Dr. Vivek Deshmukh, director of cerebrovascular and endovascular neurosurgery at George Washington University in Washington, D.C., said hyponatremia is "very commonly seen" in subarachnoid hemorrhage patients, and the risk of the complication is in fact one of the reasons that doctors monitor these patients so closely in the intensive care unit.
Deshmukh also said it is unlikely that the condition will affect Michaels' prognosis, though the occurrence of such sodium fluctuations may prolong a patient's hospitalization.
"Hyponatremia that is detected early should not be associated with any long-term complications and the overall prognosis remains unchanged," he said. "Treatment is typically straightforward and requires simply replacing the sodium in the blood."
Wright said, however, that determining exactly how this new complication will factor in to Michaels' chances of a normal recovery are as yet unclear.
"We do not have much information at this time about Mr. Michaels' clinical condition to understand how significant a setback this is," she said. "Best case scenario, this would be something that was found pre-emptively, will be treated sufficiently and will not cause any further harm to Mr. Michaels."
If the condition had gone undetected, however, Michaels could have been at risk of such serious side effects as seizures, brain swelling and neurological decline. "Some of these side effects can be permanent," Deshmukh said.
Wright said swelling would pose the greatest threat.
"Swelling of the brain would typically present as progressive loss of consciousness, or even coma," she said. "The treatment is to correct the hyponatremia, but even treating the sodium levels too rapidly can have complications."
Still, Tuesday's statement on Michaels' website said he was remaining positive and responding well to tests and treatments, and that he remained hospitalized and conscious in critical but stable condition.
"Even though today was a minor setback, doctors remain hopeful for a full recovery and plan to release more specific information next Monday," it read.
Doctors have yet to detail exactly what caused the bleeding in the first place. However, some neurologists have said they are optimistic that Michaels would survive the ordeal -- although the recovery process could take several weeks to months.
In a bit of hopeful news, Michaels' father reported that his son could talk the day after the hemorrhage, albeit with slurred speech. He was also reportedly experiencing blurred vision.
"The fact that he's made it to a hospital and is apparently in some sort of reasonable condition ... that's a good sign," said Dr. Arno Fried, chairman of neurosurgery at Hackensack University Medical Center in Hackensack, N.J. "I would describe [Michaels' condition] as guarded. If the bleed has not caused too much damage, the possibility of recovery is quite good."
Dr. Daniel Barrow, who is chairman neurosurgery at Emory University Hospital, agreed the past week's reports suggest that Michaels' condition could be far worse.
"If he is hospitalized and speaking, he is in a much, much better category with regard to the possibility of a good recovery," Barrow said. "The best outcome is that he will be able to resume all of his previous activities with no complications. That is conceivable."