Alzheimer’s spreads like an infection

A new US study has found that Alzheimer’s disease spreads from one part of the brain to another like an infection, a discovery that could aid the development of treatments to slow its progress.

The Columbia University Medical Centre study on transgenic mice found that the abnormal tau protein linked to the disease travels along brain circuits, jumping from neuron to neuron.

The findings, published on Wednesday in the online journal PloS One, could one day help researchers develop treatments to slow or halt the progression of the disease, which causes increasingly severe dementia.

“The most effective approach may be to treat Alzheimer’s the way we treat cancer – through early detection and treatment, before it has a chance to spread,” said study co-author and neurology professor Scott Small.

“The best way to cure Alzheimer’s may be to identify and treat it when it is just beginning, to halt progression. It is during this early stage that the disease will be most amenable to treatment.

“That is the exciting clinical promise down the road.”

Alzheimer’s disease, the most common form of dementia, is characterised by the accumulation of plaques and fibrous tangles (composed of abnormal tau) in brain cells called neurons.

Previous studies have also suggested that the disease begins in the entorhinal cortex – which plays a key role in memory – before spreading to other regions important for higher brain functions.

An estimated 5.4 million people suffer from the disease, which is the sixth leading cause of death in the United States, according to the Alzheimer’s Association.

The disease cannot be prevented, cured or even slowed, but some treatments can temporarily slow the worsening of dementia symptoms.