Decline in brainstem auditory-evoked potentials coincides with loss of spiral ganglion cells in arylsulfatase A-deficient mice.

Arylsulfatase A (ASA)-deficient mice constitute an animal model for the inherited lysosomal storage disease, metachromatic leukodystrophy (MLD). Brainstem auditory-evoked potentials (BAEPs) were recorded in control and ASA-deficient mice of 3, 6, 9 and 12 months. BAEPs were evoked in control mice of all ages studied, but were completely absent in ASA (-/-) mice of 9 and 12 months. A significant delay in the wave pattern was noted in 6-month-old ASA (-/-) mice. Histological examination and morphometric analysis showed that the decline of BAEPs in ASA (-/-) mice was paralleled by a decrease in spiral ganglion cell numbers.