Clinical Neurophysiology – Charith Cooray's research group

Our research

The research conducted within our research group is largely clinically oriented and spans several different areas of neurophysiology and neurology, including research projects in both central neurophysiology, central neurology, peripheral neurophysiology and preclinical basic science neurophysiology research.

The research group is led by Associate Professor and Adjunct Lecturer Charith Cooray, who is a dual specialist in both neurology and clinical neurophysiology.

Dr. Cooray has an overall leadership role over all the different subgroups of the research group, but each subgroup, or team, in turn has independent researchers (all clinical neurophysiologists) who run the individual lines of research, either in small groups or individually.

For more information on our projects, see the Research Projects tab.

Our different research projects and teams/subgroups within the research group are described below:

Team Cooray

Team members: Charith Cooray, Jakob Pansell, Megan Gjordeni

Associate Professor Charith Cooray started his clinical rotation as a neurology resident at KS in 2014, and in parallel he worked on a registry-based PhD project on the prediction of large vessel occlusion in the acute phase of ischemic stroke. He completed his PhD in 2017 and became a specialist in neurology in 2019. Soon after, he started a clinical training program in clinical neurophysiology and became a clinical neurophysiologist in 2023. He has been an associate professor of neurology at KI since 2023 and an adjunct associate professor since 2024.

Charith's current research activities at KI are centered around three main areas: 

1. Non-invasive estimation of intracranial pressure
2. Blood biomarkers for the identification of stroke subtypes in the acute phase.
3. Transcranial Doppler in the neurointensive care setting.

These studies, centered on how ultrasound-based measurements of the optic nerve sheath can be used as a non-invasive way to estimate elevated intracranial pressure, have been the subject of a thesis work at CNS that specialist nurse Jakob Pansell at PMI Karolinska has immersed himself in. Charith has been the main supervisor for Jakob, who successfully defended his thesis in May 2024. Jakob continues his clinical research in non-invasive estimation of intracranial pressure with in-depth studies in ultrasound of the optic nerve sheath, with broadening the research to transcranial Doppler and quantitative pupillometry, and with applications of all three methods on, among other things, patients in intensive care after cardiac arrest.

In recent years, Charith has been the principal investigator together with Associate Professor Michael Mazya (associated with Niaz Ahmed's research group at CNS) of a project collecting blood samples in the acute phase of stroke patients treated at Karolinska Hospital. At present, the collection of blood samples is completed, and about 150 patients have been included in the study. We are currently planning several sub-studies, in collaboration with Dr. Thelin's research group, where we intend to study several different blood biomarkers that can be used to distinguish between different stroke subtypes and identify so-called stroke mimics (patients without stroke but with stroke-like symptoms). The analyses will be carried out in collaboration with SciLife Lab. Megan Gjordeni, a final year medical student at Karolinska Institutet, is planned to be responsible for these sub-studies within the framework of a PhD project with Charith as the main supervisor.

In addition to the above-mentioned studies, in collaboration with colleagues in the neurointensive care unit, studies based on transcranial Doppler technology and studies of, among other things, patients with vasospasm problems after subarachnoid hemorrhage are planned.

Team Pourhamidi

Team members: Kaveh Pourhamidi, Dimitrios Avramidis, Atif Sepic 

Kaveh Pourhamidi is a specialist physician in clinical neurophysiology and holds a PhD in medical science. His research focuses on peripheral nerve function, with the goal of improving the diagnosis and follow-up of nerve and muscle disorders. The work is conducted at the Department of Clinical Neurophysiology at Karolinska University Hospital, in collaboration with the Departments of Clinical Neuroscience and Laboratory Medicine at Karolinska Institutet. The research combines clinical examinations, neurophysiological methods, and tissue analyses to study the structure and function of the nervous system.

Inflammatory polyneuropathies and registry-based research

Dimitrios Avramidis’s doctoral project focuses on inflammatory polyneuropathies. The project involves registry-based research—utilizing the Swedish registry for inflammatory polyneuropathies (the IPN registry)—as well as clinical and neurophysiological characterization. The objective is to increase knowledge regarding the prevalence and clinical manifestations of these conditions, while contributing to more reliable diagnostics and improved follow-up.

Sensory nerve function and pain

Atif Sepic’s doctoral project investigates sensory nerve function and pain processing. By combining quantitative sensory testing with pain-related evoked potentials, the study explores how different examination methods can complement one another in the assessment of sensory dysfunction. The project aims to deepen the understanding of pain mechanisms and evaluate potential neurophysiological markers for impaired sensory function.

Skin biopsies and small-fiber diagnostics

A key area of ​​research is the diagnosis of small-fiber neuropathy. The work involves the analysis of intraepidermal nerve fiber density in skin biopsies, the development of reference values, and the investigation of the relationships between nerve fiber structure, sensory function, and clinical symptoms. By combining skin biopsies with functional assessments, the goal is to improve the evaluation of patients experiencing pain and sensory disturbances, as well as to facilitate the interpretation of findings in clinical practice.

SPAF – Peripheral Nerve Function and Neuromuscular Aging

Within the population-based, longitudinal SPAF-1958 study (Swedish Longitudinal Physical Activity and Fitness Cohort Born in 1958), Pourhamidi participates in research on how peripheral nerves and muscles change with advancing age. The neurophysiological component includes, among other things, nerve conduction studies (neurography), sensory testing, and the estimation of the number of motor units. These measures are analyzed in relation to factors such as physical capacity and symptoms. The objective is to gain a better understanding of neuromuscular aging and to improve the ability to distinguish age-related changes from pathological findings.

For researchers planning longitudinal studies or clinical trials, collaboration is offered regarding the design and implementation of neurophysiological examination protocols. These assessments are tailored to the specific research questions of each project, with a focus on standardized and reproducible measurements of nerve and muscle function over time.

Lars Hyllienmark

Lars Hyllienmark, consultant in clinical neurophysiology and previously active as a consultant in neurology, defended his PhD in 1996 and is since 2009 associate professor in clinical neurophysiology at KI. Research-wise, he has experimentally studied the effect of hypoxia and metabolic inhibition on K+ and Na+ channels in rat CA1 neurons using the patch-clamp method. For 30 years he has been conducting clinical studies of peripheral and central nervous system function in patients with type 1 diabetes, currently in collaboration with colleagues based in Linköping. He has previously conducted clinical research on continuous EEG (cEEG), where he concentrated on developing the method in the context of the care of critically ill children and adolescents at BIVA.

Gerald Cooray

Gerald Cooray is a consultant in clinical neurophysiology and received his PhD in 2010 from Karolinska Institutet. He has been an associate professor in clinical neurophysiology since 2019. He works in the field of computational and theoretical neuroscience. This work is a collaboration between Karolinska Institutet, Uppsala University and University College of London.

See Research Gate for more information https://www.researchgate.net/profile/Gerald-Cooray

Una Smailovic

Una Smailovic, MD, PhD, is a resident in Clinical Neurophysiology and a researcher with a primary focus on electroencephalography (EEG) and quantitative EEG (qEEG) methods applied in different neurological disorders. She completed her PhD in 2021 at Karolinska Institutet as part of the European Training Network SyDAD (Synaptic Dysfunction in Alzheimer’s Disease), supported by a Marie Curie Fellowship. Her doctoral research focused on identifying novel qEEG and cerebrospinal fluid (CSF) biomarkers of Alzheimer’s disease, specifically related to synaptic function which is known to deteriorate early during the disease course. Her projects encompassed both clinical and preclinical (mouse model) studies, conducted in collaboration with the Memory Clinic at Karolinska University Hospital, Sahlgrenska University Hospital in Gothenburg, and Janssen (Johnson & Johnson) Pharmaceutical Company in Belgium. 

Una has since been involved in applying qEEG methods in several collaborative projects focused on different neurodegenerative disorders - including dementia with Lewy bodies (DLB), frontotemporal dementia (FTD) and familial Alzheimer’s disease (fAD) headed by prof. Caroline Graff and doc. Vesna Jelic at Division of Neurogeriatrics. Recently, Una initiated a project involving a novel wireless and portable EEG system with integrated real-time quantitative analysis, supported by the Region Stockholm Innovationsfonden. She is a member of the newly established FTD-ALS Research Network at KI — a multidisciplinary consortium aiming to develop innovative research questions from an integrated FTD and amyotrophic lateral sclerosis (ALS) research perspective.