Cervical spondylodiscitis following cricopharyngeal botulinium toxin injection.

BACKGROUND: Iatrogenic cervical spondylodiscitis is rare, but may occur after various medical interventions. METHODS: We report a case of a diabetic 70-years-old female with C5-C6 spondylodiscitis and symptomatic epidural abscess with neck pain and upper limb paresis after endoscopic botulinum toxin injection for the treatment of dysphagia. Treatment included antibiotic therapy with amoxicillin and later on benzylpenicillin for the next ten weeks and corporectomy with spondylodesis. RESULT: The patient made an excellent recovery, with complete resolution of paresis and only minor residual hypoesthesia at one year after operation. CONCLUSION: Cervical spondylodiscitis should be considered early, in patients with neck pain after endoscopic cricopharyngeal injection, as timely diagnosis and treatment can prevent serious and irreversible neurological deficit.

Tonic GABAA Receptors as Potential Target for the Treatment of Temporal Lobe Epilepsy.

Tonic GABAA receptors are a subpopulation of receptors that generate long-lasting inhibition and thereby control network excitability. In recent years, these receptors have been implicated in various neurological and psychiatric disorders, including Parkinson's disease, schizophrenia, and epilepsy. Their distinct subunit composition and function, compared to phasic GABAA receptors, opens the possibility to specifically modulate network properties. In this review, the role of tonic GABAA receptors in epilepsy and as potential antiepileptic target will be discussed.

The effects of vagus nerve stimulation on tryptophan metabolites in children with intractable epilepsy.

BACKGROUND: The mechanism of action of vagus nerve stimulation (VNS) in intractable epilepsy is not entirely clarified. It is believed that VNS causes alterations in cytokines, which can lead to rebalancing the release of neurotoxic and neuroprotective tryptophan metabolites. We aimed to evaluate VNS effects on tryptophan metabolites and on epileptic seizures and investigated whether the antiepileptic effectiveness correlated with changes in tryptophan metabolism. METHODS: Forty-one children with intractable epilepsy were included in a randomized, active-controlled, double-blind study. After a baseline period of 12 weeks, all children underwent implantation of a vagus nerve stimulator and entered a blinded active-controlled phase of 20 weeks. Half of the children received high-output (therapeutic) stimulation (n=21), while the other half received low-output (active control) stimulation (n=20). Subsequently, all children received high-output stimulation for another 19 weeks (add-on phase). Tryptophan metabolites were assessed in plasma and cerebrospinal fluid (CSF) by use of liquid chromatography-tandem mass spectrometry (LC-MS/MS) and compared between high- and low-output groups and between the end of both study phases and baseline. Seizure frequency was recorded using seizure diaries. Mood was assessed using Profile of Mood States (POMS) questionnaires. RESULTS: Regarding tryptophan metabolites, anthranilic acid (AA) levels were significantly higher at the end of the add-on phase compared with baseline (p=0.002) and correlated significantly with improvement of mood (τ=-0.39, p=0.037) and seizure frequency reduction (τ=-0.33, p<0.01). No significant changes were found between high- and low-output groups regarding seizure frequency. CONCLUSION: Vagus nerve stimulation induces a consistent increase in AA, a neuroprotective and anticonvulsant tryptophan metabolite. Moreover, increased AA levels are associated with improvement in mood and reduction of seizure frequency.

The influence of neuropathology on brain inflammation in human and experimental temporal lobe epilepsy.

It is unclear to what extent neuropathological changes contribute to brain inflammation observed in temporal lobe epilepsy (TLE). Here, we compared cytokine levels between histopathologically-confirmed sclerotic hippocampi and histopathologically-confirmed normal hippocampi from TLE patients. We analyzed a similar cytokine panel in the hippocampi of amygdala-kindled rats and we evaluated neuropathological changes by immunohistochemistry. In TLE patients, cytokine levels were not significantly different between sclerotic and non-sclerotic hippocampi. Though kindling resulted in increased astrocyte activation, cytokine levels and microglia activation were unchanged. These results suggest that the chronic epileptic state in TLE can also occur in the absence of intracerebral inflammation. Highlights.

Rat vagus nerve stimulation model of seizure suppression: nNOS and ΔFos B changes in the brainstem.

Vagus nerve stimulation (VNS) is a moderately effective treatment for intractable epilepsy. However, the mechanism of action is poorly understood. The effect of left VNS in amygdala kindled rats was investigated by studying changes in nNOS and ΔFos B expression in primary and secondary vagus nerve projection nuclei: the nucleus of the solitary tract (NTS), dorsal motor nucleus of the vagus nerve (DMV), parabrachial nucleus (PBN) and locus coeruleus (LC). Rats were fully kindled by stimulation of the amygdala. Subsequently, when the fully kindled state was reached and then maintained for ten days, rats received a single 3-min train of VNS starting 1min prior to the kindling stimulus and lasting for 2min afterwards. In control animals the vagus nerve was not stimulated. Animals were sacrificed 48h later. The brainstems were stained for neuronal nitric oxide synthase (nNOS) and ΔFos B. VNS decreased seizure duration with more than 25% in 21% of rats. No VNS associated changes in nNOS immunoreactivity were observed in the NTS and no changes in ΔFos B were observed in the NTS, PBN, or LC. High nNOS immunopositive cell densities of >300cells/mm(2) were significantly more frequent in the left DMV than in the right (χ(2)(1)=26.2, p<0.01), independent of whether the vagus nerve was stimulated. We conclude that the observed nNOS immunoreactivity in the DMV suggests surgery-induced axonal damage. A 3-min train of VNS in fully kindled rats does not affect ΔFos B expression in primary and secondary projection nuclei of the vagus nerve.

Horner's syndrome: a complication of experimental carotid artery surgery in rats.

PURPOSE: To report on the occurrence of iatrogenic Horner's syndrome (HS) in epileptic rats after implantation of an electrode for vagus nerve stimulation and to describe the possible consequences of this new complication of carotid artery surgery in rats. METHODS: A bipolar circular electrode was placed around the left carotid artery and vagus nerve of 31 rats. The incidence of HS was evaluated by visual inspection within 24 h after surgery. RESULTS: 68% of rats suffered from HS immediately after surgery. This complication did not affect epileptogenesis. CONCLUSION: The occurrence of HS in the rat is a frequent complication of vagus nerve electrode implantation, which does not affect epileptogenesis in this study. However, rats affected by HS may suffer from damage to the sympathetic innervation of the gut, due to rat-specific neuroanatomy. Therefore, caution towards other research questions is warranted.