Direct projections from the nucleus retroambiguus to cricothyroid motoneurons in the cat.

Vocalization can be elicited by stimulation in the periaqueductal gray (PAG). Light-microscopical tracing and physiological studies have revealed that the PAG uses the nucleus retroambiguus (NRA) as a relay to excite the vocalization muscle motoneurons. Direct NRA projections have been demonstrated to pharyngeal and abdominal wall muscle motoneurons, but not to laryngeal motoneurons. In two cats 0.1% cholera toxin subunit b was injected in the cricothyroid muscle of the larynx to retrogradely label its motoneurons, and 2.5% wheat germ agglutinin-horseradish peroxidase was injected into the NRA to anterogradely label its fibers. The electronmicroscopical results indicate that the NRA fibers make monosynaptic contacts with cricothyroid motoneuronal dendrites. Almost all NRA terminal profiles had asymmetrical synapses and contained mostly round or pleiomorphic vesicles, which strongly suggests that the NRA-cricothyroid motoneuronal projection is an excitatory pathway.

[The immobile vocal cord]. / De stilstaande stemband.

Usually dysphonia is the result of a functional disorder of the larynx. It can also result from paresis or paralysis of a hemilarynx. Four patients, men aged 57, 41, 42 and 18 years, had a neurological cause of paralysis of a hemilarynx. Processes responsible for this kind of pathology can appear at three different levels: central, nuclear and peripheral. Each of the four patients had a disorder at the peripheral level: two had a tumour, in one the vagus nerve was severed during lobectomy for squamous cell carcinoma (iatrogenic), and in the last one an upper respiratory viral infection was the probable cause. Other causes of these peripheral lesions are toxicological, traumatic or idiopathic. When dysphonia does not improve within three weeks, inspection of the larynx and palpation of the neck, including examination of the aspect and mobility of the vocal folds by an otorhinolaryngologist should be performed. If paresis of a hemilarynx is seen, an orientation examination of the cranial nerves and selective additional examination is necessary, as paresis of a hemilarynx is a symptom, not a diagnosis.

[Complaints and complications associated with removal of the mandibular third molar. A prospective clinical study]. / Nabezwaren en complicaties na verwijdering van de derde molaar in de onderkaak. Een prospectief klinisch onderzoek.

OBJECTIVE: To study the incidence of complaints and complications after removal of the mandibular third molar and to evaluate the influence of this procedure on functioning of the patient during the first post-surgical week. DESIGN: Prospective, clinical. SETTING: Department of Oral and Maxillofacial Surgery, University Hospital Groningen. METHODS: Patients referred for removal of a mandibular third molar were asked to return one week after the procedure and to keep a daily record of the use of pain medication, duration of the pain and intensity of the pain. RESULTS: Removal of mandibular third molars resulted in an overall complication rate of 12%. Pain medication was used more frequently and for a longer period by patients with post-surgical complications. Due to complaints following the removal of the mandibular third molar, the mean absence from work was one and a half day. Work was generally resumed with decreased perceived efficiency. CONCLUSION: After this commonly performed procedure in dento-alveolar surgery most of the patients were hampered as a result of pain during the first four post-surgical days. Over 10% of the patients developed complications leading to more frequently and prolonged use of pain medication. Removal of the mandibular third molar gave rise to complaints which influenced the patients relatively strong in their daily functioning.