis is one of the biggest challenges faced by the global poultry industry. Recent studies have highlighted the ubiquitous distribution of all Eimeria species which can cause this disease in chickens, but intriguingly revealed a regional divide in genetic diversity and population structure for at least one species, Eimeria tenella. The drivers associated with such distinct geographic variation are unclear, but may impact on the occurrence and extent of resistance to anticoccidial drugs and future subunit vaccines. India is one of the largest poultry producers in the world and includes a transition between E. tenella populations defined by high and low genetic diversity. The aim of this study was to identify risk factors associated with the prevalence of Eimeria species defined by high and low pathogenicity in northern and southern states of India, and seek to understand factors which vary between the regions as possible drivers for differential genetic variation. Faecal samples and data relating to farm characteristics and management were collected from 107 farms from northern India and 133 farms from southern India. Faecal samples were analysed using microscopy and PCR to identify Eimeria occurrence. Multiple correspondence analysis was applied to transform correlated putative risk factors into a smaller number of synthetic uncorrelated factors. Hierarchical cluster analysis was used to identify poultry farm typologies, revealing three distinct clusters in the studied regions. The association between clusters and presence of Eimeria species was assessed by logistic regression. The study found that large-scale broiler farms in the north were at greatest risk of harbouring any Eimeria species and a larger proportion of such farms were positive for E. necatrix, the most pathogenic species. Comparison revealed a more even distribution for E. tenella across production systems in south India, but with a lower overall occurrence. Such a polarised region- and system-specific distribution may contribute to the different levels of genetic diversity observed previously in India and may influence parasite population structure across much of Asia and Africa. The findings of the study can be used to prioritise target farms to launch and optimise appropriate anticoccidial strategies for long-term control
A novel mutation in the FGD4 gene causing Charcot-Marie-Tooth disease.
Demyelinating forms of Charcot-Marie-Tooth (CMT) result from mutations in a number of genes, the majority of which show an autosomal dominant pattern of inheritance [1]. Recessive patterns of inheritance are less common. We report a case of demyelinating CMT resulting from compound heterozygous mutation in the FGD4 gene
Extrinsic inhomogeneity effects in magnetic, transport and magnetoresistive properties of La_{1-x}Ca_{x}MnO_{3} (x\approx 0.33) crystal prepared by the floating zone method
The paper describes a study of the magnetic, transport and magnetoresistive
properties of La_{1-x}Ca_{x}MnO_{3} (x\approx 0.33) crystals prepared by the
floating-zone method. We found that these properties testify to rather good
crystal perfection of the sample studied. In particular, a huge
magnetoresistance ([R(0)-R(H)]/R(H) in the field H = 5 T is about 2680 %) is
found near the Curie temperature (216 K). At the same time, some distinct
features of measured properties indicate the influence of extrinsic
inhomogeneities arising due to technological factors in the sample preparation.
Analysis of the data obtained shows that these are rare grain boundaries and
twins. Specific influence of the grain-boundary-like inhomogeneities on the
transport and magnetoresistive properties are considered.Comment: Submitted to Physica
Electronic structure, phase stability and chemical bonding in ThAl and ThAlH
We present the results of theoretical investigation on the electronic
structure, bonding nature and ground state properties of ThAl and
ThAlH using generalized-gradient-corrected first-principles
full-potential density-functional calculations. ThAlH has been reported
to violate the "2 \AA rule" of H-H separation in hydrides. From our total
energy as well as force-minimization calculations, we found a shortest H-H
separation of 1.95 {\AA} in accordance with recent high resolution powder
neutron diffraction experiments. When the ThAl matrix is hydrogenated, the
volume expansion is highly anisotropic, which is quite opposite to other
hydrides having the same crystal structure. The bonding nature of these
materials are analyzed from the density of states, crystal-orbital Hamiltonian
population and valence-charge-density analyses. Our calculation predicts
different nature of bonding for the H atoms along and . The strongest
bonding in ThAlH is between Th and H along which form dumb-bell
shaped H-Th-H subunits. Due to this strong covalent interaction there is very
small amount of electrons present between H atoms along which makes
repulsive interaction between the H atoms smaller and this is the precise
reason why the 2 {\AA} rule is violated. The large difference in the
interatomic distances between the interstitial region where one can accommodate
H in the and planes along with the strong covalent interaction
between Th and H are the main reasons for highly anisotropic volume expansion
on hydrogenation of ThAl.Comment: 14 pages, 9 figure
Multi-dimensional electrical impedance myography of the tongue as a potential biomarker for amyotrophic lateral sclerosis
Objective
In amyotrophic lateral sclerosis (ALS) bulbar disease biomarkers are lacking. We evaluated a novel tongue electrical impedance myography (EIM) system, utilising both 2D and 3D electrode configurations for detection of tongue pathology.
Methods
Longitudinal multi-frequency phase angle spectra were recorded from 41 patients with ALS (baseline, 3 and 6 months) and 30 healthy volunteers (baseline and 6 months). ALS functional rating scale-revised (ALSFRS-R) data and quantitative tongue strength measurements were collected. EIM data were analysed for reliability (intra-class correlation coefficient; ICC) and differences between patients and volunteers ascertained using both univariate (Mann-Whitney U test) and multivariate techniques (feature selection and L2 norm).
Results
The device produced highly reliable data (pooled ICC: 0.836). Significant EIM differences were apparent between ALS patients and healthy volunteers (P<0.001). EIM data demonstrated a significant relationship to tongue strength and bulbar ALSFRS-R scores (P<0.015). The EIM recordings revealed a group level longitudinal change over 6 months and consistently identified patients in whom symptoms or tongue strength changed.
Conclusions
The novel EIM tongue system produces reliable data and can differentiate between healthy muscle and ALS-related disease.
Significance
Tongue EIM utilising multiple frequencies and electrode configurations has potential as a bulbar disease biomarker in ALS
- …