Distribution of the hypoglossal nerve at the base of the tongue and its clinical importance in radiofrequency ablation therapy.

AIM: To identify the course of the hypoglossal nerve at the base of tongue and to determine a safe area for the placement ofradiofrequency ablation therapy (RAT) probes to protect the nerve trunk from any damage. MATERIALS AND METHODS: Anatomical structures located at the base of the tongue were investigated in 10 cadaveric human half-heads. On the base of our landmarks, which are clinically important sign points, measurements were made. RESULTS: The safe area was found to be: in the transverse plane, the 1/2 medial part of the half-tongue between the lateral edge and the foramen caecum of the tongue, and in the vertical plane, a 14.5-mm depth. Despite the presence of minor branches of the hypoglossal nerve in this area, we think that the trunk of the nerve would be preserved. CONCLUSION: We suggest that the landmarks that we determined to avoid motor deficit of the tongue will be helpful for clinicians during RAT to the tongue base.

A methemoglobinemia case who was previously diagnosed and treated as asthma.

Methemoglobinemia, one of the rare causes of cyanosis and hypoxemia, may occur in congenital and acquired forms. Coexistence of cyanosis and hypoxemia suggests an etiology associated with an underlying cardiac disease firstly, but if any cardiac pathology exists pulmonary diseases are investigated generally. Considering bronchial asthma in a young patient with shortness of breath is usual. On the other hand, evaluating all the signs and symptoms together with laboratory results is important in diagnosis of rare diseases such as methemoglobinemia. In this paper we present a congenital methemoglobinemia case who was treated with bronchodilator therapy for a period of nearly five years because of misdiagnosis of asthma.