alternative methods like laryngeal masks or even an urgent tracheostomy may be needed (30). It is important to remember that patients with pontine involvement may develop a central hypoventilation syndrome owing to a lesion that includes the para-facial respiratory group of neurons . Feeding problems are extremely important and can be life-threatening if not diagnosed and appropriately treated. Failure to protect the airway results in massive aspiration in some patients; In less severe cases swallowing disorders may go unnoticed or be subclinical and be misdiagnosed as reactive bronchitis and can be the cause of multiple admissions and chronic pulmonary damage. Aspiration leading to bronchial syndrome requires respiratory physiotherapy, antibiotics, and anti-inflammatory agents. Treatment of pulmonary disease must be complemented by measures such as food texture modification, dietetic review, parental counselling, and re-education aimed at preventing failure to thrive. Nasogastric tube feeding is indicated when the food volume required to meet the caloric needs is greater than the oral abilities of the infant to accommodate this volume load  In some patients, gastrostomy feeding is imperative. In these circumstances it is important to establish the presence and degree of concomitant gastroesophageal reflux. Gastrostomy is necessary in cases of severe dysphagia persisting for several months and when it is associated with gastroesophageal reflux. The issue of simultaneous surgical correction of gastroesophageal reflux when performing gastrostomy to avoid massive aspiration is still under debate [3,30,36]. Abnormal growth and shape of the jaw and palate, due to the inappropriate innervation of facial and intra-oral structures, are common in BSD patients and cause progressive tooth misalignment and/or malocclusion. Infants and children with facial diplegia, in addition to their initial difficulty with sucking and swallowing, will suffer from diminished or lost facial expression and difficulties with oral and mimic communicative functions along with the resulting psychological consequences. In addition to the initial difficulties in feeding, velopalatine incoordination, facial diplegia, and TMA may be the origin of the speech articulatory problems that are quite frequent in this group of patients as they grow older . Persistent drooling is common in BSD because of difficulties with swallowing and lip closure. Less-affected patients accommodate to this problem while others improve with age. In some cases, poor handling of only saliva can produce repeated silent micro-aspiration and lead to chronic lung injury [3,30]. Drooling cause distress, as it is socially isolating, interferes with school or work, and leaves chronically irritated skin that may become infected. Tooth decay is particularly common in children who are tube fed or who have reduced saliva due to medication or surgery. Surgery has been proposed to improve facial expressions and lip closure; the recommended age for this type of intervention is 5 to 6 years . Development of language in children with BSD who present with facial and lower brainstem involvement is delayed and always accompanied by problems with speech articulation. The patterns of speech dysfunction seen in these patients range from mild to severe dysarthria associated with dyspraxic inconsistencies. The main articulatory problems relate to phonemes that require intact labial motor function such are P,B,M, or sounds that involve friction of the tongue against the palate such are R, FR, PR. The quality of speech production may be worsened by conductive hearing problems secondary to chronic serous otitis which is caused by Eustachian tube malfunction due to the secondary deformities of intra-oral structures and velo-palatine insufficiency . It has been common to loosely refer to the defects in ocular motility in patients with multiple CN involvement as abducens paralysis or external rectus paralysis. However, in almost every case in which they have been examined in detail later in childhood or adulthood, it is evident that ocular motility pointing at the pathways reaching the center for horizontal saccades or the center itself, as the site of the lesion in congenital ocular motor apraxia. Furthermore, a common pathogenic mechanism could underlie the speech articulatory problems observed in the BSD patients and those with congenital oculo-motor apraxia of unknown origin . Lack of appropriate innervation of palpebral muscles and lacrimal glands gives rise to a poor corneal humidification and increases the risk of ulcers that may require surgical replacement by amniotic membrane. Cognitive development of patients with BSD is closely related to its clinical form; is seldom involved in the intermediate or restricted forms but is frequently altered in the diffuse forms of BSD. In the cohort of patients with expanded MS, reported by Fons et al. , psychomotor retardation was recorded in 60% of the subjects during the first few years of live and, on follow-up, 27 % of the surviving members of the cohort had moderate to severe intellectual disability. In the cohort of 22 patients with the diagnosis of MS and older than 18 years, Pérez Aytés  (Fundación SM web page) reported that 6 of them completed university studies; 7 concluded high school studies and 9 finished elementary studies. Social and work integration was adequate and 11 of these 17 individuals, however, episodes of fear and anxiety were reported during adolescence in all of them. Chorazy and cols. (40) described the natural history of a 32 years old patient with MS who was able to complete university studies and his major disability were social interaction difficulties owing to his lack of facial expression and dysarthria. Most individuals of our cohort were in school age, half of those who could reliably perform an IQ test, gave abnormal results, most of them fulfilling criteria of attention deficit disorder. Three patients of our BSD cohort have shown signs compatible with the Autistic Disorder Spectrum (ADS). It should be noted that although most experts relate ADS to cerebral cortical dysfunction, BS involvement has been reported as another possible pathogenic mechanism of autism. Hashimoto et al. in 1993 (41) described a decrease in size of the BS and cerebellar vermis in a MRI study of children with autism. Courchesne et al. in 1997 (42) summarized the BS pathological findings in ADS: a) superior olive agenesis, b) facial nuclei dysgenesis, c) reductionof Purkinje neurons and d) BS and cerebellar hypoplasia. Gillberg and cols  reported ten cases of ADS in a cohort of patients with “expanded MS”; they postulated an early neuro-embryologic defect giving rise to a dysfunction of BS structures as the basis of ADS. This syndrome has also been reported in individuals prenatally exposed to thalidomide, misoprostol or cocaine [44,45]. In our opinion, the lack, of an accurate clinical selection criteria in most published cohorts does not allow a reliable correlation between BS involvement and ADS. Our experience shows that no patient with intermediate or restricted forms of BSD presented with ADS. The diffuse forms of BS involvement are at more risk to associate with the ADS. Hopefully, future research on different clinical forms of BSD will point to the disrupted areas of BS most likely to give raise to ADS.
Finally, social psychologists comment that the perception of an individual by others is heavily influenced by first appearance [3,46]. The interaction with someone who has diffuse or intermediate forms of BD is therefore compromised before spoken communication even begins. In addition to facial inexpressiveness and speech involvement, more intimate issues such as drooling result in the social exclusion of disabled individuals from school or society. To improve the prognosis in this group of patients, it is imperative to anticipate these issues and consider interventions that will help children to develop and maintain relationships as they grow into adulthood and avoid the risk of social exclusion.
Diagnosis in infancy and childhood
Diagnosis of BSD relies heavily on the appropriate interpretation of clinical findings during the neonatal period and it is difficult to achieve unless is suspected as early as possible. Once hypotonia subsides and the other presenting symptoms improve, facial diplegia, feeding difficulties, poor handling of oral secretions, dysarthria, and signs of pyramidal tract involvement, including a brisk jaw jerk are the remaining symptoms. Therefore, it is conceivable that patients in whom the diagnosis of BSD was missed in early infancy will be diagnosed as atypical forms of cerebral palsy or Worster-Drought syndrome when evaluated during childhood .
All of the available electrophysiological studies (NCV, EMG, blink reflex, BAEPs, sleep EEG with polysomnographic recording) are difficult to perform and evaluate in neonates or infants; nonetheless, they are crucial for identifying the brainstem origin of this disorder [1,31,48,49]. Moreover, EMG/NCV studies performed soon after birth are essential for excluding other muscular or PNS involvement. Myotonic dystrophy, spinal muscular atrophy, or other congenital myopathies that may present with a clinical picture similar to BSD can additionally be excluded by the appropriate molecular genetic studies . Neurophysiological studies performed in most of our cohort of patients throughout their follow-up period showed abnormalities in more than one test depending on the extent of the brainstem involvement. The blink reflex