Chapter 22 Two physiological aspects of the electrically elicited blink reflex: motor unit potentials recruitment and levator palpebrae inhibitory components

2006 ◽  
pp. 266-273
Author(s):  
Ángel Esteban ◽  
Julio Prieto ◽  
Alfredo Traba
Keyword(s):  
Motor Unit ◽  
Blink Reflex ◽  
Levator Palpebrae ◽  
Inhibitory Components

Spastic paretic hemifacial contracture in multiple sclerosis: a neglected clinical and EMG entity

2008 ◽  
Vol 14 (7) ◽  
pp. 927-932 ◽  
Author(s):  
G Koutsis ◽  
P Kokotis ◽  
P Sarrigiannis ◽  
M Anagnostouli ◽  
C Sfagos ◽  
...  
Keyword(s):  
Multiple Sclerosis ◽  
Motor Unit ◽  
Motor Units ◽  
Blink Reflex ◽  
Voluntary Contraction ◽  
Facial Nucleus ◽  
Facial Paresis ◽  
Relapsing Remitting ◽  
Uncommon Condition ◽  
Resting Activity

Background Spastic paretic hemifacial contracture (SPHC) is an uncommon condition, originally described as a sign of brainstem neoplasia, characterized by sustained unilateral contraction of the facial muscles associated with mild ipsilateral facial paresis. SPHC has only rarely been reported in the context of multiple sclerosis (MS). To further study and assess the frequency of SPHC in patients with MS. Methods We screened clinically 500 consecutive patients with MS for the presence of SPHC and further studied electrophysiologically any cases identified. Results We identified two patients who developed the condition during the course of an MS relapse. The estimated frequency of the condition was 0.4%. Both patients had relapsing–remitting MS. SPHC was characterized on Electromyography (EMG) by continuous resting activity of irregularly firing motor unit potentials, associated with impaired recruitment of motor units on voluntary contraction. Myokymic discharges were not present. Blink reflex studies were partly consistent with midpontine lesions in the vicinity of the facial nucleus ipsilateral to SPHC. MRI showed lesions in the ipsilateral dorsolateral midpontine tegmentum. Conclusions SPHC constitutes a rare but distinct clinical and EMG entity in patients with MS.

scholarly journals Electrophysiological assessment of the cranial reflexes

2021 ◽  
Vol 15 (4) ◽  
pp. 78-85
Author(s):  
Yury A. Seliverstov ◽  
Anna A. Abramova ◽  
Konstantin M. Evdokimov ◽  
Amayak G. Broutian ◽  
Marina Yu. Maximova ◽  
...  
Keyword(s):  
Nervous System ◽  
Neurological Disorders ◽  
Objective Assessment ◽  
Silent Period ◽  
Blink Reflex ◽  
Reflex Inhibition ◽  
Cutaneous Silent Period ◽  
Reflex Blink ◽  
Reflex Arc ◽  
Levator Palpebrae

Electrophysiological assessment methods play a key role in the diagnosis of various neurological disorders. Electrophysiological evaluation of cranial reflexes is particularly valuable for neurologists. This article provides an overview of electrophysiological evaluation methods for cranial reflexes, which are most commonly used in clinical practice. They provide objective assessment of the functional integrity of nervous system structures that make up the cranial reflex arc, identify the level and, in some cases, the nature of disease, as well as pathophysiological mechanisms of central and peripheral nervous system disorders. We describe the instruments and main approaches to analysing the results for the standard blink reflex, blink reflex with prepulse inhibition, blink reflex with paired stimuli and recovery curve evaluation, reflex inhibition of the levator palpebrae superioris, jaw jerk reflex, and reflex inhibition (cutaneous silent period) of the masseter muscle.

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