In 2019, neurologists can expect to see better neuroimaging techniques for stroke, non-invasive treatments for Parkinsons’s disease, the first new class of drugs for migraine in many years, and re-purposing of old epilepsy drugs for improved outcomes in seizures. Speaking to the limbic, Dr Andrew Evans, head of the Movement Disorder Service at the Royal Melbourne Hospital and a consultant neurologist with Epworth Hospitals, gave us his predictions of what the big issues for neurologists will be in 2019.
New neuroimaging techniques have identified more people who can be treated in a longer window of time after a stroke.
Several Australian studies in recent years have increased understanding of the mechanisms of stroke, showing it is preferable to treat a large artery occlusion with intravenous thrombolysis and convert to thrombectomy, says Dr Evans. Since then, two pivotal publications in the NEMJ in 2018 have changed the simplistic view that treatment within 4.5 hours of an event provides the most optimum results.
One, by Albers and colleagues concluded: “Endovascular thrombectomy for ischemic stroke 6 to 16 hours after a patient was last known to be well plus standard medical therapy resulted in better functional outcomes than standard medical therapy alone among patients with proximal middle-cerebral-artery or internal-carotid-artery occlusion and a region of tissue that was ischemic but not yet infarcted.”
The second paper by DAWN trial investigators also supported late thrombectomy plus standard care among patients who had last been known to be well up to a full day earlier.
“New perfusion CT scans can now identify individuals with an ischaemic core and who have large vessel occlusions and potentially treat them up to 24 hours after a stroke,” said Dr Evans. This was particularly important for that sub-group of patients who wake with stroke symptoms with actual stroke onset time unknown.
While device-aided therapies have significantly improved in recent years, and there is now better access to a range of infusion therapies that allow patients to be treated with continuous dopaminergic stimulation, the biggest advance in this incurable disease is in deep brain stimulation.
“In the last year or so we have now directional electrodes that allow us to shape the direction of the stimulation to optimise the benefits of the treatment, minimise side effects and also save battery life,” Dr Evans said.
Dr Stephen Tisch, a neurologist at Sydney’s St Vincent’s Hospital, was the first to recently utilise focussed-ultrasound therapy for tremor treatment. Rather than implanting an electrode to stimulate a particular area of the brain, more use is expected of new state-of-the-art, non-invasive Magnetic Resonance Thermography.
This allows the area of the brain to be targeted “very, very carefully” by the ultrasound beam so a lesion can be created to deactivate a particular tremor – all while the patient remains conscious in the MR scanner.
“The big news really for migraine is the development of a new class of therapies that are effective, particularly for chronic migraine but also potentially acute migraine.” Dr Evans said they evolved out of a targeted research program, led to a large extent by Australian neurologist, Professor Peter Goadsby, in London.
Several pharmaceutical companies have developed a class of biologic agents that inhibit the Calcitonin Gene Related Peptide (CGRP) or block the receptor. One of these CGRP inhibitors, erenumab (Aimovig), has been approved by the TGA, and [PBS] pricing negotiations are continuing over what is estimated to be a cost of up to $800 per month.
Without the unpleasant side effects of current migraine therapies that include antiepileptic medications, Dr Evans said CGRP inhibitors evolved out of research that looked at the neurobiology of migraine, initially identified in an MRI scanner. “They’re very well tolerated, it’s a once-a-month injection and they reduce the frequency and the severity of migraine.”
The cost of either whole-exome or whole-genome sequencing is coming down and will soon become “nearly routine practice”, particularly with childhood-onset epilepsy, according to Dr Evans.
Therapeutics-wise, Dr Mark Cook, chair of medicine at St Vincent’s Hospital, Melbourne, has had some early success in several individuals with direct infusion into or around the brain via a custom-made device of the old antiepileptic drug, valproate. Continued success, if it occurs, “may allow us to improve the efficacy of these drugs and reduce the side effects” from whole body treatment.