Research projects and clinical studies

A major challenge in neuro-oncological surgery is the intraoperative identification of fiber tracts and the differentiation between tumorous and healthy tissue. In search of an innovative approach to overcome this challenge, neurosurgeons at Inselspital launched the HORAO project.

It started with a crowdfunding challenge to generate financial resources and a subsequent crowdsourcing challenge which resulted in a research collaboration with the winning research team from Ecole Polytechnique in Paris in 2019. In 2021, the HORAO research project won a 4-year Sinergia grant for groundbreaking projects from the Swiss National Science Foundation (SNSF).

After a promising initial series of near-in-vivo measurements at the Department of Neurosurgery of the University of Bern, the HORAO research team has grown and continues with enhanced expertise, now re-enforced with a machine-learning sub-group.

Project leader: Prof. Dr. Philippe Schucht, MD

Project manager: David Hasler

HORAO

Information = relevance

The "Peers for Peers" platform was founded by medical professionals to help doctors and researchers find the really important articles from the plethora of current publications – new findings that could already flow into the treatment of patients, but are usually found only later in textbooks. Peers for Peers offers the easiest and fastest route to new therapies in neurosurgery. The platform starts as an initiative of the European Association of Neurosurgical Societies (EANS) initially in the vascular area.

Project leader: Prof. Dr. Andreas Raabe, MD

Project manager: Luisa Tonarelli

Peers for Peers

The effect of increasing transcranial electric stimulation current or pulse duration on intraoperative patient movement and motor evoked potential amplitude

In this study, a medical product, the IOM device (IOM = intraoperative neuromonitoring) is used, which is certified for this use and has been used successfully for several years. In the study, we compare the effects of different stimulation parameters. Specifically, different combinations of current strength and pulse duration are tested to find out which of them causes the patient to move minimally and thus affects the surgeon the least. During an operation on the brain, it is important to act with millimeter precision and thus any unnecessary movement of the patient should be avoided.

Comparison between transcranial and direct cortical stimulation of motor evoked potentials during the resection of supratentorial brain tumors in terms of prognostic accuracy for postoperative motor deficits

During operations on tumors within the skull, which are located in an area of the brain which, among other things, controls the movement of certain parts of the body (hand, arm, leg or foot), it is necessary to monitor the movement functions during the operation in order to remove the tumor as much as possible without impairing the movement function.

The aim of this study is to compare two methods of motor function monitoring: transcranial stimulation and direct cortical stimulation. The transcranial stimulation is carried out by electrodes that are fixed at certain points on the scalp. The direct cortical stimulation is carried out by strip electrodes, which are pushed under the meninges after opening the skull and come to rest directly on the brain surface.

Swiss pilot screening study for unruptured intracranial aneurysms to prevent subarachnoid hemorrhage in smokers

(Schweizer Pilot-Screening-Studie für unrupturierte intrakranielle Aneurysmen bei Rauchern zur Verhinderung von Subarachnoidalblutung)

The aim of the study is to find out whether smokers between 30 and 60 years of age who have smoked more than one pack of cigarettes per day on average for 10 years (10 pack-years) have an increased incidence of unruptured aneurysms of the cerebral vessels. Furthermore, we would like to investigate the consequences of such an examination on further treatment if an aneurysm is discovered (if necessary, elimination of the aneurysm, smoking cessation) and quality of life.

Approximately 3% of the population have a so-called aneurysm of the cerebral vessels. These aneurysms are bulges in the blood vessels that can burst and cause a life-threatening cerebral haemorrhage. As aneurysms of the cerebral vessels do not cause any symptoms, they are usually discovered by chance or as soon as a cerebral haemorrhage occurs.

Smoking is one of the most important risk factors for the development of a cerebral hemorrhage from an aneurysm. 40% of all patients with cerebral hemorrhages from aneurysms are smokers. If smokers are known to have an unruptured aneurysm, the risk of a cerebral hemorrhage later in life is increased.

Recent findings from smaller studies suggest that smokers are significantly more likely to have aneurysms of the brain vessels (> 10%) than the general population (3%). This raises the question of whether there is a benefit to screening heavier smokers, as is done for other diseases such as bowel cancer, in order to prevent future cerebral hemorrhages.

Stimulation of the cervical medulla in patients with vascular spasms of the cerebral arteries after bleeding from a ruptured vascular sac: VasoStim study

Subarachnoid hemorrhage (SAH) is a life-threatening brain hemorrhage. One third of those affected die before arriving at the hospital, another third survive with permanent disabilities, and only one third have no or only minor abnormalities. In addition, dangerous vasospasms can occur from the fourth day after the hemorrhage, which worsen the course of the disease. Patients with grade 3 hemorrhage according to the Fisher classification are at particularly high risk for these vasospasms. Current therapies are only partially effective. 

In this study with 15 patients at the Inselspital, we are investigating the effect and mechanisms of neurostimulation in reducing vasospasms. The neurostimulator has not yet been tested and approved for vasospasms. 

Thalamic-Burst-DBS for Neuropathic Pain

About 1-10% of all stroke patients subsequently develop a chronic neuropathic pain syndrome, which can often only be inadequately treated with conventional therapies and medications. In these cases, there are alternative treatment methods such as deep brain stimulation (DBS). In this procedure, electrodes are implanted in specific anatomical structures of the brain to deliver therapeutic electrical pulses. Despite an initially good response to this therapy, many patients unfortunately experience a return of pain to baseline levels.

In our research project, we now want to find out whether a new form of stimulation, known as burst stimulation, works well or equally well or better in patients with deep brain stimulation in the area of the thalamus.

Burst-DBS study