According to an investigation led by Dr. Thomas Blauwblomme and his team of Great Ormond Street Hospital, London, in the December issue of Operative Neurosurgery, a quarterly supplement to Neurosurgery, official journal of the Congress of Neurological Surgeons, almost half of all children suffering with severe epilepsy who receive invasive electroencephalography (EEG) recordings, experience some type of side effect.
The study reveals that no other method can obtain the vital information needed for planning complicated epilepsy procedures that EEG recordings provide.
Risks of Invasive EEG in Children?
The team examined side effects associated to invasive EEG recordings in 95 children between 1994 and 2009. The majority of epilepsy cases in children can be controlled with drugs, although surgery is highly effective when medications are not successful. In order to plan the surgery, surgeons need accurate information on the region of the brain which controls seizure activity.
EEG recordings are required in some complex cases to gather this information. EEG recordings use electrodes placed on the brain surface or into the brain tissues. The novel investigation set out to obtain detailed information regarding the risks connected with EEG recordings. In the study the children had extremely severe epilepsy, averaging over 200 seizures per month. The average age of the children was around 11 years.
The researchers discovered that in total, nearly half of the children (49%) experienced some form of side effect. Approximately 30% of children had more severe events that increased the time they were hospitalized. None of the adverse events caused permanent neurological damage or death.
Side effects included:
- Infection – 15%
- Brain swelling – 6%
- Bleeding – 17%
- Cerebrospinal fluid leakage – 11%
In most of the children who experienced bleeding and in some of those with infection, further surgery was required. After surgeons began using a novel type of graft material in 2002, no further problems with CSF leakage were reported.
Brain swelling was more prevalent among older children, while the complication rate was lower (20%) in children under the age of 2. Length of EEG recording, or if recordings used electrodes on the surface or implanted in the brain, was not associated with the risk of side effects.
In 69% of patients, EEG recordings successfully recorded the location of the seizure zone in brain activity during seizures. In total, 89% of children received surgery for epilepsy. The success rate of surgery was highest the more precise the invasive EEG recordings were in localizing the seizure zone.
The investigation notes the considerable risk of side effects associated to EEG recordings in children with the condition. Although the EEG is invasive, it provides “invaluable information” for locating the source of seizure activity within the brain.
The team highlight the relatively low risk of adverse events in children under 2 years – which adds to recent evidence backing early surgery for children with epilepsy that doesn’t respond to drugs.
Dr. Blauwblomme and coauthors explain:
“For all children undergoing invasive EEG recordings, parents should receive detailed information on the risks and benefits of the procedure.”
In addition, the researchers stress that the surgery should be performed at a treatment center with experience in invasive EEG recording, with cautious planning prior to the procedure and close patient follow-up afterward.
Source: Medical News Today
