Countdown to Moebius Syndrome Awareness Day 2019
test was the most sensitive for detection of brain stem dysfunction and was abnormal in most patients in whom it was performed. BAEPs also have the power to localize the lesion at the brain stem but have lower sensitivity. There was no correlation between the severity of the neurological impairment and the number of abnormal tests. Until neuroradiological studies designed to detect brain stem malformations in neonates or infants are routinely available, the combined use of different electrophysiological techniques provides the greatest diagnostic information during this period of life in BSD patients . Conventional radiology can be of great help in cases where bone malformations, TMA, velo-palatine incoordination, or gastroesophageal reflux are identified. Despite its poor diagnostic efficiency, standard MRI examination of suspected BSD patients is mandatory because it is crucial for detection of other pathologic conditions and allows the identification of patients with congenital oromotor disorders associated with CNS malformations, especially those with symmetrical perisylvian polymicrogyria [47,50].
Verzijl et al.  reviewed neuroradiological studies reported in 57 patients carrying the diagnosis of Möbius syndrome. Findings in 42 patients were considered unremarkable. Hypoplasia of the brain stem was demonstrated in 5 patients by CT studies and in 13 patients by MRI studies; a hypoplastic cerebellum was seen in 4 CT and 7 MRI studies. The use of modern MR imaging sequences, particularly current steady-state free precession (SSFP) sequences are particularly informative to delineate the morphology of the posterior part of the pons and medulla and for the reliable identification of the cranial nerves in their cisternal course, owing to greater spatial resolution for assessment . In our cohort, using the aforementioned sequences, more than 70% of cases depicted tegmental hypoplasia of varying degrees that mainly involved the dorsal aspects of the pons and medulla and, in three of them, the neuroradiological findings were asymmetric. In accordance with Verzjil and cols we have found that patients with mild or subtle BS hipoplasia have a better prognosis tan those with obvious BS hypoplasia who present clinically with swallowing and respiratory difficulties. It is likely that a more general application of these sequences will improve MR imaging efficacy for the diagnosis of brain stem malformations.
The prognosis of BSD depends on the cause and extent of the disruptive lesion or the impact of the abnormal developmental process involving the BS. In most non-genetic cases, the outcome is better than the initial clinical manifestations would indicate [9,12,29]. As mentioned previously, some neonates can present with a dysmaturative, reversible BS disorder described as ‘transient pharyngeal incoordination in the newborn’ or ‘syndrome de retard de maturation de la succion-déglutition’, for which the prognosis is excellent [52,53]. Once the diagnosis of BSD is made, a multidisciplinary team approach that covers developmental, neurological, behavioral, speech and language, and cognitive areas is essential [30,34].The sequelae and prognosis for the survival of BSD patients is determined by the severity of respiratory insufficiency and heart rate disturbances, the extent of the deglutition disorder, and the degree of gastroesophageal reflux. It is crucial to evaluate each patient individually in order to stablish a specific plan of treatment. Intervention programs must start soon after diagnosis is made and address the following goals: a) respiratory ; b) Safe and efficient oral feeding, in case of severe dysphagia determine the most appropriate moment to practice gastrostomy; c) Prevent joint ankylosis or deformities and, when indicated, use orthesis; d) Provide maximal limb motor independence; e) Improve, as much as possible, the level of verbal communication and provide alternative /augmentative methods of communication for those patients unable speak; f) Psicological g) educational [3,54].
The concept behind the term BSD has turned out a useful one: a) It provides a frame work that enables a systematic approach to diagnosis and research of most congenital disorders involving the brainstem; b) This generic term has the advantage over the eponyms MS, “expanded” or “unrestricted” MS, PRS, CFZS in that it provides a less restrictive view for this uncommon group of patients, allowing the inclusion of patients that present with concomitant alteration of high and low CN or in whom either the 6th or 7th cranial nerves are spared or when oculomotor apraxia is part of the clinical picture; and c) Places the emphasis on the natural history of this group of disorders which is of outmost importance for anticipating health problems and facilitate a better care. The challenge is to be able to predict the natural history of each of the forms of BSD and consequently offer the parents an accurate genetic counselling and the best possible therapies for the BSD form of their child. Children with congenital lesions involving selectively the brainstem are an extraordinary model through which to learn about, among other things, the relationship between initial feeding difficulties and speech motor disorders as well as the role of the brain stem in higher cortical functions.
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