Jamir Pitton Rissardo Profile picture
Nov 30, 2022 16 tweets 7 min read Read on X
Glabellar reflex (Myerson's sign)!!!

"the preliminary note on a new cranial reflex"

British doctor Walker Overend (1858–1926)

#MedTwitter #neurotwitter #EndNeurophobia #tweetorials

1/ Image
Glossary

Glabellar reflex
Habituation
Myerson’s sign
Primitive reflex

2/ Image
History

1896, Dr. Walker Overend
- first report

1901, Dr. Daniel J. McCarthy
- published a 2nd report without acknowledging Overend

1944, Dr. Abraham Myerson
- observed, mainly, in PD

1954, Dr. Doshay
- called Myerson’s sign

3/ Image
Pathophysiology

poorly understood, probably partially related to the blink reflex

Afferent: V CN (supraorbital nerve)
Efferent: VII CN (orbicularis oculi muscle)

moderated by
- cortical areas, especially the frontal lobe
- subcortical areas, especially basal ganglia

4/ Image
Clinical use

a)may present healthy pts & infants

b)inc prevalence w/ age

c) disease severity

d)differentiate PD from ET (Nuuttila 2021)
- sensitivity 78.3% & specificity 36.2%

e)reverse after levodopa in PD (Klawans 1969)
- 50%
- no reverse: dementia & severe PD

5/
Definition

“unable to resist blinking when tapped repetitively on the glabella”

How many times to tap till be abnormal?

The magic number is “five” based in pediatric studies
(Zametkin et al 1979)

6/
Glabellar reflex – features

“unable to resist blinking when tapped repetitively on the glabella”

- primitive reflex
- aka Myerson's sign
- PD and dementia, severity?

7/
Glabellar reflex

“unable to resist blinking when tapped repetitively on the glabella”

- primitive reflex
- aka Myerson's sign
- PD and dementia, severity?

via: Neurology Made Interesting

8/
Glabellar reflex

“unable to resist blinking when tapped repetitively on the glabella”

- primitive reflex
- aka Myerson's sign
- PD and dementia, severity?

via: Neurology Made Interesting

9/
Glabellar reflex

“unable to resist blinking when tapped repetitively on the glabella”

- primitive reflex
- aka Myerson's sign
- PD and dementia, severity?

via: Dr. Sourya Acharya

10/
Glabellar reflex

“unable to resist blinking when tapped repetitively on the glabella”

- primitive reflex
- aka Myerson's sign
- PD and dementia, severity?

youtube.com/shorts/GRqAgon… via: Neurozone videos

11/
Glabellar reflex

“unable to resist blinking when tapped repetitively on the glabella”

- primitive reflex
- aka Myerson's sign
- PD and dementia, severity?

via: Osama SM Amin

12/
Glabellar reflex

“unable to resist blinking when tapped repetitively on the glabella”

- primitive reflex
- aka Myerson's sign
- PD and dementia, severity?

via: Neurolibrary

13/
Glabellar reflex

“unable to resist blinking when tapped repetitively on the glabella”

- primitive reflex
- aka Myerson's sign
- PD and dementia, severity?

youtube.com/shorts/UFokLDz… via: Dr Hamza Khan Malezai

14/
Glabellar reflex

“unable to resist blinking when tapped repetitively on the glabella”

- primitive reflex
- aka Myerson's sign
- PD and dementia, severity?

via: Dr. Ravi Ranjan Kindo

15/
Other frontal release signs

Palmar grasp, palmomental, rooting & sucking, snout, corneomandibular reflex, and head retraction reflex


16/

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1/ imdb.com/pt/name/nm0000031/?reasonForLanguagePrompt=browser_header_mismatch
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2/ youtube.com/shorts/uMA_wPY…
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