Olfactory Evaluation in Children: Application to the CHARGE Syndrome

Abstract

ABSTRACT. Objective. To find an efficient tool for testing olfactory function in children and use it to investigate a group of children with CHARGE (coloboma, congenital heart disease, choanal atresia, mental and growth retardation, genital anomalies, and ear malformations and hearing loss) syndrome.Methods. We adapted for children an olfaction test that had just been validated in an adult French population and investigated a control group of 25 healthy children aged 6 to 13 years. We then tested the olfactory capacity of a group of 14 children with CHARGE syndrome, aged 6 to 18 years. A questionnaire was completed with the parents about their children's feeding difficulties and their ability to recognize odors in everyday life. We recorded and scored the histories of feeding behavior anomalies, the visual and auditory status, and current intellectual levels. MRI of the olfactory tracts and bulbs was analyzed for 9 of 14 children.Results. We showed that healthy children have similar olfactory function to that of the adult control group, which was representative of the general population, without any difference for either gender or age. We also showed that all children with CHARGE syndrome had olfactory deficiency. Half of them were anosmic, and the others had olfactory residual function (hyposmic). We found no association between olfactory deficiency and feeding behavior, visual or auditory impairment, or intellectual level. Parental subjective evaluations were accurate for only half of the group. All of the MRIs showed anomalies of the olfactory tracts and bulbs varying from moderate hypoplasia to complete aplasia, without any relation between the radiologic and the functional results.Conclusions. Olfaction can be assessed in children, even the young and disabled. Our results support the proposition that rhinencephalon anomalies should be included as a major criterion for the diagnosis of CHARGE syndrome. ABBREVIATIONS. CHARGE, coloboma, congenital heart disease, choanal atresia, mental and growth retardation, genital anomalies, and ear malformations and hearing loss; PEA, phenylethylalcohol. O lfaction has always been and remains the most neglected sense in studies of child development and behavior, the main reasons being the poor knowledge concerning the role of olfaction in human development and behavior and the lack of available tools for investigating olfaction, in particular in children. Development of the olfactory system begins very early in the human embryo; olfactory bulbs have their definitive structure at day 56. Then, cells of the olfactory placode differentiate to gonadotropic cells and migrate to the hypothalamic region along the terminal nerve (cranial nerve 0), the olfactory nerve (cranial nerve 1), and the vomeronasal nerve. One part of the olfactory system projects to the anterior part of the hypothalamus for odor perception and discrimination; the other projects to the limbic system and the hippocampus for the behavioral impact of olfaction and olfactory emotional memory. 1 The Jacobson vome...

Embryonic expression profile of chicken CHD7, the ortholog of the causative gene for CHARGE syndrome

“…Documentation of cChd7 in the olfactory placode may shed light on the pathogenesis of genital anomalies in CHARGE syndrome. Chalouhi et al (2005) recently demonstrated that CHARGE syndrome patients fulfill the criteria for Kallmann syndrome, which combines hypogonadotropic hypogonadism with various degrees of deficiency in the sense of smell as a result of olfactory bulb aplasia or hypoplasia. Because hypogonadism in Kallmann syndrome results from the failed embryonic migration of GnRH-synthesizing neurons along the olfactory nerve pathway (Schwanzel-Fukuda et al, 1989), they suggested that hypogonadotropic hypogonadism in CHARGE syndrome may result from the same embryonic defect (Chalouhi et al, 2005).…”

CHARGE syndrome: an update

“…39 It was observed by MRI scan in 18/18 patients. 38 Anosmia has recently be found to be a common anomaly, 40 in relation with abnormal olfactory bulbs.…”

Abnormal Basiocciput Development in CHARGE Syndrome

“…15 In the radiologic diagnostic methods, Chalouhi et al 11 reported that anomalies of the olfactory bulbs and tracts might be pathognomonic for CHARGE syndrome and should be included as a major criterion for the diagnosis of this syndrome; Blustajn et al 10 recently reported that these anomalies were the most prevalent features of CHARGE syndrome. The present study showed that basioccipital hypoplasia and basilar invagination are significantly prevalent in the syndrome.…”

“…[10][11][12] We encountered a few children with severe hypoplasia of the basiocciput during a radiologic assessment of patients with CHARGE syndrome. Basiocciput hypoplasia results in shortening of the clivus and is always associated with basilar invagination.…”