Erik H. Waldman

A “Synaptoplasmic Cistern” Mediates Rapid Inhibition of Cochlear Hair Cells

Cochlear hair cells are inhibited by cholinergic efferent neurons. The acetylcholine (ACh) receptor of the hair cell is a ligand-gated cation channel through which calcium enters to activate potassium channels and hyperpolarize the cell. It has been proposed that calcium-induced calcium release (CICR) from a near-membrane postsynaptic store supplements this process. Here, we demonstrate expression of type I ryanodine receptors in outer hair cells in the apical turn of the rat cochlea. Consistent with this finding, ryanodine and other store-active compounds alter the amplitude of transient currents produced by synaptic release of ACh, as well as the response of the hair cell to exogenous ACh. Like the sarcoplasmic reticulum of muscle, the “synaptoplasmic” cistern of the hair cell efficiently couples synaptic input to CICR.

Factors contributing to cost in partial versus total tonsillectomy

To examine differences between total tonsillectomy and partial intracapsular tonsillectomy techniques that may lead to differences in overall cost and resource utilization between these procedures. Preoperative, perioperative, and postoperative management and outcome factors were examined.

Ablation Studies on the Developing Inner Ear Reveal a Propensity for Mirror Duplications

The inner ear develops from a simple ectodermal thickening known as the otic placode. Classic embryological manipulations rotating the prospective placode tissue found that the anteroposterior axis was determined before the dorsoventral axis. A small percentage of such rotations also resulted in the formation of mirror duplicated ears, or enantiomorphs. We demonstrate a different embryological manipulation in the frog Xenopus: the physical removal or ablation of either the anterior or posterior half of the placode, which results in an even higher percentage of mirror image ears. Removal of the posterior half results in mirror anterior duplications, whereas removal of the anterior half results in mirror posterior duplications. In contrast, complete extirpation results in more variable phenotypes but never mirror duplications. By the time the otocyst separates from the surface ectoderm, complete extirpation results in no regeneration. To test for a dosage response, differing amounts of the placode or otocyst were ablated. Removal of one third of the placode resulted in normal ears, whereas two‐thirds ablations resulted in abnormal ears, including mirror duplications. Recent studies in zebrafish have demonstrated a role for the hedgehog (Hh) signaling pathway in anteroposterior patterning of the developing ear. We have used overexpression of Hedgehog interacting protein (Hip) to block Hh signaling and find that this strategy resulted in mirror duplications of anterior structures, consistent with the results in zebrafish. Developmental Dynamics 236:1237–1248, 2007.

Not a “sound” decision: Is cochlear implantation always the best choice?

OBJECTIVE To review the candidacy criteria used to counsel parents of profoundly deaf children, to determine if these criteria have changed over time, and to evaluate eventual communication outcomes for these patients. DESIGN Retrospective review of 483 pediatric cochlear implant candidates from September 1995 to December 2006 seen at a tertiary care pediatric hospital. RESULTS Out of 483 implant candidates, 191 patients were initially felt not to be favorable candidates based on CI team evaluation. Of this group, 3 had insufficient records to review and were excluded. The remaining 188 patients underwent a detailed analysis of specific possible contraindications to implantation. This included audiologic, medical and psychosocial parameters. The data was divided into two time periods: Group 1 included 44 patients from 1995 to 2000, and Group 2 included 144 patients from 2001 to 2006. In Group 1, there was a higher percentage of children with language deprivation and developmental concerns and patients not ready, compared to Group 2 which had a higher percentage of families not ready and inadequate support systems. Group 1 had a higher percentage of patients who ultimately underwent cochlear implant, but otherwise the two groups were largely similar. CONCLUSION Analysis of our data showed that the degree of concern that the cochlear implant team has in relationship to specific candidacy criteria has changed over time. Recommendations against a cochlear implant were often revisited after initial concerns were addressed. The use of a team approach, in conjunction with a validation tool, is important for establishing criteria for successful cochlear implantation in children to support appropriate counseling of patients and families and to plan post-implant management.

Sir Charles Alfred Ballance: contributions to otology and neurotology.

Study Design: A review of primary and secondary historical and scientific literature concerning the life and writings of Sir Charles Alfred Ballance (1856-1936). Results: Sir Charles Alfred Ballance was a pioneer in otology and neurotology, responsible for many “firsts” in the field, including the complete removal of a cerebellopontine angle tumor with significant patient survival and grafting the mastoid cavity with epithelium to speed healing. He was a strict abdicator of the complete mastoid operation with ligature of the jugular vein and drainage of the lateral sinus, and he advanced many other neurotologic procedures during his lifetime. He successfully sectioned the VIIIth cranial nerve, relieving a patient from intractable vertigo, developed a meticulous system for treating the complications of suppurative infections of the mastoid, diligently studied facial nerve reanastomosis, and was the first to perform a spinal accessory to facial nerve anastomosis for the relief of facial palsy. Ballance published over 75 original articles and was the primary author on two landmark books concerning temporal bone and neurologic surgery. He was the leader of many surgical societies and maintained a life of research and science until his death. Conclusion: Sir Charles Ballance was a pioneer in neurotologic and skull base surgery and greatly advanced the field during its inception. This work focuses on the otologic and neurotologic endeavors of Sir Charles Alfred Ballance, bringing his accomplishments into modern relief.

CPAS: Surgical approach with combined sublabial bone resection and inferior turbinate reduction without stents

Congenital pyriform aperture stenosis (CPAS) is a form of nasal obstruction caused by congenital narrowing of the maxilla at the medial processes. Traditionally, surgical correction involves a sublabial approach with subperiosteal dissection, widening of the aperture by drilling, and the use of nasal stents postoperatively. Although this approach may lead to symptomatic improvement, it alone may fail to provide a patent airway secondary to unaddressed posterior narrowing. Additionally, the use of stents is problematic because they are prone to clogging and can cause internal nasal scarring and septal or alar necrosis. We present the surgical management of this condition in six patients using a novel approach that aims to correct these limitations by including both the traditional sublabial procedure and an endonasal reduction of the inferior turbinates, without the use of stents postoperatively.

Venous malformation of the sternomastoid muscle

Venous malformations of skeletal muscle are rare, making up 1% of all vascular malformations. Liston reported the first description of an intramuscular vascular malformation in 1843. Only 13.5% of intramuscular vascular lesions have been reported in the head and neck. The entity often has been called an intramuscular hemangioma and occasionally is called a giant hemangioma. These lesions appear and behave more like intramuscular venous malformations on examination, radiographs, and histologic specimens. A 4-year-old girl presented to the Pediatric Otolaryngology Clinic at Johns Hopkins Hospital with a several-month history of a nontender, left neck mass. Computed tomography (CT) of the neck with and without intravenous contrast revealed a solid mass with calcifications medial to the sternomastoid muscle but lateral to the great vessels. Fineneedle aspiration revealed bloody fluid and no abnormal cells. Magnetic resonance imaging (MRI) suggested the diagnosis of vascular malformation involving the sternomastoid muscle. The patient was asymptomatic, and her family chose to defer intervention. Three years later, this child presented with slight enlargement of the neck swelling. Clinically, the 5 3 cm soft mass was localized to the left neck centered about the middle to upper portion of the sternomastoid muscle. At age 10 years, the mass swelled abruptly, and the patient returned for evaluation. She had no respiratory embarrassment, dysphagia, trismus, or shoulder weakness. She was treated with antibiotics with resolution of the acute swelling, but the mass remained large. MRI at this time showed an inhomogenous enhancement similar to that seen previously. Excision was recommended. When she returned at age 12 years, the mass filled the entire left neck extending to the midline. MRI-MR angiog-

Venous malformation of the sternomastoid muscle: A case report and review

Objectives: Intramuscular venous malformations occur rarely in the head and neck. Only 11 cases involving the sternomastoid muscle have been reported. Methods: We present a case involving a 12-year-old female. We review the literature and discuss diagnostic and therapeutic aspects of this unusual entity. Results: Definitive evaluation of venous malformations of the head and neck skeletal muscles is best accomplished with T1- and T2-weighted magnetic resonance imaging coupled with the clinical history and physical exam. Complete surgical excision is recommended and is usually curative, with little morbidity. Our patient first presented at the age of 4 with a nontender neck swelling within the sternomastoid muscle. The mass had enlarged dramatically by age 12, thereby necessitating surgical excision. Fine needle aspiration yielded gross blood. The mass was hyperintense on a T2-weighted magnetic resonance image consistent with a vascular malformation. Transcervical surgical excision was performed, dissecting the mass from feeding vessels within an envelope of attenuated sternomastoid muscle, preserving the spinal accessory nerve. Histologic evaluation revealed medium-sized and thin-walled channels that were lined with a flattened endothelial layer and surrounded by a poorly developed and variably evident smooth muscle sheath, consistent with a venous malformation. She is doing well now 4 months after surgery without signs of recurrence or functional compromise. Conclusion: Venous malformations of skeletal muscle are frequently labeled as intramuscular hemangiomas. These are more accurately called intramuscular venous malformations based on clinical imaging and pathologic criteria. We add the twelfth case of a venous malformation of the sternomastoid muscle to the literature.