Other than the weakness, which lasted for three days, medical staff noted that he didn't have any confusion, facial weakness, vision or speech problems, and was otherwise reportedly feeling fine. These air pockets are seen more commonly in patients who have facial trauma or infections, or who have had brain surgery, according to a report of the case, published February 27 in the journal BMJ Case Reports.
Following a routine trip to the doctor's office, an 84-year-old man from Ireland discovered that most of the right side of his brain was missing and a large air pocket taking its place.
According to Brown, the 84-year-old patient was in ideal health, with no history of smoking or drinking.
When doctors were told that neither of these scenarios applied to the patient, they were "left very curious as to the cause of these findings", Brown said. Dr. Finlay Brown, co-author and physician at Causeway Hospital in Northern Ireland, told Newsweek via email. Usually, such air pockets are seen-on a smaller scale-in those who have undergone brain surgery.
Brown said it turned out the man had pneumocephalus, also known as pressurised air cavity, meaning the presence of air in the cranium.
Brown said air could have entered when the man sniffed, sneezed or coughed, each time making the air pocket larger.
Based on the small number of similar cases reported, the doctors speculated that the tumor had created a small opening that pushed air into the brain like a "one-way valve".
In the patient's case, the condition was facilitated by an osteotoma, a benign bone tumor, which erodes his sinuses.
Surgery is the most obvious treatment to remove the air pocket and to restore the man's brain cavity back to the correct shape.
"From speaking to the specialists, it seems it has been progressing insidiously over months to years", Brown said.
But the patient said he had suffered none. "When the patient sniffed/sneezed/coughed he would most likely be pushing small amounts of air into his head".
The patient declined surgery due to the risks it presented, and the case report stated, "the left-sided weakness was noted to have resolved on follow-up 12 weeks later and he remained well".
In addition to the alarming air pocket, the CT scan also disclosed that the man had a benign tumor in his skull.
According to the BMJ report, he had been prescribed medication to prevent another stroke and was also given instructions to monitor the feeling in his left side.
Dr Brown said the 84-year-old patient's case was a warning to other physicians not to write off common symptoms.
"Because every now and then, there will be a rare [or] unknown causation of these that could be overlooked", he told the science news site.