Protecting speech function before operating on a brain tumour
A Guttmann study co-led by a researcher from IRBLleida supports the early use of non-invasive neuromodulation
Non-invasive neuromodulation, based on magnetic fields or low-intensity electrical currents, combined with intensive language training prior to surgery to remove a brain tumour, can promote the reorganisation of the brain networks involved in language without compromising cognitive or linguistic functioning. This has been demonstrated by a study from the Guttmann Research Institute, co-led by Kilian Abellaneda Pérez, a lecturer at the University of Lleida (UdL) and a researcher at IRBLleida.
The research, published in the journal NeuroImage, forms part of the Prehabilita project. This is a scientific initiative promoted and coordinated by Guttmann, funded by the Joan Ribas Araquistain Foundation. Professionals from the Autonomous University of Barcelona, the University of Barcelona, IDIBAPS, the Catholic University of Valencia, the Eugenio Medea Research Institute (Italy) and Harvard Medical School (United States) have also contributed to the study.
The team worked with a sample of 26 patients (10 women and 16 men) with operable brain tumours affecting the language or motor regions. Eleven of the participants received non-invasive neuromodulation targeting the language production network, combining transcranial magnetic or electrical stimulation with intensive language training, including tasks involving semantic fluency, completing incomplete words, and narrating a story in alternating languages (usually Catalan, Spanish and English). Meanwhile, the comparison group underwent non-invasive neuromodulation targeted primarily at the motor networks.
Before and after this pre-rehabilitation, specialist staff assessed them using a neuropsychological battery focusing on the main cognitive and language domains, as well as functional magnetic resonance imaging (fMRI), which makes it possible to identify changes in brain activity and determine which areas of the brain are involved in a specific task.
The assessments covered aspects such as spontaneous speech, verbal repetition of words and reading comprehension. The intervention, based on non-invasive neuromodulation, was then tailored to each individual, comprising between 10 and 20 sessions, each lasting approximately one hour.
"This intervention promotes the topographical reorganisation of brain networks and encourages the activity associated with the at-risk function to reorganise towards regions further away from the area to be operated on," explains Kilian Abellaneda Pérez, a lecturer at the UdL and co-principal investigator on the project. In other words, "targeted neuromodulation helps to promote selective neuroplasticity prior to surgery and constitutes a safe pre-operative strategy", he adds.
'This method may reduce the constraints in neurosurgery and allow for more extensive and safer resections in patients with tumours affecting regions critical for language,' concludes Abellaneda.
The study also found that, in most participants, prehabilitation reduced language-related activation within the affected hemisphere. "However, the brain did not reorganise itself in the same way across the board: in some cases, the changes occurred within the same hemisphere, and in others, towards the opposite hemisphere," explains Nuria Brault-Boixader, a researcher at the Guttmann Research Institute and the article's lead author. She emphasises that this "reinforces the need to personalise prehabilitation".
The team notes that these findings will help to deepen our understanding of neuroplasticity and optimise non-invasive prehabilitation strategies in neurosurgery. However, future research will need to determine how language networks are restructured in the long term and how these functional changes are maintained following surgery.
Furthermore, the research team emphasises that this knowledge could open up new avenues for applying prehabilitation to other cognitive domains, as well as to other neurosurgical procedures.
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Text: Press UdL
Image from the study on how the brain changes
