The study, revealed Thursday by the Canadian public broadcaster CBC, was commissioned by Canadian authorities to scientists affiliated with the Dalhousie University and the Nova Scotia Health Authority, reports Efe news.
The conclusions of the study indicated that the cause of brain injuries suffered by diplomats and their families could be neurotoxins and not a "sonic attack", as Washington has theorized.
The mysterious symptoms suffered since 2017 caused a diplomatic crisis between Cuba and the US after Washington that year pulled non-essential embassy staff from the Cuban capital.
In April 2018, Canada withdrew the families of its diplomats stationed in Cuba before also reducing staff.
Washington had accused the Cuban authorities of being behind the injuries, which the Cuban regime denied.
Ottawa and Havana have been working to discover the causes of ailments, which included concussion-like symptoms including headaches, dizziness, nausea and difficulty concentrating, while some described hearing a buzzing or high-pitched sounds before falling sick with the unexplained illness.
Canadian scientists noted in their study that, "in contrast to previous reports on American diplomats, most Canad did not describe an acute, directional, unusual sensory and/or auditory stimulus, but rather a gradual development of debilitating symptoms".
The researchers studied 26 individuals, including a control group that never lived in Havana, and discovered a damaged area of ??the brain responsible for memory and ability to concentrate, among other functions.
"(The results) all support the diagnosis of acquired brain injury in the Canadian diplomats and their families posted in Cuba," the report said.
In addition, the scientists were able to examine several individuals before and after returning from Havana, and found changes in their brains after their stay on the island.
"There are very specific types of toxins that affect these kinds of nervous systems... and these are insecticides, pesticides, organophosphates - specific neurotoxins," according to the lead author of the study, Alon Friedman.
In 2016, Cuban authorities launched aggressive fumigation campaigns to eradicate mosquitoes carrying the Zika virus.
In addition, Canadian researchers found that embassies also sprayed the offices of embassies, as well as inside and outside the residences of their diplomats, up to five times more frequently than usual.
Canadian researchers are now interested in working with Cuban scientists to check if Cuban citizens have suffered injuries similar to those described by Canadian and US diplomats.
( With inputs from IANS )