One in four women are diagnosed with Epilepsy at some point in their life. It is a chronic health condition that affects us differently to men due to our hormones, yet little research is conducted for women suffering, writes Dr Emily Handley, Medical Researcher and Women’s Health Advocate.
The brain is constantly generating tiny, patterned electrical impulses that control our movements, cognition and consciousness through chemical messengers received by brain cells. When these electrical networks become imbalanced or are perturbed, unregulated bursts of electricity can cause a loss of consciousness, or lack of control over movements and sensations, known as seizures. After experiencing two or more of these events, a person may be diagnosed with epilepsy. While the incidence of epilepsy diagnosis is relatively similar between males and females, sex differences still must be accounted for. Some women may experience fluctuations in seizures that are related to the menstrual cycle, and biological differences underpin susceptibility to varying forms of epilepsy disorders. Still, the exact changes that dictate these sex differences are poorly understood, and neurosteroids – a potential therapy for seizures related to hormonal changes – remain under-researched.
What is epilepsy?
Epilepsy is a chronic condition that is characterised by recurring seizures and is the fourth most common neurological disorder in the world. For the most part, these seizures occur spontaneously, though they can also be triggered by external factors or by psychological events. Approximately 30-40% of epileptic diagnoses are attributed to genetics: first-degree relatives of a person with epilepsy have at least double the risk of developing recurrent seizures. And while many forms of epilepsy occur without any co-morbidities, there are cases when a second condition is linked to recurrent seizures.
In infants, fever, infection and brain tumours can induce epilepsy, whilst in children and adults head trauma, neurodegenerative disease, and congenital conditions – including Down’s syndrome and Angelman’s syndrome – are associated with epileptic seizures. As we age, stroke and Alzheimer’s disease also bring an increased risk of developing epilepsy.
It’s important to remember that not everyone who has a seizure has epilepsy, with seizures also being one-off or rare events provoked by illness, trauma or psychological conditions. Additionally, the disorder exists on a spectrum, and diagnosis depends on seizure type, frequency and severity; on the brain areas impacted; the effect of treatments; and co-morbidities present.
What are the different forms of epilepsy?
Seizures can be defined by three general parameters: where and when they start in the brain (onset), a person’s level of awareness during the event (consciousness), and the symptoms experienced (seizure type).
Focal onset seizures start on one side of the brain, or in a specific group of neurons. When the person is awake during a focal seizure, it is considered an aware seizure.
Conversely, if the person is confused or experiencing impaired awareness, it is termed focal onset impaired seizure. Generalised seizures affect both sides of our brain at the same time, whilst unknown seizures are when the beginning of the event is unknown.
The types of symptoms a person experiences during a seizure are important for classifications and subsequent treatments. Clonic seizures involve the muscles, and may manifest as jolting or jerking; tonic seizures are characterised by sudden rigidity; atonic seizures feature muscle weakness or limp limbs; and myoclonus seizures are identified through muscle twitching. During focal seizures, these symptoms can look slightly different, and may also involve repeated automatic movements.
Epileptic seizures can also manifest as non-motor or absence seizures, meaning they don’t appear as a physical event. This can be as subtle as changes in perception, emotions, sensation and thinking, as well as changes to our body’s normal functions, such as sudden changes in temperatures, heart rate, and halted movement. Myoclonus absence seizures involve brief twitches of specific parts of the body, while atypical absence seizures involve staring, or ‘vacant’ episodes. These types of seizures can lead to this form of epilepsy being considered a ‘silent condition’, as it isn’t obvious when someone is suffering from a seizure event.
To the outsider, epileptic seizures in general may look like uncontrollable shaking; a loss of awareness or blank staring; confusion; collapsing; sudden stiffness; and a person may report the onset of a strange taste or smell, nausea or tingling in their limbs. In some instances, people report seizures occurring in specific situations, after certain events, or in a pattern. It’s important to keep track of your circumstances before a seizure to recognise in future whether an environment or state may be a seizure initiator. Some triggers may be:
- Alcohol and drug use
- Flashing lights or intricate patterns
- Fatigue and sleep disruptions
- Certain times of the day or night
- Poor nutrition and dehydration
- Excess caffeine
- Specific medications
For women in particular, the menstrual cycle is also a trigger for epileptic events. Women may also be more susceptible to specific forms of epilepsy due to levels of sex hormones and brain structure.
How does epilepsy effect women?
Throughout a woman’s life, hormonal changes can influence – and in turn, be influenced – by epileptic seizures and by therapeutics used to combat symptoms of epilepsy. While not every woman with epilepsy will experience these hormone-related impacts, even the type of epilepsy disorder that manifests can be influenced by sex – with absence epilepsy in childhood and photosensitive epilepsy more common in females.
One in three women report that their seizures are affected by their period. Puberty and the onset of the menstrual cycle is a common time for epilepsy to start, and the side effects of some anti-epileptic drugs (AEDs) can affect the menstrual cycle, or even delay the beginning of menses. Catamenial epilepsy is an epileptic form that follows a specific timeline and pattern, linked to the menstrual cycle and split into three categories: perimenstrual, periovulatory and inadequate luteal phase.
While traditional anti-epileptic therapies are not effective for this type of epilepsy, certain molecules in the brain have been discovered that are uniquely altered in catamenial epilepsy that point to sex steroids in the brain having therapeutic potential.
Progesterone – a key female sex hormone – has antiseizure effects, and an increase in the hormone during the mid-luteal phase, when progesterone is elevated, is linked to a decrease in seizure risk. Conversely, seizures can increase during the premenstrual phase when progesterone levels fall. Progesterone has been observed interacting with a specific chemical receptor in our brain, and it may be that this interaction is what mediates the hormone’s impact on seizure activity.
Estrogen can also impact the frequency and occurrence of seizures, where a drastic decrease of estrogen, or an increase in the estrogen/progesterone ratio, can exacerbate seizures during specific menstrual phases. For women experiencing catamenial epilepsy, it’s important to keep a diary that tracks both seizure activity and menses over at least two menstrual cycles to be accurately diagnosed.
Menopause brings further considerations, as the body stops making sex hormones and levels of both estrogen and progesterone plummet. While hormone replacement therapy undertaken to combat the symptoms of menopause generally has too little estrogen to trigger seizures, any change in seizure activity after beginning medication should be noted and discussed with a doctor.
With menopause also comes an increased risk of developing osteoporosis, where calcium is lost from the bones and renders them brittle. Taking AEDs may increase the risk of developing osteoporosis, as they may interact with chemicals in the body that destroy vitamin D, required for strong bones. To combat this, post-menopausal women taking AEDs should have vitamin D levels checked regularly, as well as bone density scans, to ensure that any medications are not interfering with other facets of health and wellbeing.
Even the structure of the female brain can contribute to differences in the experience of epilepsy disorders. The male brain has a greater number of white matter connections within the same hemisphere, while in comparison the female brain has more connectivity between hemispheres. This difference may explain why women are more likely to be diagnosed with generalised epilepsy disorders. Women can also experience certain symptoms of epilepsy more often than men, particularly that of an aura.
An aura is a sensation that often precedes a seizure, and can be a perception of seeing glowing shapes, or a rising feeling in the stomach. Often, these seizures come with impaired awareness and fainting – and may be due to connections between brain cells in the limbic system. Women have larger structures of their limbic system – a collection of structures in the brain controlling emotion and behaviour – and this might be linked to these specific symptoms.
How can epilepsy be managed?
Most forms of epilepsy are treated with AEDs, but can also be supplemented by changes in diet and surgery. Though medication can only treat epileptic symptoms and not cure the condition, they can completely control seizures in approximately 70% of sufferers. These drugs act by lowering the chance of surging electrical signals occurring, maintaining homeostasis in the brain. There are many types of AEDs, and choosing the correct medication for the individual can be complicated – accounting for type of seizure and epilepsy, other medical conditions and medications, age, gender and side effects.
Diet therapy is used for specific forms of epilepsy that resist AEDs, occurring in around 30% of sufferers. Most commonly, the ketogenic and the Atkins diets are used to reduce seizures in almost 50% of patients identified as AED resistant, and most commonly in children for whom surgery is considered too drastic. Both diets feature high fat and low carbohydrate foods, and are initiated and regulated by a multidisciplinary team. Someone with epilepsy will likely work with specialists, nurses, neurosurgeons, technicians, psychologists, psychiatrists, radiologists, dietitians…the list goes on. This means it is incredibly important to assemble a care team that fits the individual’s needs and care requirements.
For patients who are medically resistant and show no benefits from dietary changes, surgery is an option to control seizures. Only a subset of patients is eligible for this intervention: onset needs to be focal rather than generalised, and the brain region impacted needs to avoid major complications from removal. To decide whether surgical removal of the affected brain region will positively benefit the wellbeing of the patient, two phases of evaluations will be undertaken.
Phase I testing is first initiated with electroencephalography (EEG) testing, which records electrical signals and can determine several factors of the type of epilepsy present. EEG testing can occur over several days, known as inpatient monitoring, and is critical for detailed analysis of epilepsy symptoms. Magnetic resonance imaging (MRI) can also detect abnormalities in the brain that may be triggering epileptic symptoms, while positron emission tomography (PET) can determine whether the brain is functioning correctly.
Phase 2 testing involves EEG monitoring from electrodes placed inside the skull, which is a more invasive and therefore riskier method. There are different types of electrodes that can be implanted, with each coming with pros and cons. If both phases of testing show that removing the brain region triggering epileptic fits will not negatively impact the sufferer, surgical procedures can then be discussed.
Outlook
It is critical to work closely with a multi-disciplinary team of healthcare workers to optimise treatment and medications for epilepsy, and to track symptoms to empower your healthcare team to individualise your treatment options. Managing epileptic symptoms means taking medications as prescribed; sleeping well; reducing stress; avoiding alcohol and drug intake; eating healthily and exercising regularly; and keeping your healthcare provider as informed as possible about your symptoms. Epilepsy comes with it many risks, some life-threatening, if left unmanaged and untreated. Yet between 70-80% of people can successfully control their seizures, allowing them to live normally and enjoy a high quality of life.
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Disclaimer: This article provides general information only, and does not constitute health or medical advice. If you have any concerns regarding your mental or physical health, seek immediate medical attention.
