A new study may change the way patients are tested for and diagnosed with Alzheimer’s.

According to the BBC, a University of Kansas study has found that declining spatial skills like reading a map or doing a puzzle can be the first sign of the debilitating disease. Memory-loss has long been thought to be the primary indicator of dementia in the elderly.

Researchers say spatial skills decline up to three years prior to diagnosis. They were followed by an overall decline in mental abilities two years prior to diagnosis and a sharp decline in memory skills one year before being diagnosed.

"Early intervention will be crucial to the effectiveness of the Alzheimer’s treatments of the future, so methods of improving detection will become increasingly important," Rebecca Wood, chief executive of the Alzheimer’s Research Trust told BBC News.

Alzheimer’s disease is the most common form of dementia, with an estimated 5.3 million Americans living with the disease. The Alzheimer’s Association says it is the seventh leading cause of death in the U.S.