Adaptation of the vertical vestibulo-ocular reflex in cats during low-frequency vertical rotation.

OBJECTIVE: We examined plastic changes in the vestibulo-ocular reflex (VOR) during low-frequency vertical head rotation, a condition under which otolith inputs from the vestibular system are essential for VOR generation. METHODS: For adaptive conditioning of the vertical VOR, 0.02Hz sinusoidal pitch rotation for one hour about the earth's horizontal axis was synchronized with out-of-phase vertical visual stimulation from a random dot pattern. RESULTS: A vertical VOR was well evoked when the upright animal rotated around the earth-horizontal axis (EHA) at low frequency due to the changing gravity stimulus and dynamic stimulation of the otoliths. After adaptive conditioning, the amplitude of the vertical VOR increased by an average of 32.1%. CONCLUSION: Our observations showing plasticity in the otolithic contribution to the VOR may provide a new strategy for visual-vestibular mismatch training in patients with otolithic disorders. This low-frequency vertical head rotation protocol also provides a model for investigating the mechanisms underlying the adaptation of VORs mediated by otolith activation.

[Effect of S-1 in a patient with metastatic eyelid sebaceous carcinoma].

We report a 68-year-old female with a history of repeated right cervical lymph node metastasis secondary to eyelid sebaceous carcinoma. She had undergone right neck dissection due to lymph node metastasis at the department of surgery in an other local hospital. After the orbital exenteration, she underwent multiple operations, including 2 right partial parotidectomy and then total parotidectomy, 4 right cervical lymph node excisions and 1 left upper neck dissection due to lymph node metastasis. Adjuvant chemotherapy with S-1(at a dose of 80 mg per day)alone was applied as tumor dormancy therapy on an outpatient basis. Any adverse events during S-1 medication were observed. New metastatic lesions were not found until 29 months after the beginning of chemotherapy with S-1 alone. Although the effectiveness of S-1 for eyelid sebaceous carcinoma has not been demonstrated, S-1 might be useful in patients with recurrent eyelid sebaceous carcinoma based on our patient's recurrence-free survival.

Solitary neurofibroma of the floor of the mouth: a case report.

We present a case of a solitary neurofibroma of the floor of the mouth protruding into the submandibular region. A 51-year-old female presented with a 2-year history of swelling of the floor of the mouth. MRI revealed that the mass measuring 50 × 70 mm showed a homogenous, low signal intensity on a T1-weighted image and high signal intensity on a T2-weighted image. The tumor was completely removed through a cervical approach. Cases of a solitary neurofibroma originating from the floor of the mouth are extremely rare.

Directional preponderance of vertical eye movements induced by cross-axis adaptation of the vestibulo-ocular reflex in the cat.

OBJECTIVE: We examined the emerging vertical component after cross-axis vestibulo-ocular reflex (VOR) adaptation. METHODS: For the adaptive conditioning, the whole body of a subject was rotated horizontally while a visual pattern was rotated vertically for 1h. RESULTS: During the conditioning period, the vertical component in response to the vertical visual stimulation was an up-down asymmetric, and its amplitude gradually increased as the stimulus progressed. After conditioning, the direction of VOR was changed via an emerging vertical component during horizontal head rotation in total darkness. Even though the retinal slip-velocity was greater for downward than for upward during the conditioning period, the emerging upward component was significantly larger than the emerging downward component. CONCLUSION: These results may be helpful for developing an optimal vestibular-compensation system by visual-vestibular mismatch/optokinetic training.

Mumps virus infection in adults: three cases of supraglottic edema.

Mumps virus infections primarily involve the parotid glands and most frequently affect school-aged children. We present three unusual adult cases of mumps with dyspnea secondary to severe swelling of the salivary glands and review previously reported cases in the literature. Dyspnea developed progressively after the onset of salivary gland swelling. Laryngoscopy revealed an advanced edematous change in the supraglottis obstructing the airway. In two cases, tracheotomy was needed because of rapid worsening of the supraglottic edema. Questioning regarding breathing problems and laryngoscopic examination is therefore recommended when one encounters a mumps case with combined parotid and salivary gland swelling.

Efficacy of tilt-suppression in postrotatory nystagmus in cats.

The phenomenon of tilting the head away from an upright position immediately after a horizontal head-rotation, thus reducing the duration of postrotatory nystagmus (PRN), has more than once been called "tilt-suppression." It represents an example of the semicircular canal-otolith interaction in the central vestibular system. In the present study we investigated how head roll-tilt influences the time constants of PRN in the horizontal and vertical planes in cats. The head/body was roll-tilted by 30 degrees toward the upright or the side down from initial roll positions immediately after termination of earth-vertical axis (EVA) rotation. Changes in head orientation either towards or away from the EVA reduced horizontal PRN. The reducing effect was small when the head was roll-tilted toward the EVA. Vertical nystagmus decreased only when the head orientation moved toward alignment with the EVA. Otolithic "tilt-suppression" may be a central neuronal mechanism that is activated to minimize the tumbling sensation of turning about a tilted axis and postural instability, but our results indicate that tilt-suppression of PRN depends on a change in head orientation with respect to the EVA.

MRI of intranasal pleomorphic adenoma.

A pleomorphic adenoma in the nasal cavity constitutes a rarity. A 48-year-old woman presented with intranasal pleomorphic adenoma revealed by unilateral continuous obstruction and occasional epistaxis. Nasal endoscopy showed a mucosa-covered and opalescent polypoidal mass arising from the left nasal septum. Unlike cases affecting the major salivary gland, magnetic resonance image (MRI) revealed that the mass showed a low signal intensity on T1-weighted image and a heterogeneous, intermediate signal intensity on T2-weighted image. MRI findings can aid in diagnosis and help exclude the possibility of other neoplasms that occur at this site.

Asymmetric adaptive gain changes of the vertical vestibulo-ocular reflex in cats.

The present study was conducted to examine adaptive gain changes of vertical vestibulo-ocular reflex (VOR) after exposure to a vertical visual-vestibular mismatch in cats. The visual-vestibular mismatch was induced by oscillating the animals for an hour about an inter-aural axis at frequencies of 0.16 and 0.32 Hz with the peak velocity of 20 degrees/s, coupled with either in-phase ("gain decrease" conditioning) or out-of-phase ("gain increase" conditioning) sinusoidal rotation of a random-dot pattern. Eye movements were measured with a magnetic search coil system. Before conditioning, vertical VOR showed up-down asymmetric responses. That is, upward slow phase eye velocity (SPV) in response to downward head rotation was significantly larger than downward SPV in response to upward head rotation. After adaptation to "gain increase" conditioning, VOR gain increased in both stimulus directions. The increase in VOR gain was significantly larger for upward SPV than for downward SPV. After adaptation to "gain decrease" conditioning, VOR gain decreased in both stimulus directions. The decrease in VOR gain was, however, significantly larger for downward SPV than for upward SPV. Our results indicate that VOR in the vertical plane adaptively changes but that the gain change shows a directional asymmetry. This asymmetry was dependent on the direction of the slip of visual image rather than the direction of head rotation, and the gain change was smaller when the retinal slip was generated downward. Possible explanations for the asymmetry are discussed on a physiological and anatomical basis.

Effects of roll tilt on the direction of vertical postrotatory nystagmus in cats.

The rotation axis of horizontal postrotatory nystagmus (PRN) changes as the head is tilted, so that it becomes directed toward gravity (spatial reorientation). Here, we examined the vertical PRN orientation during roll tilt in cats. Unlike the case in horizontal PRN, in vertical PRN no significant cross-coupled components emerged to reorient the eyes toward gravity. Our results indicate that otolith input contributes differently to horizontal VOR than to vertical VOR.

[Middle ear overpressure treatment in severe Menière's disease].

To evaluate the therapeutic effect of middle ear pressure pulse on endolymphatic hydrops in humans, Meniett20k was used for 12 months in two severe elderly patients with definite Meniere's disease. The average number of vertigo occurrences in the 6 months before treatment and in the 12 months after treatment started was compared. Numeric values (NV) among patients were calculated and categorized into an improved group (NV = 1-40). For hearing function, the pure-tone average (PTA) before and 12 months after treatment started was compared. PTA was calculated based on the following equation: PTA = (A + 2XB + C)/4. A, B, and C were thresholds of the pure-tone audiometory at 0.5, 1.0, and 2.0 kHz. In one case, hearing function was unchanged, but deteriorated in the other. Pressure pulse treatment may thus be useful in severe cases of Meniere's, especially in the elderly, bilateral cases, and in endolymphatic hydrops in a single hearing ear.