How AI is changing the diagnostic game of stroke

Dr Jayesh Sardhara, Senior Consultant - Neuro & Spine Surgery, Fortis Hospitals Mumbai, spoke to THE WEEK about how AI imaging tools can help diagnose stroke during the “golden window”. He also touched upon how tele-neurology can increase access to quality of care for patients in remote areas. Here is the full excerpt

How are AI-powered imaging tools transforming the speed and accuracy of stroke diagnosis in emergency settings?

A stroke is quite simply defined as the loss of blood supply or perfusion to the brain suddenly. The cause is generally, and acutely, the result of a blockage, due to a clot within a blood vessel. When a stroke happens, the patient has immediately some weakness. There is an essential time period known as the "golden window" which are the first three hours after a stroke. We need to quickly intervene with using thrombolysis to dissolve the clot or surgical intervention to physically remove it. Why are these three hours important? Because every second that ticks away, millions of neurons are dying due to a lack of perfusion, and literally a race against time to save the patient. Early diagnosis is the most critical step to the process. Here is where the role of AI comes in. In either CT imaging or MRI imaging, AI will be capable of detecting gross differences in grey and white matter, any subtle differences in colour. AI will find perfusion deficits in a matter of seconds, and in fact AI assisted imaging tools are changing the diagnostic game of stroke due to the speed of accurately diagnosing a stroke. In addition, AI enabled imaging through teletherapy through telehealth or direct access offer opportunities to apply AI based technologies allowing specialists to diagnose strokes hundreds of miles away, is a major option that can enable local first responders to effectively implement acute treatment even in the most remote settings.

Can wearables today detect early signs of mini-strokes (TIAs) or atrial fibrillation before a major stroke hits?

To a certain degree, yes. There are a lot of tools such as smartwatches that can provide a lot of information about the pulse beyond just counting it. They can evaluate the rhythm, regularity, frequency, and overall quality of the pulse. Atrial fibrillation (AF) does in fact, often precede stroke, and while one can be seeing AF on wearables, the wearable detection of AF is still being defined/researched in terms of stroke risk. So while it is not fully established, wearables can be helpful in identifying irregular heart rhythms and then getting people in for a timely medical assessment that could prevent a major event.

What’s the potential of brain-computer interfaces or neurostimulation in helping stroke survivors regain motor or cognitive functions?

These devices are exceptionally useful. A brain computer interface/brain machine interface works by providing stimulation to the motor cortex which provides the signal to the peripheral body (like the hand) to move. If a patient has a stroke that affected their right motor cortex, their left hand and leg can be non-functional. With brain computer interfaces and neurostimulation, we can work to stimulate the neurons around this area. There are many techniques but one of the most used is Transcranial Magnetic Stimulation (TMS), where we stimulate the brain's motor cortex with the hope this could help the tissues drive neuroplasticity or to prompt the potential new neural connections. Research shows that from these techniques some motor and cognitive functions could be regained through stimulation of regeneration and improving the performance of some of the surrounding healthy neurons.

Are virtual reality neuro-rehab platforms showing measurable outcomes in stroke recovery?

Absolutely, yes. The application of Virtual Reality (VR) is showing to be a very effective modality for stroke rehabilitation. A traditional rehab activity includes repetitive activities like moving a paralyzed hand or leg for hundreds of repetitions throughout the day. And this could be boring and demotivating. VR changes all of that and takes these exercises and makes them really entertaining and enjoyable. For example, a patient could be virtually kayaking down a river, catching paper butterflies that are flying in the park, or climbing a mountain. While the patient is performing these activities, they are likely to perform the movement with more engagement and greater repetitions during these activities or let’s say an adventure. VR allows for consistent and meaningful movements which improve limb strength and ultimately provides a catalyst for recovery. VR is not intended to replace the standard therapy that is the central intervention for stroke rehabilitation. However, many patients find VR to be a great complement to their therapy. VR can provide motivation and measurable increases of progress along their recovery journey.

With rapid advancements in tele-neurology, can rural stroke patients now expect the same quality of care as those in metros?

It is somewhat accurate. In tele-neurology, a metro city neurosurgeon can assist a stroke patient in rural villages, such as Sangli - after which he or she may get off a tele-call. For example, when a stroke patient receives a CT scan at a local facility, that scan can (and will) be immediately shared with a neurologist in another city on electronic mail or tele-communicating software, upon the patient's arrival. With a video-conferencing consultation, specialists can instruct the local medical team on administering clot-busting medications or provide guidance during an emergency patient care transfer – and all of this happens while we still have time left during the golden three-hour window. New mobile stroke units with CT scanners in them are becoming newly developed to provide diagnosis and begin treatment before even reaching the patient in the hospital. While this is not the routine care yet in developing countries because of financial or resource limitations, tele-neurology presents a good sense of where this type of care is going. Tele-neurology is going to greatly increase access to quality of care while also reducing post-stroke disabilities.