Infant aspiration and associated signs on clinical feeding evaluation.

OBJECTIVES: Few studies have examined clinical signs of aspiration in infants <51 weeks post-menstrual age (PMA) for whom the laryngeal cough reflex is not fully developed. This retrospective study explored 1) the association between signs of aspiration on a clinical feeding evaluation (CFE) and/or comorbid conditions with aspiration (silent or overt) on a modified barium swallow study (MBS) for infants in this age range, 2) the association between lower respiratory infection (LRI) and aspiration on MBS, and 3) the sensitivity and specificity of detecting aspiration according to signs on CFE and the evaluating speech-language pathologist's (SLP) years of experience. METHODS: A retrospective review of charts of patients with MBS completed January 1, 2012-December 31, 2014 was performed. Patients were included if they were <51-weeks PMA at the time of MBS and had a CFE conducted no more than seven days prior to the MBS. Patient age, comorbidities, and MBS and CFE details were collected. The impact of CFE findings, patient age, comorbid syndromes/associations, and aerodigestive diagnoses on the odds of demonstrating silent aspiration (SA) or overt aspiration during MBS with thin liquids was determined using logistic regression, and the sensitivity and specificity of CFE for identifying SA was calculated. RESULTS: Results from 114 patients indicated that 46 (40 %) of the infants had SA and nine (8 %) had overt aspiration on MBS. Notable signs on CFEs were cough (36 %), oxygen desaturations (33 %), and chest congestion (32 %). On multiple regression analysis there was increased odds of SA on MBS with at least one clinical sign on CFE (OR: 24.3, p = 0.02), chronic lung disease, (OR: 18.2, p = 0.01), and airway abnormalities (OR: 2.94, p = 0.01). Cough on CFE was associated with increased odds of overt aspiration on MBS (OR: 5.69, p = 0.04). Neither SA nor overt aspiration were significantly associated with LRI. Sensitivity and specificity of CFE for correctly identifying the presence of SA were 98 % and 15 %, respectively; experience of the SLP was not a contributing factor. CONCLUSION: Further study is required to determine if specific signs on CFE are predictive of aspiration.

Consideration of Cough Reflex Development When Ordering Modified Barium Swallow Studies in Infants.

Infants < 51 weeks post-menstrual age (< 51 PMA) are often referred for modified barium swallow (MBS) studies for suspected silent aspiration (SA) given a possible association between SA and aspiration pneumonia. Infants this young are unlikely to have developed a mature laryngeal cough reflex, most likely rendering SA an expected finding in those who aspirate. The aims of this retrospective review were to (1) determine if SA resolves in a significant proportion of infants around the expected emergence of the laryngeal cough reflex, (2) determine which factors or characteristics are associated with and without SA resolution in these infants, and (3) determine if SA, or any aspiration, is associated with increased rates of lower respiratory infection (including aspiration pneumonia) in these infants. Results from the chart review revealed that 79/148 (53.4%) infants had SA on MBS < 51 PMA. 16/48 (33.3%) infants assessed for SA by the time of the expected emergence of the cough reflex had resolution. SA resolution was less common in infants with obstructive sleep apnea (p = 0.037). A total of 50/70 (71.4%) infants with a follow-up MBS had eventual SA resolution. Aspiration was not significantly associated with LRI, including aspiration pneumonia. The results suggested that the laryngeal cough reflex might develop later than reported in the literature and there is no association between aspiration and LRI. These findings may indicate that age should be considered before ordering an MBS solely to assess for SA in this population. The study provides preliminary evidence for future prospective research regarding SA resolution.

Infantile hypophosphatasia secondary to a novel compound heterozygous mutation presenting with pyridoxine-responsive seizures.

Hypophosphatasia (HPP) is a rare metabolic disease with the hallmark finding of deficient serum tissue nonspecific alkaline phosphatase (TNSALP) activity. TNSALP is primarily known for its role in mineralization; hence, HPP is characterized by defective mineralization of bone and/or teeth. TNSALP is also necessary for proper vitamin B6 metabolism and its participation as a cofactor for neurotransmitters in the central nervous system. Defective TNSALP activity in the brain can result in intractable seizures responsive to pyridoxine. The pathophysiology of pyridoxine-responsive seizures (PRS) in severe HPP remains to be clearly defined. We review the case of a 2-month-old Caucasian boy presenting with seizures refractory to conventional antiepileptic medications. Empiric treatment with favorable response to pyridoxine in conjunction with severe metabolic bone disease, extremely low serum alkaline phosphatase, elevated phosphoethanolamine, hypercalcemia, hypercalciuria, and nephrocalcinosis led to a clinical diagnosis of infantile HPP. Sequence analysis revealed compound heterozygosity of the TNSALP gene with a novel mutation in exon 9 and a previously reported mutation in exon 12. This case reminds the physician that severe infantile HPP can present with PRS as its major initial manifestation and should alert clinicians to consider HPP in their differential of PRS. In addition, despite this severe genotype, the clinical diagnosis of our patient was delayed because of minimal phenotypic features initially. This highlights that the phenotype-genotype correlation could be variable even in severe disease. This case also demonstrates that HPP should be classified as PRS and not a form of pyridoxine-dependent epilepsy (PDE) as our patient was able to stop the pyridoxine supplementation without seizure recurrence once enzyme replacement was initiated. With the advent of enzyme replacement therapy, this once fatal disease may have improved morbidity and mortality.