Essential Tremor – why MRgFUS is performed while patients are awake

MR-guided Focused Ultrasound (MRgFUS) – a non-invasive brain procedure performed while the patient is fully awake – recently caught public attention after Julian Fellowes, writer and creator of Downton Abbey, shared his experience of undergoing MRgFUS, telling The Times “it was one of those terrifying procedures where you’re kept awake the whole time.” His candid comments have sparked interest and raised important questions about how and why such advanced procedures are done without general anaesthesia.

Mr Harith Akram, a consultant neurosurgeon and part of the world-leading team for the procedure at Queen Square Imaging Centre (a not-for-profit organisation), explains why patients need to be awake during MRgFUS.

Why are patients kept awake during MRgFUS?
It’s a valid concern, especially for those undergoing treatment for conditions like essential tremor or Parkinson’s disease. However, according to Mr Akram, the answer lies in the unique way the procedure works – combining real-time monitoring, precision targeting and patient safety.

Real-time monitoring for maximum accuracy
Unlike traditional surgical interventions, MRgFUS is a non-invasive procedure that uses focused ultrasound waves to target specific areas of the brain responsible for tremor. The key to its effectiveness is precision – and that precision depends heavily on patient feedback during the procedure.

“The initial stage involves applying low levels of focused ultrasound energy to temporarily ‘stun’ the neurons in the target area,” explains Mr Akram. “This helps us to assess two crucial factors – whether the tremor improves, and whether there are any side effects such as tingling, speech changes or muscle weakness.”

Because the effects at this stage are reversible, clinicians can fine-tune the targeting based on the patient’s responses. Only when the desired effect is achieved without side effects is the full therapeutic dose delivered, creating a permanent impact. This step-by-step approach makes the procedure both safer and more effective.

Avoiding the risks of anaesthesia
Another important reason for keeping patients awake is to avoid the risks associated with general anaesthesia inside an MRI scanner.

“Administering anaesthesia within the MRI environment introduces unnecessary complexity and potential risks,” says Mr Akram. “By having patients awake, we can continuously monitor their neurological status and make real-time decisions, all while avoiding the complications of sedation.”
This awake protocol not only enhances safety but also enables a more personalised, responsive treatment.

What can patients expect while undergoing MRgFUS?
Understandably, patients may feel apprehensive about being conscious during a brain procedure. But Mr Akram reassures them that the experience is usually well tolerated.

“The brain itself doesn’t have pain receptors, so while patients may feel pressure from the head frame or hear noises from the MRI scanner, they do not experience pain in the brain itself,” he explains. “We also provide pain relief and anti-sickness medication beforehand to ensure maximum comfort.”

Throughout the procedure, a dedicated clinical team is present to offer reassurance and monitor the patient closely, ensuring they feel supported at every stage.

A patient-centred approach
Being awake during MRgFUS is not just a technical requirement – it is central to the procedure’s success. Patient feedback enables a level of tailoring and precision that would be impossible under general anaesthesia.

“Once patients understand the rationale, most feel reassured and even empowered by their role in guiding the treatment,” Mr Akram adds.