Brain–computer interfaces: A spark of hope for brain disease patients

Taking a cocktail of medicines to slow the brain’s deterioration while slowly losing the ability to remember, walk, and speak, until they are trapped in isolation despite the presence of loved ones. This is the reality of millions of Americans affected by neurodegenerative diseases, and scientists are yet to find cures. 

While many treatments exist to help manage and slow symptoms, their effectiveness is limited. However, as our computers and our understanding of neuroscience evolve, brain–computer interfaces (BCIs) may provide a more promising method of helping patients stay connected to their lives and families as we continue searching for definite cures.

To understand the role of BCIs in treatments, it is important to understand how they work. The brain consists of a neuronal network that fires electrical signals called action potentials. These action potentials are carried by the wire–like part of a neuron called an axon. Similar to wires being insulated with rubber, axons are insulated with a fatty substance called a myelin sheath that prevents most of the action potential from escaping during its journey. The tiny voltage that slips through the cracks is what an EEG captures. It then amplifies and filters the signal before passing it on to the BCI for processing. 

Once the scientist operating the computer “translates” the neural signals, they can calibrate them to a device that looks for neural input so that the patient can move a prosthetic or spell out words on a screen by simply thinking about it. The latter was achieved in 2024 at the BrainGate clinical trial, where scientists helped an ALS patient speak by implanting a BCI and connecting the electrodes to the brain region responsible for coordinating speech. They recorded the neural activity from this region and translated those patterns into phonemes to decipher his speech. Within two days, the BCI achieved 90.2% accuracy using a 125,000 word vocabulary, which is a much higher accuracy rate than most smartphone apps, assistive devices, and eye–gaze trackers that serve a similar purpose.

Since being unable to communicate increases risk of depression and isolation in patients, communication is a crucial part in maintaining quality of life and willingness to continue treatment. Another application utilizing neural output was tested in a study done by researchers at Università di Roma, which targeted patients with spinal muscular atrophy type II (SMA2) or Duchenne muscular dystrophy (DMD) who had limited ability to use manual controls, like a joystick or mouse. In this study, the patients were trained to command a control system including an ECG–based BCI. The patients learned to conjure motor imagery such that the BCI could detect two main states: imagery and rest. Using the signals sent during the patients’ imagery state, the BCIs operated appliances like TVs, wireless cameras, and alarms. By the end of the study, the patients maintained a solid amount of control over the system.

“…communication is a crucial part in maintaining quality of life and willingness to continue treatment.”

Unfortunately, there are significant barriers preventing the general population from accessing BCIs. Some BCIs, which require implants for more accurate readings, are more invasive than the ones that simply connect to the brain using EEGs. The surgery for BCI implants is expensive, and patients must meet certain requirements to be eligible. The patient’s privacy also matters — recording their brain activity reveals personal information to the scientists operating the BCIs, raising ethical concerns. Finally, despite the promising nature of the few studies done on the possible BCI–based treatment options for SMAII and DMD patients, there is a significant research gap in this topic.

With more time and research, perhaps we can find better ways to connect patients to their lives and families. After all, the first computers were just as inaccessible to the public before they became more durable and easy to use. Neurotechnology might be the next step in improving patients’ quality of life.