Weight loss surgery is becoming increasingly popular. The latest method is the Roux-Y gastric bypass, in which part of the small intestine is shortened. This means that less food can be absorbed and stored by the body. In addition, the feeling of fullness occurs more quickly and the person loses weight as a result.

It has already been proven several times that the procedure is associated with a significant reduction in body weight, diabetes rates and other cardiovascular risk factors, such as heart failure.

Functional magnetic resonance imaging (fMRI) is used to analyse the effects of the operation on brain function.

Mobility has a decisive influence on independence, which is why walking plays an important role in quality of life and walking restrictions are perceived as particularly impairing. Numerous neurological conditions, including neuropathies, strokes, multiple sclerosis and Parkinson's disease, are also characterised by gait disorders. Sensor-based gait analyses are used to detect abnormalities in the gait pattern at an early stage. The GAITRite® system has established itself as the gold standard and enables gait parameters such as walking speed, stride length, stride width and their fluctuations to be detected by simply stepping over a carpet containing numerous sensors. However, the disadvantages of the system are its considerable cost and the need for trained personnel, which is why the GAITRite® system is only available in specialised clinical facilities. Simpler and more cost-effective systems are therefore needed to enable gait analysis in doctors' surgeries and care homes. As part of a study conducted in co-operation with the Institute for Computing Science (OFFIS), the first aim is to investigate whether a 3D consumer camera, the Microsoft® 40 Azure™ Kinect™ (Microsoft Corporation, WA, USA), can validly measure gait parameters in comparison to the gold standard of the GAITRite® Electronic Walkway (2). As the camera-based detection also enables the recording of arm sway as well as an analysis of the speed, amplitude and rhythm of hand movements, a complex analysis of movement patterns with the Microsoft® 40 Azure™ Kinect™ in the clinical setting and in the patient's home will be carried out.

References

(1) Bamji, C.S.; Mehta, S.; Thompson, B.; Elkhatib, T.; Wurster, S.; Akkaya, O.; Payne, A.; Godbaz, J.; Fenton, M.Rajasekaran, V.; Prather, L.; Nagaraja, S.; Mogallapu, V.; Snow, D.; McCauley, R.; Mukadam, M.; Agi, I.; McCarthy, S.; Xu, Z.; Perry, T.; Qian, W.; Chan, V.H.; Adepu, P.; Ali, G.; Ahmed, M.; Mukherjee, A.; Nayak, S.; Gampell, D.; Acharya, S.; Kordus, L.; O'Connor, P. IMpixel 65nm BSI 320MHz demodulated TOF Image sensor with 3µm global shutter pixels and analogue binning. Digest of Technical Papers - IEEE International 337 Solid-State Circuits Conference 2018, 61, 94-96. doi:10.1109/ISSCC.2018.8310200.

(2) Inc, C.S. GAITRite electronic walkway technical reference manual, 2013.

Sleep apnoea syndrome (SAS) is one of the most common sleep disorders, with one in four men and one in ten women experiencing relevant pauses in breathing during sleep, which is a risk factor for vascular diseases. Patients with obstructive sleep apnoea syndrome (OSAS) are mainly found in ENT clinics and neurology departments. 75% of all stroke patients have OSAS, but only 2% of these patients are diagnosed, presumably because it is time-consuming and resources are limited.

In sleep medicine, the apnoea-hypopnoea index (AHI) refers to the average number of apnoea and hypopnoea episodes per hour. It defines and grades sleep-related breathing disorders such as OSAS in terms of severity and serves as a guideline for treatment. Screening methods are either expensive or scientifically poor or not validated, so that a ubiquitously available and inexpensive method that simply and effectively investigates suspected OSAS is lacking. The AHI is calculated from the parameters of respiratory flow, thoracic excursion and blood oxygen desaturation determined in the sleep laboratory, which leads to an arousal reaction. There are some promising approaches in the literature to combine simpler biomarkers to predict the AHI.

In this project, information from mobile recorded biosignals (acoustics, electroencephalogram, respiratory movements, electrocardiogram, pulse oximetry) will be reduced using machine learning algorithms and combined to reliably predict the AHI. The robust prediction of the AHI would create the basis for a diagnostic support system for prevention.

Cognitive neurology deals with cognitive impairments (e.g. memory, perception, language) as a result of diseases of the central nervous system. Our focus is specifically on the cognitive symptoms of Parkinson's disease. Parkinson's is a neurodegenerative disease that is primarily associated with a deterioration in motor skills. It is less well known that Parkinson's also causes deficits in cognitive functions, such as the ability to make decisions (in the context of experimental psychology) and the cognitive control of patients. Several studies are currently being carried out at the University Hospital.

One of our projects focusses on how patients with Parkinson's disease use known information to make decisions. Current studies indicate that patients with Parkinson's disease have a deficit in the integration of previously known information into their decision-making process. This deficit is not a side effect of Parkinson's-typical medication, but is rather associated with a dysfunction of the basal ganglia. The aim of this study is to investigate the cause of this deficit in more detail and to narrow down the phenomenon. To this end, behavioural data will be used together with electrophysiological recordings of cortex activity.

In another project, we are looking at possible deficits in cognitive control in Parkinson's disease. Basically, cognitive control describes the ability to adapt and regulate one's own behaviour to a variable environmental context. Theoretical models of this function postulate that two different mechanisms can be distinguished in control functions: A mechanism of conscious active control and an unconscious mechanism of passive control. Both mechanisms have been insufficiently investigated in patients with Parkinson's disease. Using behavioural experiments and electrophysiological evaluations of cortex activity, we would like to investigate the extent to which active and passive control mechanisms are impaired or preserved in Parkinson's disease.

The immune system works throughout the entire organism. As a defence system, it serves to protect and maintain the integrity of the body. However, auto-aggressive behaviour of the immune system can occur in different organ systems, leading to diseases. For example, polyneuropathy can occur in the peripheral nervous system (PNS) and multiple sclerosis (MS) can occur in the central nervous system (CNS) as its most common form of autoimmune disease.

In MS, structures of the brain and spinal cord are recognised as foreign and attacked. A network of different cells of the immune system triggers a local inflammatory reaction, resulting in tissue damage and symptoms of disability. However, the clinical picture of MS is much more colourful and is not only explained by local damage. Systemic symptoms such as chronic fatigue and, in some cases, cognitive impairment can impair everyday life.

Our research interest therefore relates not only to experimental research into the immune system (e.g. interaction of B and T cells) and its interaction with the nervous system, but also to clinical investigations, e.g. the systematic aspects of MS.

Non-motor symptoms in Parkinson's disease

Parkinson's disease is one of the most common neurodegenerative diseases worldwide and although the treatment of Parkinson's disease often focusses on motor symptoms, studies show that non-motor symptoms have a greater impact on patients' quality of life than motor symptoms. As the importance of non-motor symptoms in Parkinson's patients and their need for treatment has increased in recent years, studies are currently being carried out at the Department of Neurology.

One study is investigating how reliably Parkinson's patients can indicate the severity of non-motor symptoms in the OFF from memory (as is done during outpatient medical consultations). As part of the study, extensive testing is being carried out under controlled conditions in an inpatient setting to determine whether the information provided by Parkinson's patients on the severity of non-motor symptoms in an imagined poorly medicated state differs from the information provided in a real poorly medicated state (before an L-dopa test, which is indicated as part of Parkinson's diagnosis). An Ipad-based questionnaire was developed for the survey, which could possibly be made available to Parkinson's patients as an app in the future.

Another project is investigating the effect of a non-invasive, non-drug treatment method, transcutaneous vagus nerve stimulation (t-VNS), on non-motor symptoms, especially mood and cognitive functions in Parkinson's patients. The t-VNS is based on the fact that a sensitive branch of the vagus nerve in the region of the auricle can be stimulated with electrical impulses through the skin and has European admission (CE mark) for the treatment of epilepsy, depression and pain. In addition to the effect of t-VNS on the mood of depressed Parkinson's patients, we are also investigating the influence on cognitive functions, as t-VNS indirectly leads to activation of brainstem nuclei such as the locus coeruleus, a nuclear area whose dysfunction in Parkinson's disease is held responsible for symptoms such as impaired executive functions and depression. The acute effects of t-VNS on physiological parameters such as pupillomotor function are also being investigated.