Volume 16, Number 3
FROM THE JOURNALS
Brainwaves Offers a Sampling of Recent Journal Articles:
Exactly how HIV damages brain neurons, causing the cognitive and motor function decline that characterize HIV dementia, (HIVD) has long evaded researchers. But Norman Haughey, Ph.D., and Mark Mattson, Ph.D., propose that ceramide, an offshoot of a membrane lipid, sphingomyelin, may be at fault. An increase in ceramide metabolites was detected in brain tissues of HIVD patients and in cultured neurons treated with toxic HIV proteins. In the latter, heightened ceramide synthesis increased cell death while blocking the molecules' protected cells. The authors suggest that inhibiting the toxic agents in patients with HIV-1 infection could reduce HIVD.
Ann Neurol 2004;55(2):257-267.
Diagnosing Sturge-Weber syndrome, the congenital illness that disorders meningeal blood vessels and leads, via hypoperfusion, to brain injury, has been difficult. Conventional imaging that confirms the brain is involved unfortunately does so after damage exists. In this case report, Doris Lin, M.D., Ph.D., and Anne Comi, M.D., show that MR perfusion imaging and proton MR spectroscopic imaging may detect cerebral perfusion and metabolism abnormalities, respectively, early in the course of disease, perhaps before irreversible damage occurs.
AJNR 2003;24(9):1912-1915.
Both laboratory and clinical techniques are important in the diagnosis of Huntington disease (HD), the fatal neurodegenerative disorder, according to a literature review by Russell Margolis, M.D., and Christopher Ross, M.D., Ph.D. Because diagnosis now involves gene analysis as well as clinical signs and, often, neuroimaging, authors caution clinicians to update laboratory techniques, use multiple molecular tests, weed out similar diseases and consider ethical issues. This paper is an excellent guide for clinicians seeking to avoid misdiagnosis and to prevent stress in patients and their families.
Clin Chem 2003;49(10):1726-1732.
Pilocytic astrocytoma (PA) is a common pediatric brain tumor with excellent prognosis. A Hopkins group, including Peter Burger, M.D., Benjamin Carson, M.D., Henry Brem, M.D., and Alessandro Olivi, M.D., has offered confirmation of a new subgroup of PA with unique histology and aggressive growth. A pilot study that compares the neoplasm, called pilomyxoid astrocytoma (PMA), with PA tumors of the hypothalamus/chiasm, supports earlier work showing PMA patients are younger at initial diagnosis and have decreased mean survival times. Recognition of PMA as a unique tumor type should lead to better treatment.
Neurosurgery 2004;54(1):72-79.
The childhood form of X-linked adrenoleucodystrophy (ALD) is a devastating disease, leading to total disability and death by age 10. In this chapter from a text on peroxisomal disorders, an international team of researchers, led by Kennedy Krieger's Hugo W. Moser, M.D., and Gerald Raymond, M.D., report on two studies-one at KKI and one in Europe-of as-yet asymptomatic children treated with "Lorenzo's oil." The oil succeeds in altering metabolism of certain toxic fatty acids. Though, for ethical reasons, the matched control group was historical, the resulting data are sufficiently robust to conclude there's a delay in onset of neurological symptoms.
Peroxisomal Disorders and Regulation of Genes, Roels et al., eds., Kluwer Academic/Plenum Publ., New York 2003.