Impairment of habituation of the auditory brain stem response in migrainous vertigo.

OBJECTIVES: We evaluated the auditory brain stem response (ABR) in migrainous vertigo (MV). METHODS: Four subjects who met clinical criteria for definite MV and 4 subjects with non-vertiginous migraine (NVM) underwent ABR testing while asymptomatic and within 16 hours of a symptomatic episode. Four control subjects were also tested. A set of 4 consecutive 750-click series was administered at 50-, 60-, and 70-dB intensities. We compared the groups in terms of habituation of the amplitude of wave IV-V (habituation of IV-V) from the first through fourth series for each set. RESULTS: The habituation of IV-V amplitude to 50-dB stimuli was significantly less (p = 0.047) in the symptomatic MV group (5.08% +/- 22.32%) than in the symptomatic NVM group (-21.44% +/- 13.50%) or the control group (-26.06% +/- 9.76%). The habituation of IV-V amplitude to 70-dB stimuli in the MV group was significantly less (p = 0.031) during symptomatic testing (-3.43% +/- 8.89%) than during asymptomatic testing (-21.23% +/- 6.41%). CONCLUSIONS: The habituation of IV-V amplitude is reduced during MV attacks. This finding suggests impaired brain stem inhibition at the level of the inferior colliculus, which shares serotonergic connections with the dorsal raphe nucleus, an area hyperactive in migraine.

Effects of anesthesia on DPOAE level and phase in rats.

Many studies of the auditory system are performed on animals under general anesthesia. A concern for researchers is that these agents may significantly alter the underlying neurophysiologic mechanisms being studied. The effects may very across species, and even among individuals within a species. An investigation was undertaken to study whether DPOAE measures differ using three different anesthetic regimens: acetylpromazine-ketamine, xylazine-ketamine, and sodium pentobarbital. The same rat was anesthetized in three consecutive weeks using a different anesthetic regimen each week. DPOAE magnitude and phase temporal responses were recorded from which several measures were taken: DPOAE levels at the onset of the primaries, changes in DPOAE level as a function of time during presentation of the primaries (DeltaLI) and changes in DPOAE level (DeltaLC) and phase (DeltaPC) during presentation of a broad-band noise presented contralateral to the probe. Each week the same measurements were repeated with the rat anesthetized using a different regimen and at the end of the third week, the middle ear muscles were sectioned and the measurements repeated once again. Results showed that the anesthetic regimens did not differentially alter the DPOAE onset levels. When sodium pentobarbital was used as the anesthetic regimen, DeltaLC and DeltaPC were significantly smaller relative to those measured when the rats were anesthetized with acetylpromazine-ketamine and xylazine-ketamine. Based on the assumption that large, positive (DeltaPC) values are related to middle ear muscle activation, the middle ear muscle reflex remained at least partially active in some rats under sodium pentobarbital anesthesia. The DeltaLI measures were significantly smaller when the animals were anesthetized with xylazine-ketamine and sodium pentobarbital than when they were anesthetized with acetylpromazine-ketamine. Recordings taken after sectioning the middle ear muscles suggested that the middle ear muscle reflex substantially contributes to DeltaLC and DeltaPC measures under the anesthetic regimens xylazine-ketamine and acetylpromazine-ketamine. Data indicated that anesthetic agents variably alter neurophysiologic mechanisms involved with the complex control of the auditory signal even among individuals in the same species. Extreme care should be taken when comparing DeltaLI, DeltaLC and DeltaPC across studies when different anesthetic regimens are used within and across species.

Nontraumatic cerebrospinal fluid rhinorrhea as a result of pseudotumor cerebri.

OBJECTIVE: The purpose of this study is to demonstrate that pseudotumor cerebri, also known as benign intracranial hypertension, can be an overlooked cause of spontaneous, nontraumatic cerebrospinal fluid (CSF) rhinorrhea. STUDY DESIGN AND METHODS: This study presents a literature review and 2 case reports. The medical records of 2 patients who had nontraumatic CSF rhinorrhea were reviewed. RESULTS: The patients were diagnosed as having spontaneous, nontraumatic CSF rhinorrhea, believed to have been caused by pseudotumor cerebri, and were surgically treated. The patients are obese, middle-aged women. CONCLUSIONS: Cerebrospinal fluid rhinorrhea is most often the result of trauma, but it may also occur spontaneously because of nontraumatic causes in some patients. Pseudotumor cerebri can be an overlooked cause of spontaneous, nontraumatic CSF rhinorrhea. A patient with signs and symptoms of pseudotumor cerebri should be evaluated and treated, if the condition is present, to prevent complications that include irreversible visual loss and CSF rhinorrhea.

Primary pleomorphic liposarcoma of the parotid gland: a case report and review of the literature.

Although liposarcomas are the most common type of sarcoma in adults, they are rare in the head and neck region. Pleomorphic liposarcoma is the least common histologic subtype in all locations. To our knowledge, there have been only 11 reported cases of primary liposarcomas of the major salivary glands, and the pleomorphic variant arising in the parotid gland has been reported only once before. Only 2 of the 11 reported cases of liposarcoma of the major salivary glands in the literature have died of disease, and both cases were of the pleomorphic subtype. We report a case of pleomorphic liposarcoma arising in the left parotid gland of an 80-year-old woman. This case report highlights that, despite conservative surgery followed by 2 local recurrences, our patient is doing well with minimal local morbidity and no demonstrable metastases 30 months after the initial diagnosis. We also present a review of the literature on the subject.

Craniometaphyseal dysplasia: a case report and review of medical and surgical management.

Craniometaphyseal dysplasia (CMD) is a genetic syndrome involving cranial and tubular bone anomalies that commonly present at a young age, often with otolaryngologic manifestations. In this paper, we report a rare case of a sporadic form of the disease resulting in an early state of hypocalcemia with secondary hyperparathyroidism. A conductive hearing loss is also documented prior to 12 months of age. The clinical aspects of CMD will be covered along with its pathogenesis. The current concepts surrounding medical and surgical treatments will be reviewed, and the management of our patient will be discussed.

Craniometaphyseal dysplasia: a case report and review of medical and surgical management.

Craniometaphyseal dysplasia (CMD) is a genetic syndrome involving cranial and tubular bone anomalies that commonly present at a young age, often with otolaryngologic manifestations. In this paper, we report a rare case of a sporadic form of the disease resulting in an early state of hypocalcemia with secondary hyperparathyroidism. A conductive hearing loss is also documented prior to 12 months of age. The clinical aspects of CMD will be covered along with its pathogenesis. The current concepts surrounding medical and surgical treatments will be reviewed, and the management of our patient will be discussed.