Neuro Rehab, the UK's leading event for rehabilitation professionals, brings you the latest research findings from studies conducted around the world. These studies explore various pioneering treatments for patients affected by neurological conditions or injuries, and potential new ways of improving diagnosis and long-term outcomes.
Traumatic Brain Injury: Blood protein linked to lower risk of depression and PTSD after TBI
Scientists in the US have identified an antibody that could make people more resistant to depression and post-traumatic stress disorder (PTSD) following traumatic brain injury (TBI).
The study, conducted on U.S. Marines, discovered that natural anti-NMDARL, an antibody known to be involved in a rare brain disease called anti-NMDAR encephalitis, may serve a protective role in the brain.
The researchers, based at the University of California San Diego School of Medicine, analysed blood samples and clinical psychiatric assessments collected from 1,025 Marines before and after a seven-month combat deployment to Afghanistan between 2011 and 2013.
They found that among participants with a lifetime history of TBI, those in the top quarter for natural anti-NMDAR1 antibody levels had about 25% lower depression symptom scores and 22% lower PTSD symptom scores after deployment than those with lower levels.
These participants were also significantly less likely to report moderate-to-severe depression, and they used fewer psychiatric medications after returning from deployment.
No association was found between anti-NMDAR1 levels and anxiety, suggesting that these antibodies are associated with specific kinds of psychiatric symptoms.
The analysis was part of the Marine Resiliency Study II, a long-term research project investigating the factors that contribute to heightened risk for, or resilience to, PTSD.
Every year, an estimated 20 million people worldwide sustain a concussion or other TBI, which leads to a two- to four-fold increase in the risk of depression, anxiety and post-traumatic stress disorder, according to the researchers.
"We were excited to find that a naturally-occurring immune marker could act almost like a built-in protective factor against some of the most disabling consequences of brain injury,” said co-senior author Victoria B. Risbrough.
“If we can understand how these antibodies work, it may open a new path toward identifying who is most at risk after a TBI, and eventually, toward new ways to intervene."
Stroke: Study finds long-term benefits of stroke thrombectomy
A one-year follow-up analysis of a landmark clinical trial suggests that patients with severe strokes experienced better long-term outcomes after undergoing endovascular thrombectomy compared with medical management alone.
The study, conducted by researchers at Northwestern Medicine in Illinois, evaluated ischemic stroke patients presenting with large-core infarcts, meaning a significant amount of brain tissue had suffered damage.
These patients are historically considered less likely to benefit from mechanical clot removal because of the amount of brain damage that has already occurred by the time treatment begins, according to Sameer A. Ansari, co-author of the study.
While the original trial did not show meaningful benefit at 90 days, the newly reported one-year data show functional gains among patients who received thrombectomy.
“At one year, it’s quite evident based on the statistical analysis that there’s significant benefit with thrombectomy,” said Ansari.
In the study, investigators found that 23.6% of patients treated with endovascular thrombectomy achieved functional independence one year after their stroke, compared with 6.8% of patients who received medical management.
Patients in the thrombectomy group were also significantly more likely to regain the ability to walk independently, with 35.4% achieving independent walking versus 18% in the medical-management group.
The trial enrolled patients at 47 U.S. stroke centers who presented within 24 hours of symptom onset and had large strokes identified using noncontrast computed tomography (CT) imaging.
Patients who underwent thrombectomy also reported better quality of life one year after stroke, while one-year mortality rates were similar between the treatment groups.
The findings add to growing evidence from other large core interventional stroke trials that patients with extensive brain injury can still benefit from rapid thrombectomy to restore blood flow, according to researchers.
One possible explanation for the delayed benefit, Ansari said, is that recovery from severe stroke continues long after the standard 90-day assessment period used in most clinical trials.
“We know that people continue to improve after a stroke for the next one to two years,” Ansari said. “Three months has been an arbitrary standard used in prior stroke trials to assess benefit and functional outcomes after targeted interventions.”
Restoring blood flow may also support long-term neuroplasticity, the brain’s ability to reorganise and form new neural connections after injury, Ansari said.
The study reported that patients who received thrombectomy continued to improve between 90 days and one year, while outcomes remained static or declined in the medical-management group.
Dementia: HRT link to lower dementia risk in major UK study
Hormone replacement therapy (HRT) may reduce the risk of dementia, according to a study from the University of East Anglia and the University of Exeter.
Researchers followed more than 180,000 postmenopausal women in the UK for this, the largest study of its kind to date.
They found that women who had used HRT had a 16% lower risk of developing Alzheimer’s compared with those who had never used it.
The greatest reduction was seen in women who had undergone surgical menopause, with a 26% lower risk of developing any type of dementia, compared with non-users.
The study also found that women who naturally had lower lifetime oestrogen exposure, due to starting their periods late or early menopause, seemed to benefit more from HRT – with a 16% lower risk of any type of dementia.
Prof Anne-Marie Minihane, from UEA’s Norwich Medical School and director of the Norwich Institute for Healthy Aging at UEA, led the study.
She said: “Dementia affects millions of people worldwide, with women making up almost two thirds of Alzheimer’s disease cases.
“In addition to living longer, the reason behind the higher female prevalence is thought to be related to the effects of menopause on brain metabolism and the impact of the main genetic risk factor APOE4 being greater in women.
“We wanted to better understand how HRT could prevent dementia and to assess if particular groups of women may respond differently.”
Researchers analysed health data from the UK Biobank, tracking 183,450 postmenopausal women over an average follow up period of 13.3 years.
During that time, almost 4,000 cases of dementia were identified.
The team also took into account other factors that could influence dementia risk and HRT use, such as age, socio-economic factors, other health issues and medication use.
Prof Minihane said: “We found that women who had used HRT were about 10 per cent less likely to develop dementia, and 16 percent less like to develop the Alzheimer’s disease form of dementia, than women who had never used it.”
Genetics also played a role. The associations between HRT use and dementia were stronger in women who carry the APOE4 gene variant – a known risk factor for Alzheimer’s disease.
The age at which women started hormone therapy also appeared to influence outcomes. Those who began HRT between the ages of 46 and 56 experienced the greatest reduction in dementia risk.
This supports the so called “critical window” hypothesis, which suggests that hormone therapy may be more beneficial when initiated closer to the menopausal transition, rather than later in life.
“Our findings contribute to growing evidence that hormone therapy’s effects on brain health are complex and influenced by individual biological factors,” said Prof Minihane.
This research builds on a previous study from UEA, which found that HRT use is associated with better memory, cognition and larger brain volumes in later life among women carrying the APOE4 ‘dementia gene’.
The team say their latest results provide a foundation for more personalised approaches to HRT prescribing – taking into account menopause type, genetic risk, lifetime hormone exposure, and age at initiation.
Traumatic Brain Injury: Nasal spray may be used to treat TBI after promising study
Researchers in Portugal are exploring a potential new treatment for Traumatic Brain Injury (TBI) after discovering that both sides of the brain develop markedly different levels of inflammation and cellular stress following trauma.
The team at the University of Coimbra (UC) found that an initially unilateral brain injury triggers distinct responses in the two hemispheres of the brain.
They reached this conclusion by analysing the hippocampus, the brain region associated with memory and emotions.
Building on this discovery, the team is now further exploring the potential of neuropeptide Y as a therapeutic target.
Project leader Ricardo Leitão said the team’s first study demonstrated that early administration of neuropeptide Y after TBI attenuates changes to the blood-brain barrier, reduces neuroinflammatory responses and improves behavioural parameters associated with memory and anxiety.
Specifically, neuropeptide Y was administered intranasally to an animal model of traumatic brain injury at an early stage after the trauma.
The researchers then assessed a range of molecular, cellular and behavioural changes, observing that neuropeptide Y reduced those associated with inflammation and blood-brain barrier dysfunction.
Ricardo Leitão states that "these initial results reinforce the importance of continuing to investigate, as we are doing, the mechanisms responsible for the protective effects of neuropeptide Y, as well as ways of enhancing its therapeutic application and its future translation into the clinical setting".
In addition to studying these protective mechanisms, the research team aims to develop innovative approaches to delivering potential therapies to the brain and to study the biomarkers and biological changes that occur in patients with traumatic brain injury.