Epileptic seizure disorders. Developments in diagnosis and therapy

A rare case of isolated myoclonus in an elderly male without a history of epilepsy

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We describe a unique presentation of isolated lingual myoclonus presenting as intermittent expressive aphasia associated with uninterrupted intrusion-protrusion movement of the posterior tongue and adjoining hyoid.

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We discuss the paucity of evidence and suggest differential diagnosis as well as a brief discussion on possible underlying pathophysiology.

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Highlight previously described movement disorders and associated cases and draw parallels to isolated lingual myoclonus.

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Consolidate literature regarding the management of lingual myoclonus

Aim

Through this case report we attempt to highlight the presentation, initial investigation and management of lingual myoclonus as well as consolidate relevant literature.

Case

We present a unique case of a 72-year-old man who was admitted to the hospital for a sudden onset episodic speech arrest. Lingual myoclonus, an isolated movement disorder, manifested as an intermittent expressive aphasia secondary to the intrusion-protrusion movements of his tongue. During this time, the patient remained conscious and was able to continue to follow commands. Initial diagnostic evaluation with a CT scan, MRI and EEG failed to illicit a clear underlying etiology and the patient was empirically treated with valproic acid with complete resolution of his symptoms.

Discussion

This unusual presentation represents a rare disorder which is not well described in literature. Initial evaluation of which required excluding associated etiologies including strokes, seizures, medications/toxins or CNS infections. Without a clear etiology on initial diagnostic evaluation, the patient was empirically treated as no clear guidelines exist. This case presentation is an attempt to add to the current understanding of lingual myoclonus.

Metabolomic method: UPLC-q-ToF polar and non-polar metabolites in the healthy rat cerebellum using an in-vial dual extraction

Unbiased metabolomic analysis of biological samples is a powerful and increasingly commonly utilised tool, especially for the analysis of bio-fluids to identify candidate biomarkers. To date however only a small number of metabolomic studies have been applied to studying the metabolite composition of tissue samples, this is due, in part to a number of technical challenges including scarcity of material and difficulty in extracting metabolites. The aim of this study was to develop a method for maximising the biological information obtained from small tissue samples by optimising sample preparation, LC-MS analysis and metabolite identification. Here we describe an in-vial dual extraction (IVDE) method, with reversed phase and hydrophilic liquid interaction chromatography (HILIC) which reproducibly measured over 4,000 metabolite features from as little as 3mg of brain tissue. The aqueous phase was analysed in positive and negative modes following HILIC separation in which 2,838 metabolite features were consistently measured including amino acids, sugars and purine bases. The non-aqueous phase was also analysed in positive and negative modes following reversed phase separation gradients respectively from which 1,183 metabolite features were consistently measured representing metabolites such as phosphatidylcholines, sphingolipids and triacylglycerides. The described metabolomics method includes a database for 200 metabolites, retention time, mass and relative intensity, and presents the basal metabolite composition for brain tissue in the healthy rat cerebellum.

Epilepsy: Ever-changing states of cortical excitability

It has been proposed that the underlying epileptic process is mediated by changes in both excitatory and inhibitory circuits leading to the formation of hyper-excitable seizure networks. In this review we aim to shed light on the many physiological factors that modulate excitability within these networks. These factors have been discussed extensively in many reviews each as a separate entity and cannot be extensively covered in a single manuscript. Thus for the purpose of this work in which we aim to bring those factors together to explain how they interact with epilepsy, we only provide brief descriptions. We present reported evidence supporting the existence of the epileptic brain in several states; interictal, peri-ictal and ictal, each with distinct excitability features. We then provide an overview of how many physiological factors influence the excitatory/inhibitory balance within the interictal state, where the networks are presumed to be functioning normally. We conclude that these changes result in constantly changing states of cortical excitability in patients with epilepsy.

A closed-loop brain computer interface for real-time seizure detection and control

The worldwide prevalence of epilepsy is approximately 1%, and 25% of epilepsy patients cannot be treated sufficiently by available therapies. Brain stimulation with closed-loop seizure control has recently been proposed as an innovative and effective alternative. In this paper, a portable closed-loop brain computer interface for seizure control was developed and shown with several aspects of advantages, including high seizure detection rate (92-99% during wake-sleep states), low false detection rate (1.2-2.5%), and small size. The seizure detection and electrical stimulation latency was not greater than 0.6 s after seizure onset. A wireless communication feature also provided flexibility for subjects freeing from the hassle of wires. Experimental data from freely moving rats supported the functional possibility of a real-time closed-loop seizure controller.

CT brain scan and EEG in the diagnosis of adult onset seizures

Incidence of CT abnormalities and their correlation with clinical and EEG features were evaluated in a consecutive series of 202 adult patients with newly diagnosed epileptic seizures. Abnormal CT findings were found in 36% of these patients; the abnormalities consisted of brain tumors (17%), atrophic lesions (11%) and other organic findings (8%) such as arteriovenous malformations. Focal features of seizures, in neurological examination and/or in EEG, correlated significantly with CT abnormalities. The absence of these findings did, however, not exclude the possibility of brain lesions, which in many cases were treatable by surgery.