Up to 1.2 million people in Germany live with Alzheimer's. The disease is thus the most common form of dementia.
Early diagnosis of Alzheimer's is particularly important: Can the disease be recognized on the pupils?
The brain is changed and damaged long before the onset of the first symptoms. Early detection of the risk of contracting Alzheimer's is therefore extremely important in order to be able to initiate the first treatment steps.
According to a recent study by the "University of San Diego" in California, one should be able to recognize an increased genetic risk for Alzheimer's disease long before the onset of symptoms due to one's own pupil movements.
Pupillary reaction may indicate Alzheimer's
Research into the causes of Alzheimer's has been limited to two contributing factors: the clumping of a protein – tau – and the accumulation of protein plaques – amyloid-beta – in the brain. Researchers report that both factors are associated with the destruction of neurons in the brain, leading to progressive cognitive dysfunction.
In a new study published in the journal Neurobiology of Aging, attention was now focused not only on the causative factors of the disease, but on a new method to aid in early detection: the movement of the pupils in conjunction with cognitive tests.
Neuron cluster in the brain stem plays an important role
The pupil reactions of humans are controlled by the locus Coeruleus. This is a neuron cluster in the brain stem. This part of the brain is responsible for the excitation and regulation of cognitive functions.
The protein "tau", which has been shown to clump together with Alzheimer's disease, first appears in the neuron cluster and is strongly associated with perception. While the test patients now fulfill cognitive tasks, the locus Coeruleus controls the changing diameter of the pupils. It was found that individuals with mild cognitive impairment, and thus also the clumped protein "Tau" showed a greater pupil dilation and more cognitive effort, although both test groups achieved the same results.
By the larger pupil dilation and cognitive effort so slight cognitive impairments could be recognized early, although in the test results actually no deficits could be seen to the result of the undisturbed test group.
Can one rely on the measurement of the pupil reaction?
Since the link between the pupillary reaction, the protein "Tau" and the work of the locus Coeruleus could be detected, the observation of the pupil can be used according to the researchers as a screening method for the early detection of increased Alzheimerrisikos. The method helps to detect the risk of the disease before symptoms appear, thus facilitating treatment.
However, scientists are not only working to improve the early detection of the disease, but have also been seeking a cure for years. Now, the development of a vaccine against Alzheimer seems to be within reach.