Recurrent Diplopia in a Pediatric Patient with Bickerstaff Brainstem Encephalitis.

Introduction. Acute complete external ophthalmoplegia is a rare finding in clinical practice that is associated with diseases affecting the neuromuscular junction, the oculomotor nerves, or the brainstem. Ophthalmoplegia has been reported with acute ataxia in Miller Fisher syndrome (MFS) and Bickerstaff brainstem encephalitis (BBE). Up to 95% of these cases are associated with anti-GQ1b antibodies. Only a small number of cases of anti-GQ1b negative MFS have been documented in pediatric patients. This is the first case reporting a recurrence of ocular symptoms in an anti-GQ1b antibody negative patient with BBE. Case Presentation. An 8-year-old Caucasian boy presented with complete external ophthalmoplegia without ptosis, cerebellar ataxia, and a disturbance of consciousness. He had recently recovered from a confirmed Campylobacter jejuni infection. On subsequent laboratory testing he was anti-GQ1b antibody negative. He had a recurrence of diplopia at four-week follow-up. Conclusions. This patient's recurrence of diplopia was treated with a five-week course of oral corticosteroids which did not worsen his condition, and this may be a therapeutic option for similar patients. We will discuss the symptoms and treatment of reported pediatric cases of anti-GQ1b antibody negative cases of MFS and the variation between cases representing a spectrum of illness.

Hydrocortisone administration increases pulmonary artery pressure in asphyxiated newborn piglets reoxygenated with 100% oxygen.

In severely asphyxiated neonates developing vasopressor-resistant shock, hydrocortisone is commonly used to improve perfusion. However, its acute haemodynamic effects in asphyxiated neonates are largely unknown. In a swine model of neonatal asphyxia, effects of hydrocortisone on systemic and pulmonary circulations were examined. Piglets (1-3d, 1.5-2.4kg) were acutely instrumented to measure heart rate, systemic and pulmonary artery pressures, and pulmonary artery flow. After 2h of normocapnic hypoxia, animals were resuscitated with 100% oxygen for 1h followed by 21% oxygen for 3h. Intravenous hydrocortisone (1mg/kg) or saline was given in a blinded, randomized fashion 2h after reoxygenation (n=6/group). Haemodynamic parameters, blood gases, plasma cortisol, as well as levels of endothelin-1, nitrite/nitrate, nitrotyrosine, matrix metalloproteinases-2 and -9 in the lung were analysed. Severe hypoxia caused metabolic acidosis (mean pH: 6.91-6.97, mean plasma lactate: 17.2-18.3mM), tachycardia and shock. Hydrocortisone did not affect systemic haemodynamics which recovered with reoxygenation, but it increased pulmonary artery pressure at 90-120min after administration (36±3 vs. 27±2 and 26±1mmHg for hypoxia-reoxygenation control and sham-operated piglets, respectively, P<0.05). In the lung tissue, hydrocortisone significantly increased endothelin-1 and nitrite/nitrate levels, but had no effect on nitrotyrosine. Further, it decreased lung matrix metalloproteinase-9, but not matrix metalloproteinase-2, activity, which were both elevated with hypoxia-reoxygenation. It is most likely that the increase in pulmonary artery pressure observed after hydrocortisone treatment was associated with increased endothelin-1 level in the lung. Our findings caution the use of hydrocortisone as a first-intention treatment of shock in asphyxiated neonates.

Plasma cortisol response to ACTH challenge in hypoxic newborn piglets resuscitated with 21% and 100% oxygen.

Although the use of supplemental oxygen to resuscitate asphyxiated neonates remains controversial, the effects of hypoxia and reoxygenation (room air versus pure oxygen) on the hypothalamo-pituitary-adrenal axis are unknown. We aimed to evaluate the effect of hypoxia and reoxygenation with either 21% or 100% oxygen on plasma cortisol before and after an adrenocorticotrophin (ACTH) challenge in newborn piglets. Thirty-five piglets (aged 1-3 days, weighing 1.5-2.4 kg) were instrumented to measure heart rate, MAP, and cardiac output. After 2 h of normocapnic hypoxia (PaO2, 20-30 mmHg; pH, <6.95), piglets were resuscitated with 21% or 100% oxygen for 1 h and then 21% oxygen for 3 h. Sham-operated piglets had no hypoxia-reoxygenation (H-R). Serial plasma cortisol levels were determined after a blinded randomized administration of ACTH (4 microg/kg, i.v.) or saline at 2 h reoxygenation. The expression of steroidogenic factor 1 in the adrenals was studied. Cardiac output decreased with hypoxia and recovered with resuscitation. Piglets developed hypotension similarly in 21% and 100% H-R groups during reoxygenation (versus sham-operated group, P < 0.05). Both H-R groups had increased plasma cortisol levels (versus sham-operated group, P < 0.05) at 2 h of reoxygenation after hypoxia, with a further increase in levels in 21% H-R piglets at 4 h reoxygenation (versus 100% H-R piglets, P < 0.05). The response to ACTH was delayed in H-R groups, with the maximum increase at 120 min post-ACTH administration (versus 30-60 min post-ACTH for sham-operated piglets). Plasma cortisol levels increased significantly post-ACTH administration in 21% H-R and sham-operated piglets (115% +/-50% and 126% +/- 25% at 120 min, respectively, P < 0.05 vs. pre-ACTH baselines) but not in 100% H-R piglets (51% +/-14%), which had a lower expression of steroidogenic factor 1 than the other groups. Although the clinical significance of high cortisol levels and cortisol response to ACTH in H-R newborn piglets is uncertain, a preserved cortisol response may support using room air in neonatal resuscitation.