In the past 10 years, approximately 24,000 Americans have undergone heart transplantation, according to background information in the article. Improvements in surgical techniques and immunosuppressive medications have resulted in increased survival rates for transplant recipients.
Diederik van de Beek, M.D., Ph.D., and colleagues at the Mayo Clinic College of Medicine, Rochester, studied 315 consecutive patients who underwent heart transplants there from January 1988 through June 2006. Data were gathered from the clinic databases, electronic and paper medical records, laboratory records and cranial imaging tests.
Eight patients (3 percent) developed central nervous system infections, all within four years after transplantation. The most common symptoms were confusion or headache (88 percent), often without the classic signs of fever and neck stiffness. Three of the eight patients died (38 percent), and two (25 percent) survived with mild complications.
Three patients developed cryptococcal meningitis, two had progressive multifocal leukoencephalopathy, two had varicella-zoster virus encephalitis, and one had Aspergillus fumigatus infection. "Varicella-zoster virus encephalitis has not been previously reported in heart transplant recipients, to our knowledge, but has been described in patients after bone marrow transplantation or in patients with HIV infection," the authors write. "Whether varicella-zoster virus encephalitis is emerging in other transplant populations should be a subject of further research."
Examining the cerebrospinal fluid did not necessarily help determine the cause of central nervous system infections, though protein levels were usually elevated in infected patients. "Nevertheless, appropriate management and rapid diagnosis can be achieved by taking a careful history and with physical examination, neuroimaging and diagnostic microbiological techniques," the authors write. "Because the mortality and morbidity rates are high, aggressive diagnosis and intervention are warranted in heart transplant recipients with suspected central nervous system infection."