The effects of cocaine can be much more profound than pounding hearts, sweaty palms, and tested nerves. These MRI scans show how heavy cocaine abuse can lead to permanent physical changes to the brain by "eating away" at the white matter.

As reported in BMJ Case Reports, a 45-year-old man showed up to the emergency room in Malta with confusion and unusual behavior. 

“The patient was not cooperative, unable to perform simple tasks and was not following commands,” Dr Ylenia Abdilla, the doctor who treated the man at Mater Dei Hospital in the Maltese city of Msida, explains in the case report. “He was moving all four limbs in purposeful movement.”

His behavior then took a further turn for the worse when he became uncommunicative and eventually catatonic. Blood tests and other examinations were all relatively normal, except for MRI scans of his brain that revealed parts of his white matter appeared to have been "eaten away". 

Based on these scans, doctors eventually reached the diagnosis of leucoencephalopathy, the progressive damage or inflammation of the white matter of the brain. A similarly rare condition, known as progressive multifocal leukoencephalopathy, is known to be caused by an infection. Oddly, this man showed no sign of such an infection, either viral or bacterial.

They did, however, find significant quantities of cocaine in his urine. Although the man hadn’t taken any drugs for two to three days, he was a regular cocaine user. Based on this insight, the doctors concluded that his condition was the result of cocaine abuse. 

Instances of cocaine causing toxic leucoencephalopathy are incredibly rare, but it has been documented a handful of times in medical literature. It’s also not exactly clear why cocaine causes this effect on the brain, but other studies have suggested that heavy drug use can result in “splitting and unraveling” of the insulating layer that forms around nerves as well as swelling of the brain’s axons.

The case study notes that cocaine-induced leucoencephalopathy is often fatal. Fortunately, he made a recovery and was fully independent within a year and scored normally on neurological tests, although MRI scans did reveal persistent white matter changes. Doctors treated the man with a cocktail of drugs used to decrease inflammation, boost the immune system, and remove antibodies from blood plasma. He even went to rehab to treat his issues with addiction.

"He had not used drugs for 1 year. Apart from some complaints of low mood, he was fully independent and had returned to his previous functional status," the study author added.