Paired-Pulse Inhibition in the Auditory Cortex in Parkinson's Disease and Its Dependence on Clinical Characteristics of the Patients

Abstract

We aimed to determine the value of the paired-pulse inhibition (PPI) in the auditory cortex in patients with Parkinson's disease (PD) and analyze its dependence on clinical characteristics of the patients. The central (Cz) auditory evoked potentials were recorded in 58 patients with PD and 22 age-matched healthy subjects. PPI of the N1/P2 component was significantly (P < .001) reduced for interstimulus intervals 500, 700, and 900 ms in patients with PD compared to control subjects. The value of PPI correlated negatively with the age of the PD patients (P < .05), age of disease onset (P < .05), body bradykinesia score (P < .01), and positively with the Mini Mental State Examination (MMSE) cognitive score (P < .01). Negative correlation between value of PPI and the age of the healthy subjects (P < .05) was also observed. Thus, results show that cortical inhibitory processes are deficient in PD patients and that the brain's ability to carry out the postexcitatory inhibition is age-dependent.

Prepulse Inhibition of Auditory Cortical Responses in the Caudolateral Superior Temporal Gyrus in Macaca mulatta

“…The decreased cortical response to the Pulse when it is preceded by a Prepulse has been explained by neural mechanisms related to short-term plasticity [43][44][45]. It has been suggested that the diminished response to the Pulse is due to a decrease in the release probability of excitatory neurotransmitters from afferent axon terminals and to the release of gamma-aminobutyric acid (GABA) from the terminals of inhibitory interneurons [46][47][48][49][50][51].…”

The Influence of Bilateral Subthalamic Nucleus Deep Brain Stimulation on Impulsivity and Prepulse Inhibition in Parkinson's Disease Patients

“…Disorders with impaired PPI including PD all generate abnormalities in cortico-striato-pallido-pontine and cortico-striato-pallido-thalamic circuitry, which notably modulate PPI. [8–10] Therefore, neurodegeneration associated with PD is likely to affect both information gating and reward processing. PPI is known to be improved by DAs.…”

“…There is some evidence that sensorimotor gating, as measured by pre-pulse inhibition (PPI), may be irregular in patients with PD, schizophrenia, and OCD. [7–10] PPI is known to be disrupted in disorders with basal ganglia dysfunction due to lack of midbrain dopamine. [9,10] A common measure of sensorimotor gating is a startle response.…”

“…[7–10] PPI is known to be disrupted in disorders with basal ganglia dysfunction due to lack of midbrain dopamine. [9,10] A common measure of sensorimotor gating is a startle response. [9] PPI can be induced when a weak sensory event preceding a strong startle-inducing stimulus reduces the magnitude of the startle response.…”

Widespread inter-ictal excitability changes in patients with temporal lobe epilepsy: A TMS/MEG study

“…A high PPI ratio indicates either an increase in excitation or a decrease in inhibition of the target region of the brain. The electroencephalographic reactivity in auditory cortex (Lukhanina et al, 2010) or somatosensory cortex (Frasson et al, 2001) can be evaluated when corresponding paired-pulse sensory stimuli were delivered to the subjects. Some recent MEG studies have also applied paired-pulse paradigm to investigate cortical excitability in auditory Hanlon et al, 2005;Thoma et al, 2005) and somatosensory Thoma et al, 2007;Cheng and Lin, 2013;Hsu et al, 2013) cortices.…”