Intraoperative Thermography of the Electrical Stimulation Mapping: A Safety Control Study.

A standard procedure for continuous intraoperative monitoring of the integrity of the corticospinal tracts by eliciting muscle responses is the electric stimulation mapping (ESM). However, standard ESM protocols are ineffective in 20% of young children. We have developed a novel, highly efficient paradigm consisting of short-time burst (30 ms) of high frequency (500 Hz) and high peak current (≤100 mA), which may cause local tissue overheating. The presented safety control study was therefore designed. The infrared thermography camera captured to-be-resected cortex of 13 patients in vivo during ESM. Thermograms were image processed to reveal discrete ESM thermal effect of currents from 10 to 100 mA. Peak 100 mA currents induced a maximal increase in temperature of 3.1 °C, 1.23±0.72 °C in average. The warming correlated with stimulating electrode resistance ( ). The measurement uncertainty was estimated ± 1.01 ºC for the most skeptical conditions. The histopathological evaluation of stimulated tissue (performed in all cases) did not show any destructive changes. Our study demonstrates the ability of the thermographic camera to measure the discrete thermal effect of the ESM. The results provide evidence for the safety of the proposed protocol for full range currents with minimal risk of brain tissue damage.

Application of a Scale for the Assessment and Rating of Ataxia (SARA) in Friedreich's ataxia patients according to posturography is limited.

BACKGROUND: A scale for the Assessment and Rating of Ataxia (SARA) was developed for evaluation of autosomal dominant cerebellar ataxias (ADCA) and was also recommended for clinical trials of Friedreich's ataxia patients (FRDA). FRDA, unlike ADCA, is characterized as being a sensory type of ataxia for which the disease-specific Friedreich ataxia rating scale (FARS) was developed. The objective of this study was to determine whether SARA and FARS scores are associated with posturographic parameters in FRDA patients. METHOD: Adult patients with genetically confirmed FRDA (n=11) and ADCA (n=13) were evaluated by SARA, FARS and posturography. RESULTS: FRDA patients' postural stability parameters, in stance with visual control, correlated with balance impairment in FARS (r=0.622; p<0.05) and SARA (r=0.735; p<0.05). Without visual control, only FARS correlated with balance impairment (r=0.732; p<0.05). CONCLUSION: The SARA, in FRDA patients, correlates with stance with visual control but not without visual control which emphasizes sensory ataxia. This suggests that application of the SARA in Friedreich's ataxia patients according to posturography is possible but presumably limited and FARS, although being a more time consuming scale, may have advantages over SARA in FRDA patients.

Distinctive MRI features of the epileptogenic zone in children with tuberous sclerosis.

OBJECTIVE: Localization of the epileptogenic zone (EZ) is challenging in children with tuberous sclerosis complex (TSC). We sought to ascertain whether brain MRI could identify the EZ in TSC patients independent of the clinical and diagnostic data. METHODS: Presurgical MRI's of 34 children with TSC who underwent epilepsy surgery at Miami Children's Hospital were retrospectively reevaluated by experts blinded to all other data. Changes typical of TSC (tubers, calcifications, cystic changes) and abnormalities of the perituberal cortex typical of focal cortical dysplasia (FCD) (increased cortical thickness, abnormal gyration, transmantle change, gray/white matter junction blurring) were identified and their localization was compared with the resection site. Sensitivity, specificity and accuracy of individual MRI features to localize the EZ were determined and statistically compared between postoperatively seizure-free and non-seizure-free patients as well as clusters of features typical of FCD and TSC. RESULTS: MRI alone correctly localized the resection cavity in all 19 postoperatively seizure-free patients and 12 of 15 non-seizure-free subjects. Sensitivity, specificity and accuracy of MRI features typical of FCD to localize EZ (90%, 96% and 96%, respectively) were superior to those typical of TCS (79%, 75% and 75%, p<0.0001). Increased cortical thickness and abnormal gyral formation outside tubers occurred only in the resection site. Resection sites were better predicted by MRI in seizure-free than in non-seizure-free patients. CONCLUSION: Thorough MRI evaluation identifies the EZ in a significant proportion of TSC patients. Epileptogenic regions were mostly characterized by "FCD-like" changes outside cortical tubers. The findings may have important practical consequences for surgical planning in TSC.

Uses of the postural stability test for differential diagnosis of hereditary ataxias.

Friedreich's ataxia (FRDA) and spinocerebellar ataxia type 2 (SCA 2) are among the most commonly diagnosed hereditary ataxias in Czech Republic. Although criteria differentiate the ataxias, disorder onset symptoms may be similar. Our goal was to determine whether and to what degree of validity posturographic examination may be utilized, with the aim of differential diagnosis; which specific posturographic parametres are suitable for differential diagnosis; and which differences in FRDA and SCA 2 patient posturographic findings may be established. 17 SCA 2 and 12 FRDA patients were examined with ten healthy controls. A multi-sensor tenzometric platform was used for posturographic examination. Toe standing position was added to basic tests, including standing position with and without visual control. There was no difference between patients in standing position with visual control but there were distinct differences between FRDA and SCA 2 patients, based on upright stance without visual control and medio-lateral deviation. There were no differences between patients in toe standing position, suggesting not only the cerebellum, but also deep sensation, helps to create the so-called adaptive controller. Posturography is attested to as a useful method for differential diagnosis of hereditary ataxias and provides neurophysiological findings in cerebellar and sensoric ataxias.

Infections with weakly haemolytic Brachyspira species in pigs with miscellaneous chronic diseases.

The prevalence of infections with different Brachyspira species was assessed in 202 pigs with various chronic herd problems using different methods. Twenty-seven pigs (13.4%) were positive for Brachyspira spp. with at least one of the methods used. The highest number of positives was identified with mucosal scraping-PCR (23), followed by PET-PCR (22) and bacteriological-biochemical analysis (15). With the exception of three cases of B. pilosicoli infections, only weakly pathogenic Brachyspira species were identified. The majority was B. murdochii, followed by B. innocens and B. intermedia. Concurrent infections with two or more Brachyspira species were common and accounted for 37.1% of the total. Presence of weakly haemolytic Brachyspira was associated with wasting and diarrhoea in a number of cases. This investigation shows that infections with weakly haemolytic Brachyspira spp. may contribute to colonic pathology in pigs with chronic herd problems and that mixed infections seem to occur more frequently than previously noticed.

[Calprotectin levels in patients with idiopathic inflammatory bowel disease comparison of two commercial tests]. / Stanovení koncentrace kalprotektinu ve stolici u nemocných s idiopatickými strevními zánety-srovnání dvou komercních testu.

BACKGROUND: Fecal calprotectin test is a simple, non-invasive, rapid and inexpensive diagnostic tool allowing differentiation between GIT functional disorders and inflammatory conditions and relapse prediction in non-specific inflammatory bowel disease. In the last year, commercially available ELISA diagnostic kits, using either monoclonal or polyclonal antibodies against a heterodimeric complex, calprotectin, for the detection of fecal calprotectin, started to be marketed. OBJECTIVE: To compare two ELISA kits for the detection of fecal calprotectin differing from each other in the used type of antibody (monoclonal versus polyclonal). MATERIAL AND METHODS: Two ELISA kits were assessed: Calprotectin ELISA (Bühlmann, Basel, Switzerland) using a monoclonal antibody against calprotectin and PhiCal Calprotectin ELISA (R-Biopharm, Darmstadt, Germany) using a polyclonal antibody against calprotectin. We analyzed fecal eluates from patients with Crohn's disease (CD, n=36) and ulcerous colitis (UC, n=29) and from healthy controls (n=98). Data were analyzed using software Statistica CZ 8.0 (Statsoft, Tulsa, U.S.A.) and measurement variability parameters (linearity, repeatability, stability) and test sensitivity and specificity were established and the methods were compared. RESULTS: The two kits showed adequate accuracy (intra- and inter-assay variation < 10%). The dilution linearity test indicated superiority of the Calprotectin ELISA Bühlmann kit, in particular for high calprotectin levels. The results of the two methods showed good correlation: Pearson's correlation coefficient r = 0.83, limit difference according to Bland-Altman plot ranged from 17% to 30%. Diagnostic sensivity rates were 79% for the Calprotectin ELISA Bühlmann kit and 74% for the Calprotectin ELISA R-Biopharm kit, the test specificity rates were 87% and 84%, respectively. CONCLUSIONS: Both of the tested kits have comparably good measurement parameters, the Bühlmann kit using monoclonal antibody against calprotectin showed higher sensitivity and specificity. In view of their availability, sensitivity and performance, the fecal calprotectin ELISA kits are helpful diagnostic tools for clinical practice.

Densities of parvalbumin-immunoreactive neurons in non-malformed hippocampal sclerosis-temporal neocortex and in cortical dysplasias.

The changes in density of inhibitory parvalbumin-immunoreactive interneurons were quantitatively studied by immunohistochemistry in a series of human neocortical samples comprising the spectrum of malformations of cortical development (MCD) encountered in epilepsy surgery and the non-malformed hippocampal sclerosis-temporal neocortex in patients with refractory temporal lobe epilepsy. The highest relative density of parvalbumin-immunoreactive cells was obtained in the control samples (n = 21). The number of parvalbumin-immunoreactive neurons was significantly decreased in non-malformed hippocampal sclerosis-temporal neocortex (n = 73, 80.5% of control values). In a proportion of the latter samples as well as in two controls we observed patchy regions of absence of parvalbumin staining. The total counts of parvalbumin-immunoreactive cells in all the categories of MCD - "mild MCD" (n = 25), focal cortical dysplasia type I (n = 19) and type II (n = 15) - were decreased representing 72.4%, 55.0% and 12.2% of control values, respectively. Significantly different parvalbumin-immunoreactive cell densities were demonstrated between the focal cortical dysplasia types IIA and IIB. In "mild MCD", we observed a more pronounced decrease of parvalbumin-immunoreactive cells in the infragranular layers. No significant differences were revealed between the temporal and extratemporal examples of analogous MCD types. This study provides evidence for reduction of inhibitory parvalbumin-immunoreactive interneurons in the epileptic neocortex affected by MCD as well as in morphologically unaffected epileptic temporal neocortex, thus representing a possible mechanism for their epileptogenicity.

[Microscopic disorders of cortical development of the brain and its etiopathogenic importance for detection in patients with temporal epilepsy associated with hippocampal sclerosis]. / Mikroskopické poruchy kortikálního vývoje mozku a etiopatogenetický význam jejich detekce u pacientu s temporální epilepsií pri skleróze hipokampu.

Hippocampal sclerosis represents a common structural basis of temporal lobe epilepsy. However, the etiological factors and mechanisms leading to its development still remain unexplained. In our study, we present neuropathological findings in the resected hippocampus and the pole of the temporal lobe in 15 patients with hippocampal sclerosis. "Initial precipitating injuries" that are thought to cause the development of hippocampal sclerosis (febrile seizures in early childhood, head injury or meningoencephalitis) were present in the history of 12 patients. In the remaining 3 cases, no predisposing factors were found. Attention was paid to the histopathological identification of disturbed neuronal migration and differentiation in the temporal lobe. These defects were observed in 7 cases; in three of these, no predisposing factors were stated in the patients' histories. We suggest that in these cases, hippocampal sclerosis arises due to previously undetected disorders of cortical development. A latent neocortical malformation may also contribute to the development of hippocampal sclerosis in patients with an initial precipitating injury in anamnensis. Histopathological examination of resected epileptic brain tissue can provide insights into the individual pathogenesis of epileptic disorders, especially by the detection of microscopic disorders of cortical development.

Synchronization as adjustment of information rates: detection from bivariate time series.

An information-theoretic approach for studying synchronization phenomena in experimental bivariate time series is presented. "Coarse-grained" information rates are introduced and their ability to indicate generalized synchronization as well as to establish a "direction of information flow" between coupled systems, i.e., to discern the driving from the driven (response) system, is demonstrated using numerically generated time series from unidirectionally coupled chaotic systems. The method introduced is then applied in a case study of electroencephalogram recordings of an epileptic patient. Synchronization events leading to seizures have been found on two levels of organization of brain tissues and "directions of information flow" among brain areas have been identified. This allows localization of the primary epileptogenic areas, also confirmed by magnetic resonance imaging and pasitron emission tomography scans.

Acquisition and retrieval of conditioned taste aversion is impaired by brain damage caused by two hours of pilocarpine-induced status epilepticus.

The effect of Cavalheiro's pilocarpine model of epileptogenesis upon conditioned taste aversion (CTA), an important example of nondeclarative memory, was studied in adult Long Evans rats. Deterioration of CTA was studied during the silent period between pilocarpine-induced status epilepticus (SE) and delayed spontaneous recurrent seizures. SE was elicited by i.p. injection of pilocarpine (320 mg/kg ) and interrupted after 2 hours by clonazepame (1 mg/kg i.p.). Peripheral cholinergic symptoms were suppressed by methylscopolamine (1 mg/kg i.p.), administered together with pilocarpine. CTA was formed against the salty taste of isotonic LiCl. In the experiment of CTA acquisition, the CTA was formed and tested during the silent period after SE. In the experiment of CTA retrieval, the CTA was acquired before SE and the retrieval itself was tested during the silent period. Retrieval of CTA acquired before SE was impaired more than the retrieval of CTA formed during the silent period. Our findings indicate that epileptic seizures can disrupt even non-declarative memory but that CTA formed by the damaged brain can use its better preserved parts for memory trace formation. Ketamine (50 mg/kg i.p.) applied 2 min after the onset of pilocarpine-induced status epilepticus protected memory deterioration.

Cost minimization analysis of antiepileptic drugs in newly diagnosed epilepsy in 12 European countries.

A recent United Kingdom cost minimization analysis (CMA) of four antiepileptic drugs (AEDs) used to treat newly diagnosed adult epilepsy demonstrated that a new drug, lamotrigine (LTG), incurred higher costs than carbamazepine (CBZ), phenytoin (PHT), and valproate (VPA), whose costs were similar. This analysis took account of each drug's side-effect and tolerability profile. The present analysis investigated the costs of treatment with LTG, CBZ, PHT, and VPA in 12 European countries. Data were derived from published sources and from a panel of locally based experts. When no published data were available, estimates were obtained using expert opinion by a consensus method. These data were incorporated into a treatment pathway model, which considered the treatment of patients during the first 12 months after diagnosis. The primary outcome considered was seizure freedom. Randomized controlled trials demonstrate that the drugs considered are equally effective in terms of their ability to achieve seizure freedom, and thus the most appropriate form of economic evaluation is a CMA. These trials provided data on the incidence of side effects, dosages, and retention rates. The economic perspective taken was that of society as a whole and the analysis was calculated on an "intent-to-treat" basis. Only direct medical costs were considered. In each country considered, LTG was twofold to threefold more expensive than the other drugs considered. A sensitivity analysis demonstrated that varying each of the assumptions (range defined by expert panels) did not significantly alter the results obtained.

Interstrain differences in cognitive functions in rats in relation to status epilepticus.

Cognitive functions of Long Evans (N=30) and Wistar rats (N=32) were compared using a Morris water maze. Under control conditions the Long Evans rats were more efficient in this test, their average escape latency after 5 days of training (6.4+/-0.1 s, mean+/-S.E.M.) was significantly shorter than that of the Wistar rats (11.0+/-0.1 s). When the training was completed seizures were induced by an intraperitoneal injection of pilocarpine (330 mg/kg in the Long Evans strain and 350 mg/kg in the Wistar rats) 30 min after pretreatment with N-methylscopolamine (1 mg/kg i.p.). Clonazepam (1 mg/kg i.p.) was used to interrupt clonic seizures after 2 hours of continuous activity. Approximately one quarter of rats in both strains did not develop seizures. Severe convulsive status epilepticus was common in Long Evans rats (23 out of 30). In contrast, only 12 Wistar rats generated convulsive status epilepticus and the same number of animals exhibited only bursts of motor seizures separated by periods without convulsions (temporary seizures). Mortality after pilocarpine-induced status epilepticus was considerably higher in the Long Evans rats than in the Wistar rats. After a latency of 2-3 weeks spontaneous recurrent seizures appeared in all animals surviving status. Cognitive memory was tested during the 'silent period' between status and recurrent seizures. The Long Evans rats were unable to find the platform at the 3rd and 6th day after status but then their performance rapidly improved. The performance of the Wistar rats undergoing status epilepticus was seriously deteriorated and it never normalized, whereas the animals with temporary seizures exhibited only a transitory marginal prolongation of latencies. The hippocampal formation was damaged by status epilepticus in rats of both strains - the Long Evans rats exhibited more extensive damage of subfields CA1 and CA3, whereas in the Wistar rats a complete destruction of hilar neurons was observed in addition to partial CA1 and CA3 damage.

Cognitive functions after pilocarpine-induced status epilepticus: changes during silent period precede appearance of spontaneous recurrent seizures.

PURPOSE: To study the possible relation between spontaneous recurrent seizures (SRS) and the derangement of cognitive memory. METHODS: Status epilepticus (SE) was induced in adult Long-Evans rats by pilocarpine (320 mg/kg, i.p.) and interrupted after 2 h by clonazepam (CZPs mg/kg, i.p.). In addition to the animals that were given pilocarpine and CZP (group P), two groups received ketamine (100 mg/kg, i.p.): the first group 15 minutes after SE onset (group K15), and the second immediately after the CZP (group K120). Control groups were formed from animals not treated with pilocarpine as well as animals that received pilocarpine but did not develop motor seizures. Spatial cognitive memory was tested in the Morris water maze. RESULTS: Testing was impossible for more than 6 days after SE in group P. Ketamine shortened this period for the two groups that received it. During the silent period, deteriorated cognitive memory progressively improved, but the performance of group P started to worsen before the appearance of SRS. Group K120 only expressed a tendency toward declining performance, whereas group K15 never developed SRS, and the behavior of these animals did not differ from that of the controls after the postseizure period was over. Histologically, massive hippocampal cell loss was seen in group P. Ketamine protected hippocampal cells in a time-dependent manner; group K15 did not exhibit any obvious necrosis in the hippocampus. CONCLUSIONS: There is no close relation between cognitive functions and the appearance of SRS, because ketamine, administered 120 min after the beginning of SE, prevented the derangment of cognitive functions but not the appearance of SRSs.

1H MR spectroscopy in patients with mesial temporal epilepsy.

The study provides a review of the basic examination procedures and results of proton magnetic resonance spectroscopy (1H MRS) in patients suffering from mesial temporal lobe epilepsy (MTLE). The source of seizures in MTLE is most often an epileptogenic focus secondary to hippocampal sclerosis. 1H MRS currently plays an important role in the non-invasive diagnosis of this type of epileptogenic lesion. The decisive 1H MRS parameter characterizing an epileptogenic lesion is a statistically significantly decreased value of N-acetylaspartate levels compared with control values, most often associated with a decrease in the ratios of the intensities of NAA/Cr, NAA/Cho and NAA/(Cr + Cho) signals. Moreover, MRS makes it possible to distinguish bilateral involvement of mesial temporal structures typically associated with a bilateral decrease in the levels of metabolites and/or their ratios. As regards other metabolic compounds which play an important role in the pathobiochemistry of epilepsy, MRS is employed to study the action of gamma-aminobutyric acid (GABA), inositol, lactate, glutamine, and glutamate, the clinical function of which has not been fully clarified as yet. It is in this context that one should consider the application of 1H MRS in evaluating the action of some new anti-epileptic agents affecting excitatory and inhibitory amino acids. There is no doubt that in vivo 1H MRS, along with other imaging methods, has made a significant contribution to the clinical and biochemical description of epileptic seizures and has assumed a prominent position among the techniques of pre-operative examination in epileptic surgery.

[Vaccination in children with neurologic diseases]. / Ockování detí s neurologickým onemocnením.

The authors explain the main risks of immunization of children with affections of the central nervous system. For practical reasons the diseases are divided into four groups: 1. Perinatal affections and developmental diseases of the CNS. 2. Neurodegenerative and metabolic affections of the CNS. 3. Acquired affections of the CNS. 4. Paroxysmal diseases. The objective of the paper is to reduce the risk of postvaccination complications in children with serious affections of the CNS, while ensuring the contemporary necessary vaccination rate of the population.

[Neurologic disorders after vaccination against measles and mumps]. / Neurologické poruchy po ockování proti spalnickám a príusnicím.

The authors analyse neurological disorders which developed after immunization with vaccines against measles (Movivac) and after immunization against measles and mumps (Mopavac) in 60 children. The majority of reactions developed at the time of the side-reaction after immunization and was manifested by febrile attacks.

[Neurologic complications after vaccination against diphtheria, tetanus and whooping cough]. / Neurologické komplikace po ockování proti záskrtu, tetanu a dávivému kasli.

The authors analyze the character and prognosis of neurological complications after immunization against diphtheria, tetanus and whooping cough (ADTP vaccine) in children free from neurological disease in the case-history (n = 91) and in children with neurological disease in the case-history (n = 9). In both groups the most frequent type of complications were encephalopathies and febrile attacks as a consequence of metabolic and toxic changes following vaccination. Persisting neurological disorders had in both investigated groups in the majority the character of epilepsy.