Epilepsy

Epilepsy


Myths and Misconceptions

Taken from a lecture given by Dr Romi Saha, given to Epilepsy Action Patient Support Group in 2007:

There are many causes of loss of consciousness, epilepsy is just one:

Some studies estimate the mis-diagnosis rate of epilepsy to be as high as 20%. The most common cause of loss of consciousness is faints. It is not uncommon after a faint to have a few jerks and twitches and sometimes even urine incontinence and such patients may be erroneously given a diagnosis of epilepsy.

Given the major implications of the diagnosis of epilepsy, I believe that epilepsy should only be diagnosed by someone who is experienced in looking after such patients. In my opinion the diagnosis of epilepsy should be made after carefully considering other potential causes of loss of consciousness or blackouts, as some of these may also be potentially quite serious. Disorders causing blackouts may include cardiac disorders, blood pressure abnormalities, a result of certain drugs or alcohol and metabolic disorders such as diabetes to name but a few.

Epilepsy may present in unusual fashions as described below:

Epileptic attacks may occur during sleep and be confused with sleep disorders. Other attacks may result in abnormal perceptions or thoughts or cause periods of abnormal behaviour, memory loss or visual/olfactory hallucinations without manifesting with generalised body shaking or twitching. Some patients with epilepsy do not lose consciousness, but describe focal sensations or twitches affecting an isolated body part. In others the attack may start in one body region and spread to the other. Even when you lose consciousness, some patients may not jerk but there may be stiffening or posturing/head/eye turning, grimacing or even fiddling or cycling type movements of the hands and legs respectively. Some patients may just drift off for a few seconds and appear as if they are daydreaming, others may have brief electronic shock like jerks.

Epilepsy is a clinical diagnosis based on a description of the attack by reliable witnesses and supported by clinical investigations:

Unfortunately many patients with epilepsy are unable to recall details of the attack itself (but they may recall symptoms prior to the attack) and they may be confused and/or amnesic after the event. It is vital when a diagnosis of epilepsy is being considered that you bring along someone who witnessed at least one or more of the attacks. The most important single factor in coming to a robust diagnosis of epilepsy is a clear history of the event itself, rather than relying on the results from any tests.

A normal EEG does not mean that you do not have epilepsy and why a scan may be helpful:

Apart from blood tests and cardiac tests, patients with a suspected diagnosis of epilepsy may undergo brain scans and/or a test known as an EEG or electroencephalogram. The brain scan is not a test that will diagnose epilepsy in itself. It is used where the diagnosis of epilepsy is suspected and there is concern that the seizures are arising from a structural abnormality within the brain. In this case usually a MRI head scan is preferred to a CT head. The exception to this is patients presenting to casualty departments where a head injury or intracerebral bleed is suspected as the cause of the seizures, in which case a CT head may be preferred.

The EEG is extremely helpful in paediatric patients as it can be used to determine the type of epilepsy and the prognosis and need for medications. In adult neurological practice the EEG has a few more limitations. In practice patients rarely suffer from seizures whilst EEG is being recorded and what one is looking for is subtle abnormalities in background ‘brain wave activity’ which may give a clue to the sort of seizure type the patient has. However many adult patients with epilepsy have normal background brain wave activity in between the attacks so a normal EEG cannot be used to exclude the diagnosis. The longer the EEG recording the more likely an abnormality will be detected. One can enhance the results of the EEG by performing certain procedures – for example an EEG recording whilst the patient is transitioning from sleep to wake, or when the patient is sleep deprived with just 4 hours of sleep, or doing provocation procedures such as hyperventilation or exposure to flashing lights.

Driving and loss of consciousness:

The DVLA is concerned about any loss of awareness that may impede your ability to operate a motor vehicle. Given epilepsy is just one of the disorders that may cause loss of consciousness (see above) the fact that you are not diagnosed with epilepsy will not automatically entitle you to retain your driving licence.

The DVLA accepts that it may be difficult in some cases to determine what the exact cause of loss of awareness is and the decision to drive will then be made on the likelihood of further attacks occurring behind the wheel of the car. This may take into account factors such as the time when the attacks occur (for example if they are always in sleep), factors that may provoke the attacks (and whether these factors would be avoidable in future), the position in which the attacks occur (eg the possibility that they will occur whilst seated), and the results of any tests performed (for example any cardiac or brain scan or EEG abnormalities). Usually the DVLA will ask for a medical report from your Hospital Specialist and you may not be able to drive during this period of assessment.

If you have epilepsy the DVLA will not usually make an exception for type of seizures you have. They will count any (even partial loss of awareness) as a seizure as it is argued that even a momentary loss of awareness (such as in an absence attack) will pose a risk whilst driving.

After a first or isolated seizure, you are not usually diagnosed with epilepsy providing your tests/investigations are normal and in this situation it may be possible to return to driving 6 months following the date of that isolated event. But even if you have more than one seizure and are diagnosed with epilepsy, this may not be a bar to driving in the future. If it is possible to demonstrate that your last seizure was over 1 year ago (with or without medication) then the driving licence may be reinstated subject to periodic reviews confirming that you remain seizure free.

There are also guidelines produced by the DVLA with regards to coming off anti-epileptic medication, usually whilst the medication is being titrated down (this often has to be done slowly) and for a period of up to 6 months afterwards you are asked to exercise caution whilst driving but individual cases may vary.

You can find out more information about epilepsy and driving from the Quick Links webpage.

There is no first choice medication that is suitable for all patients:

Epilepsy is an area of considerable ongoing medical progress and almost every year there are new anti-convulsant medications that become available. However, as a general rule there is little evidence that any of these newer drugs are more potent at controlling epilepsy than the drugs we already have available. But the newer drugs may offer advantages in other ways, for example in the frequency of doses, speed of action, fewer or different side effects.

NICE has produced guidelines on the use of anticonvulsant medications (see quick links web page) and it is clear that the choice of anti-convulsant therapy has to be tailored to the individual, taking into account the age of the patient, type of epilepsy, other medications taken, pregnancy risk, planned or otherwise, presence of learning difficulty or psychiatric problems, other co-morbid medical conditions, weight and body mass index, likelihood of adherence to medication regime to name just a few!

In my opinion, except in emergencies, the choice of anti-convulsant medications should be made by a specialist and patients should be involved in the decision making process.

There is no easy answer to how long you may require medication for:

It is important to realise that the medications may control seizures but are not a cure; if the medications are stopped there is a risk in some patients of the seizures returning. The length of time an individual needs to take medication is a difficult decision, depending not only on the type of epilepsy but also taking into account individual factors – for example the wish to fall pregnant or the consequences of future seizures (such as difficulties with childcare, loss of driving licence, hobbies, occupation or threat to livelihood). For every patient there needs to be a careful risk/benefit analysis, taking into account not just the individual risks of stopping medications but also the risks of staying on medications (medication side effects). As a rough rule of thumb, I re-assess the need for continuing medications once patients have been completely seizure free for 3-5 years.

Seizures carry risks:

There are risks of coming to harm during a seizure not only from accidents and drowning but also from other mechanisms. It is thought for some patients that during a seizure there are irregularities in their heart rate and respiration and there may also be a risk of choking.

The risk of coming to harm during a seizure will depend again not just on the seizure type but also individual factors – for example the amount of warning you have before a seizure and whether it is possible to get to a safe place, the frequency of the seizures, whether the seizures are prolonged, whether they occur during sleep, whether you live alone, other medical factors such as age, other co-morbid medical conditions, medication taken, drugs and alcohol misuse to name but a few.

If you suffer from epilepsy there are sensible precautions that can be taken with regards to hobbies and lifestyle – for example with regards to swimming and bathing, operating machinery, the environment you work in (working at heights) are just some of the situations where someone with uncontrolled epilepsy may come to harm.

It is important that medication prescribed is taken in a reliable fashion and that you are seen periodically by a Medical Professional with experience in looking after epilepsy patients.

I work closely with an Epilepsy Nurse Specialist who is able to provide ongoing support, advice and monitoring for my patients.

We (myself or more often our highly experienced Epilepsy Nurse) are now routinely discussing with patients the risk of SUDEP (sudden unexplained death in epilepsy); though this will normally not be done in the first consultation and will be done in a time and manner to suit the individual patient. Although in absolute terms the risk is small (<1% per year), the patients at highest risk of SUDEP are felt to be those that suffer from frequent generalised convulsive seizures at night, who live alone, have difficulty taking medication as prescribed and where there is a history of cardiac/respiratory disorders or alcohol/substance misuse. Younger men are thought to be at a slightly higher risk but it can occur in anyone and is not predictable.

What local epilepsy services are available?

My practice is based around the Regional Neuroscience Centre at Hurstwood Park on the Princess Royal Hospital site at Haywards Heath. I have access to a full range of diagnostic investigations including EEG, MRI, cardiac tests as well as inpatient video-telemetry at Hurstwood Park Neurological Unit.

Patients are given a diagnosis of epilepsy by a Consultant Neurologist and are offered regular follow up appointments either by the Consultant or the Epilepsy Specialist Nurse who has been looking after my patients with epilepsy for a considerable number of years. She is able to see patients in side-by-side clinics working next door to myself at the Royal Sussex County Hospital, Brighton.

We are currently unable to offer highly specialised neurosurgical procedures for the control of epilepsy, but as a result of my previous training I have maintained links with the Epilepsy Centres at both King’s College Hospital, London, as well as the National Hospital for Neurology and the Epilepsy Centre at Chalfont. Locally we have also taken steps to improve the services for patients with complex epilepsy and are endeavouring to see patients promptly after a first fit. To this end we have appointed an NHS Consultant with a specialist interest in epilepsy, Dr Julia Aram.

I am also committed to improving the quality of care for patients with epilepsy and regularly lecture GPs and Patient Support Groups on the subject of epilepsy and was responsible for medical student training at Brighton and Sussex Medical School (BSMS).

For more information epilepsy see my Quick Links webpage

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