NMR spectroscopic evaluation of cerebral metabolism in hydrocephalus: a review.

Cerebral ischemia contributes to cerebral damage in hydrocephalus. Many studies have reported changes in cerebral blood flow and metabolism, supporting this hypothesis. Magnetic resonance spectroscopy (MRS) enables us to investigate cerebral metabolism in a non-invasive and longitudinal manner, thereby providing a promising way of evaluating pathophysiological changes in experimental and clinical hydrocephalus. In this review, the potential of 1H (proton) and 31P (phosphorus) MRS in the assessment of cerebral metabolism will be summarized, and a synopsis of in vitro and in vivo MRS studies in experimental and human hydrocephalus will be presented. Changes in high-energy phosphate metabolism, intracellular pH and lactate production in several MRS studies are presumed to reflect cerebral ischemia. In vivo information on neuronal damage, maturational delay and membrane phospholipid metabolism may also be derived from 1H and 31P MRS data. Technical, methodological and pathophysiological considerations, which are important for a correct interpretation and comparison of different MRS studies, will be discussed. Finally, we will draw some conclusions on the significance of these MRS findings and the applicability of MRS in the diagnosis and evaluation of clinical hydrocephalus.