Chondrosarcomas of the skull base and temporal bone.

OBJECTIVE: To evaluate the clinical presentation and outcomes of treatment for patients with chondrosarcomas involving the skull base and temporal bone. STUDY DESIGN: Retrospective review. SETTING: Tertiary medical centre. PATIENTS: Cases of histologically confirmed chondrosarcoma involving the skull base and temporal bones. INTERVENTION: Surgery. MAIN OUTCOME MEASURES: Demographic features of presenting patients; presenting symptoms and signs; surgical approach employed; use of post-operative radiation therapy; histological grade of tumour; and interval of post-operative follow up. RESULTS: Twelve patients were identified with chondrosarcomas involving the skull base, with post-operative follow up ranging from three to 33 years. The average age at presentation was 42 years. The most common presenting symptoms were diplopia, decreased visual acuity and headaches. Five of the 12 patients required multiple surgical procedures. CONCLUSIONS: Patients with chondrosarcoma involving the skull base and temporal bone may present in a variety of ways. Surgical resection, even subtotal, in combination with radiation therapy, can often provide good tumour control over many years for these rare tumours.

Fibrous dysplasia involving the skull base and temporal bone.

OBJECTIVE: To gain a broader appreciation of the clinical presentation, operative treatment, and outcome of patients with fibrous dysplasia involving the skull base. DESIGN: Retrospective review of a clinical case series. SETTING: A single tertiary academic medical center. PATIENTS: Twenty-one patients with histopathologically confirmed fibrous dysplasia involving the skull base cared for over a 15-year-period (1983-1998). MAIN OUTCOME MEASURES: Clinical and radiographic location of the fibrous dysplasia lesions within the skull base, clinical presentation, surgical intervention, and clinical outcome were tabulated for each patient. RESULTS: The ethmoids were most commonly involved (71%), followed by the sphenoid (43%), frontal (33%), maxilla (29%), temporal (24%), parietal (14%), and occipital (5%) bones. The most common presenting features included atypical facial pain and headache, complaints referable to the sinuses, proptosis and diplopia, hearing loss, and facial numbness. Surgical treatment, guided by clinical presentation, ranged from simple biopsy with conservative follow-up to craniofacial resection. CONCLUSIONS: Fibrous dysplasia can present in myriad ways within the skull base. Modern imaging modalities and histopathologic analysis have made diagnosis relatively straightforward. Surgery, particularly in such a challenging region as the skull base, should be reserved for patients with functional impairment or a cosmetic deformity. Because of the benign nature of the condition, the surgery itself should be relatively conservative, with the primary goal being preservation of existing function.

Late-onset facial nerve degeneration after vestibular schwannoma surgery: incidence, putative mechanisms, and prevention.

Delayed facial nerve dysfunction after vestibular schwannoma surgery is a poorly understood phenomenon that has been reported to occur in 15 to 29% of patients undergoing microsurgery. It is a condition characterized by spontaneous deterioration of facial nerve function in a patient who has otherwise normal or near-normal facial function in the immediate postoperative period. This delayed paralysis is generally reported to occur in the first few days postsurgery, with the majority of patients eventually recovering their immediate postoperative facial function. However, infrequently, it can also occur more than 1 week after surgery (so-called late-onset facial nerve palsy). The authors reviewed facial nerve outcome in 611 patients who underwent microsurgery between 1973 and 1994. The facial nerve was anatomically preserved in 596 patients (97.5%), and 90% of patients had House-Brackmann[6] Grade 1 or 2 function 1 year after surgery. Late-onset facial dysfunction was seen in 13 patients (2.1%). All of these had significant deterioration in facial nerve function between 1 and 4 weeks postoperatively, and all showed improvement by 1 year. In this study, the focus on these patients who developed late-onset facial palsy. The incidence, treatment strategies, and outcomes will be discussed with emphasis on possible pathophysiological mechanisms that contribute to this relatively rare condition.

Decompression of the labyrinthine segment of the facial nerve in acoustic neuroma surgery: a consideration for minimizing postoperative delayed facial nerve dysfunction.

Delayed facial nerve palsy, a condition characterized by spontaneous deterioration of facial nerve function in patients who had otherwise normal or near-normal facial function in the immediate postoperative period, has been reported in 15 to 29% of patients undergoing microsurgical resection of vestibular schwannomas. One putative mechanism for its occurrence suggests that edematous entrapment of the facial nerve in the meatal foramen (the narrowest segment of the internal auditory canal) may lead to nerve ischemia or necrosis and subsequent facial nerve dysfunction. To assess whether meatal decompression may help reduce the incidence of delayed facial nerve palsy during microsurgical resection of acoustic tumors, we compared 25 patients undergoing translabyrinthine removal of acoustic neuromas who received prophylactic decompression of the labyrinthine segment of the facial nerve (Group 1) with 40 patients who did not receive facial nerve decompression (Group 2). No patients in Group 1 had a delayed progressive facial paralysis with degeneration. In contrast, when Group 2 patients with larger, average-sized tumors were reviewed, eight patients (20%) developed delayed degeneration. These findings suggest that decompression of the labyrinthine segment may be of value in acoustic tumor surgery in reducing delayed facial nerve dysfunction. Further study is indicated in this important area.

Facial nerve injury in acoustic neuroma (vestibular schwannoma) surgery: etiology and prevention.

Facial nerve injury associated with acoustic neuroma surgery has declined in incidence but remains a clinical concern. A retrospective analysis of 611 patients surgically treated for acoustic neuroma between 1973 and 1994 was undertaken to understand patterns of facial nerve injury more clearly and to identify factors that influence facial nerve outcome. Anatomical preservation of the facial nerve was achieved in 596 patients (97.5%). In the immediate postoperative period, 62.1% of patients displayed normal or near-normal facial nerve function (House-Brackmann Grade 1 or 2). This number rose to 85.3% of patients at 6 months after surgery and by 1 year, 89.7% of patients who had undergone acoustic neuroma surgery demonstrated normal or near-normal facial nerve function. The surgical approach appeared to have no effect on the incidence of facial nerve injury. Poor facial nerve outcome (House-Brackmann Grade 5 or 6) was seen in 1.58% of patients treated via the suboccipital approach and in 2.6% of patients treated via the translabyrinthine approach. When facial nerve outcome was examined with respect to tumor size, there clearly was an increased incidence of facial nerve palsy seen in the immediate postoperative period in cases of larger tumors: 60.8% of patients with tumors smaller than 2.5 cm had normal facial nerve function, whereas only 37.5% of patients with tumors larger than 4 cm had normal function. This difference was less pronounced, however, 6 months after surgery, when 92.1% of patients with tumors smaller than 2.5 cm had normal or near normal facial function, versus 75% of patients with tumors larger than 4 cm. The etiology of facial nerve injury is discussed with emphasis on the pathophysiology of facial nerve palsy. In addition, on the basis of the authors' experience with these complex tumors, techniques of preventing facial nerve injury are discussed.

Vestibular adaptation exercises and recovery: acute stage after acoustic neuroma resection.

The use of exercises in the treatment of patients with vestibular deficits has become increasingly popular, and evidence exists that these exercises are beneficial in patients with chronic vestibular deficits. The question as to whether patients with acute unilateral vestibular loss would benefit from vestibular adaptation exercises is particularly compelling, however, because animal studies have demonstrated that the acute stage after unilateral vestibular loss is a critical period for recovery. Deprivation of visuomotor experience during that period can delay the onset of recovery as well as prolong the recovery period. Patients often avoid movement during the early stage because, with movement, they experience an increase in dysequilibrium and nausea. We examined the recovery of postural stability in patients during the acute stage after resection of acoustic neuroma to determine whether vestibular adaptation exercises facilitate the onset of recovery and improve the rate of recovery. The results suggest that vestibular adaptation exercises result in improved postural stability and in a diminished perception of dysequilibrium.

Neuro-ophthalmologic Aspects of Ameloblastoma.

Ameloblastomas are histologically benign tumors derived from the odontogenic apparatus. Although these tumors are locally invasive, they rarely invade the paranasal sinuses, orbits, or intracranial cavity, and, thus, they rarely produce ophthalmologic signs and symptoms. In this report, we describe the neuro-ophthalmologic features of three patients with chronically aggressive ameloblastoma. Two of the patients developed a progressive and recurrent orbital apex and cavernous sinus syndromes. One of these patients is, to our knowledge, the first patient described with orbital and cavernous simus involvement by an ameloblastoma initially arising in the mandible. The other is only the second case described with bilateral orbital involvement. The third patient in this series developed a trigeminal sensory neuropathy as the only sign of the tumor. Although ameloblastomas are benign, slowly growing tumors, they may, often over a long period of time, cause significant neuro-ophthalmologic and orbital manifestutions that can only be partially ameliorated by surgery.

Association of heterotopic neuroglial tissue with an arachnoid cyst in the internal auditory canal.

An arachnoid cyst arising within the internal auditory canal, or within the cerebellopontine angle and subsequently extending into the internal meatus and enlarging it, is a rare occurrence. Nevertheless, the neurootologist and the neurosurgeon have an interest in its existence because its clinical manifestations are identical with the ones produced by a schwannoma, involving overwhelmingly the cochleovestibular nerve in that region. An equally rare observation in that location is the presence of ectopic neuroglial tissue. The two can occur independently or in combination. Examples of such lesions are presented, and their possible pathogenesis is discussed.

Clivus chordoma: a report of 12 recent cases and review of the literature.

Twelve patients with histologically confirmed clivus chordoma were treated at the Johns Hopkins Hospital between 1971 and 1989. Eight of the patients were men and four were women. The mean age at first operation was 51 years (range, 10 to 80). The most common presenting symptoms were headache, diplopia, dysphagia and dysarthria, and facial sensory changes. Computed tomography, with and without contrast enhancement, proved adequate for tumor identification and localization. Magnetic resonance imaging and angiography were occasionally employed to localize the tumors further and to define tumor vascular supply and proximity to vascular structures. Twenty-two resections were performed in 11 patients, and another patient underwent biopsy only. Seven were also treated with radiation therapy. Tumors recurred in eight patients, six of whom underwent further operations. The mean time to first recurrence was 22 months (range 8 to 36 months). Six of the patients are still alive, with a mean follow-up of 31 months (range, 3 to 89 months) from first surgical resection. The mean survival time from first treatment was 31 months (range, 4 to 62 months) among those patients who died. There was no operative mortality. The 5-year cumulative survival rate was 20%. Six patients with long follow-up have had fair to good results, being free of recurrences for at least a year. However, none of the patients returned to their premorbid baseline of activities. Five of the patients had tumors with the histologic diagnosis of chondroid chordoma. Three of these patients are still alive. The mean age at first treatment was 44 (compared with 62 for typical chordomas). The mean time from symptoms to diagnosis was 29 months (typical chordomas, 18 months). The mean length of survival and time to tumor recurrence were not significantly different between chondroid and typical chordomas.

3-D CT for cranial facial and laryngeal surgery.

Three-dimensional imaging is a new digital technology which interpolates two-dimensional computer tomography information to render a "life-like" anatomic display of the diagnostic information. We have found that this new methodology significantly improves the assessment and therapy of patients undergoing surgical procedures of the head and neck. The technique has been used in cranial-facial and laryngeal pathology, and in preoperative planning of tumor resection, particularly skull-base neoplasms. The use of three-dimensional computer tomography improves the display of the location and volume of pathology and affords accurate therapeutic and surgical planning. The choice and extent of surgery is better defined, and precise bone removal can be performed. In reconstructive surgery, an accurate prefabricated model of the bony defect can be made to aid reconstruction. Representative cases demonstrating the use of three-dimensional computer tomography in head and neck surgery, and its benefits in saving operative time and improving the postoperative result, will be discussed.

The versatile midface degloving approach.

The exposure obtained using the degloving approach is superb and the absence of resultant facial scar or deformity provides a dramatic new addition to the otolaryngologist's surgical repertoire. The advantages of the degloving technique in exposure of the midface, nasal cavities, paranasal sinuses, nasopharynx, skull base, and clivus have led to its increasing importance in the otolaryngology literature. Within 2 years of the technique's introduction in our department, it had been used 48 times for a wide variety of problems, including inverting papilloma, juvenile angiofibroma, chordoma and selected cases of fungal disease of the sinuses. This article describes the procedure, reports the results from a panel of 48 patients, and discusses potential complications. The authors' experience with this procedure indicates that it should become a procedure of choice for management of inverting papilloma and juvenile angiofibroma, as well as a major alternative method in many other circumstances.

Ear disease in patients with inflammations of Waldeyer's ring.

The etiologies of otitis media with effusion are certainly multiple but remain incompletely understood. The treatment of otitis media with effusion varies considerably. A discussion of known facts as well as debated issues underlying these differences is presented.

Infantile subglottic hemangiomas. An update.

Between 1913 and 1985, 323 cases of infantile subglottic hemangiomas have been reported in the English language literature. The purpose of this study is to review these cases, to report The Johns Hopkins Hospital experience with ten additional cases, and to compare the various methods of treatment in an attempt to identify the regimens associated with the best outcome. The majority of the patients presented before the age of 6 months with respiratory distress, most commonly inspiratory stridor. There was a 2:1 female to male preponderance. The diagnosis was established by endoscopy in the majority and confirmed by biopsy in one third, without serious bleeding complications. A plethora of treatment methods have been described, including the following: corticosteroids, tracheotomy, radiation therapy, radioactive implant therapy, surgical excision, cryotherapy, and carbon dioxide laser. These methods were reviewed and their results compared to our own. We conclude that several methods are effective, each having its advantages and disadvantages. We believe that immediate tracheotomy should be performed in cases with severe airway obstruction. Smaller lesions may be vaporized with the carbon dioxide laser without tracheotomy if postoperative care is provided in a pediatric intensive care unit. Corticosteroids may be used alone or in combination with other modalities. External radiation therapy and injection of sclerosing agents are not advised.

Fibrous dysplasia of the temporal bone. Update with case reports.

Fibrous dysplasia is a fairly common, well demarcated, misdifferentiation of the bone-forming mesenchyme affecting a single, several, or many bones, in which skeletal changes are the salient feature, but in which certain endocrinopathies, abnormal pigmentation of skin and mucous membranes, and occasionally other abnormalities form part of the entire disease process. The clinical and pathological aspects of the disease and its involvement with the temporal bone have been previously discussed. Two recent case histories are added here.

Transsphenoidal approach to the sella: the Johns Hopkins experience.

The transsphenoidal hypophysectomy has become a relatively frequent procedure in recent years, with the otolaryngologist playing a major role in its renewed popularity. This paper reviews the evolution of pituitary surgery, discusses the surgical technique currently used, and reviews the results and complications of 114 cases over a 13-year period. Of the 129 procedures performed at Johns Hopkins Hospital between 1970 and 1983, 114 charts were available for review. Twelve of these were palliative hypophysectomies and 102 were for sella tumors. Sixty-eight patients were treated with surgery alone, and 34 received surgery and postoperative irradiation. Significant complications such as CSF rhinorrhea, diabetes insipidus, meningitis, septal perforation, anosmia, and visual field defects are discussed. The mortality rate for the series was 1.7%. These results are compared with those of previously published series and the differences are discussed in detail. In analyzing these data we feel that the transseptal, transsphenoidal hypophysectomy has become a safe and effective therapy for sella lesions.

Sclerosteosis involving the temporal bone: clinical and radiologic aspects.

Sclerosteosis is one of the rare, potentially lethal, autosomal recessive, progressive, craniotubular sclerosing bone dysplasias. Syndactyly of the second and third or other fingers is evident at birth. Hyperostosis and sclerosis are most prominent in the skull and tubular bones, and are frequently associated with excessive height and weight. The typical facial deformity is apparent by the age of 5 years. The changes involving the temporal bone include a marked increase in overall dimensions, extreme sclerosis, and narrowing and constriction of the external ear canal, middle ear cleft, internal acoustic meatus, and falloppian canal. Impairment of hearing, as a rule bilateral, is a frequent presenting symptom which may manifest in early childhood. Initially it is an expression of interference with sound conduction; later it may become associated with a loss of sound perception. Impairment of facial nerve function is another salient feature which occasionally is present at birth. As a rule, it manifests initially as a unilateral, recurrent paresis, eventually progressing to a bilateral permanent partial loss of facial nerve function. Since impairments of hearing and facial nerve function are two of the salient features, present at birth or in early childhood, the responsibility for recognizing the disease often falls upon the otolaryngologist. The clinical and radiologic features permit not only early recognition of the disorder but also differentiation from similar bony dysplasias. Hyperosteosis and sclerosis of the skull lead to thickening and distortion of the calvaria, cranial base, and foramen magnum resulting in reduction of the intracranial volume, interference with the cerebral blood flow, resorption of cerebrospinal fluid, and gradual increase of intracranial pressure. Severe headaches resulting from this mechanism often develop in early adulthood, and several patients have died suddenly from impaction of the medulla oblongata in the foramen magnum. Decompression of the transverse sigmoid sinus and jugular bulb may be lifesaving, combined with a posterior, and if necessary, an anterior, craniectomy for decompression. Early decompression of the internal acoustic meatus and falloppian canal may help in the preservation of cochlear and facial nerve function.

Hearing patterns in dominant osteogenesis imperfecta.

Audiologic evaluations and impedance audiometry were obtained on persons from 13 families with dominant osteogenesis imperfecta (OI). Hearing impairment appeared in the late second or early third decade, usually with a conductive loss. Older patients had mixed or sensorineural losses. There was an increasing risk for hearing loss with advancing age. Impedance tests suggested that ossicular fixation may be the primary cause of middle ear disorders in patients with mixed or conductive hearing losses. The cause of sensorineural hearing loss could not be determined. The long-term success of otologic surgery in OI is uncertain. Amplification may be a reasonable alterative to surgery.