What is epilepsy?

Epilepsy is a chronic disease that affects brain neurons, which show uncontrolled and improvised electrical activity that causes physical and psychological consequences of different types, affecting the quality of daily life in a variable way depending on the severity of the disorder.

It affects around 50 million people worldwide (400,000 in Spain) and around 5 million cases are diagnosed each year (20,000 in Spain), with onset mostly before the age of 20 or after the age of 65, tripling the risk of premature death. The frequency of epileptic seizures can vary widely, from one a year to several on the same day.

Epileptic seizures usually last a few minutes and can affect a specific brain area (partial seizures) or spread over the whole brain surface (generalised seizures), causing seizures of 4 types:

• Absence episodes: the mildest but generalised type, the person remains absent, unresponsive to stimuli and unconscious, although they can perform automatic repetitive movements without later remembering them.
• Tonic seizures: characterised by rigidity and partial or generalised muscle contractions, affecting consciousness depending on the area involved.
• Clonic seizures: characterised by partial or generalised muscle twitching and spasms, with varying degrees of impairment of consciousness.
• Tonic-clonic seizures: the most severe and generalised, characterised by an initial tonic phase followed by muscle twitching, loss of consciousness, often loss of sphincter control and tongue biting.

Epilepsy symptoms, diagnosis and consequences

The disease is diagnosed by the presence of two or more unprovoked seizures, plus a careful neurological examination that can record the abnormal electrical pattern and the brain focus of onset of the discharges.

Some people just before having an epileptic seizure experience an aura: a set of sensory (smells, colours, abnormal sounds), psychological (deja-vu, fear) and physical (tingling, nausea) sensations specific to each person, warning that a seizure is about to begin.

Some of the consequences of these attacks are:

Physical problems:

• Fractures and bruises resulting from trauma and falls due to loss of consciousness.
• Muscle aches and pains
• Headaches
• Death caused by the seizure itself (rarely), by the traumas resulting from the loss of consciousness or by the environment in which they occur.

Psychological problems:

• Mental confusion
• Disturbances of cognitive functions (attention, memory, executive functions)
• Mood disturbances, such as anxiety and depression, resulting from the presence of the disease itself and/or from stigma and social discrimination (in ancient times it was considered a "possession of the devil" and until the 1970s in the USA and UK people with epilepsy could be restricted from public places and jobs and/or banned from marriage as is the case today in China and India).

Limitations in daily life: many daily or work activities are not recommended, such as driving, operating machinery, swimming, as well as avoiding dangerous places in case of loss of consciousness. It is advisable to carry an electronic device to call for quick help or a medical identification bracelet, and to wear a helmet depending on the activity undertaken.

Causes and treatment for epilepsy

The causes are unknown (idiopathic) in 50-70% of cases, while the others may be caused by underlying structural, genetic, infectious, metabolic or immunological diseases. The most common are: brain injuries, genetic malformations, strokes, infections or brain tumours.

There are some seizures (reflex epilepsy) that are facilitated by repetitive sensory stimuli such as lights or sounds (e.g. some video games), while seizures caused by factors such as lack of sleep, high fever, stress or substance abuse are not considered epilepsy, as they do not originate from a neurological brain problem.

Children

Children can suffer from epileptic seizures caused by a feverish state and by their own brain development and can develop Dravet or Lennox-Gastaut Syndrome, two pathologies that cause frequent epileptic seizures of the clonic or tonic-clonic type from early childhood, which can severely limit psychomotor development and can be resistant to pharmacological treatment.

With appropriate pharmacological treatment, 70% of people can live without seizures, and withdrawal may be considered after the age of two years without seizures, depending on the case.

In some cases it is necessary to resort to a combination of different drugs.

If there is no response to drugs (drug-resistant epilepsy), it is possible to resort to surgery depending on the origin of the brain focus or by implanting a vagus nerve stimulator (VNS).

How does CBD help epilepsy?

The anti-epileptic effect of CBD has been demonstrated in pre-clinical in vivo studies (with animals) in different experimental models.

There is a large amount of scientific information both from studies and surveys on real cases (especially in children with Dravet's Syndrome or Lennox-Gastaut), the results of which show a high capacity to reduce and even cancel the number of epileptic seizures.

The first clinical trial carried out on children with Dravet Syndrome has shown type 1 evidence for the use of CBD as an adjuvant to pharmacological treatments.

Epilepsy and the endocannabinoid system

A reduction in Anandamide levels and CB1 receptor activity has been reported in people suffering from epilepsy.

The anti-epileptic effects of THC seem to be due to the stimulation of CB1 receptors, whereas CBD acts by modulating different mechanisms related to epilepsy, as well as indirectly helping to increase Anandamide levels and consequently increasing CB1 receptor activity.

According to studies, the anti-epileptic effect of CBD could also be due to modulation of GPR55 receptors, stimulation of TRPV and 5-HT receptors and inhibition of adenosine transport.

Clinical efficacy of CBD for the treatment of epilepsy

CBD could be of great help in coping with epilepsy and its consequences due to its different properties:

• Anti-epileptic and anticonvulsant effect: helps to reduce seizure frequency and intensity.
• Neuroprotective and antioxidant effect: helps to reduce the damage and neuronal wasting caused by epilepsy, improving cognitive problems.
• Anxiolytic and antidepressant effect: helps to improve mood and the psychological and emotional consequences of the disease itself and social discrimination.
• Anti-inflammatory and analgesic effect: helps to improve physical problems resulting from epileptic seizures.

How many CBD drops are recommended for epilepsy?

Various human clinical studies have used a minimum dosage of 2-5 mg/kg/day, increasing to around 25-50 mg/kg/day depending on the onset of effects, although studies in children with Dravet or Lennox-Gastaut syndrome have used lower amounts. There are also many studies with more standardised dosing of 200mg to 300mg per day.

In general, for internal use (not regulated in the EU) it is recommended to use a medium-high concentration oil (10%-20%), starting with minimal doses and gradually increasing until the most appropriate effect is achieved.

It is essential to be able to consult specialised health professionals for advice and follow-up, considering that CBD is used as an adjuvant to pharmacological treatment and interactions with drugs (especially Clobazam and Valproate) can be observed.

Precautions and possible adverse effects

CBD is a very safe substance even if used in large quantities, but care should be taken when taking medication or if you have heart or blood pressure problems. For this reason in these cases it is always advisable to contact a health professional.

Adverse effects are usually mild to moderate and may include tiredness, drowsiness, dry mouth, dizziness and decreased appetite.

Bibliography

1.  https://www.who.int/es/news-room/fact-sheets/detail/epilepsy
2.  https://www.clinicbarcelona.org/asistencia/enfermedades/epilepsia/signos-y-sintomas
3. https://vivirconepilepsia.es/que-es-la-epilepsia
4.  https://medlineplus.gov/spanish/ency/article/000694.htm
5.  https://www.msdmanuals.com/es/professional/trastornos-neurol%C3%B3gicos/trastornos-convulsivos/trastornos-convulsivos
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