What Is the Blink Reflex?

Blink reflex, as its name implies, uses stimulus to activate the action of blink reflex. Shock reflection is a defensive reflection of humans and animals during the evolution process, and is an important indicator of the body's response to threats. For humans, the most continuous and persistent startle reflex pattern is the blink reflex.

Startle reflex is a kind of human and animal evolution

That is the auditory blink reflex technology.

OBJECTIVE: To study the value of blink reflex (BR) in the evaluation of early peripheral facial paralysis within 3 days of onset.

Methods: BR examinations were performed on 60 healthy people and 32 patients with peripheral facial paralysis within 3 days after onset of disease. The prognosis was followed up for 6 months. As a result, a normal BR value was obtained. In the case group, the BR results were abnormal within 3 days, showing delayed incubation period, irregular spread and no response. The BR manifestation was significantly correlated with the clinical facial paralysis. Within 3 days, those with BR response recovered well, while those with BR response disappeared partially. Conclusion BR is a sensitive indicator for observing facial nerve injury. It can reflect the degree of facial paralysis within 3 days after the onset of peripheral facial paralysis and has certain evaluation value for prognosis.

Blink reflexes have been an important topic in basic and applied physiological research since Bender et al.'S research in 1969. Whether it is polysynaptic or oligosynaptic reflex, many studies of basic neurophysiology have been probed, and many parts of the brainstem synaptic connection have been studied. Many studies of applied neurophysiology have promoted the investigation of blink reflexes through the cerebral hemisphere. Methods: Patients relax their muscles, close their eyes, and do not fall asleep. If the surface electrode is used for recording, the main pole is placed on the outside of the lower orbicularis oris, and the auxiliary pole is placed on the outside of the sacrum or the nasal. For the coaxial needle electrode, the electrode is inserted on the outside of the lower orbicularis oris. recording. Place the ground electrode under the cheek. The stimulation electrode was placed on the supraorbital foramen on one side. The stimulation pulse frequency was 0.5 to 2 Hz, the time limit was 0.1 to 0.2 milliseconds, and the voltage was 100 to 300 volts. Each patient stimulated the left and right sides, but the stimulation pulse intensity should be the same. The first reflection excitation potential on the ipsilateral side and the second reflection excitation potential on the ipsilateral and contralateral sides can be recorded on the stimulation side. Inspect the latent time of the first reflected excitation potential (R _{1 for} short), the latency of the second reflected excitation potential on both sides (R _{2 for} short), and the amplitude of the first three excitation potentials (R ₁ amplitude, R ₂ amplitude) .

Normal values: The authors determined 30 patients with no neurological disease, with an average age of 38 years, R ₁ = 10.6 ± 0.8 ms, and R ₂ = 29.7 ± 4.0 ms. The authors also determined the healthy side of 20 patients with hemiplegia, with R ₁ = 10.2 ± o.9 milliseconds and RZ = 30.1 ± 3.9 milliseconds. R, and R _{Z have} amplitudes of 450 to 550 microvolts and are equal on both sides. The author points out that the standard deviation is less than 20% of the average, the R ₁ difference on both sides of the same person should be less than or equal to 1.2 milliseconds, and the R ₂ difference on both sides should be less than or equal to 5.0 milliseconds.

Brainstem damage: limited or focal lateral rostral damage, R _{1 is} normal, and R _{2 is} prolonged. In localized or focal pontine damage, R _{1 is} prolonged on one side and R ₂ is prolonged on one side but mostly normal. Extensive pontine and medulla lesions, with R ₁ and R _Z both prolonged or missing on one side. In the upper or midbrain, R ₁ and R ₂ are normal. Cerebral hemisphere damage: reduced bilateral R ₂ amplitude, vascular or tumor lesions in patients with coma, prolonged R _2, decreased R ₂ amplitude, and reduced duration on both sides of R ₂ when stimulating the affected side; unilateral cerebrovascular disease with central facial paralysis R ₁ and R _{2 are} normal, but the amplitudes of R _I and R ₂ are changed, the hemiplegia side is reduced, the healthy side is increased, and acute patients with cerebrovascular damage within one week, R _{1 is} prolonged, and R _{2 is} missing on both sides. Abnormality indicates that the excitability of the brainstem is limited or the lesion is reduced.

Discussion: Some authors consider R ₁ as a type of synapto-reactive skin-pontine reflex. The amplitude of the H reflex seems to increase due to blinking and flexor reflex disappearing during sleep. But Pompeiano. It is believed that the inhibition of multiple synapses and single synapses is related to the depth of sleep, and R ₁ cannot be taken as an indication of less synaptic skin reflexes. R ₃ is a multisynaptic reflex, which is widely distributed outside the medullary bulb and in the pontine. The authors studied 50 patients with middle cerebral artery occlusion. All patients were normal at incubation, but the amplitudes of R ₁ and R _{2 on the} hemiplegia side were only 30% and 49% on the healthy side, respectively. These findings support Dehen's findings and hypothesis: R ₁ and R ₂ are not nociceptive skin reflexes, but tactile reflexes. ^[2]

CONCLUSION: Blink reflexes have been included in a tactile reflex study and have only just begun. Much clinical and animal research is needed to clarify this issue. From a clinical point of view, blink reflexes can help distinguish between true and pseudobulbar medulla, and help patients with aphasia and dysarthria to distinguish brain hemisphere damage from brainstem damage. ^[2]