In a case study of an 82-year old male spontaneous magnetoencephalography recordings revealed lower magnetic fields at frontal and frontotemporal regions compared to central and posterior regions. This finding correlated well with the significant ventricular distention, and specifically the enlargement of the frontal horns of the lateral ventricles, observed in presurgical computed tomography. The regional pattern of magnetoencephalography signal decrease in normal pressure hydrocephalus seems to be quite different from that encountered in brain atrophy. In the latter case, a more generalized distribution of low magnetic fields is observed, possibly reflecting the high sensitivity of magnetoencephalography to activity originating in sulci. Acquired data suggest that magnetoencephalography may be able to differentiate between normal pressure hydrocephalus and brain atrophy. Furthermore, magnetoencephalography could potentially constitute a non-invasive, non-imaging tool, useful in the selection of patients with normal pressure hydrocephalus suited to undergo shunt surgery.