- Email: [email protected]
Types and characteristics of direction-changing positional nystagmus
OtolaryngologyHead and NeckSurgery August T999
P224 Scientific Posters
7O
Magnetic Resonance Imaging to Diagnose Subglottic Cysts of Infancy STEVEN R MOBLEY MD; GARY D JOSEPHSON MD FAAP; ESPERANZA PACHECO MD; Miami FL
Objectives: Subglottic cysts may be a cause of stridor and respiratory distress in the infant. The diagnosis is often confirmed during direct laryngoscopy and bronchoscopy; however, the astute clinician must be able to differentiate this from other lesions found in the subglottic region. We present a case of a 6-month-old infant with stridor in whom the diagnosis of subglottic cyst was confirmed on MRI. This allowed for appropriate surgical planning and counseling for the parents on expectations of the surgical outcome. We review and present the current literature on the diagnosis and treatment of subglottic cysts as well as present the novel approach of the use of MR1 in the diagnosis of this lesion. Methods: The study involved a case report and a literature review through MEDLINE of the English language literature. Results: A total of 63 cases of subglottic cysts were identified in the literature from 1968 to present. Most cases were diagnosed by direct laryngoscopy and bronchoscopy. We believe our case to be the first reported case diagnosed using MRI scanning. Treatments included direct rupture, cupped forceps excision, and laser ablation. Recurrence rates reported in the literature were low. Our case was successfuUy treated with laser ablation. Conclusion: The relative incidence of subglottic cysts in the newborn population has increased. This may be due to better identification and reportage and/or the advances in neonatology that have led to increased survival of intubated premature infants. Proper management of subglottic cysts requires early recognition, accurate diagnosis, and directed treatment. The majority of these lesions can be accurately diagnosed and treated during laryngoscopy and bronchoscopy. The use of MR/scanning has not been previously described to assist in the diagnosis of subglottic cysts. We advocate its use in selected cases as it assists in confirming the diagnosis preoperatively, allows a more definitive surgical plan, and allows directed parental counseling on expectations and outcomes from the surgical procedure. 71
Types and Characteristics of Direction-Changing Positional Nystagmus WOON KYO CHUNG MD; JUNG PYOE HONG MD; WON SANG LEE MD; SEUNG CHUL LEE MD; Seoul South Korea; Seoul South Korea; Seoul South Korea; Inchon South Korea
Objectives: Clinical features of positional nystagmus may be different according to its etiology. There have been some reports suggesting that direction-changing positional nystagmus (DCPN) could be seen in canalolithiasis and cupulolithiasis of the lateral semicircular canal. But DCPN can be seen
by other causes. The purpose of the study is to determine the etiologies and clinical features of various forms of DCPN and to assess the effectiveness of treatment. Methods: We investigated 27 patients with DCPN among 210 patients who had positional nystagmus. We classified DCPN into canal, cupular, and atypical types according to the duration and direction of positional nystagmus. Clinical features of DCPN were evaluated according to electronystagmographic reports and their etiologies. The results of physical therapy were evaluated. All the patients were followed up from 6 to 12 months prospectively. Results: We noted a canal type of DCPN in 13 patients, cupular type in 7 patients, and atypical type in 7 patients. The clinical features of the canal and cupular types were compatible with lateral semicircular canal lesions, but the atypical type was seen in other lesions such as congenital vestibular aplasia, acute labyrinthitis, brain stem arteriovenous malformation, and lesions of unknown origin. Patients with cupular or canal types were cured by physical therapy with or without a vibrator for the lateral semicircular canal, but the effect of treatment in the atypical type was variable. Conclusion: DCPN develops mainly in lateral semicircular canal lesions. But DCPN from nonlateral semicircular canal lesions presented as an atypical type. Physical therapy was successful for the lateral semicircular canal in DCPN of a peripheral lesion. Further studies are needed for the atypical type of DCPN. 72
The Role of the Two Bellies of Cricothyroid Muscle during Running Speech KI-HWAN HONG MD; WOO CHUL JUNG MD; Chonbuk South Korea
Objectives: The contraction of the cricothyroid (CT) muscle resulting in a decrease in the distance between the thyroid and cricoid cartilage is considered to be the main factor in lengthening the vocal folds. This CT muscle is composed of 3 distinct bellies: pars recta, pars oblique, and pars horizontalis. The function of each subunit is not clearly understood, although it is believed that they act differently because their fibers run in different directions. This study is designed to determine whether a difference exists in pars recta and pars oblique activity during running speech. Methods: Subjects were patients undergoing thyroidectomy during which the cricothyroid muscle was exposed. During surgery, pairs of hooked wire electrodes were inserted into the bellies of the pars recta and pars oblique. Several days after the surgery, the electrical activities of these were evaluated with running speaking tasks. The EMG signals were rectified, integrated, and smoothed using the Viking II EMG system. The EMG activities were analyzed according the patterns of intonation during running speech.
P224 Scientific Posters
7O
Magnetic Resonance Imaging to Diagnose Subglottic Cysts of Infancy STEVEN R MOBLEY MD; GARY D JOSEPHSON MD FAAP; ESPERANZA PACHECO MD; Miami FL
Objectives: Subglottic cysts may be a cause of stridor and respiratory distress in the infant. The diagnosis is often confirmed during direct laryngoscopy and bronchoscopy; however, the astute clinician must be able to differentiate this from other lesions found in the subglottic region. We present a case of a 6-month-old infant with stridor in whom the diagnosis of subglottic cyst was confirmed on MRI. This allowed for appropriate surgical planning and counseling for the parents on expectations of the surgical outcome. We review and present the current literature on the diagnosis and treatment of subglottic cysts as well as present the novel approach of the use of MR1 in the diagnosis of this lesion. Methods: The study involved a case report and a literature review through MEDLINE of the English language literature. Results: A total of 63 cases of subglottic cysts were identified in the literature from 1968 to present. Most cases were diagnosed by direct laryngoscopy and bronchoscopy. We believe our case to be the first reported case diagnosed using MRI scanning. Treatments included direct rupture, cupped forceps excision, and laser ablation. Recurrence rates reported in the literature were low. Our case was successfuUy treated with laser ablation. Conclusion: The relative incidence of subglottic cysts in the newborn population has increased. This may be due to better identification and reportage and/or the advances in neonatology that have led to increased survival of intubated premature infants. Proper management of subglottic cysts requires early recognition, accurate diagnosis, and directed treatment. The majority of these lesions can be accurately diagnosed and treated during laryngoscopy and bronchoscopy. The use of MR/scanning has not been previously described to assist in the diagnosis of subglottic cysts. We advocate its use in selected cases as it assists in confirming the diagnosis preoperatively, allows a more definitive surgical plan, and allows directed parental counseling on expectations and outcomes from the surgical procedure. 71
Types and Characteristics of Direction-Changing Positional Nystagmus WOON KYO CHUNG MD; JUNG PYOE HONG MD; WON SANG LEE MD; SEUNG CHUL LEE MD; Seoul South Korea; Seoul South Korea; Seoul South Korea; Inchon South Korea
Objectives: Clinical features of positional nystagmus may be different according to its etiology. There have been some reports suggesting that direction-changing positional nystagmus (DCPN) could be seen in canalolithiasis and cupulolithiasis of the lateral semicircular canal. But DCPN can be seen
by other causes. The purpose of the study is to determine the etiologies and clinical features of various forms of DCPN and to assess the effectiveness of treatment. Methods: We investigated 27 patients with DCPN among 210 patients who had positional nystagmus. We classified DCPN into canal, cupular, and atypical types according to the duration and direction of positional nystagmus. Clinical features of DCPN were evaluated according to electronystagmographic reports and their etiologies. The results of physical therapy were evaluated. All the patients were followed up from 6 to 12 months prospectively. Results: We noted a canal type of DCPN in 13 patients, cupular type in 7 patients, and atypical type in 7 patients. The clinical features of the canal and cupular types were compatible with lateral semicircular canal lesions, but the atypical type was seen in other lesions such as congenital vestibular aplasia, acute labyrinthitis, brain stem arteriovenous malformation, and lesions of unknown origin. Patients with cupular or canal types were cured by physical therapy with or without a vibrator for the lateral semicircular canal, but the effect of treatment in the atypical type was variable. Conclusion: DCPN develops mainly in lateral semicircular canal lesions. But DCPN from nonlateral semicircular canal lesions presented as an atypical type. Physical therapy was successful for the lateral semicircular canal in DCPN of a peripheral lesion. Further studies are needed for the atypical type of DCPN. 72
The Role of the Two Bellies of Cricothyroid Muscle during Running Speech KI-HWAN HONG MD; WOO CHUL JUNG MD; Chonbuk South Korea
Objectives: The contraction of the cricothyroid (CT) muscle resulting in a decrease in the distance between the thyroid and cricoid cartilage is considered to be the main factor in lengthening the vocal folds. This CT muscle is composed of 3 distinct bellies: pars recta, pars oblique, and pars horizontalis. The function of each subunit is not clearly understood, although it is believed that they act differently because their fibers run in different directions. This study is designed to determine whether a difference exists in pars recta and pars oblique activity during running speech. Methods: Subjects were patients undergoing thyroidectomy during which the cricothyroid muscle was exposed. During surgery, pairs of hooked wire electrodes were inserted into the bellies of the pars recta and pars oblique. Several days after the surgery, the electrical activities of these were evaluated with running speaking tasks. The EMG signals were rectified, integrated, and smoothed using the Viking II EMG system. The EMG activities were analyzed according the patterns of intonation during running speech.