NEURO NEWS

A 13 year-old Somerset boy with severe epilepsy has become the first patient in the world to trial a new device fitted in the skull to control seizures. The neurostimulator, which sends electrical signals deep into his brain, has reduced Oran Knowlson’s daytime seizures by 80%.

The surgery was carried out in October as part of a trial at Great Ormond Street Hospital in London. Oran has Lennox-Gastaut syndrome, a treatment-resistant form of epilepsy which he developed at the age of three. Since then he has suffered several daily seizures ranging from two dozen to hundreds.

His mother, Justine, says Oran’s epilepsy dominated his life and has robbed him of his childhood. He had a range of different seizures, including those where he fell to the ground, shook violently, and lost consciousness. At times he would stop breathing and require emergency medication to resuscitate him.

Oran is also autistic and has ADHD, but Justine says his epilepsy is by far the biggest hurdle: "I had a fairly bright three-year-old, and within a few months of his seizures commencing he deteriorated rapidly, and lost a lot of skills."

Oran is part of the CADET project, a series of trials assessing the safety and effectiveness of deep brain stimulation for severe epilepsy. The partnership involves Great Ormond Street Hospital, University College London, King’s College Hospital and the University of Oxford.

The Picostim neurotransmitter is made by UK company Amber Therapeutics. The device, which emits a constant pulse of current, aims to block or disrupt the abnormal bursts of electrical activity in the brain that cause epilepsy seizures.

The surgical team, led by consultant paediatric neurosurgeon Martin Tisdall, inserted two electrodes deep into Oran’s brain until they reached the thalamus, a key relay station for neuronal information. The margin of error for the lead placement was less than a millimetre.

The ends of the leads were connected to the neurostimulator, a 3.5cm square and 0.6cm thick device which was placed in a gap in Oran’s skull where the bone had been removed. The neurostimulator was then screwed into the surrounding skull, to anchor it in place.

Deep brain stimulation has been tried before for childhood epilepsy, but until now neurostimulators were placed in the chest, with wires running up to the brain. Oran was given a month to recover from the operation before the neurostimulator was turned on.

When it is on, Oran cannot feel it. He can recharge the device every day via wireless headphones, while getting on with things that he enjoys, like watching TV. His mother says there has been a massive improvement: "He is more alert and with no drop seizures during the day. His night-time seizures are also shorter and less severe. I'm definitely getting him back slowly."

Currently, Oran gets a constant electrical stimulus from his device but, in future, the team plan to make the neurostimulator respond in real time to changes in his brain activity, in an attempt to block seizures as they are about to happen.

As part of the trial, three more children with Lennox-Gastaut syndrome will be fitted with the deep brain neurostimulator. The Picostim neurostimulator has also been used to treat patients with Parkinson’s disease.