A new study has outlined the risks of Cigarette smoking in patients with multiple sclerosis (MS) which can lead to brain damage.
Scientists at the University at Buffalo have shown that MS patients who smoked for a little as six months during their lifetime had more destruction of brain tissue and more brain atrophy than the patients who never smoked.
"Cigarette smoking is one of the most compelling environmental risk factors linked to the development and worsening of MS," said Dr Robert Zivadinov, UB professor of neurology, director of the Buffalo Neuroimaging Analysis Centre (BNAC) where the research was conducted and first author on the study.
"The biological basis of the potential link between smoking and MS has not yet been fully elucidated.
"In addition to nicotine, cigarette smoke contains hundreds of potentially toxic components, including tar, carbon monoxide and polycyclic aromatic hydrocarbons.
"In MS patients, smoking was associated with higher increased lesion burden and greater brain atrophy. Our results indicate that a wide range of quantitative brain MRI markers are affected by smoking in MS patients," he added.
The study involved 368 patients from the Baird Multiple Sclerosis Center of the Jacobs Neurological Institute (JNI), where 128 had a history of smoking: 96 were active smokers who had smoked more than 10 cigarettes-per-day in the three months prior to the study start and 32 were former smokers who had smoked cumulatively for at least six months sometime in the past.
The remaining 240 participants were lifelong nonsmokers.
They found that that smokers with MS had a greater breakdown of the blood-brain barrier.
They had nearly 17 percent more brain lesions - patches of inflammation in the sheath surrounding the nerve fibres that impair their function - than nonsmokers with MS, and also had less brain volume.
Smoking also was associated with increased physical disability.
"The findings underscore the detrimental effect of smoking, providing a link between smoking and a more severe brain injury in MS patients," said Dr Bianca Weinstock-Guttman, director of the Baird MS Center, UB associate professor of neurology and a principal co-author on the study.
The study appears in Neurology(r), the medical journal of the American Academy of Neurology.