Related Experiment Video
Updated: Feb 14, 2026

Author Spotlight: Establishing a New Fluorescence-Based Protocol for In Vivo Mitochondrial Morphology Analysis in Parkinson's Disease
Published on: June 23, 2023
Disinhibited Blink Reflex Recovery Is Related to Lateral Trunk Flexion in Parkinson Disease
Takashi Sugiyama1, Hitoshi Mochizuki, Yoshine Hara
1Department of Internal Medicine, Division of Neurology, Respirology, Endocrinology and Metabolism, University of Miyazaki, Miyazaki, Japan.
Purpose:
Lateral trunk flexion is often observed in patients with Parkinson disease (PD) and causes poor quality of life. Asymmetrical function of the basal ganglia is believed to be the main cause of lateral trunk flexion, and dysfunction of the basal ganglia facilitates the blink reflex by disinhibiting the spinal trigeminal nucleus. Our aim was to investigate whether a disinhibited blink reflex recovery curve (BRrc) was associated with lateral trunk flexion in PD patients.
Methods:
We enrolled 21 PD patients, including 11 with marked lateral trunk flexion (F-PD) and 10 with normal posture (N-PD), and 10 normal controls. Blink reflex recovery curves at interstimulus intervals of 200, 300, and 500 ms were compared between F-PD, N-PD, and normal controls.
Results:
The BRrc in F-PD patients was more disinhibited than in N-PD patients and controls, and this disinhibition was asymmetrical.
Conclusions:
The asymmetrically disinhibited BRrc in F-PD patients was associated with lateral trunk flexion. This is the first neurophysiological study of patients with PD with abnormal posture. Examination of the BRrc may permit early detection of asymmetrical basal ganglia dysfunction that can eventually cause lateral trunk flexion.
Related Concept Videos
Parkinson's Disease: Treatment
Parkinson's Disease is primarily a result of the loss of dopaminergic neurons in the substantia nigra pars compacta. The cornerstone of...
Parkinson's Disease: Overview
Reflex Activity
A reflex exam is a diagnostic procedure performed by a healthcare professional to evaluate the functionality of a patient's...
The Micturition Reflex
The process begins with bladder filling, where the bladder wall stretches as urine accumulates. This stretching activates the urine storage reflex, mediated by the sacral spinal segments and the pontine storage center. Efferent sympathetic impulses stimulate the detrusor muscle to relax and the internal urethral sphincter to contract, facilitating...
Somatic Spinal Reflexes
One of the most well-known somatic spinal reflexes is the stretch reflex, which is activated by the sudden stretching of a muscle. This reflex involves the activation of specialized sensory receptors called muscle spindles, which are located in the muscle tissue and detect changes in the length and speed of muscle contractions. When a muscle is suddenly...
Lateralization

