Corrigendum for: Evaluation of Blood-Brain Barrier Integrity by the Analysis of Dynamic Contrast-Enhanced MRI - a Comparison of Quantitative and Semi-Quantitative Methods.

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Posterior circulation stroke diagnosis in unselected group of acutely dizzy patients.

BACKGROUNDS: Diagnostics of a posterior circulation ischemia (POCI) in patients with acute vertigo is a challenging task. Recently, the combination of HINTS (Head Impulse, Nystagmus and Test of Skew) exam and ABCD2 has been recommended to identify stroke in these patients. Until now, studies regarding HINTS have mostly been tested on preselected patient groups and their results are only partially applicable to real clinical practice. AIMS: To compare the sensitivity and specificity of HINTS and ABCD2 and their combination in unselected acutely dizzy patients in the emergency department (ED) toward posterior circulation stroke detection. METHODS: A prospective cross-sectional monocentric study in ED patients with acute onset of dizziness lasting less than 72 h. Their clinical characteristics, HINTS, vascular risk factors, ABCD2 scores and neuroimaging data were analyzed. RESULTS: 140 patients were recruited. Acute stroke was identified by MRI in 39 patients. All patients had central pattern nystagmus, skew deviation or further focal neurological finding. The age (≥60) and arterial hypertension clearly distinguished stroke and non-stroke group (p < 0001). The sensitivity of HINTS, ABCD2 and their combination in the unselected group was high (82,1 - 97,4%), but specificity low. After removing patients with inconclusive diagnosis, including transitory ischemic attack, specificity was much higher and comparable to previously published results. CONCLUSIONS: The sensitivity and specificity of HINTS in previously published studies may vary because of their selection criteria. Even though, our study was performed on the unselected patient cohort, combination of HINTS and ABCD2 remained highly sensitive in detecting POCI and outperformed each of these tests alone.

Risk stratification of neurological decompression sickness in divers.

INTRODUCTION: Patent foramen ovale (PFO) is a risk factor of decompression sickness (DCS). However, data on risk stratification of divers with a PFO are sparse. This study sought to evaluate the risk of neurological DCS (DCSneuro), based on the presence and grade of a right-to-left shunt (RLS). METHODS: A total of 640 divers were screened for a RLS using TCD between 1/2006 and 4/2017. RLS was graded as low, medium, or high grade with two subgroups - after a Valsalva maneuver or at rest. Divers were questioned about their DCS history. Survival analysis techniques were used to assess risk factors for unprovoked DCS. RESULTS: A RLS was found in 258 divers (40.3 %). 44 (17.1 %) divers with a RLS experienced DCSneuro compared to 5 (1.3 %) divers without a RLS (p <0.001). The proportion of DCSneuro increased from 4.6 % in the low-grade RLS subgroup to 57.1 % in the subgroup with high-grade RLS at rest. The hazard ratio for DCSneuro and RLS was11.806 (p <0.001). CONCLUSIONS: Divers with a RLS had a higher risk of DCSneuro and the risk increased with RLS grade. We suggest that TCD is an appropriate method for RLS screening and risk stratification in divers (Tab. 4, Fig. 2, Ref. 29).

Evaluation of blood-brain barrier integrity by the analysis of dynamic contrast-enhanced MRI - a comparison of quantitative and semi-quantitative methods.

Disruption of the blood-brain barrier (BBB) is a key feature of various brain disorders. To assess its integrity a parametrization of dynamic magnetic resonance imaging (DCE MRI) with a contrast agent (CA) is broadly used. Parametrization can be done quantitatively or semi-quantitatively. Quantitative methods directly describe BBB permeability but exhibit several drawbacks such as high computation demands, reproducibility issues, or low robustness. Semi-quantitative methods are fast to compute, simply mathematically described, and robust, however, they do not describe the status of BBB directly but only as a variation of CA concentration in measured tissue. Our goal was to elucidate differences between five semi-quantitative parameters: maximal intensity (Imax), normalized permeability index (NPI), and difference in DCE values between three timepoints: baseline, 5 min, and 15 min (delta5-0, delta15-0, delta15-5) and two quantitative parameters: transfer constant (Ktrans) and an extravascular fraction (Ve). For the purpose of comparison, we analyzed DCE data of four patients 12-15 days after the stroke with visible CA enhancement. Calculated parameters showed abnormalities spatially corresponding with the ischemic lesion, however, findings in individual parameters morphometrically differed. Ktrans and Ve were highly correlated. Delta5-0 and delta15-0 were prominent in regions with rapid CA enhancement and highly correlated with Ktrans. Abnormalities in delta15-5 and NPI were more homogenous with less variable values, smoother borders, and less detail than Ktrans. Moreover, only delta15-5 and NPI were able to distinguish vessels from extravascular space. Our comparison provides important knowledge for understanding and interpreting parameters derived from DCE MRI by both quantitative and semi-quantitative methods.

Congenital cervical kyphosis in two young sighthounds.

INTRODUCTION: Cervical vertebral (C) malformation is rarely reported in large breed dogs. Congenital cervical kyphosis (CCK) may result from defects of vertebral segmentation, failure of formation or both. This report describes two cases of C3-C4 CCK in young sighthounds, treated surgically. CASE DESCRIPTION: An 18-month-old female Deerhound and a six-week-old female Borzoi dog were presented because of the complaints of reluctance to exercise and signs of of neck pain. Both dogs were neurologically normal. Diagnostic imaging revealed C3-C4 deformity, moderate kyphosis, and spinal canal stenosis associated with chronic spinal cord pressure atrophy. Both dogs underwent surgical treatment. RESULTS: A staged two-step surgery starting with dorsal decompression was elected in the Deerhound. After the first surgical procedure, the dog developed focal myelomalacia and phrenic nerve paralysis and was euthanatized. A ventral distraction-fusion technique with two locking plates was performed in the Borzoi. This patient recovered uneventfully and long-term follow-up computed tomography revealed complete spondylodesis. CLINICAL SIGNIFICANCE: Until now, CCK has only been described in sighthounds. Congenital cervical kyphosis might be considered a differential diagnosis in these breeds that are presented with signs of cervical pain. Ventral realignment-fusion and bone grafting may be considered for surgical treatment, although the earliest age at which this procedure can and should be performed remains unclear.

Distraction-stabilisation of two adjacent intervertebral spaces in a Dalmatian dog with caudal cervical spondylomyelopathy.

A 4-year-old, 40-kg, male, entire Dalmatian was presented for evaluation of chronic neck pain and pelvic limb ataxia. Myelography revealed ventrodorsal (hourglass) extradural compression over the intervertebral space between the 5th and 6th cervical vertebra and ventral extradural compression between the 6th and 7th cervical vertebra. Cranial compression disappeared and caudal compression markedly diminished after performing cervical traction. MRI scan confirmed protrusion of intervertebral discs and spinal cord compression in previously mentioned intervertebral spaces. Surgical distraction-stabilization of both intervertebral spaces was performed using threaded pins and polymethylmethacrylate. The convalescence from surgery was uneventful and the dog was walking without any signs of paresis until 5 months after surgery when radiography revealed implants loosening. The dog recovered fully of the implant removal and remained asymptomatic for more than 30 months.

[Application of warfarin pharmacogenetics]. / Vyuzití farmakogenetiky pri lécbe warfarinem.

Even with its narrow therapeutic index, interindividual variability in daily dose and possible serious bleeding complications, is warfarin the mainstay of therapy and prevention of thromboembolic disease. The application of pharmacogenetics in testing individual polymorphisms of two genes CYP 2C9 (pharmacokinetics of warfarin) and VKORC1 (sensitivity on warfarin) is promising tactics leading to a safe anticoagulation. The first of two applications of pharmacogenetics is assesment of the daily dose of warfarin for individual patients even before starting the therapy. The second is the risk stratification of already warfarinized patients: The carriers of variant genotype are in a greater risk of bleeding complications. The following article is dedicated to the evaluation of literature and our own laboratory and clinical experience with these applications in clinical practise.

Electroencephalography in the diagnosis of hydrocephalus in golden hamsters (Mesocricetus auratus).

The golden hamster (Mesocricetus auratus) is a popular laboratory animal and is used in a multitude of behavioural studies. However, it has been shown that it suffers from different forms of hereditary hydrocephalus, which may result in behavioural changes. This prospective study was designed to look into the usefulness of electroencephalography (EEG) measurements in the diagnosis of hydrocephalus in hamsters. The EEGs of the hydrocephalic hamsters were evaluated double-blind and showed a high-voltage slow wave activity, with a fast activity superimposed onto it. This pattern has already been well described in other hydrocephalic species and differed significantly from the EEGs that were obtained from the normal hamsters. It was concluded from our study that a background activity with an amplitude over 50 muV in combination with a frequency of < or =5 Hz was highly indicative of hydrocephalus in young hamsters. We believe that the EEG could be a very useful diagnostic tool in the screening for hydrocephalus in hamsters.

Intracranial meningiomas associated with cervical syringohydromyelia in a cat.

A 13-year-old, female neutered, domestic shorthair indoor cat was referred to our hospital for treatment of multiple meningiomas. A slight generalized ataxia was seen, proprioception was severely decreased on all four limbs, and menace reaction was bilaterally reduced. Pre- and postoperatively MRI examination were performed. Three supratentorial extra-axial lesions were imaged. The fourth mass was localized infratentorial extra-axial overlying the left cerebellar hemisphere. The caudoventral cerebellum had herniated caudally, approximately one cm through the foramen magnum. Cervical syringohydromyelia was found as coincidental finding. Multiple craniotomies, centered over the meningiomas were performed. Postoperative outcome two years after the surgery is excellent. The authors also reviewed the veterinary and human literature about intracranial tumors associated syringohydromyelia. Generally, the treatment of syringohydromyelia should be targeted at the pathological process, which causes the obstruction of the cerebrospinal fluid flow, and leads to syringohydromyelia formation.

Lumbar pressure and transcranial Doppler sonography in children with scaphocephaly.

The primary aim of this study was to assess whether there exists a relationship between lumbar cerebrospinal fluid (CSF) pressure and intracranial blood flow velocities as measured by transcranial Doppler sonography (TCD) in children with scaphocephaly. Another aim was to compare pre- and postoperative TCD. Using a transducer, lumbar CSF pressure (LP) was assessed in 21 children with scaphocephaly. TCD was performed, and the pulsatility index (PI) and the resistance index (RI) were obtained before and after cranioplasty. In 17 children LP was higher than the reference values. No significant differences were found in PI and RI indices before and after cranioplasty. LP values were significantly higher in children older than 6 months. There was no association between LP and PI and RI indices. In children with scaphocephaly a higher LP can be expected with age. Moreover, TCD is not a reliable tool in predicting abnormal LP values.

Lumbar spinal 'juxtaarticular' cyst in a Gordon setter.

An 11-year-old Gordon setter bitch was presented with a history of progressive weakness in the right hind limb associated with pain in the lumbar spine. Neurological deficits consisted of ataxia, monoparesis, muscle atrophy and spontaneous over-knuckling of the affected limb. A large 'juxtaarticular' cyst located in a right dorsolateral position of the intervertebral foramen at L3-L4 was diagnosed by magnetic resonance imaging. The cyst was removed through a modified laminectomy. The dog recovered quickly and returned to the owners 4 days after surgery with slight neurological symptoms. During the follow-up examination 2 and 6 months later, the Setter showed normal gait and neurological examination.

Empty sella syndrome, hyperadrenocorticism and megaoesophagus in a dachshund.

A five-year-old, entire, male dachshund was presented with a five day history of hypersalivation and regurgitation as well as polyuria and polydipsia for several months. Chest radiographs demonstrated megaoesophagus and aspiration pneumonia. Furthermore, hyperadrenocorticism was demonstrated by means of elevations in levels of serum alkaline phosphatase and cholesterol, decreased urinary specific gravity, increased response to adrenocorticotropic hormone stimulation, insufficient suppression of the post-dexamethasone plasma cortisol levels, an increased endogenous adrenocorticotropic hormone concentration and bilaterally enlarged adrenal glands on abdominal ultrasound. The dog became severely dyspnoeic and was euthanased after magnetic resonance imaging was performed. The magnetic resonance imaging and necropsy revealed the sellar region mainly filled with fluid, with only small tissue remnants, a condition defined as empty sella syndrome in human medicine. To the author's knowledge, this is the first dog described with empty sella syndrome and only the second dog described with hyperadrenocorticism secondary to ectopic adrenocorticotropic hormone production. However, the association between empty sella syndrome and hyperadrenocorticism may be no more than incidental.

[Paradoxical embolization and patent foramen ovale in scuba divers: screening possibilities]. / Paradoxní embolizace pri foramen ovale patens u potápecu: moznosti screeningu.

INTRODUCTION: The cause of decompression sickness (DCS) in scuba-divers is bubble formation in tissues and in venous blood during ascent. Divers with patent foramen ovale (PFO) have an increased risk of paradoxical embolization to the brain or other vital organs. The aim of our study was to assess the incidence of PFO in scuba-divers with DCS, to compare the group with asymptomatic controls, and to evaluate ultrasound contrast methods suitable for screening. METHODOLOGY: We examined 28 scuba-divers (more than 100 dives). The right-to-left shunt detection was performed by bubble contrast transthoracic echocardiographic examination (TTE) and transcranial Doppler sonography over arteria cerebri media (TCD) in all divers. In divers with shunting, transoesophageal echocardiography (TEE) was performed to prove PFO. RESULTS: 15 divers had DCS associated with the ascent. In this group, PFO was diagnosed in 53% (8/15). The symptoms of all of them retrospectively were of paradoxical embolization (neurological form of DCS). In the group of asymptomatic divers, PFO was proven on the basis of right-to-left shunt screening in 1 diver (8% 1/13). TCD proved right-to-left shunt in all divers with PFO. CONCLUSION: DCS can unmask a so far asymptomatic intracardiac right-to-left shunting. PFO is a risk factor for paradoxical embolization in divers. TCD is suitable for screening; TEE is a gold standard in PFO detection. Our results showed that PFO detection is a useful clinical tool after repeated DCS and in all frequent divers and instructors.

Neurodegenerative diseases in domestic animals: a comparative review.

Neurodegenerative diseases are characterised by selective damage to specific neurons in the nervous system. Interest in such diseases in humans has resulted in considerable progress in the molecular understanding of these disorders in recent decades. Numerous neurodegenerative diseases have also been described in domestic animals but relatively little molecular work has been reported. In the present review, we have classified neurodegenerative disease according to neuroanatomical criteria. We have established two large groups, based on whether the neuronal cell body or its axon was primarily affected. Conditions such as motor neuron diseases, cerebellar degenerations and neuroaxonal dystrophies are discussed in terms of their clinical and neuropathological features. In the most studied disorders, we also present what is known about underlying pathomechanisms, and compare them with their human counterparts. The purpose of this review is to re-kindle interest in this group of diseases and to encourage veterinary researchers to investigate molecular mechanisms by taking advantage of current diagnostic tools.

Fluorescent multiplex PCR--fast method for autosomal dominant spinocerebellar ataxias screening.

Expansion of CAG trinucleotide repeats has been shown to cause a number of autosomal dominant spinocerebellar ataxias such as SCA1, SCA2, SCA3/MJD, SCA6 and SCA7. These disorders are characterized by a wide inter- and intrafamiliar variation in clinical features. The same mutation can result in different phenotypes and the very similar phenotypes can be caused by different mutations. Therefore it is necessary to investigate more SCA genes (according to prevalence) to identify the causal elongation. We developed a fast and efficient screening method based on touchdown multiplex PCR with fluorescent labelled primers for the most common types of SCAs (SCA 1, 2, 3 and 7). It has been reliable in 113 probands tested. Fragment analysis was performed by using 6% denaturing polyacrylamide gel and employing the automated DNA sequencer. This method considerably shortens the process of molecular genetic screening of SCAs and might be used as a tip for designing other SCA screening sets.

[Tetanus in cats: 3 case descriptions]. / Tetanus bei Katzen: 3 Fallbeschreibungen.

Three cats with spasticity on one leg or on all four limbs were presented between 1996 and 1998 at the Department of clinical veterinary medicine, Section of neurology, Vetsuisse-Faculty of Bern. The presumptive diagnosis was tetanus. A focal form was present in two cases and generalised tetanus in one cat. All cats had a history of injury at the affected legs respectively at the neck. The first clinical signs were seen between two days and three weeks after injury. The bacteriologic examination of serous fluid from the site of injury revealed an infection with Clostridium. EMG in one cat during anaesthesia showed motor united potentials (MUPs) on the spastic leg. All patients received antibiotics (Penicillin, respectively Amoxicillin/Clavulanic acid and Metronidazol). Supportive aid were initially sedation, wound revision and in one cat nutrition through oesophageal sonde. In a second phase physiotherapy was performed. All three animals were significantly better after a couple of weeks, two cats were without symptoms after eight and five weeks respectively.

Thrombophilic markers in patients with congenital bleeding disorders.

We have studied the presence or absence of thrombophilic markers in 59 patients with congenital bleeding disorders. Theoretically, the coexistence of coagulation factor deficiency and thrombophilia in patients with haemophilia may cause the bleeding tendency to decline. In 8 cases we have found thrombophilic marker positivity, in 7 patients APC resistance and in 1 patient protein S deficiency has been revealed. The presence of thrombophilic markers did not affect the frequency of bleeding episodes or the development of haemophilic arthropathy. The factor concentrate utilization, however, was lower in the group carrying thrombophilic markers, which indicates that the bleeding episodes were less severe. Relying on the strength of these findings, the medicinal influencing of inhibitor mechanisms may present itself as a potential therapy.

A dc Method for the Absolute Determination of Conductivities of the Primary Standard KCl Solutions from 0 °C to 50 °C.

A new method for the absolute determination of electrolytic conductivity based on direct current and Potentiometric measurements is described. The unique design of the cell uses a removable center section whose length and cross-sectional area are accurately known. Two pairs of matched Ag, AgCl electrodes are used in a four terminal mode of resistance measurement. Measurements of the electrolytic conductivity of primary standard potassium chloride solution using [his novel dc conductance cell are compared with the currently adopted IUPAC and OIML recommendations. In addition, measurements have heen made of the electrolytic conductivity of a solution of potassium chloride having a molality of 1 mol/kg (mole KCl per kilogram H2O). The values so obtained over the temperature range of 0 °C to 50 °C are recommended as the new primary standards for electrolytic conductivity.