Epilepsy

Epilepsy is by definition a pattern of recurrent seizures (at least two or more) though sometimes it is appropriate to prevent further seizures after only one has occurred. In epileptic seizures there is a pattern of abnormal electrical activity in the brain, and the tendency to such electrical disturbance can be caused by genetic factors or environmental factors or both. For example, the most common cause of seizures arising from the temporal lobes is hippocampal sclerosis, in other words a scar in the hippocampus on one side of the brain, but whilst this is usually thought to be caused by a febrile convulsion after the child develops a high temperature, most children who have a febrile convulsion don't develop such a scar and the tendency to do so can run in families.

Some attack disorders look like epilepsy but are not, and these require a careful diagnostic workup and then appropriate management planning, since they can be quite as disruptive as epilepsy. Some of these are due to cardiac or other physical causes and others seem to be a kind of stress reaction though again there must be some other factor causing the individual to have this rather than some other response to stress and recent theories propose abnormal frontal lobe functioning. For further information see non-epileptic attacks.

Epilepsy can usually be controlled by the range of modern anticonvulsant medications, often in combination. Sometimes it cannot and surgery to remove the scar or other abnormal brain area can be very successful. Again, careful evaluation is necessary to ensure the operation is likely to work and unlikely to cause unacceptable side effects. Most New Zealand epilepsy patients undergoing surgery for their condition are operated on at Auckland City Hospital, the neurosurgeon usually being Edward Mee, but sometimes if the workup process is very technically demanding patients will be sent to Australia (often the Austin Hospital in Melbourne).

People with epilepsy are at risk for psychological difficulties both because of the unpleasant nature of the disorder, social effects such as stigmatisation, unemployment and financial hardship, and the biological aspects of their condition such as abnormal brain structure and function. It is relatively common to see fluctuating mild depressive symptoms that can still impact on function and quality of life (Dysthymic Disorder on DSM-IV, or what Dietrich Blumer in Memphis calls the Interictal Dysphoric Disorder), more serious depression (Major Depression) which is of concern as many epilepsy patients have stockpiles of toxic medications to overdose with, and occasionally people develop a psychotic disorder with beliefs that others eg neighbours are plotting against them, unusual religious beliefs, and so on. Sometimes psychosis can arise temporarily after a cluster of seizures, the so called post ictal psychosis, and if this is repeated then a long term psychotic disorder, interictal psychosis, can develop. These disorders are treatable but all the commonly used antidepressants and antipsychotics can increase the seizure frequency so its best for your doctor to have some advice from an epilepsy specialist before prescribing such medication. Often simply improving sleep with a medication such as lorazepam or clonazepam can be sufficient, and since these have anticonvulsant properties there is no risk of making the epilepsy worse.

Mental disorders can disrupt recovery from epilepsy surgery, even if the individual is now seizure free. The group at Auckland Hospital are doing some research on this and recently presented some results at the RANZCP college congress in Christchurch in 2004. The abstract will be available here shortly.

Suggested Reading

Journals: Epilepsia; Seizure; Epilepsy & Behaviour

Books: