Clinical Neuroscience

[Thallium poisoning induced polyneuropathy - clinical and electrophysiological data]


DECEMBER 20, 2003

Clinical Neuroscience - 2003;56(11-12)

[Introduction - The aim of the study was the electrophysiological investigation of thallium induced polyneuropathy. Beyond the rarity of the illness, the motivation of this work was the possibility of following up the pattern of neuronal damage. Thallium is one of the most toxic heavy metal and its wide use increases the chance of chronic or accidental acute poisoning. The entero-hepatic circulation makes the accumulation of this toxic agent in tissues possible, mostly in neurons, in the epithelial cells of the digestive tract, in the germinative cells of the skin and testicles. In addition to alopecia and digestive complaints, the clinical picture of thallium poisoning is dominated by neurological signs. Severe axonal polyneuropathy develops in almost all cases, with further damage to the retina and impairment of cognitive functions being not unusual. The diagnosis is confirmed by finding high levels of thallium in body fluids, especially in saliva and urine. Case report - Electrophysiological examination of our accidentally poisoned patient revealed severe, sensory-motor, predominant motor axonal polyneuropathy and pointed out some aspects of the pattern of neurotoxic process: the initially distal lesion, the dying-back course and the capacity for regeneration. Conclusion - Because thallium has the same molecular targets as potassium ion thus impairing the energetical supply of the nerve cell, the most effective treatment is carefully loading with potassium. If recognized and treated early, thallium poisoning has a favourable prognosis.]



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Clinical Neuroscience

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Clinical Neuroscience

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A case with reversible neurotoxicity induced by metronidazole

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Clinical Neuroscience

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[Objective - We summarize our experiences on intraoperative electrophysiological monitoring during neurosurgical procedures on eloquent neuronal structures. Patients, methods - Sixty patients were enrolled retrospectively in our study with pathologies involving eloquent neuronal structures. They were operated between May 2011. and March 2012. at the University of Debrecen, Department of Neurosurgery and at the National Institute of Neurosciences. Patients underwent standard preoperative examinations due to the primary pathology. In all cases we used intraoperative electrophysiological monitoring. We had 22 cases with cranial nerve monitoring, 10 cases with cauda monitoring, 16 cases with motor system monitoring, six cases with complex spinal cord monitoring, three degenerative spine reconstructions and 3 awake surgeries. Results - We found that with the use of intraoperative electrophysiology we could make these neurosurgical procedures safer, and were able to optimize the extent of resection in the cases of oncological pathologies. Conclusions - Our experiences as well as the international literature suggests that in certain high risk neurosurgical procedures intraoperative electrophysiology is indispensible for safe and optimally extended operation.]

Clinical Neuroscience


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Hungarian Radiology

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Clinical Neuroscience

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HORVÁTH Tamara, PAPP András, KOVÁCS Dávid, KÁLOMISTA Ildikó, KOZMA Gábor, VEZÉR Tünde

Introduction and aims - Particles of titanium dioxide (TiO2) with typical size below 100 nm have gained a broad range of application by now, partly involving direct human exposure. Their known properties - high specific surface, mobility within the organism, induction of oxidative stress, release of inflammation mediators etc. - raise the possibility of nervous system damage but the available data regarding this are scarce and contradictory. Based on that, and the experiences with other metal oxide nanoparticles, the aim of the present study was to investigate certain general end nervous system toxic effects of TiO2 nanoparticles applied in the airways of rats. Materials and methods - Young adult Wistar rats (5 groups of 10 rats each) received, daily for 28 days, intratracheal instillations of titanium dioxide nanoparticles of ca. 10 nm diameter, suspended in 1% hydroxyethyl cellulose dissolved in phosphate-buffered saline, in the doses of 1, 3, and 10 mg/kg b. w. Vehicle controls received the suspension medium and there was also an untreated control group. During treatment, the rats’ body weight was measured, and their clinical state observed, daily. After the 28 days, spontaneous cortical activity, sensory evoked potentials and tail nerve action potential was recorded in urethane anesthesia, then the rats were dissected and tissue samples were taken for Ti level determination and biochemical measurements of some oxidative stress indicators. Results - The two higher doses reduced the rate of body weight gain significantly. Sensory evoked potentials and tail nerve action potential were significantly slowed, but the change in the spectrum of spontaneous cortical activity was not significant. Correlation of moderate strength was found between certain evoked potential parameters and brain Ti level and oxidative stress data. Conclusion - Our results underlined the possible neurotoxicity of TiO2 NPs but also the need for further investigations.