Neurofibromatosis type 2 (NF 2) or schwannomatosis?--Case report study and diagnostic criteria.

INTRODUCTION: Neurofibromatosis type 2 (NF2) and schwannomatosis are entities that may, due to the similarity of clinical symptoms, cause diagnostic difficulties. Incidence rate of both diseases is similar and estimated between 1:25,000 and 1:40,000. The genes associated with the development of the aforementioned disorders are located on chromosome 22 and lay in proxmity. Schwannomatosis is characterized by an incomplete penetrance and the risk of its transmission to the offspring is significantly lower than in the case of NF 2. Schwannomatosis clinical characteristic is similar to the NF2, however vestibular schwannomas are not present. Therefore the imaging studies evaluated by an experienced radiologist play a key role in the diagnostic process. CASE REPORT: Forty two-year-old female hospitalized three times because of the tumors of the spinal canal was admitted to the Department of Neurosurgery and Peripheral Nerve Surgery in 2008 because of the cervical pain syndrome with concomitant headache. She was diagnosed with a schwannomatosis, recently distinguished, the third form of neurofibromatosis. MRI imaging revealed craniocervical junction tumor. Suboccipital craniectomy with concomitant C1-C2 laminectomy was done in order to remove the lesion. After the surgery the patient did not present any deficits in neurological examination and was discharged from hospital in good general condition. CONCLUSIONS: The patient was diagnosed with schwannomatosis, recently established neurofibromatosis entity which may resemble NF2 clinically. In patients after the age of 30, in whom we observe multiple schwannomas without the concomitant hearing impairment, the diagnosis of schwannomatosis is very likely.

The use of calcium phosphate cement in vertebroplasty of the base of odontoid process.

The authors describe the use of bone cement containing calcium phosphate for vertebroplasty of the cavity in the base of odontoid process. A 23-year-old female patient was operated on by incision in lateral cervical area (anterior open access). After a blunt dissection, the working cannula (Kyphon) was introduced under fluoroscopic guidance through the C2 vertebral body to the cavity in the base of the odontoid process. Intraoperatively, biopsy of the lesion was taken and histo-pathological examination excluded the presence of neoplasm. The cavity, presumably haemangioma, was successfully filled with calcium phosphate bone cement KyphOsTM FS (Ky-phon). The proper filling without paravertebral cement leak was confirmed by postoperative computed tomography (CT). The CT and magnetic resonance imaging performed 9 months after the procedure showed that cement was still present in the cavity. This is the first use of calcium phosphate cement to conduct the vertebroplasty of C2 vertebra.

[Spinal cord diffusion tensor tractography as a diagnostic tool in difficult cases of spinal cord intramedullary tumours]. / Traktografia rdzenia jako metoda diagnostyczna w trudnych przypadkach guzów sródrdzeniowych.

Diffusion tensor-based spinal cord tractography is a technically complicated but rapidly evolving diagnostic method. The difficulties result from the volume of the spinal cord, the constant pulsing of the cerebrospinal fluid and respiratory movements. The method is being used more and more frequently to examine long spinal tracts in patients with intramedullary tumours. The method can be especially useful for ambiguous cases investigation. The presented case with coincidental intramedullary tumour and severe cervical spondylosis has been described by the authors to show their own experience with spinal cord tractography as a useful tool in determining an effective treatment method.

Behavioral effects following repeated exposure to hexachloronaphthalene in rats.

Polychlorinated naphthalenes (PCNs), including hexachloronaphthalene (HxCN), are widespread global environmental contaminants. Our experiments were aimed at assessing HxCN effects on motor behavior, long-term memory, pain sensitivity, magnitude of stress-induced analgesia, auditory function and sensorimotor gating, following repeated intragastric administration (28 days) of HxCN at 0.3 and 1.0 mg/kg body weight. Three weeks after the exposure termination, male Wistar rats were subjected to the neurobehavioral tests battery performed in the following order: open-field test, passive avoidance test, hot-plate test and acoustic startle response test. Repeated administration of HxCN induced disorders of motivational processes manifested by: anorectic effect caused by aphagia and adipsia; significantly reduced motor activity (hypokinesia); impaired long-term memory and acquired passive avoidance reaction; reduced pain threshold and shortened duration of anxiety reaction after pain stimulus (sensory neglect). Some of these neurobehavioral effects (impaired long-term memory, reduced pain threshold and stress-induced analgesia) were observed at 0.3 mgHxCN/kg body weight without any signs of overt toxicity. The outcome of our study shows that HxCN, like other compounds of the persistent organic pollutants (POPs) group, creates a potential risk of behavioral changes in the central nervous system in the general population as a result of environmental exposure.

Extracerebral metastases of glioblastoma have a different vasculature than primary tumour. A case report of glioblastoma extracranial metastases.

The paper presents a case report of a 38-year-old female suffering from metastatic glioblastoma in the jugular lymph node that developed 9 months after craniotomy and tumorectomy in the left temporal region of the brain. The histological evaluation of metastatic tumour reveals lower density of vasculature as well as less significant pathologic changes in blood vessels morphology in comparison to primary tumour. Moreover, in this report we present cytological characteristics of the material obtained by fine needle aspiration of the metastatic mass.

Neuroendocrine and behavioral response to amphetamine challenge after exposure to an organophosphorus pesticide.

OBJECTIVES: Exposure to various stressors is known to result in sensitization to psychostimulants, a state related to the psychostimulant dependence and addiction. It has been shown in some studies that the rise in corticosterone (CORT) concentration is indispensable for both the induction and the expression of behavioral sensitization. Therefore, it might be suspected that behavioral hyposensitivity to amphetamine (AMPH) is somehow related to a reduced CORT response to the psychostimulant subsequent to the chlorphenvinphos (CVP) intoxication. MATERIALS AND METHODS: The male adult Wistar rats received single i.p. injections of CVP at the doses 0.5, 1.0 or 3.0 mg/kg b.w., or pure corn oil. CORT concentration was determined in samples of blood drawn from the tail vein before and then 30, 60, 180 min and 24 h after injection. The other rats were divided into two groups and tested, three weeks after the CVP injection for the effect of AMPH (0.5 mg/kg b.w. i.p.) on the serum CORT concentration. In addition, behavioral sensitivity to AMPH was assessed by measuring locomotor activity of the animals in an open-field. RESULTS: 1) The stressor property of CVP was confirmed. The injection resulted in up to tenfold increase in the serum CORT concentration. The magnitude and duration of this response were dose-related. 2) Three weeks after the CVP exposure, the CORT response to AMPH was significantly increased. 3) The behavioral response to the psychostimulant, i.e. augmented locomotion, was significantly reduced compared to the control. CONCLUSIONS: The results confirm that CVP exposure causes behavioral hyposensitivity to AMPH. This effect, however, could not be ascribed to a diminished CORT response.

Effects of stress pretreatment on the dynamics of blood cholinesterase activity after exposure to an organophosphorus pesticide in the rat.

A single i.p. administration of 1.0 mg/kg of chlorphenvinphos (CVP), an organophosphorus pesticide, results in an acute stress response, evidenced by a marked (6-7 fold) rise in plasma corticosterone (CORT) concentration, and a diminished behavioural sensitivity to amphetamine (AMPH) three weeks postexposure. Surprisingly, in rats subjected to a single series of inescapable electric footshocks (60 10 msec triplets of 3.0 mA, 2 msec, square pulses during 20 min - IF ) two weeks prior to the CVP exposure, these effects are not observed. It has been assumed that the reduced effectiveness of CVP might be related to some persisting alterations in the functional state of the cholinergic system. The aim of the present work was to discover whether and in what way the IF pretreatment affects i) the cholinesterase activity in blood, and ii) the dynamics of the alterations in the cholinesterase (ChE) activity following the CVP exposure. The experiments were performed on 3 mo. old, male Wistar rats. In the first experiment, the blood samples were taken from the tail vein 15, 60 and 180 min after the IF. In the second experiment, the rats were pretreated with IF and 14 days later given 1.0 mg/kg of CVP i.p. Blood samples were taken 15 min, 60 min, 180 min, 24 h, 7 days, and 14 days after the CVP exposure. In the first experiment no differences in the ChE activity in plasma (pChE) and erythrocytes (rbcChE) were found between the shocked and control rats. In the second experiment, however, in rats pretreated with IF the rbcChE activity of was reduced by CVP less and pChE activity returned to normal faster than in rats not pretreated with IF. The results confirm that exposure to IF, a nonchemical stressor, induces some long-lasting adaptive changes which render the cholinergic system less susceptible to the harmful action of ChE inhibitors. It has been hypothesized that the changes consist in an increase of the antioxidant potential in blood and possibly other tissues.

Contrasting effects of 4-week inhalation exposure to pseudocumene or hemimellitene on sensitivity to amphetamine and propensity to amphetamine sensitization in the rat.

OBJECTIVES: Some data suggest that increased behavioural sensitivity to psychostimulants may develop after exposure to volatile chemicals in common use. The purpose of the present experiment was to find out whether and in what way inhalation exposure to pseudocumene (PS) or hemimellitene (HM) at low concentrations alters behavioural sensitivity to the psychostimulant amphetamine (AMPH), and propensity to develop behavioural sensitization to AMPH. MATERIAL AND METHODS: Adult male Wistar rats were exposed 6 h/day, 5 days a week for 4 weeks to PS or HEM at 0, 25, 100 or 250 ppm. Behavioural sensitivity to AMPH was assessed by measuring locomotor activity of the animals in an open-field. Behavioural sensitization to AMPH was induced by a repeated AMPH treatment. RESULTS: In rats exposed to HEM, the behavioural sensitivity to AMPH was increased, but remained unchanged in rats exposed to PS. The second testing revealed an augmented behavioural response to AMPH in control rats. In the HM exposed rats this augmenting was significantly more evident and in the PS exposed rats significantly less evident than in controls. For each of the two solvents, the concentration-effect relationship was nonlinear; out of the three concentrations used, 100 ppm was the most effective. CONCLUSIONS: The results confirm that low-level inhalation exposure to trimethylbenzene isomers may induce behavioural sensitisation and/or increase the susceptibility of the animals to develop this state upon repeated psychostimulant treatment. They show, however, that HM and PS differ markedly in their ability to induce such alterations.

Neurobehavioural functions in adult progeny of rat mothers exposed to methylmercury or 2,2', 4,4', 5,5'-hexachlorobiphenyl (PCB 153) alone or their combination during gestation and lactation.

OBJECTIVES: Methylmercury (MeHg) and polychlorinated biphenyls (PCBs) are ubiquitous environmental pollutants. Both are neurotoxic, especially for the developing brain. The main source of human exposure to MeHg and PCBs is seafood. The aim of the present work was to find out whether and how separate or combined perinatal exposure to these neurotoxicants affects neurobehavioural functions in maturity. MATERIALS AND METHODS: The study was performed on adult Wistar rats, the progeny of rat mothers exposed to MeHg (0.5 mg/kg/day or 2.0 mg/kg/day), PCB 153 (1.0 mg/kg/day or 5.0 mg/kg/day), or to MeHg 0.5 mg/kg/day + PCB 153 5.0 mg/kg/day, from day 7 of pregnancy to day 21 post partum. The following functions were assessed: spontaneous locomotor activity (open field test), spatial short-term memory (radial maze test), long-term memory (passive avoidance test), sensitivity to pain and vulnerability to stress (hot plate test), efficiency of the sensorimotor gating (startle response test), and sensorimotor coordination (the rotarod test). RESULTS: The results obtained in the MeHg part of the study showed a reduced locomotor activity in the female progeny of both exposed groups, an impaired passive avoidance in the male progeny of the high and low exposure group and a faster recovery from the effects of the stressful experience (hot plate test) in the male progeny of the high dose group. Results obtained in the PCB part showed an increased locomotor activity in the female progeny of both exposure groups and impairment in rotarod performance in males of the high dose group. Neurobehavioural alterations were not found in either the females or males exposed jointly to MeHg and PCB 153. CONCLUSIONS: The results suggest that in condition of the combined exposure, MeHg may protect against the effects of PCB 153 and vice versa.

Exposure to chlorphenvinphos, an organophosphate insecticide, prevents from behavioral sensitization to amphetamine.

OBJECTIVES: Exposure to organophosphorus (OP) pesticides, irreversible inhibitors of acetylcholinesterase (AChE), may result in long-lasting alterations in the functional state of the central nervous system. In earlier studies, we found that a single exposure of the rat to chlorphenvinphos (CVP), an OP pesticide, made the animal hyposensitive to amphetamine (AMPH) three weeks posttreatment. A repeated administration of AMPH is known to result in a progressive increase in the behavioral sensitivity to the psychostimulant. It makes it likely that treatment with AMPH after the CVP exposure may result in amelioration of the CVP-induced hyposensitivity to the psychostymulant. The purpose of the present experiment was to check out this supposition. MATERIALS AND METHODS: At the first stage, the relationship between the CVP dose and the effect on sensitivity to AMPH was tested. The rats were given CVP once intraperitoneally (i.p.) at a dose of 0.0, 1.0 or 3.0 mg/kg. Three weeks later their open field behavior was assessed before and after i.p. administration of 0.25, 0.5 or 1.0 mg/kg of AMPH. At the subsequent stage, the susceptibility of the CVP-treated rats to AMPH sensitization by repeated AMPH treatment was investigated. For this purpose each of the rats was repeatedly treated with AMPH in its home cage (one injection/day for five days). At stage two, the daily AMPH dose received by each animal was of the same magnitude as that received at stage one. Two weeks after the last AMPH treatment dose, the motor response to a test AMPH dose (0.5 mg/kg) was measured in all rats. RESULTS: The results of stage one confirmed a significant reduction of behavioral sensitivity to AMPH in the CVP-treated rats. The results of stage two indicated that the CVP-induced decrease in sensitivity to AMPH was not ameliorated by a repeated treatment with AMPH at any of the used doses. In fact, in the rats exposed to the high CVP dose, repeated treatment with AMPH resulted, dose dependently, in augmenting of the depressive effect of the pesticide. CONCLUSIONS: It appears then that treatment to an OP pesticide reduces the rat's sensitivity to AMPH and makes the animal resistant to sensitization by repeated treatment with the psychostimulant.

Amphetamine- and scopolamine-induced locomotor activity following treatment with chlorphenvinphos or chlorphyriphos in rats.

OBJECTIVES: Effects of acute exposure to organophosphorous pesticides (OPs), chlorphenvinphos (CVP) or chlorphyriphos (CPF) on amphetamine (AMPH)- or scopolamine (SCOP)-induced open-field locomotion were compared in rats. MATERIALS AND METHODS: CVP and CPF were administered intraperitoneally, both at doses resulting in about 50% inhibition of erythrocyte acetylcholinesterase (rbcAChE). The pesticide groups did not differ one from another in the magnitude of the acute behavioral effects. RESULTS: Three weeks after the exposure, i.e. when AChE activity returned to normal level, the behavioral response to AMPH and SCOP was significantly reduced in CVP-, but not in CPF-pretreated rats. CONCLUSIONS: These results confirm that a single exposure to organophosphorous pesticides may result in neurobehavioral effects detectable after restitution of AChE. They also show that CVP and CPF differ in respect of long lasting functional consequences of exposure, which suggests a difference in the mechanism of toxicity.

Alteration in behavioral sensitivity to amphetamine after treatment with oxotremorine. Effect of dose and test environment.

Our earlier experiment revealed that rats pretreated once with an anticholinesterase develop hyposensitivity to amphetamine (AMPH). One of the likely causes of this effect might be a transient hyperexcitation of the central muscarinic receptors. It has appeared, however, that rats pretreated with oxotremorine (OX), a muscarinic agonist, show an augmented behavioral response to AMPH weeks later. The present experiments were performed in order to obtain more information on the relationship between the OX-induced sensitization to AMPH and the OX dose and dosing regime (single or repeated), and to find out whether the environment associated with the acute effects of OX could affect the response to AMPH. In experiment 1, adult male rats were given a single i.p. injection of OX in home cages at a moderate (0.5 mg/kg) or high (1.0 mg/kg) dose. In experiment 2, the rats received eight 1.0 mg/kg doses of OX in the course of three days. After each injection, some animals returned to their home cages, and some were placed in the test cages for 30 min. In both experiments, the response to AMPH was assessed on day 21 after the treatment. The obtained results indicate that: (i) a single i.p. exposure to OX results in an increase of the rat's behavioral sensitivity to AMPH but the moderate dose is more effective in inducing this effect; (ii) repeated exposure to OX at high doses, in a regime enabling development of tolerance to the acute OX effects, does not alter the rat sensitivity to AMPH, and (iii) expression of the AMPH response is suppressed in environment which has been associated with acute effects of OX.

Pseudocumene in brain, liver, lung and blood of rats after single and repeated inhalation exposure.

Male Wistar rats were exposed to pseudocumene vapors at nominal concentration of 25, 100 or 250 ppm in the dynamic inhalation chambers for 6 h or 4 weeks (6 h/day; 5 days/week). Following the inhalation exposure, pseudocumene concentrations were estimated in the brain, liver and lung homogenates, as well as in the brain (brainstem, hippocampus, temporal cortex, cerebellum) and blood (arterial, venous) structures. To estimate pseudocumene concentrations in biological material gas chromatography using the headspace technique was applied. The elimination of pseudocumene from venous blood after repeated inhalation exposures followed an open two-compartment model. Venous blood concentration was about twice as high as that in arterial blood. In tissues, the highest values were found in the liver after single exposure to pseudocumene vapor at concentrations of 100 and 250 ppm. There were no statistically significant differences in pseudocumene concentrations between the brain, lungs or arterial blood. In the brain structures of the animals exposed to pseudocumene vapors, significantly higher concentration of psedocumene was found in the brainstem.

Behavioral sensitivity to amphetamine after repeated exposure to an organophosphorous pesticide in the rat. Effect of coexposure to restraint.

In the work environment, chemical stressors coexists frequently with physical or psychological stressors. The purpose of the present experiment was to find out whether the effects of a repeated exposure to chlorphenvinphos (CVP), an organophosphorus pesticide, could be modified by a concurrent exposure to restraint, a psychological stressor. The experiment was performed on male Wistar rats. CVP was administered ten times (one injection/day) at doses of 0.5 or 1.0 mg/kg i.p. (1/30 and 1/10 of LD50, respectively) within a period of two weeks. A half of the rats from each group were immobilized in restraint chambers for 120 min/day starting 10-15 min after CVP injection. In each rat, the effect of 0.5 mg/kg of amphetamine (AMPH) and 0.75 mg/kg of scopolamine (SCOP) on motor activity in an open-field was tested three weeks or six weeks (in rats exposed to 0.5 mg/kg or 1.0 mg/kg doses of CVP, respectively) after the last exposure day. No clear cut effect on the behavioral responsiveness to AMPH or SCOP were noted in rats subjected to repeated restraint, repeated 0.5 mg/kg doses of CVP, or combination of these two stressors. In rats exposed to CVP at the 1.0 mg/kg doses, the behavioral response to AMPH was augmented and this effect was not apparently altered in rats coexposed to restraint. The above result indicates that the repeated exposure to CVP may lead to functional alterations within the central nervous system and that coexposure to restraint neither facilitates nor prevents these alterations from development.

Assessment of long-term effects of exposure to toluene based on the analysis of selected behavioral responses with particular reference to the ability to trigger behavioral hypersensitivity in rats.

Toluene is a major component of numerous commercial organic solvent formulations. It is often listed among the chemicals capable of producing the organic solvent syndrome and a neurobehavioral hypersensitivity condition. The hypersensitivity condition (continued long-term intensification of some behavioral reactions in response to pharmacological or environmental stressors) is usually associated with the increased tonus of the functional dopaminergic system. The aim of our current research was to determine whether, under conditions of inhalation exposure, toluene can produce long-term behavioral changes or modify the intensity of the behavioral response to apomorphine, a dopaminergic receptor agonist. In our experiment, male rats were exposed to 25, 100 and 250 ppm toluene for 4 weeks (5 days/week, 6h/day). The following behaviors were tested: finding water in a radial maze; open field motor activity, acquiring the conditional response of passive avoidance; sensitivity to a thermal pain stimulus (hot plate test) and changes in this sensitivity caused by stress; and acquiring the conditional response of two-directional active avoidance. The behavioral response to apomorphine, i.e. the increased spontaneous locomotor activity, was assessed on day 10 after the termination of the exposure in the rotary drum test. In the behavioral experiment, significant differences between groups were recorded only for the hot plate test; in the 100 and 250 ppm rats, electric-shock-related anxiety response was stronger than in the control group. In the experiment using pharmacological provocation, the behavioral response to apomorphine in the rats exposed to 100 ppm or 250 ppm toluene was significantly lower. Our results indicate that low concentrations of toluene may produce long-term behavioral changes in rats. However, these changes seem to be linked with reduced rather than increased functional tonus of the dopaminergic system.

Assessment of long-term neurotoxic effects of exposure to mesitylene (1,3,5-trimethylbenzene) based on the analysis of selected behavioral responses.

Trimetylbenzene isomers: pseudocumene, hemimellitene and mesitylene, are major components of numerous commercial solvents and high-grade fuels. In our earlier research on rats we have proved that inhalation exposure to pseudocumene or hemimellitene at concentrations close to the MAC value results in behavioral changes detectable many weeks after cessation of the exposure. The aim of our present study is to determine whether exposure to mesitylene causes effects similar to those observed for pseudocumene and hemimellitene. Male rats were used in the experiment. The animals were exposed in the inhalation chambers to mesitylene vapors at the following concentrations: 0 ppm--group MES0; 25 ppm (125 mg/m3)--group MES25; 100 ppm (500 mg/m3)--group MES100 and 250 ppm (1,250 mg/m3)--group MES250 for 4 weeks (6 h/day, 5 days/week). The following behaviors were tested: 1) ability to find water in a radial maze (14-19 days after the exposure); 2) open field locomotor activity (25 days after the exposure); 3) acquiring the conditioned reaction of active avoidance (35-45 days after the exposure); 4) sensitivity to pain and stress-induced changes of pain sensitivity (50-51 days after the exposure); and 5) acquiring the conditioned reaction of two-way active avoidance (54-60 days after the exposure). Significant between-group differences were noted in passive and active avoidance tests and sensitivity to pain. In the MES25, MES100 and MES250 rats, the persistence of the passive avoidance reaction was shorter, and more trials were required to produce the active avoidance reaction than in controls (group MES0), the MES100 group appeared to be more fearful on the second day of testing on the hot plate. The exposed groups did not differ in the magnitudes of the detected changes (no concentration-effect relationship). These results indicate that inhalation exposure to mesitylene, like that to pseudocumene and hemimellitene, at concentrations close to the current hygiene standard value for trimethylbenzene, may produce long-term functional changes in the rat central nervous system.