Fifty-one brains showing lacunae and 30 with cribriform cavities have been identified out of 191 examined brains. A histologic and immunohistochemical study with the peroxidase-antiperoxidase method for glial fibrillary acidic protein has been carried out in selected cases. The number, site, associated arterial lesions and the microscopic appearance of lacunae and cribriform cavities are reported. Lacunae are small cavities usually, but not always due to softenings; cribriform cavities are dilatations of the perivascular space. Two types of cribriform cavities have been identified, according to the histological appearance of the surrounding tissue: type 1 with normal and type 2 with rarefied and abnormally gliotic surrounding nervous tissue. Sixteen cases showing a cribriform state in the basal ganglia exhibited a pseudobulbar palsy or extrapyramidal rigidity. Pseudobulbar palsy of striate form or parkinsonism may be ascertained in some cases only by histological and immunohistochemical examination.