Our findings in 19 new patients with
cerebellar ataxia establish the existence of an ataxic syndrome due to primary
CoQ10 deficiency and responsive to
CoQ10 therapy. As all patients presented
cerebellar ataxia and cerebellar
atrophy, this suggests a selective vulnerability of the cerebellum to
CoQ10 deficiency. We investigated the regional distribution of
coenzyme Q10 in the brain of adult rats and in the brain of one human subject. We also evaluated the levels of
coenzyme Q9 (
CoQ9) and
CoQ10 in different brain regions and in visceral tissues of rats before and after
oral administration of
CoQ10. Our results show that in rats, amongst the seven brain regions studied, cerebellum contains the lowest level of CoQ. However, the relative proportion of
CoQ10 was the same (about 30% of total CoQ) in all regions studied. The level of
CoQ10 is much higher in brain than in blood or visceral tissue, such as liver, heart, or kidney. Daily
oral administration of
CoQ10 led to substantial increases of
CoQ10 concentrations only in blood and liver. Of the four regions of one human brain studied, cerebellum again had the lowest CoQ10y concentration.