Reactive arthritis induced by tonsillitis: a type of 'focal infection'.

OBJECTIVE: The clinical manifestation of reactive arthritis (ReA ) induced by tonsillitis is demonstrated. METHODS: Medical records of 21 patients with ReA induced by tonsillitis were analyzed. RESULTS: Nine male and 12 female patients were recorded. The mean age was 31.7 years ranging from 20 to 51 years. The mean duration of arthritis was 29.8 months (2 weeks to 10 years). Acute or recurrent origoarthritis involved in ankle, knee and sternoclavicular joints associated with Achilles tendon enthesitis were demonstrated. Thirteen of 21 (62%) patients were demonstrated positive for ASO and/or ASK. Group A streptococcus was demonstrated in 12 of 21 (57.1%) patients and other bacteria were demonstrated by culture of tonsillar swab or from resected tonsillar microabscess. No bacteria was demonstrated in synovial fluid from 3 patients. Rheumatoid factor was demonstrated only in 2 of 21 patients. HLA-B39 and BW61 (B40) were significantly demonstrated in 5 and 7 patients (p=0.0004, 0.0006, respectively) compared with those of healthy controls. All patients were treated with antibiotics and nonsteroidal anti-inflammatory drugs (NSAIDs). Eight of 21 patients underwent tonsillectomy. Arthritis ceased after the treatments and no recurrence was found. DISCUSSION: Sterile inflammatory arthritis induced by tonsillitis was cured by resection of the microabscess in the tonsils. Therefore, ReA induced by tonsillitis is one form of 'focal infection'.

The effect of surgical treatment of obstructive sleep apnea syndrome on the plasma TNF-alpha levels.

Obstructive sleep apnea syndrome (OSAS) is defined as intermittent complete or partial upper airway obstruction during sleep, causing mental and physical effects. Both the local and systemic inflammation observed in OSAS induce certain potent pro-inflammatory mediators, which may contribute to the development of cardiovascular consequences. The present study was designed to evaluate the plasma levels of TNF-alpha, which is one of the known pro-inflammatory cytokines, in patients with OSAS and to assess the effect of surgical treatment on the levels of TNF-alpha levels. Twenty seven patients diagnosed to have OSAS, 7 non-apneic patients with chronic tonsillitis (non-OSAS patients), and 4 healthy subjects were enrolled in this study. Blood samples were collected one week preoperatively and postoperatively, and the plasma TNF-alpha levels were measured using high-sensitivity ELISA. The plasma TNF-alpha levels in patients with OSAS were significantly elevated in comparison to normal healthy subjects. In contrast, there was no difference between the patients with non-OSAS and healthy subjects. Moreover, the surgical treatment to enlarge the upper airway in patients with OSAS significantly decreased the levels of TNF-alpha levels. Surgical treatment of patients with OSAS reduces the plasma TNF-alpha levels, thereby ameliorating the systemic inflammation and preventing the development of cardiovascular consequences.

A facial nerve study using transcranial magnetic paired stimulation.

OBJECTIVE: The purpose of this study was to evaluate the refractory period of the facial nerve by transcranial magnetic paired stimulation (TMPS) with as short interstimulus interval (ISI) as possible. Also, by applying TMPS, the long latency response obtained at the same time was recorded and its neurophysiological characteristics were studied. METHODS: (Experiment 1) The subjects comprised of 30 normal volunteers and 19 patients with Bell's palsy. The experiments were carried out using two sets of Magstim model 200 and Bistim modules, a large coil measuring 90 mm in diameter with a maximal output of 2.0 tesla (T), and a Neuropack 8 (Nihon Kohden Co., Japan) to control the stimulation and record the electromyographic findings. The amplitude of compound muscle action potentials (CMAP) to the orbicularis oris muscle was studied by TMPS at the parieto-occipital region. The ISI was set at 0.9, 1.1, 1.3, 1.5, 1.7, 1.9 and 2.1 ms in order to measure the refractory periods of the nerve. (Experiment 2) The subjects comprised of ten normal volunteers. The same method as in experiment 1 was carried out. However, this time, the lead electrodes were placed on the orbicularis oculi muscle, similar to that of the blink reflex. The ISI was set at 40, 60, 80, 100, 200, 300, 500, 800 and 1000 ms, and the effects of the facilitation and inhibition were studied. RESULTS: (Experiment 1) In normal subjects, when the ISI was less than 1 ms, a significant decrease in the amplitude was noted. In severe palsy cases with House-Brackmann Grade IV-V TMS yielded no response. In two of the cases of House-Brackmann Grade III, the CMAP was obtained. (Experiment 2) The long latency response with TMPS was most strongly inhibited when ISI was 80 ms. CONCLUSION: We were able to investigate the refractory periods, the reflex pathway of the facial nerve and the trigeminal nerve including the pons and the medulla oblongata by TMPS.

Cervical reflex induced by click stimuli in cats.

We studied click-evoked potentials in the anterior horn of the spinal cord in 17 cats. A concentric needle electrode was inserted into the anterior horn of the spinal cord at levels C3-C6. Potentials evoked with 105 dB SPL clicks were recorded with a peak latency of 4.89-5.10 ms only at the C3 level. These responses were observed 45-60 dB SPL above the auditory brainstem response (ABR) threshold, and no potentials were evoked by stimulation of the contralateral ear. Average was performed 100 times with changes in stimulation frequency of 1-20 Hz. The amplitude of the potentials decreased with increasing stimulus frequency, but there were no changes in ABRs. The responses disappeared after destruction of the medial vestibulospinal tract at the obex level, but ABRs were still recorded. The spinal nucleus of the accessory nerves was located in the anterior horn of the spinal cord at levels C1-C6, and the sternocleidomastoid muscle motoneurons were found at levels C1-C3. The click-evoked potentials recorded in this study reflect responses of the spinal nucleus of accessory nerves through the vestibulospinal tract to click stimulation. The responses have the same characteristics as vestibular-evoked myogenic potentials that can be recorded using surface electrodes over the sternoclei-domastoid muscles of humans.