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Modulation of autonomic activity in neurological conditions: Epilepsy and Tourette Syndrome.

Nagai Y - Front Neurosci (2015)

Bottom Line: Investigation is more limited in Tourette Syndrome.The role of the autonomic nervous system in the generation and prevention of epileptic seizures is largely overlooked.This approach also takes advantage of the current practical opportunity to utilize growing digital health technology.

View Article: PubMed Central - PubMed

Affiliation: Department of Clinical Medicine, Clinical Imaging Sciences Centre, Brighton and Sussex Medical School, University of Sussex Brighton, UK.

ABSTRACT
This manuscript considers the central but neglected role of the autonomic nervous system in the expression and control of seizures in epilepsy (small) and tics in Tourette Syndrome (TS). In epilepsy, consideration of autonomic involvement is typically confined to differential diagnoses (e.g., syncope), or in relation to Sudden Unexpected Death in Epilepsy (SUDEP). Investigation is more limited in Tourette Syndrome. The role of the autonomic nervous system in the generation and prevention of epileptic seizures is largely overlooked. Emotional stimuli such as anxiety and stress are potent causes of seizures and tic activity in epilepsy and TS, respectively. This manuscript will describe a possible neural mechanism by which afferent autonomic projections linked to cognition and behavior influence central thalamo-cortical regulation, which appears to be an important means for controlling both seizure and tic activity. It also summarizes the link between the integrity of the default mode network and autonomic regulation in patients with epilepsy as well as the link between impaired motor control and autonomic regulation in patients with TS. Two neurological conditions; epilepsy and TS were chosen, as seizures and tics represent parameters that can be easily measured to investigate influences of autonomic functions. The EDA biofeedback approach is anticipated to gain a strong position within the next generation of treatment for epilepsy, as a non-invasive technique with minimal side effects. This approach also takes advantage of the current practical opportunity to utilize growing digital health technology.

No MeSH data available.


Related in: MedlinePlus

Model of behavioral modulation and seizure generation. The model describes psychological and neural interaction influencing seizure generation.
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Figure 1: Model of behavioral modulation and seizure generation. The model describes psychological and neural interaction influencing seizure generation.

Mentions: The following model illustrates how emotional stimuli may trigger epileptic seizures (Figure 1). Emotional disturbances can originate from sensory stimulation such as vision, hearing, and also from internal thoughts and memories. Whether or not such information predictably recruits autonomic activation depends on the intensity of stimulation, the significance of the timing and individual differences in sensitivity and salience to stimuli (Bauscein, 2006). Certain types of stimuli may preferentially engage autonomic systems (e.g., disturbing thoughts changing heart rate variability, Ottaviani et al., 2015). It is speculated that these visceral afferent influences affect neural excitability around seizure foci through effects mediated at the level of the reticular formation and thalamus. Indeed, in a model of complex partial seizures, a “Network Inhibition Hypothesis” proposes that impaired consciousness is attributed to suppression of midline subcortical structures (i.e., the reticular activation system). Spreading seizure activity affects the reticular activation system which leads to regional depression of frontoparietal association cortex known to be crucial for maintenance of consciousness (Blumenfeld, 2011). It is hypothesized that changes in thalamo-cortical regulation impacts on seizure threshold via physiological arousal and visceral feedback (Nagai, 2011). The typical emotional and behavioral triggers of seizures (stress, sleep deprivation, and fatigue) represent events that commonly disturb autonomic regulation. In cognitive behavioral terms, disrupted autonomic regulation in turn affects perception and cognition, potentially creating a vicious circle in a patient's emotional state. Looking at autonomic dysregulation from a different angle, seizure events themselves also affect autonomic activity: post ictal autonomic dysregulation is one candidate as a cause for SUDEP (Poh et al., 2012). Thus, autonomic dysregulation, reflecting interaction between underlying brain pathology (e.g., temporal lobe damage), seizure activity, the effect of anti-epileptic drugs and the psychosocial consequences of societal conditioning and stigma is inherently linked to the emotional resilience and vulnerability of patients. Patients with epilepsy have specific predisposing psychological and neural dynamics which underlie seizure generation (Ridsdale et al., 2013).


Modulation of autonomic activity in neurological conditions: Epilepsy and Tourette Syndrome.

Nagai Y - Front Neurosci (2015)

Model of behavioral modulation and seizure generation. The model describes psychological and neural interaction influencing seizure generation.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4584996&req=5

Figure 1: Model of behavioral modulation and seizure generation. The model describes psychological and neural interaction influencing seizure generation.
Mentions: The following model illustrates how emotional stimuli may trigger epileptic seizures (Figure 1). Emotional disturbances can originate from sensory stimulation such as vision, hearing, and also from internal thoughts and memories. Whether or not such information predictably recruits autonomic activation depends on the intensity of stimulation, the significance of the timing and individual differences in sensitivity and salience to stimuli (Bauscein, 2006). Certain types of stimuli may preferentially engage autonomic systems (e.g., disturbing thoughts changing heart rate variability, Ottaviani et al., 2015). It is speculated that these visceral afferent influences affect neural excitability around seizure foci through effects mediated at the level of the reticular formation and thalamus. Indeed, in a model of complex partial seizures, a “Network Inhibition Hypothesis” proposes that impaired consciousness is attributed to suppression of midline subcortical structures (i.e., the reticular activation system). Spreading seizure activity affects the reticular activation system which leads to regional depression of frontoparietal association cortex known to be crucial for maintenance of consciousness (Blumenfeld, 2011). It is hypothesized that changes in thalamo-cortical regulation impacts on seizure threshold via physiological arousal and visceral feedback (Nagai, 2011). The typical emotional and behavioral triggers of seizures (stress, sleep deprivation, and fatigue) represent events that commonly disturb autonomic regulation. In cognitive behavioral terms, disrupted autonomic regulation in turn affects perception and cognition, potentially creating a vicious circle in a patient's emotional state. Looking at autonomic dysregulation from a different angle, seizure events themselves also affect autonomic activity: post ictal autonomic dysregulation is one candidate as a cause for SUDEP (Poh et al., 2012). Thus, autonomic dysregulation, reflecting interaction between underlying brain pathology (e.g., temporal lobe damage), seizure activity, the effect of anti-epileptic drugs and the psychosocial consequences of societal conditioning and stigma is inherently linked to the emotional resilience and vulnerability of patients. Patients with epilepsy have specific predisposing psychological and neural dynamics which underlie seizure generation (Ridsdale et al., 2013).

Bottom Line: Investigation is more limited in Tourette Syndrome.The role of the autonomic nervous system in the generation and prevention of epileptic seizures is largely overlooked.This approach also takes advantage of the current practical opportunity to utilize growing digital health technology.

View Article: PubMed Central - PubMed

Affiliation: Department of Clinical Medicine, Clinical Imaging Sciences Centre, Brighton and Sussex Medical School, University of Sussex Brighton, UK.

ABSTRACT
This manuscript considers the central but neglected role of the autonomic nervous system in the expression and control of seizures in epilepsy (small) and tics in Tourette Syndrome (TS). In epilepsy, consideration of autonomic involvement is typically confined to differential diagnoses (e.g., syncope), or in relation to Sudden Unexpected Death in Epilepsy (SUDEP). Investigation is more limited in Tourette Syndrome. The role of the autonomic nervous system in the generation and prevention of epileptic seizures is largely overlooked. Emotional stimuli such as anxiety and stress are potent causes of seizures and tic activity in epilepsy and TS, respectively. This manuscript will describe a possible neural mechanism by which afferent autonomic projections linked to cognition and behavior influence central thalamo-cortical regulation, which appears to be an important means for controlling both seizure and tic activity. It also summarizes the link between the integrity of the default mode network and autonomic regulation in patients with epilepsy as well as the link between impaired motor control and autonomic regulation in patients with TS. Two neurological conditions; epilepsy and TS were chosen, as seizures and tics represent parameters that can be easily measured to investigate influences of autonomic functions. The EDA biofeedback approach is anticipated to gain a strong position within the next generation of treatment for epilepsy, as a non-invasive technique with minimal side effects. This approach also takes advantage of the current practical opportunity to utilize growing digital health technology.

No MeSH data available.


Related in: MedlinePlus