The laryngeal cough reflex in congenital muscular torticollis: is it a new finding?

Cinical experience has shown us that some infants with congenital muscular torticollis have a cough reflex while stretching the sternocleidomastoid muscle. The objective of this study is to present a case series with the maneuver inducing the cough reflex and facial color change and to provide the possible mechanism underlying this phenomenon. This is a case series from a prospective cohort. Among 290 children with congenital muscular torticollis who came to a single torticollis clinic from January to December 2008, the children who showed cough reflex were consecutively enrolled. Twenty-four infants (8.28%) showed the cough reflex. The age of first presentation with congenital muscular torticollis was 37.65 +/- 19.60 days old. They showed 57.5 +/- 7.3 degrees of the passive cervical rotation to the congenital muscular torticollis side at the initial visit. The mean thickness of the sternocleidomastoid muscle in those with cough reflex was 13.79 +/- 1.96 mm at the side of congenital muscular torticollis and 5.43 +/- 0.85 mm on the contralateral side. The cough reflex disappeared, and 90 degrees of passive cervical rotation to the congenital muscular torticollis side were regained with stretching exercises and/or surgical release in all 24 children. One of the possible mechanisms for this cough reflex is surmised to be the mechanical irritation of the internal branch of the superior laryngeal nerve during the maneuver, which is one of the branches of the vagus nerve and is responsible for the sensation of the mucous membrane of the larynx. 8.28% of the infants with congenital muscular torticollis showed positive sign of cough reflex and had at least double or more thickness of the sternocleidomastoid muscle compared with that of unaffected sternocleidomastoid muscle and, at the same time, had 60 degrees or less of passive cervical rotation toward the affected side. To the best of our literature review, this laryngeal cough reflex is a new finding that has never been described before. One of the possible mechanisms for this cough reflex is surmised to be the mechanical irritation of the internal branch of the superior laryngeal nerve during the maneuver, which is one of the branches of the vagus nerve, acting as the afferent nerve of laryngeal cough reflex.

Normative data and developmental characteristics of hand function for elementary school children in Suwon area of Korea: grip, pinch and dexterity study.

This study was designed to establish norms of hand function, and to identify developmental characteristics of hand function among the Korean children. 712 elementary school children participated in measurement of grip strength, three kinds of pinch strength, and dexterity. The hand strength of the Korean children appeared to be weaker than that of western children. The grip strength of boys was significantly stronger than that of girls in all ages for both hands. The order of magnitude of three kinds of pinch strength was, in descending order, lateral pinch, palmar pinch and tip pinch for both boys and girls. There was no significant difference of hand function according to the type of hand dominance in boys. However, girls with left hand dominance showed weakness of bilateral grip, right tip pinch, and bilateral lateral pinch strength compared with girls with right hand dominance. In conclusion, this study provided normative data of hand functions including dexterity, and enabled us to identify some developmental characteristics of hand functions for the Korean elementary school children.

The prevalence of mental retardation among third grade elementary school children in the Suwon area, Korea.

The purpose of this study was to estimate the prevalence of mental retardation (MR) in Korea. The study population comprised 1,757 third-grade elementary school children residing in a single school district in Suwon, Korea. We conducted the total population survey for 1,537 children who attended one of 5 schools in the district. For the remaining 220 children who did not attend a school in the school district, we found children with MR via inspection of the register list of the disabled. A total of 16 children (7 of the 1,537 children and 9 of the 220 children) were found to have MR, yielding a prevalence of MR of 9.1/1,000. Considering that about 60% of the people with disabilities are registered in Korea, there would be at least 6 unregistered children with MR among the 220 children, so that the prevalence of MR can be estimated at 12.5/1,000 for the Suwon area.