Distribution of leptin receptors in the brain stem: possible route in the pathophysiology of neuromuscular control of airway resistance during sleep.

INTRODUCTION: Leptin, a hormone related to satiety, has been studied because of its association with obesity and sleep apnea. The distribution of leptin receptors in the brain stem, and in the hypoglossal nucleus, has not yet been described. The stimulation of these muscles has been studied in the treatment of sleep apnea. OBJECTIVE: to detail the presence of leptin receptors in the nuclei of these nerves to enable studies of stimulation of this region through leptin. METHODS: the brains of five cadavers, removed during necropsy, collected at the Death Verification Service were included. An informed consent was signed by a family member (wife, mother or son/daughter) who answered specific questionnaire concerning comorbities. Anthropometric measurements were recorded. The medulla oblongata and pons fragments were identified. Immunohistochemical staining analysis was performed to identify the location of the leptin receptors. RESULTS: In the immunohistochemical analysis an intense staining signal of the brownish coloration of neurons was evidenced in the hypoglossal nerve nucleus, moderate in the olivary nucleus and mild in the dorsal nucleus of the vagus and trigeminal nucleus. In motor neurons, more intense brown pigmentation can be observed in the nucleus and cytoplasm when compared to sensory neurons. CONCLUSION: The immunoexpression of leptin receptor was demonstrated in the motor neurons of the human hypoglossal nucleus. These results may contribute to unravel details of the pathophysiology of neuromuscular control of airway collapse during sleep and to the development of new drugs capable of improving the neuromuscular tone of upper airway in apneic individuals.

Lateral sphenoid sinus recess cerebrospinal fluid leak: a case series.

The lateral recess of the sphenoid sinus is one of the most common sites of meningocele and spontaneous cerebrospinal fluid (CSF) leak. Despite the availability of several techniques for closure of skull base defects occurring in this location, recurrence still poses a major challenge. This report reviews the experience of surgical repair of lateral sphenoid sinus recess CSF leak at a tertiary referral center and provides a brief discussion of this rare lesion. Nine surgeries were performed for six cases of spontaneous lateral sphenoid sinus recess CSF leak (two revisions and one repair of a new defect). Two patients presented with intracranial hypertension (ICH) and four with meningocele or meningoencephalocele. The transpterygoid approach was used in two procedures. A multilayer graft was used in seven cases and a nasoseptal flap in two. Three patients received lumbar or ventricular shunts, and one received acetazolamide for ICH management. Two minor complications were recorded, and the overall surgical success rate was 78 %. We conclude that nasoseptal flaps are a valid option for repair of recurrent CSF leaks, particularly in the lateral sphenoid sinus recess. Furthermore, identification and correction of ICH plays an essential role in the success of treatment in this patient population.