Evidence map›Paper›PMID 39135835›Full record

ArticleCureus2024

Stretching of Mechanoreceptors in Superior Tarsal Muscle Reflexively Contracts Slow-Twitch Fibers in Facial Expression Muscles: A Case Series.

Kiyoshi Matsuo, Ai Kaneko

Abstract readCase Reports
In one paragraph

Article in Cureus, 2024. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 3 papers.

0numbers the graph read from it
0cells of the map it votes in
3citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

3 citing papers in PubMed.

  1. Article
  2. Article
  3. Article
4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

2 authors.

Kiyoshi MatsuoPlastic Surgery Oculoplastic Surgery, Matsuo Plastic and Oculoplastic Surgery Clinic, Hamamatsu, JPN.
Ai KanekoPlastic Surgery Oculoplastic Surgery, Matsuo Plastic and Oculoplastic Surgery Clinic, Hamamatsu, JPN.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

Levator palpebrae superioris muscle (LPSM) and facial muscles comprise fast-twitch fibers (FTFs) and slow-twitch fibers (STFs) but lack muscle spindles required to contract STFs reflexively. Voluntary contractions and microsaccades of FTFs in LPSM stretch mechanoreceptors in superior tarsal muscle (STM) to induce phasic contractions of STFs in LPSM and frontalis muscle via mesencephalic trigeminal nucleus (MTN). They also induce prolonged contractions of STFs in bilateral frontalis and orbital orbicularis oculi muscles and physiological arousal via MTN and rostral locus coeruleus (LC). We hypothesized that stretching of mechanoreceptors in STM also induces prolonged contractions of STFs in other facial expression muscles (FEMs) via rostral LC. To verify this hypothesis, we reported a case series of abnormal contractions of FEMs due to aponeurosis disinsertion and disordered mechanoreceptor stretching. The first and second cases, which showed unilaterally and bilaterally sensitized mechanoreceptors, respectively, recorded increased prolonged contractions of ipsilateral and bilateral grimacing muscles, respectively. The third and fourth cases with asymmetrically and bilaterally desensitized mechanoreceptors experienced asymmetrically and bilaterally decreased prolonged contractions of grimacing and smiling muscles, respectively. Preoperatively and after surgery was performed to adjust mechanoreceptor stretching and reinsert aponeuroses into tarsi, we evaluated prolonged contractions of grimacing and smiling muscles during primary gazing and facial expression movements. Surgery satisfactorily cured abnormal prolonged contractions of grimacing and smiling muscles. Stretching of mechanoreceptors in STM by microsaccades or voluntary contractions of FTFs in LPSM might activate rostral LC via MTN, which tonically or phasically stimulates FEM motor neurons to reflexively contract their STFs, respectively.

Indexed as

blepharoptosisblepharospasmexpressionless facefacial expression musclegrimacingmesencephalic trigeminal nucleusrostral locus coeruleussmilingsuperior tarsal muscletrigeminal proprioception

Identifiers

PMID39135835
PMCPMC11318954

What OpenQuestion holds

Textmetadata
LicenceCC BY
Read underepoch 390

Registered trials

None linked

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.