Writing epilepsy: a neurophysiological, neuropsychological and neuroimaging study

Graphogenic Reflex Epilepsy: A Case Report and Literature Review

Graphogenic, or writing epilepsy, is a rare type of reflex epilepsy (RE) in which seizures are provoked by the act of writing. RE is a condition that affects between 4% and 7% of all patients diagnosed with epilepsy. In this case study, we provide a case report on a patient whose seizures were generated by the act of writing. We also present evidence that the cortical mechanisms by which writing-induced seizures occur are focal with possible secondary generalization.

Reflex epileptic features in patients with focal epilepsy of unknown cause

OBJECTIVES

There is a gap of knowledge regarding reflex seizures in patients with focal epilepsy of unknown cause (FEUC). We aimed to evaluate the prevalence, demographic and clinical characteristics of reflex seizures in patients with FEUC to provide an insight to the underlying ictogenic mechanisms and to draw attention to this important but under-investigated topic.

PATIENTS AND METHODS

After carefully questioning for reflex triggers, 186 patients diagnosed according to ILAE criteria and followed-up for a minimum of 5 years were included. The demographic and clinical properties as well as electrophysiological and neuroimaging data of these patients were reevaluated and compared to the patients without reflex seizures.

RESULTS

The reflex seizure rate was 6.5 % in patients with FEUC. Patients with reflex features had lower monotherapy rates (p = 0.005) and higher major depression rates (p = 0.001) than patients without reflex features. The distribution of the patients according to their reflex triggers were as follows: hot-water induced (n = 3, 25 %), photosensitive (n = 2, 16.7 %), eating- induced (n = 2, 16.7 %), musicogenic (n = 2, 16.7 %), startle induced (n = 2, 16.7 %) and both musicogenic and startle type (n = 1, 8.3 %) respectively. The drug resistance rate of patients with reflex seizures was 25 % (n = 3). One patient with drug resistant reflex seizures showed benefit from epilepsy surgery and became seizure-free during last 3 years of follow-up.

CONCLUSION

A careful and thoroughly history taking specifically questioning and focusing on seizure inducing factors in patients with FEUC is needed to confirm the presence of reflex seizures in patients with FEUC, who had higher rates of polytherapy and major depression. Elaborative evaluation of reflex features in FEUC might contribute to effective seizure control, ensure new therapeutic approaches, enlighten the obscurity and the resulting anxiety of having a diagnosis of FEUC in epilepsy patients.

Seizure-precipitating factors in dogs with idiopathic epilepsy

Background

Stress, sleep deprivation, and infectious diseases are important seizure‐precipitating factors in human epilepsy patients. However, these factors have not been thoroughly studied in epileptic dogs.

Objective

Seizure‐precipitating factors are common in dogs with idiopathic epilepsy and the occurrence of these factors associate with the dogs' signalment, personality, and epilepsy‐related factors.

Animals

Fifty dogs with diagnosed idiopathic epilepsy from the hospital populations of University Veterinary Teaching Hospital of University of Helsinki and Referral Animal Hospital Aisti.

Methods

In a retrospective cross‐sectional observational study, owners were interviewed about their dogs' possible seizure‐precipitating factors according to a predefined questionnaire. The dogs were identified and selected by searching the medical records of the participating animal hospitals.

Results

The prevalence of seizure‐precipitating factors in the study population was 74% (37/50). The most frequently reported factors included stress‐related situations, sleep deprivation, weather, and hormonal factors. In dogs with focal onset seizures, the number of precipitating factors was 1.9 (95% CI 1.1‐3.4) times higher compared to dogs with generalized seizures.

Conclusions and Clinical Importance

Seizure‐precipitating factors are common in dogs with idiopathic epilepsy, and the nature of these factors is consistent with those of human patients. Aside from antiepileptic medication, acknowledging and avoiding seizure‐precipitating factors could help veterinarians achieve better treatment outcomes.

Precipitation and inhibition of seizures in focal epilepsies

INTRODUCTION

There is growing awareness that reflex epileptic seizures offer unique insight into natural seizure generation in humans. In the last years, focus has mostly been on reflex seizures in generalized epilepsies whereas a comprehensive review of their role in focal epilepsies has been missing. Areas covered: This paper reviews reflex seizures strictly in focal epilepsies, not including focal reflex seizures in system epilepsies that also exist. They were categorized according to their triggers which can be sensory or cognitive, simple or complex. Numerous diverse conditions exist some of which are much better investigated than others. They required separate individual literature search in PubMed. Where recent review papers exist, it refers to these, but several conditions have never been reviewed, and here it refer to and discusses original reports. Miscellaneous case reports were only exceptionally included when they contributed aspects otherwise missing. Expert commentary: Research on focal reflex seizures with advanced methods of imaging and neurophysiology to elucidate mechanisms of focal ictogenesis will probably be rapidly increasing and will soon provide much new insight. Sensory and cognitive inhibition, i.e. the counterpart of reflex ictogenesis, is promising but needs more structured and controlled research to establish robust therapeutic approaches.

Pediatric applications of functional magnetic resonance imaging

Pediatric functional MRI has been used for the last 2 decades but is now gaining wide acceptance in the preoperative workup of children with brain tumors and medically refractory epilepsy. This review covers pediatrics-specific difficulties such as sedation and task paradigm selection according to the child's age and cognitive level. We also illustrate the increasing uses of functional MRI in the depiction of cognitive function, neuropsychiatric disorders and response to pharmacological agents. Finally, we review the uses of resting-state fMRI in the evaluation of children and in the detection of epileptogenic regions.

Do reflex seizures and spontaneous seizures form a continuum? - triggering factors and possible common mechanisms

Recent changes in the understanding and classification of reflex seizures have fuelled a debate on triggering mechanisms of seizures and their conceptual organization. Previous studies and patient reports have listed extrinsic and intrinsic triggers, albeit their multifactorial and dynamic nature is poorly understood. This paper aims to review literature on extrinsic and intrinsic seizure triggers and to discuss common mechanisms among them. Among self-reported seizure triggers, emotional stress is most frequently named. Reflex seizures are typically associated with extrinsic sensory triggers; however, intrinsic cognitive or proprioceptive triggers have also been assessed. The identification of a trigger underlying a seizure may be more difficult if it is intrinsic and complex, and if triggering mechanisms are multifactorial. Therefore, since observability of triggers varies and triggers are also found in non-reflex seizures, the present concept of reflex seizures may be questioned. We suggest the possibility of a conceptual continuum between reflex and spontaneous seizures rather than a dichotomy and discuss evidence to the notion that to some extent most seizures might be triggered.