Neuronal Loss Is Greater in the Locus Coeruleus Than Nucleus Basalis and Substantia Nigra in Alzheimer and Parkinson Diseases

To identify clinical and pathological correlates of neuronal loss in the nucleus basalis (NB), locus coeruleus (LC), and substantia nigra pars compacta (SN) in AD and PD.

The study sample comprised 86 cases with pathologically confirmed AD, 19 cases with PD, and 13 healthy elderly control subjects. The number of nucleolated neurons was counted in representative sections of the NB, LC, and SN. Effect sizes (ES) were computed to determine the standardized difference in cell counts relative to healthy controls.