A New Diagnostic Technique for Mental Diseases?
Australian Biomedical Engineer Brian Lithgow's Innovation
Oct 16, 2009
Doctors have long relied on a time honoured diagnostic triad - relying on symptoms (what the patient or observers can tell about the condition), signs (what the doctor can see, feel, feel and hear) and special tests (laboratory and other investigations like blood tests, X-rays and biopsies) - to diagnose human diseases.
This triad has proved effective in most branches of medicine - particularly in the 21st century, where sophisticated diagnostic tests making use of modern technology are available. Examples of such tests are Computerised Axial Tomography (CAT) and Magnetic Resonance Imaging (MRI) scans as well as blood tests that can measure minute levels of chemicals, hormones and proteins in body fluids.
Diagnosing Psychiatric Disease
In the field of psychiatry, however, physicians have long been hampered by the fact that they have no special tests to diagnose major psychiatric diseases. Deciding that a patient suffers from a disease like depression or schizophrenia relies on a clinician taking a comprehensive history from the patient and/or those who have observed the patient - and then carefully assessing the patient. The use of diagnostic aids like questionnaires and similar tools have helped - but thus far we have had no simple test like a blood test or ECG to help us make a foolproof diagnosis.
Says Professor Jayashri Kulkarni, Director of Monash University's Alfred Psychiatry Research Centre (MAPRC) in Melbourne, Australia, "Engineering and psychiatry are two disciplines that do not usually work together. Here at MAPRC, however, we have been collaborating - and through this collaboration, we are at the forefront of translating biotechnology into clinical tools for psychiatric practice. While there is more work to be done, electrovestibulography could provide a major breakthrough in the diagnosis of serious mental illnesses."
Electrovestibulography
The new technique is best described as analogous to doing an ECG for the mind.
The vestibular system of the human brain is connected to the primitive parts of the brain that are associated with emotional behaviour - and this gave biomedical engineer Brian Lithgow, Director of Diagnostic Neuro-signal Research at Monash University's Centre for Biomedical Engineering, the idea of measuring and comparing different patterns of electrovestibular activity. He and his colleagues believed that by measuring patterns of electrical activity in the vestibular system of affected individuals and then comparing these with the patterns from normal subjects, it may be possible to identify distinct response patterns in depression, schizophrenia and other Central Nervous System (CNS) disorders.
Working with psychiatry researchers at MAPRC, he tested volunteers and found distinct response patterns, or "biomarkers," that distinguished different CNS diseases from each other and from regular electrovestibular activity. "The patient sits in a specially designed tilt chair that triggers electrical responses in their balance system" explains Lithgow. "A gel-tipped electrode placed in the individual's ear canal silences interfering noise so that these meaningful electrical responses are captured and recorded.The responses are then compared to the distinct biomarkers indicative of particular CNS disorders, allowing diagnosis to be made in under an hour."
Monash Collaborates with Neural Diagnostics
Monash has teamed up with corporate partner Neural Diagnostics to develop and patent electrovestibulography, or EVestG™. It is hoped the simple, quick and inexpensive screening process for CNS diseases will eventually become standard practice in hospitals around the world.
Dr Roger Edwards, Chief Execuitve Officer of Neural Diagnostics, said the implications of electrovestibulography are huge. "This could be one of the most significant inventions ever to come out of Monash University. CNS disorders cost upwards of $US2 trillion globally and affect one in four people sometime in their lifetime. At present, diagnosing these conditions is done almost exclusively by qualitative measures, through questions and interviews, and it can take many years for sufferers to be correctly diagnosed," Dr Edwards said.
The technique is already attracting international interest and, if further testing goes to plan, within a few years it could be adopted in hospitals worldwide.
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