Unlocking the Mysteries of CNS Infections
Date: March 1, 2008
The first symptoms were dizziness, vomiting and hiccups—she had them for nine straight days. Then came double vision, “pins-and-needles” pain, deteriorating motor skills, difficulty swallowing. Soon, Becky Mellinger, a 33-year-old small-business owner and competitive volleyball player, always the picture of perfect health, was in and out of a coma, suffering with an acute, undiagnosed infection of the brainstem.
Surgeons at the university hospital where she was being treated were on the verge of performing a brainstem biopsy, a dangerous procedure with a high rate of complications, when Avindra Nath was consulted on the telephone. Nath, director of the Division of Neuroimmunology and Neurological Infections, immediately suspected a listeria infection in the central nervous system.
Admitted to Johns Hopkins, Mellinger was treated with appropriate antibiotics and discharged six days later. After several weeks, though still weak and on intravenous antibiotics, she was well enough to accompany her husband and 12-year-old daughter on a sightseeing trip to Washington. First, though, they drove to Baltimore from their home in Pittsburgh for a follow-up appointment with Nath. “And why not?” Mellinger remarked. “After all, he saved my life.”
Mellinger’s case is a reminder of just how difficult—and crucial—it is to diagnose CNS infections, devastating, acute conditions caused by any number of microbes, some only just now emerging—and some positively bizarre.
Nath recalls a patient who “came up with the strangest CNS disease that no one could diagnose. He was paralyzed, covered in blisters, and his brain and spinal cord just necrosed.” After his death, sophisticated detective work done by Nicoline Scheiss in the lab of Gary Hayward turned up a novel herpes virus similar to one known to affect protozoa. This patient, doctors now speculate, may have actually been poisoned with a herpes-containing protozoa.
Of course, Nath and his team of specialists mostly see the more common CNS infections, such as herpes encephalitis and newer ones like West Nile encephalitis. “Our expertise is in viral infections of the CNS,” says Nath. “We use sophisticated, research- and laboratory-based diagnostic techniques and sometimes brain biopsy to make specialized diagnoses that can lead to effective therapies.”
To harness the expertise that exists at Hopkins, Nath, with neurologist Ben Greenberg and Romer Geocadin, director of the neurosciences critical care unit at Hopkins Bayview, is establishing an encephalitis center, a collaboration between clinicians and scientists who are isolating heretofore unknown organisms that may or may not affect humans.
The neuro-infectious disease team also has established an accredited clinical fellowship in CNS infections and neuro-immunology, the first of its kind. Fellows will study infections seen not only in the United States but also elsewhere in the world.
“CNS infections vary drastically in different geographic locations,” says Nath. “Our fellows will be able to establish international programs that will help others diagnose, treat and better understand the infections that affect the brain.”
To refer a patient: 443-287-4656