The reduction of hippocampal volume in Parkinson’s disease

• Published in: Journal of Neural Transmission Vol. 129; no. 5-6; pp. 575 - 580
• Main Authors: Říha, Pavel, Brabenec, Luboš, Mareček, Radek, Rektor, Ivan, Rektorová, Irena
• Format: Journal Article
• Language: English
• Published: Vienna Springer Vienna 01.06.2022
• Subjects: Aged; Atrophy - pathology; Hippocampus - diagnostic imaging; Hippocampus - pathology; Humans; Magnetic Resonance Imaging; Medicine; Medicine & Public Health; Neurology; Neurology and Preclinical Neurological Studies - Original Article; Neuropsychological Tests; Neurosciences; Parkinson Disease - complications; Psychiatry; Aging; Hippocampus-to-cortex volume ratio; Processing speed; Parkinson’s disease
• DOI: 10.1007/s00702-021-02451-8
• ISSN: 0300-9564

The volume of the hippocampus decreases more slowly than the volume of the cortex during normal aging. We explored changes in the hippocampus-to-cortex volume (HV:CTV) ratio with increasing age in non-demented Parkinson’s disease (PD) patients as compared to healthy controls (HC). We also evaluated the association between the HV:CTV ratio and cognitive outcomes. Altogether 130 participants without dementia aged 51–88 years were consecutively enrolled, including 54 PD patients (mean age 67, standard deviation (SD) 8 years) and 76 HC (mean age 69, SD 7 years). All participants underwent structural magnetic resonance examination and psychological evaluation. Hippocampal and cortex volumes were determined from T1 and FLAIR scans using FreeSurfer software, and the HV:CTV ratio was calculated. Regression lines for age-dependence of the HV:CTV ratio for PD and HC groups were calculated. We further assessed the association between the HV:CTV ratio and cognitive tests examining hippocampus-related cognitive functions. PD patients and age-matched HC showed a significant difference in age-dependence of HV:CTV ratio ( p value = 0.012), with a decreasing slope in PD and increasing slope in HC. In the PD group, a significant correlation ( R  = 0.561, p  = 0.024) was observed between the HV:CTV ratio and the Digit Symbol-Coding test. The reduction of HV:CTV ratio is accelerated in pathological aging due to PD pathology. The HV:CTV ratio was associated with impaired processing speed, i.e., the cognitive function that is linked to subcortical alterations of both associated basal ganglia circuitry and the hippocampus.