New research suggests that neurodegenerative conditions like Huntington’s and Alzheimer’s could soon be identified and tracked before the onset of symptoms. By measuring neuronal electrical activity in mouse models of Huntington’s disease, scientists at SRI Biosciences were able to discern early abnormalities in subjects who had yet to display any of the primary cerebral dysfunctions associated with their nascent condition.

New, effective treatment programs for neurodegenerative diseases are notoriously elusive, as major symptoms indicating the presence of Huntington’s, Alzheimer’s and Parkinson’s generally do not appear until irreversible brain damage has already occurred.

The SRI team used electroencephalography (EEG) to track brain activity in their mouse models of Huntington’s disease, recording relevant signatures that could potentially allow for much earlier diagnoses in the future.

“EEG signals are composed of different frequency bands such as delta, theta and gamma, much as light is composed of different frequencies that result in the colors we call red, green and blue,” explained Thomas Kilduff, Ph.D., senior director, Center for Neuroscience, SRI Biosciences. “Our research identified abnormalities in all three of these bands in Huntington's disease mice. Importantly, the activity in the theta and gamma bands slowed as the disease progressed, indicating that we may be tracking the underlying disease process.”

In the past, EEG investigations have generally failed to identify any significant alterations in signature patterns prior to the onset of the condition’s brain dysfunctions.

“Our breakthrough is that we have found an EEG signature that appears to be a biomarker for the presence of disease in this mouse model of Huntington's disease that can identify early changes in the brain prior to the onset of behavioral symptoms,” said Professor Stephen Morairty, the paper's senior author. “While the current study focused on Huntington's disease, many neurodegenerative diseases produce changes in the EEG that are associated with the degenerative process. This is the first step in being able to use the EEG to predict both the presence and progression of neurodegenerative diseases.”

Scientists now hope to identify and catalogue these early changes in EEG patterns, as some of them may one day allow doctors to monitor the progression of neurodegenerative diseases decades before any symptoms appear.

“Longitudinal Analysis of the Electroencephalogram and Sleep Phenotype in the R6/2 Mouse Model of Huntington's Disease” is published in the journal Brain.