The findings could benefit patients living with neurodegenerative conditions.

A new study published in the journal Neurology has suggested that as the hippocampus area of the brain shrinks, the faster the decline in cognitive functions.

These new findings could be important when treating patients with Alzheimer’s disease (AD) as well as other neurodegenerative conditions.

Commonly, the loss of volume in the hippocampus, a small area of the brain responsible for learning and memory, can be seen in patients with AD.

AD is a neurodegenerative condition that affects around 55 million people worldwide and slowly destroys memory and thinking skills in the brain.

Researchers collected data on amyloid plaques, tau tangles and hippocampus volume from 128 older adults across ten years who had no signs of cognitive impairment at the beginning of the study.

After performing a series of cognitive tests throughout the study and a number of brain imaging scans, researchers discovered that shrinkage in the hippocampus correlated with cognitive decline even when they removed the factors of the tau and amyloid proteins.

These proteins, as well as other accumulated proteins in the brain, have been linked with cognitive decline in individuals both with and without AD.

Despite the hippocampus area of the brain somewhat shrinking with age, for certain health conditions like AD, this volume loss is more extreme.

Additionally, researchers also revealed that the faster this shrinkage of the hippocampus occurred, the faster the cognitive decline, and the lower a person’s hippocampal volume at the beginning of the study, the faster the shrinkage.

The results suggest that this shrinkage could indicate the presence of other conditions, suggesting that hippocampal volume could be a useful biomarker when diagnosing other conditions that affect cognitive decline.

As well as AD, a lower hippocampal volume was also recognised in individuals with other conditions such as Cushing’s disease, depression, PTSD and anxiety.

Furthermore, the discovery could also be used to determine whether or not a person will benefit from drugs that slow the progression of AD, such as those that target amyloid plaque.