Epilepsy and its management

Epilepsy and its management

Epilepsy and its management

Epilepsy is a neurological condition affecting the nervous system. Epilepsy is also known as a seizure disorder. There are two main types of seizures. Generalized seizures affect the whole brain. Focal, or partial seizures, affect just one part of the brain. It is usually diagnosed after a person has had at two seizures, or one seizure with the likelihood or more, that were not caused by some known medical condition. Seizures seen in epilepsy are caused by disturbances in the electrical activity of the brain. The seizures in epilepsy may be related to a brain injury, genetics, immune, brain structure, metabolic cause, or a family tendency, but most of the time the cause is unknown. There are 65 millions of people around the world who have epilepsy. Between 4 and 10 out of 1,000 people on earth live with active seizures at any one time. The cause is unknown in 6 out of 10 epilepsy cases. Almost 33 % of the patients with epilepsy suffers from uncontrollable seizures because no available treatments work for them.

SYMPTOMS:

symptoms of epilepsy

Seizures are the main symptom of epilepsy. Symptoms differ from person to person and according to the type of seizure.

A simple partial seizure doesn’t involve loss of consciousness. Symptoms include:

• alterations to sense of taste, smell, sight, hearing, or touch
• dizziness
• tingling and twitching of limbs

Complex partial seizures involve loss of awareness or consciousness. Other symptoms include:

• staring blankly
• unresponsiveness
• performing repetitive movements

Generalized seizures

Generalized seizures involve the whole brain. There are six types:

Absence seizures, which used to be called “petit mal seizures,” cause a blank stare. This type of seizure may also cause repetitive movements like lip smacking or blinking. There’s also usually a short loss of awareness.

Tonic seizures cause muscle stiffness.

Atonic seizures lead to loss of muscle control and can make you fall down suddenly.

Clonic seizures are characterized by repeated, jerky muscle movements of the face, neck, and arms.

Myoclonic seizures cause spontaneous quick twitching of the arms and legs.

Tonic-clonic seizures used to be called “grand mal seizures.” Symptoms include:

• stiffening of the body
• shaking
• loss of bladder or bowel control
• biting of the tongue
• loss of consciousness

Following a seizure, you may not remember having one, or you might feel slightly ill for a few hours.

Most Commonly Reported Triggers Are:

• lack of sleep
• illness or fever
• stress
• bright lights, flashing lights, or patterns
• caffeine, alcohol, medicines, or drugs
• skipping meals, overeating, or specific food ingredients

Identifying triggers isn’t always easy. A single incident doesn’t always mean something is a trigger. It’s often a combination of factors that trigger a seizure.

CAUSES:

For 6 out of 10 people with epilepsy, the cause can’t be determined. A variety of things can lead to seizures.

Possible causes include:

• Traumatic brain injury
• Scarring on the brain after a brain injury (post-traumatic epilepsy)
• Serious illness or very high fever
• Stroke, which is a leading cause of epilepsy in people over age 35
• Other vascular diseases
• Lack of oxygen to the brain
• Brain tumor or cyst
• Dementia or Alzheimer’s disease
• Maternal drug use, prenatal injury, brain malformation, or lack of oxygen at birth
• Infectious diseases such as AIDS and meningitis
• Genetic or developmental disorders or neurological diseases

Heredity plays a role in some types of epilepsy. In the general population, there’s a 1 percent chance of developing epilepsy before 20 years of age. If you have a parent whose epilepsy is linked to genetics, that increases your risk to 2 to 5 percent.

Genetics may also make some people more susceptible to seizures from environmental triggers.

Epilepsy can develop at any age. Diagnosis usually occurs in early childhood or after age 60.

DIAGNOSIS:

In order to diagnose epilepsy, other conditions that cause seizures should be ruled out. Your doctor will probably order a complete blood count and chemistry of the blood.

Blood tests may be used to look for:

• signs of infectious diseases
• liver and kidney function
• blood glucose levels

Electroencephalogram (EEG) is the most common test used in diagnosing epilepsy. First, electrodes are attached to your scalp with a paste. It’s a noninvasive, painless test. You may be asked to perform a specific task. In some cases, the test is performed during sleep. The electrodes will record the electrical activity of your brain. Whether you’re having a seizure or not, changes in normal brain wave patterns are common in epilepsy.

Imaging tests can reveal tumors and other abnormalities that can cause seizures. These tests might include:

• CT scan
• MRI
• positron emission tomography (PET)
• single-photon emission computerized tomography

Epilepsy is usually diagnosed if you have seizures for no apparent or reversible reason.

MANAGEMENT:

Most people can manage epilepsy. Your treatment plan will be based on severity of symptoms, your health, and how well you respond to therapy.

Some treatment options include:

• Anti-epileptic (anticonvulsant, antiseizure) drugs: These medications can reduce the number of seizures you have. In some people, they eliminate seizures. To be effective, the medication must be taken exactly as prescribed.
• Vagus nerve stimulator: This device is surgically placed under the skin on the chest and electrically stimulates the nerve that runs through your neck. This can help prevent seizures.
• Ketogenic diet: More than half of people who don’t respond to medication benefit from this high fat, low carbohydrate diet.
• Brain surgery: The area of the brain that causes seizure activity can be removed or altered.

Research into new treatments is ongoing. One treatment that may be available in the future is deep brain stimulation. It’s a procedure in which electrodes are implanted into your brain. Then a generator is implanted in your chest. The generator sends electrical impulses to the brain to help decrease seizures.

Another avenue of research involves a pacemaker-like device. It would check the pattern of brain activity and send an electrical charge or drug to stop a seizure.

Minimally invasive surgeries and radiosurgery are also being investigated.

 

PHARMACOTHERAPY:  The 1^st line treatment of epilepsy or seizure disorder is antiepileptic drugs.

 They work by altering the levels of neurotransmitters present in the brain. People with epilepsy are prescribed antiepileptic medications with the aim of decreasing the number, severity, and/or duration of seizures. While seizure freedom is the ideal outcome of treatment, seizures can still occur while taking antiepileptic medication.

Factors taken into consideration when prescribing antiepileptic medication include the Type of seizure,  age, other medical conditions, findings on an EEG, other medications the child is taking, drug interactions and potential for side effects.

Mechanism of action of antiepileptic drugs:

Normal brain function involves "communication" between millions of nerve cells (neurons). At any one time, there are nerve cells which are resting, exciting or inhibiting other nerve cells. A nerve cell is made up of a cell body and branches called axons and dendrites which join other neurons at junctions called synapses. Electrical signals are sent from the cell body along the axon to the synapse, these electrical signals being the result of ion (sodium, potassium, calcium) currents across channels in the nerve cell membrane. Chemical signals (neurotransmitters) pass across synapses between neurons. Neurotransmitters cross the synaptic gap between neurons and fix to receptor points of the adjoining neuron. Some neurotransmitters function to excite the joining neuron (eg. glutamate) to send a further electrical signal. Other neurotransmitters function to inhibit the joining neuron (eg. GABA) and inhibit electrical signals passing down that neuron. It is by these electrical and chemical pathways that the millions of neurons within the brain communicate and function normally.

Seizures occur when there is an imbalance within these excitatory and inhibitory circuits in the brain, either throughout the brain (generalised epilepsy) or in a localised part of the brain (focal epilepsy), such that neurons "fire off" in an abnormal fashion.

Antiepileptic medications work in different ways to prevent seizures, either by decreasing excitation or enhancing inhibition. Specifically, they act by either:

• Altering electrical activity in neurons by affecting ion (sodium, potassium, calcium, chloride) channels in the cell membrane.
• Altering chemical transmission between neurons by affecting neurotransmitters (GABA, glutamate) in the synapes.
• For some drugs, the mode of action is unknown.

As the specific mechanisms that cause epilepsy are mostly unknown, drugs with specific mechanisms of action directed at the underlying "epileptic processes" have not yet been developed.

 

 

How antiepileptics are prescribed:

The choice of medication and how each is prescribed is a specialist area of paediatrics and child neurology. Prescription of antiepileptic medication is only done by a doctor with knowledge of antiepileptic medication and epilepsy in children. General principles that doctors follow when prescribing antiepileptic medications in children include:

• starting with a low dose and slowly increasing to reach a maintenance dose (this helps to reduce or avoid side effects during the introduction phase and is important for some drugs where there is risk of allergic rash)
• aiming for control of seizures with one antiepileptic medication (monotherapy) where possible
• giving a medication a good trial period to work before changing
• recognising that doses and tolerance of antiepileptic medications vary between individuals
• spacing medication doses appropriately to maintain stable blood levels
• avoiding combinations of antiepileptic medications that are known to not interact well
• slowly withdrawing antiepileptic medications if ceasing treatment, especially the barbituate and benzodiazepine medications

Common antiepileptic medication choices for seizures in children:

Seizure Type	Commonly Prescribed Antiepileptic Medications
Focal Seizures	Carbamazepine, Clobazam, Lamotrigine, Levetiracetam, Oxcarbazepine, Phenytoin, Sodium Valproate, Topiramate, Lacosamide, Zonisamide
Generalised Tonic Clonic Seizures	Carbamazepine, Clobazam, Lamotrigine, Levetiracetam, Oxcarbazepine, Phenytoin, Sodium Valproate, Topiramate, Lacosamide, Zonisamide
Absence Seizures	Ethosuximide, Lamotrigine, Sodium Valproate
Myoclonic, Tonic And Atonic Seizures	Clobazam, Clonazepam,  Lamotrigine, Levetiracetam, Sodium Valproate, Topiramate
Infantile Spasms	Prednisolone, Vigabatrin, Acth, Nitrazepam
Neonatal Seizures	Phenobarbitone, Phenytoin, Clonazepam, Levetiracetam, Topiramate

 

Side effects

All medications have the possibility of causing side effects. There are three main types of antiepileptic medication side effects.

• Some mild side effects are common when starting antiepileptic medications, particularly if the dose is increased rapidly. These include nausea, abdominal pain, dizziness, sleepiness, irritability, anxiety or mood changes. These are usually not serious, but may worry some people and should be discussed with your doctor or pharmacist. Your doctor may slow the rate at which the medication is being introduced or may cut back another antiepileptic medication with which it may be interacting.
• Some side effects are common to antiepileptic medications when prescribed at too great a dose and are similar to being "drunk" eg. unsteadiness, poor concentration, sleepiness, double vision, vomiting, tremor. It is important to report these side effects to your doctor immediately if they occur.
• Some side effects are peculiar to individual medications and only occur in some people eg. rash, blood problems, liver problems, severe behaviour disturbance, worsening of seizure control. There are some patients or situations in which there may be increased risk of such side effects with a certain medication.

Precautions

·         Effects on ability to drive and use machines: Some antiepileptic medications can cause drowsiness, sleepiness, incoordination and slowed reaction time, especially when the medication is being introduced or the dose is being increased. Effects on individuals should be assessed prior to driving or using machinery.

·         Effects when taken with alcohol: If alcohol is taken in combination with antiepileptic medication, extra sedative effects can occur. Also, alcohol increases the likelihood of seizures.