Hajime Nakagawa

The contribution of proprioception to posture control in normal subjects.

In order to investigate the contribution of proprioceptive input to maintaining an upright position, stabilometry via 100-Hz vibratory stimulation applied to the Achilles tendon was studied and analyzed with respect to area, length and power spectra according to the method of fast Fourier transform (FFT). Twenty-one young medical students were analyzed in this study. When vibration was applied, the body sway was significantly greater than that of control in area and length with both eyes open and closed. There was a significant increase of total power in both the lateral (X) and antero-posterior (Y) directions with the eyes closed. With the eyes open, an increase was found only in the antero-posterior direction. The frequency band indicating the maximum spectrum did not shift. Significant increases in power spectra were found in the frequency range of more than 2 Hz in both two directions with the eyes closed. It was concluded that a vibration given to the Achilles tendon provoked a pronounced high frequency body sway especially in the antero-posterior direction when visual information was nullified, and that proprioceptive information may have a minor role compared with visual information.

Autonomic Nervous System Disturbance as Etiological Background of Vertigo and Dizziness

In order to investigate whether dysautonomia lies behind vertigo and/or dizziness in the neurotological clinic, an electrocardiogram (ECG) R-peak to R-peak test (R-R test) along with the Schellong test were simultaneously performed in 136 subjects. ECG data were analyzed by a microcomputer, and R-R intervals were calculated. In a dynamic test performed during postural changes from the supine to the standing position, there were 23 of 55 (41.8%) positive test results in patients with peripheral vestibular disorders, 28 of 51 (54.9%) with central vestibular disorders, and 15 of 18 (83.3%) with spinocerebellar degeneration. In a static test with the patient in the standing position, there were 13 of 55 (29.1%) positive test results in patients with peripheral vestibular disorders, 16 of 51 with central vestibular disorders, and 8 of 18 (44.4%) with spinocerebellar degeneration. A significant difference in the positive rate between spinocerebellar degeneration and both other central and peripheral vestibular disorders in the dynamic test was observed. These results also demonstrated that dysautonomia upon postural changes might play an important role in the development of vertigo and dizziness and that it is provoked by disorders of the autoregulatory mechanisms of the cerebral blood flow. This test is presumed to be excellent for detecting dysautonomia by virtue of being non-invasive, having good reproducibility and being readily available to quantitative evaluation by using a microcomputer.

Vascular cross-compression of the Vllth and VIIIth cranial nerves

A 53-year-old male patient had been suffering from severe aural symptoms (pulsatile right-sided tinnitus and paroxysmal dizziness attacks with nausea) and right hemifacial spasm. Treatment had involved stellate ganglion block with lignocaine and the injection of intravenous sodium bicarbonate solution for attacks of Menières syndrome and facial nerve block with lidocaine for hemi-facial spasm. Despite these treatments, the dizzy attacks became more frequent, developing into the clustering state. Air CT cisternography and vertebral angiography demonstrated an enlarged and curved vertebral artery. Vascular cross-compression of the VIIth and VIIIth cranial nerves was therefore suspected. Microvascular decompression was performed. After operation, the pulsatile tinnitus, dizziness and hemifacial spasm disappeared. From the present case and a review of the literature, we conclude that vascular cross-compression of the VIIIth cranial nerve should be an indication for microvascular decompression only when symptoms of vascular cross-compression of the VIIth cranial nerve are also seen.

Cerebral Autoregulation in Patients with Orthostatic Hypotension

The present study was conducted to determine the relationship between autonomic nervous function and cerebral autoregulation in 17 patients with vertigo or dizziness. Autonomic nervous function was examined by measuring systolic blood pressure response and dynamic electrocardiogram R-peak to R-peak response upon standing up. Regional cerebral autoregulation was examined by comparing cerebral blood flow in both supine and standing positions with single photon emission computed tomography. Moreover, the relationship of each of these three measures to postural provocation of symptoms was studied. The findings indicated that autonomic nervous dysfunction does not influence cerebral autoregulation, but autonomic nervous dysfunction was related to postural provocation of symptoms. This might indicate that impaired autoregulation in the brain stem or the peripheral vestibule, which could not be detected by the single photon emission computed tomography, played a role in inducing vertigo or dizziness in patients with orthostatic hypotension.

Large Tonsillolith Mimicking Peritonsillar Abscess: A Case Report

A case of large tonsillolith is described. A 26-year-old male presented with a history of recurrent throat infections. A diagnosis of peritonsillar abscess was made. A tonsillolith was spontaneously expelled on admission. A tonsillectomy was subsequently performed. The tonsillolith was yellowish-gray, measured 30 x 26 x 16 mm, and weighed 8.5 g, which was the largest reported case in Japan. Chemical analysis revealed the stone to consist of calcium phosphate.

Metastatic masseter muscle tumour: a report of a case

Both primary and metastatic malignancies of the masseter muscle are rare. We report a case of metastatic renal cell carcinoma to the masseter muscle. It was incidentally found as a hypervascular mass in carotid angiography for delineating a recurrent metastatic brain tumour. Prior to surgical removal, intravascular embolization via the left facial artery was performed in order to decrease intra-operative bleeding. The tumour was removed with minimum damage to the muscle fibres by the extraoral method, followed by a transient lower lip palsy. Metastatic intramuscular tumours, which are assumed to be due to haematogenous spread, are generally a sign of poor prognosis.

Unusual parotid gland foreign body

A foreign body in the parotid gland whether from the oral cavity or through the skin is extremely uncommon. A case is described of the tip of a golden-colored pencil accidentally piercing the deep lobe after a fall. Emergency surgical removal was performed, and the diagnosis of the foreign body was quite easy. In contrast, determination of the location in the gland had to be done by a microscope, with fluoroscopy during the operation and was quite difficult. During removal, great attention was paid to avoiding facial nerve injury. This was done by identifying the facial trunk at the pointer using a microscope. The dissolved material including copper and zinc metal powder, paste, and clay, was found in the deep lobe associated with the surrounding abscess. Although these materials are assumed to be harmless to human tissues, the complete and immediate removal is to prevent salivary fistule resulting from inflammation.

Magnetic Resonance Imaging of an Inhaled Peanut

A foreign body aspirated in the tracheobronchial tree is one of the high-risk accidents of childhood. Cohen et all reported that a peanut is the most commonly inhaled foreign body. However, its inhalation is sometimes difficult to diagnose without typical symptoms. Previous radiologic methods, including chest radiography, fluoroscopy, computed tomography (CT), and radioisotope imaging, cannot clearly visualize radiolucent foreign bodies such as peanuts.

Contribution of Vision to the Stabilization of Body Sway in Patients with Spinocerebellar Degeneration

Body sway was recorded with closed eyes, open eyes and visual feedback for 30 s each. Thirteen patients with spinocerebellar degeneration and 17 age-matched normal controls underwent the examination. Four parameters (area, length, sums of frequency spectrum in the anterior-posterior and lateral directions) were computed. Furthermore, Romberg ratios between closed and open eye conditions [Romberg c/o] and Romberg ratios between closed eyes and visual feedback conditions [Romberg c/f] were computed. Four parameters were significantly greater in the patients with spinocerebellar degeneration than in the normal controls. However, three of eight Romberg ratios were significantly greater in the patients with spinocerebellar degeneration than in the normal controls. The results implied that the proprioceptive-posture loop was mainly disordered while the visuo-postural loop was intact in patients with spinocerebellar degeneration.

Plain Radiological Findings in Ménière's Disease

In order to investigate the characteristics of plain radiography of Ménières disease, the degree of the pneumatization and the distance between the sigmoid plate and the bony wall of the vestibule in Schüllers view were examined in patients with unilateral and bilateral Ménières disease, non-Ménière vertiginous disease and healthy subjects. There was no difference of the degree of pneumatization and the distance among the patients with Ménières disease, the non-Ménière inner ear disease group and in healthy subjects. The distance of the unaffected ear was significantly shorter in patients showing a shorter distance of the affected ear. There was no relationship between the distance and age of onset of the disease, and duration of the disease. Therefore, it is concluded that the dysfunction of endolymphatic sac does not always reflect poor mastoid pneumatization and/or shorter distance in the plain radiography and that other etiological mechanisms such as autoimmune disease should be considered in some patients having evidence of endolymphatic hydrops.