There’s been huge progress in brain imaging and electrophysiology – our understanding of the electricity within our bodies – so why not use this information to improve brain surgery?
- Yaara Erez
Patients with low-grade gliomas in their brains – a slow-spreading, but potentially life-threatening tumour – will usually receive surgery to have the tumour removed. But removing brain tissue can be risky as there is no boundary between the brain and tumour – the tumour infiltrates the brain. Removal of tumour can lead to removal of vital parts of the brain and resulting impairments in functions such as speech, movement and executive function (which enables the individual to plan, organise and execute tasks).
To minimise this risk, neurosurgeons open the patient’s skull and then waken them. A local anaesthetic means the patient will feel no pain, and the brain itself contains no pain receptors. The surgeon will probe the patient’s brain, applying mild electric pulses to tissue surrounding the tumour while asking them to perform a set of tasks. For example, the patient may be asked to count from one to five: if an electric pulse applied to a certain place in the brain affects their ability to perform this task, the surgeon will leave this tissue in place.
“As surgeons, we’re always trying to minimise the risk to patients and provide them with the best possible outcomes,” says Thomas Santarius, a neurosurgeon at Addenbrooke’s, Cambridge University Hospitals. “Operating on brain tumours is always a delicate balance between removing as much diseased tissue as possible to give patients better prognosis, while minimising the risk of damage to brain functions that will have a potentially massively detrimental impact on the patient’s life.”
While the current approach is considered the ‘gold standard’, it is not perfect. It takes time to apply the pulses on different parts of the brain and it may miss out some areas that are important for certain functions. The current battery of cognitive tests that surgeons use is also limited and does not test for the essential executive function, for example.
Now, a team of scientists and clinicians from the University of Cambridge and Addenbrooke's Hospital, led by Mr Santarius, Dr Yaara Erez and Mr Michael Hart, together with Pedro Coelho from Neurophys Ltd, has collaborated to develop a new approach that will enable patients to get a more accurate, personalised ‘read-out’ of their brain networks, and will provide surgeons with real-time feedback on the patient’s brain activity in theatre.
Image: Brains
Credit: Kai Schreiber
Reproduced courtesy of the University of Cambridge