MAGNETONEUROGRAPHY - STATE-OF-THE-ART AND CLINICAL PERSPECTIVES

Superconducting Quantum Interference Devices (SQUIDs) allow to detect noninvasively exceedingly weak biological magnetic fields. Based on me asurements of the magnetic field distribution over the body surface th e underlying biocurrent distribution within the body can be estimated. In particular, when compared to electrophysiological measurements the localization of the current source is methodologically simpler and, u nder special circumstances, may be even more precise. Today, magnetone urography represents - like magnetoencephalography - a ''threshold tec hnique'' at the transition between basic research and clinical pilot s tudies. An important perspective for AC-coupled magnetoneurography is the functional 3D-localization of nerve conduction anomalies, in parti cular at proximal sites, e.g. in root compression syndromes. DC- magne toneurography might open up clinical perspectives for an early and non -invasive differentiation between neurapraxia and axonotmesis in cases of nerve trauma with electroneurographic conduction block: in the fre quency range below 1 Hz pilot studies in animal preparations have demo nstrated the capability of magnetoneurography recordings to monitor ne rve injury currents which decay slowly (within hours). A prerequisite for evaluating magnetoneurography results under clinical recording con ditions is the availability of low-noise multichannel magnetometer sys tems allowing a rapid data acquisition.