Abstract
In a series of 17 cases of Leigh's disease it has been observed that there is a close correlation between damage to the inferior olivary nuclei by vasculo–necrotic change and loss of Purkinje cells in the cerebellar cortex. It is suggested that this association may be explained on the basis of the selective loss of climbing fibres causing increased firing activity of Purkinje cells with consequent excessive entry of calcium ions. In these circumstances control of calcium ion regulation in the presence of reduced energy production, which is the basis of this metabolic disease, would be expected to put these cells' survival seriously at risk.