Chaos and COSMOS-Considerations on QSM methods with multiple and single orientations and effects from local anisotropy.

PURPOSE: Field-to-susceptibility inversion in quantitative susceptibility mapping (QSM) is ill-posed and needs numerical stabilization through either regularization or oversampling by acquiring data at three or more object orientations. Calculation Of Susceptibility through Multiple Orientations Sampling (COSMOS) is an established oversampling approach and regarded as QSM gold standard. It achieves a well-conditioned inverse problem, requiring rotations by 0°, 60° and 120° in the yz-plane. However, this is impractical in vivo, where head rotations are typically restricted to a range of ±25°. Non-ideal sampling degrades the conditioning with residual streaking artifacts whose mitigation needs further regularization. Moreover, susceptibility anisotropy in white matter is not considered in the COSMOS model, which may introduce additional bias. The current work presents a thorough investigation of these effects in primate brain. METHODS: Gradient-recalled echo (GRE) data of an entire fixed chimpanzee brain were acquired at 7 T (350 µm resolution, 10 orientations) including ideal COSMOS sampling and realistic rotations in vivo. Comparisons of the results included ideal COSMOS, in-vivo feasible acquisitions with 3-8 orientations and single-orientation iLSQR QSM. RESULTS: In-vivo feasible and optimal COSMOS yielded high-quality susceptibility maps with increased SNR resulting from averaging multiple acquisitions. COSMOS reconstructions from non-ideal rotations about a single axis required additional L2-regularization to mitigate residual streaking artifacts. CONCLUSION: In view of unconsidered anisotropy effects, added complexity of the reconstruction, and the general challenge of multi-orientation acquisitions, advantages of sub-optimal COSMOS schemes over regularized single-orientation QSM appear limited in in-vivo settings.

First Swedish case of fatal equine parasitic encephalitis by Halicephalobus gingivalis.

BACKGROUND: Halicephalobus gingivalis is a nematode with zoonotic potential which can cause fatal opportunistic infections in various mammals. The parasite has never been diagnosed in Sweden, in any species, prior to the presented case. CASE PRESENTATION: An imported 21-year-old Icelandic mare developed severe neurological signs. The horse was eventually euthanized and submitted for post-mortem examination where severe lesions in the kidneys were noted. Histopathology revealed the presence of H. gingivalis in both kidneys and the brain. Phylogenetic analysis of the parasite determined it to belong to Lineage 1. CONCLUSIONS: With the occurrence of H. gingivalis in Sweden, the disease should be added to the list of differential diagnoses in cases with acute onset of neurological disease in both horses and other mammals including humans.

Mystery of fatal 'staggering disease' unravelled: novel rustrela virus causes severe meningoencephalomyelitis in domestic cats.

'Staggering disease' is a neurological disease entity considered a threat to European domestic cats (Felis catus) for almost five decades. However, its aetiology has remained obscure. Rustrela virus (RusV), a relative of rubella virus, has recently been shown to be associated with encephalitis in a broad range of mammalian hosts. Here, we report the detection of RusV RNA and antigen by metagenomic sequencing, RT-qPCR, in-situ hybridization and immunohistochemistry in brain tissues of 27 out of 29 cats with non-suppurative meningoencephalomyelitis and clinical signs compatible with'staggering disease' from Sweden, Austria, and Germany, but not in non-affected control cats. Screening of possible reservoir hosts in Sweden revealed RusV infection in wood mice (Apodemus sylvaticus). Our work indicates that RusV is the long-sought cause of feline 'staggering disease'. Given its reported broad host spectrum and considerable geographic range, RusV may be the aetiological agent of neuropathologies in further mammals, possibly even including humans.

Cardiac Anomalies in Two White-Tailed Eagles (Haliaeetus albicilla) in Sweden.

Severe cardiomegaly with an atrial septal defect was discovered during necropsy of a subadult White-tailed Eagle (Haliaeetus albicilla) found dead in the wild. A thin membrane composed of fibromuscular tissue separated the left atrium into two chambers, most consistent with that described for cor triatriatum sinister (CTS) in other species. Seventeen months later, necropsy of an adult White-tailed Eagle again revealed CTS. This lesion has not been reported previously in raptors.

Expression of T helper type 17 (Th17)-associated cytokines and toll-like receptor 4 and their correlation with Foxp3 positive cells in rectal biopsies of horses with clinical signs of inflammatory bowel disease.

Inflammatory bowel disease (IBD) in horses is an idiopathic disorder, encompassing different types of chronic intestinal inflammation. The pathogenesis of the disease remains to be established, but it has been suggested that an imbalance between regulatory T cells (Tregs) and T helper 17 (Th17)-associated cytokines and altered toll-like receptor 4 (TLR4) expression is associated with intestinal inflammation in other species. The aim of the present study was to quantify Tregs in rectal biopsies from horses affected with IBD by immunohistochemistry and to evaluate expression of genes encoding interleukin (IL)-12p40, IL-17A, IL-23p19 and TLR4 by real-time quantitative PCR. Rectal biopsies from 11 healthy horses and 11 horses with clinical signs of IBD, showing inflammation classified as chronic simple proctitis (CSP) or chronic active simple proctitis (CASP), were evaluated. Expression of IL-17A mRNA was greater in horses affected with CASP compared with horses with CSP or healthy horses. In contrast, expression of IL-12p40 was lower in horses with CSP compared with horses with CASP or healthy horses. TLR4 expression was greater in horses with CASP compared with healthy horses. A positive correlation was seen between the numbers of Tregs and expression of IL-17A and IL-23p19. An association was demonstrated between the histopathological pattern of inflammation, cytokine profile and number of infiltrating Tregs. The research findings suggest that Th17 cells are involved in active IBD, possibly through recruitment of neutrophils via IL-17A, in combination with inadequate suppression of the inflammatory response by Tregs.

Physiological and structural anorectal abnormalities in patients with systemic sclerosis and fecal incontinence.

OBJECTIVE: Fecal incontinence is common in systemic sclerosis (SSc), but the underlying mechanisms are not fully understood. The objectives of this study were to characterize anorectal physiological and morphological defects in SSc patients and to correlate the results with incontinence symptoms. MATERIALS AND METHODS: Twenty-five SSc patients underwent anorectal neurophysiological investigations, anal manometry, and ultrasound. RESULTS: Eleven patients (44%) reported incontinence to solid or liquid feces, but no patient reported diarrhea. Increased fiber density (FD) was recorded in 78% of patients with and in 86% of patients without fecal incontinence not significant (NS). Incontinent patients had lower squeeze pressure (SP; median 49.5 mm Hg) in the high-pressure zone (HPZ) than continent patients (median 72 mm Hg; p = 0.01). In two of the incontinent patients, sonographic abnormalities of the internal anal sphincter (IAS) and the external anal sphincter (EAS) were present, whereas in another two patients isolated IAS abnormalities were seen. These four individuals had lower resting pressure at 1 cm and in the HPZ, and lower SP at 2 cm than patients with normal anorectal sonographic findings (p < 0.05). CONCLUSION: Lower voluntary SP in incontinent patients and EAS sonographic abnormalities only in patients with incontinence suggest that the EAS is more important in maintaining fecal continence in SSc patients than has previously been reported. The finding of increased FD in most patients further supports involvement of the EAS function in SSc and could indicate previous nerve injury with consequent incomplete reinnervation.

Expression of reference genes and T helper 17 associated cytokine genes in the equine intestinal tract.

There is accumulating evidence for the involvement of pro-inflammatory cytokines associated with a T helper 17 response in intestinal disorders such as inflammatory bowel disease (IBD) in humans. The involvement of interleukin (IL)-17 or IL-23 in equine IBD has not been studied and most gene expression studies in the equine intestine have been limited to the use of a single non-validated reference gene. In this study, expression of the reference gene candidates ß2 microglobulin (ß2M), glyceraldehyde 3-phosphate dehydrogenase (GAPDH), histone H2A type 1, hypoxanthine-guanine phosphoribosyltransferase (HPRT), 60S ribosomal protein L32 (RPL32), succinate dehydrogenase complex subunit A (SDHA) and transferrin receptor 1 protein coding (TFRC)in the equine intestine was evaluated by quantitative PCR. Three to four reference genes were adequate for normalisation of gene expression in the healthy duodenum, mid-jejunum, colon and rectum, although each segment required a unique combination of reference genes. No combination of the evaluated genes was optimal for the caecum and ileum. Another combination of reference genes (GAPDH, HPRT, RPL32 and SDHA) was optimal for normalisation of rectal samples from healthy and IBD-affected horses, indicating that reference genes should be re-evaluated if material from diseased specimens is analysed. Basal expression of IL-12p40, IL-17A and IL-23p19 was detected in each segment, which will enable gene expression studies of these cytokines by relative quantification.

Intramuscular administration of sodium benzylpenicillin in horses as an alternative to procaine benzylpenicillin.

The aim was to supply information about the possibility of replacing the procaine salt with the sodium salt for benzylpenicillin IM treatment in horse in order to diminish the risk for procaine adverse effects. In a crossover study eight horses were given 15 mg/kg sodium benzylpenicillin (Na-pc) twice daily or procaine benzylpenicillin (control) once daily IM for four days. The half-life of Na-pc was 1.9h, peak concentration was 14,600 ng/mL reached after about 23 min. Trough plasma concentration was 281 ng/mL and protein binding 62.8%. The fT>MIC for Staphylococcus aureus was 63% and 100% for Streptococcus equi subsp. equi and Streptococcus zooepidemicus, indicating an adequate antimicrobial therapy. However, Na-pc cannot be recommended from a welfare point of view since the horses showed more pain related behaviour and more pain and swelling compared to the control treatment.

Association between sociodemographic status and antiepileptic drug prescriptions in children with epilepsy.

PURPOSE: We investigated whether in Sweden sociodemographic differences are associated with access to expert health care and antiepileptic drug (AED) prescriptions in children with epilepsy. METHODS: Data on epilepsy, prescription of AEDs, and sociodemographic variables were obtained from several national administrative registers. We linked individual data to examine whether access by pediatric epilepsy patients to neuropediatricians and the prescription of individual AEDs differed according to gender, age, parental education, place of residence, parental region of birth, and household income. We also assessed whether AEDs are prescribed differently to patients with epilepsy by neuropediatricians as compared to other physicians. KEY FINDINGS: Of 1,788,382 children aged 1-17 years in 2006, living in the country by the end of 2006, 9,935 had a diagnosis of epilepsy (0.56%). Patients with epilepsy on AED treatment (n = 3,631) comprised 0.24% of the total Swedish population aged 1-17 years. Out of 3631 patients with epilepsy on AED treatment, 2301 (63.4%) received prescriptions from a neuropediatrician. Children with epilepsy aged 1-5 years old--as opposed to older children and adolescents--and children with epilepsy residing in large cities--as opposed to children living in smaller cities and rural areas--were more likely to be treated by a neuropediatrician. Children living in large cities received oxcarbazepine to a greater extent than children living in rural areas. Levetiracetam was prescribed more extensively to children whose parents had higher incomes. Of the five most frequently used AEDs, three (lamotrigine, oxcarbazepine, and levetiracetam) were prescribed to a larger extent by a neuropediatrician rather than by other specialists, and one AED (carbamazepine) was prescribed to a lesser extent. SIGNIFICANCE: The results of this nationwide cross-sectional study of children with epilepsy are important because they show that universal coverage for medical care does not eliminate inequalities of access to health care services among children and adolescents. No data are available that can guide us as to whether the density of child neurologists is of importance to access to expert health care, but this seems likely. Prescription patterns of AEDs differ between child neurologists and other specialists.

Simplified evaluation of the paradoxical puborectalis contraction with surface electrodes.

PURPOSE: Paradoxical puborectalis contraction during defecation is one possible explanation for constipation. The degree of paradoxical contraction can be evaluated by intramuscular electromyography from the puborectalis and external anal sphincter muscles. This study aimed to determine whether a noninvasive technique with surface electrodes placed over the subcutaneous part of the external anal sphincter is feasible in the evaluation of paradoxical activity. METHODS: Twenty-five patients with constipation were studied. Sphincter muscle activity during strain and squeeze maneuvers was recorded using surface electrodes placed 1 cm from the anal verge. In addition, intramuscular recordings were made simultaneously from the external anal sphincter and puborectalis muscles. The degree of paradoxical activation was calculated as a strain/squeeze index. The patients were examined either in the left lateral position or sitting on a commode. RESULTS: The study revealed significant (P < .01) correlations between indices obtained from the surface anal sphincter recordings and the intramuscular recordings (from the external anal sphincter and the puborectalis muscles). CONCLUSION: Surface recordings from the external anal sphincter seem to be an equally reliable, less time consuming, and less painful alternative to invasive measurements of paradoxical activity. In a few patients, however, invasive recordings may still be required.

Frontotemporal dementia-amyotrophic lateral sclerosis complex is simulated by neurodegeneration with brain iron accumulation.

We describe a case of late onset neurodegeneration with brain iron accumulation (NBIA) presenting as frontotemporal dementia (FTD) with amyotrophic lateral sclerosis (ALS). A male patient presented at age 66 with change of personality: disinhibition, emotional blunting, and socially inappropriate behavior, coupled with dysarthria, dystonia, and corticospinal tract involvement. Magnetic resonance imaging showed general cortical atrophy, iron deposits in the globus pallidus, and the "eye of the tiger" sign. Neuropsychologic performance was globally reduced, especially executive functions. Fluorodeoxyglucose positron emission tomography showed hypometabolism predominantly in frontal and temporal areas. Repeated neurophysiologic examinations showed signs of chronic denervation. The patient was diagnosed with NBIA but fulfilled consensus criteria for FTD and had a clinical picture of ALS, without neurophysiologic confirmation. Our finding introduces NBIA as a possible cause of FTD and as a differential diagnosis of the FTD-ALS complex.

Duchenne muscular dystrophy and idiopathic hyperCKemia in the same family.

Familial hyperCKemia is a rare condition, and a combination with Duchenne muscular dystrophy (DMD) is extremely rare. A boy showed muscle weakness from the age of 10 months and presented typical signs of DMD at the age of 18 months. The diagnosis was supported by markedly elevated serum creatine kinase (CK) value as well as by neurophysiological and muscle biopsy findings at the age of 23 months. The diagnosis was confirmed by identification of a stop codon in exon 43 (p.2095Arg>X) of the dystrophin gene. Interestingly, the father and his near relatives had increased serum CK values without any clinical symptoms or signs, nor a defect in caveolin-3 gene. We suggest that the occurrence of familial hyperCKemia may have triggered the early onset of symptoms in our patient.

Evaluation of the paradoxical sphincter contraction by a strain/squeeze index in constipated patients.

PURPOSE: One finding in patients with constipation is the paradoxical puborectalis contraction, i.e. , activation of the sphincter muscles during straining instead of relaxation. The aims of this study were to evaluate the importance of needle placement in sphincter-electromyography and to evaluate a strain/squeeze index in constipated patients and control subjects. METHODS: We investigated consecutively 194 constipated patients and 16 control subjects with integrated electromyography during straining and squeezing and calculated a strain/squeeze index. The examination was performed in the puborectalis and in the external anal sphincter muscle through hook-electrodes. RESULTS: There was a strong correlation between indices in the puborectalis muscle and in the external anal sphincter muscle (r = 0.70-0.80, P < 0.001). Forty-seven patients (24 percent) had a mean index of greater than 50 compared with none in the control group (P = 0.01). Mean overall index in patients was 24 (range, 0-306) vs. 18 (range, 0-45) in controls (P = 0.12). Patients with an index greater than 50 had impaired rectal evacuation (P < 0.001), increased threshold for urge (P < 0.05), and tended to have fewer stools (P = 0.06). CONCLUSION: Quantification of paradoxical contraction in the puborectalis and external anal sphincter with a strain/squeeze index differentiates patients in whom paradoxical activity may be a cause of constipation. An index above 50 may be of pathologic significance. Correlations between activity in the puborectalis and external anal sphincter muscle were strong which suggests that investigation in one of them is sufficient.

Analysis of motor pathway involvement in konzo using transcranial electrical and magnetic stimulation.

To elucidate the involvement of motor pathways in konzo, 21 konzo subjects (mean age 22 years) underwent transcranial electrical stimulation (TES) in 1998. Fourteen konzo subjects (mean age 21 years) underwent transcranial magnetic stimulation (TMS) in 2000. Three subjects underwent both TES and TMS. Motor evoked potentials (MEPs) were recorded in the abductor pollicis brevis (APB) muscle with TES, and in the abductor digiti minimi (ADM) and tibialis anterior (TA) muscles with TMS. APB-MEPs were normal in 2 of 21 subjects and absent in 9; central conduction time (CCT) was prolonged in 10. Resting ADM-MEPs were absent in 9 of 14 subjects with clinically preserved upper limbs. Among these nine, seven subjects responded after facilitation. Most subjects (13 of 14) failed to show TA-MEPs. Of the subjects who underwent both types of stimulation, one had normal TES-MEP but abnormal ADM-MEP with TMS. These findings suggest involvement of both corticomotoneurons and motor descending pathways in konzo.

Acute motor axonal neuropathy with selective involvement of the lower limbs.

We report an unusual variant of acute motor axonal neuropathy completely restricted to the lower limbs and responding rapidly to intravenous immunoglobulin (IVIG). A 31-year-old man presented with 4 weeks of progressive weakness in the lower limbs. Magnetic resonance images of the spine had been normal. On neurologic examination he had symmetric weakness in the lower limbs, but muscle strength in the arms was normal. Tendon reflexes were absent. Cranial nerves and sensation were normal. Electromyography (EMG) revealed an axonal involvement with changes restricted to the lower limbs. A lumbar puncture 4 weeks after onset showed elevated protein content; cell count was normal. The patient improved rapidly after treatment with 0.4 g/kg IVIG per day for 5 days. Eight weeks after treatment EMG revealed fast reinnervation, and the only clinical sequelae was slight weakness of ankle flexion.