Akihiko Asami

Effects of interleukin-1 and arachiodonate on the preoptic and anterior hypothalamic neurons

Effects of microelectrophoretic application of ultrapure human interleukin-1 (IL-1), an endogenous pyrogen, on the activity of 80 neurons in the preoptic and anterior hypothalamus (PO/AH) were investigated in the urethane anesthetized rat. IL-1 predominantly decreased the activity of warm-sensitive neurons (15 of 19) and increased the activity of cold-sensitive neurons (10 of 12), but had no effect on 37 of 49 thermally insensitive neurons. The neuronal responses to IL-1 were blocked or attenuated by concurrent application of mepacrine (a phospholipase inhibitor) or sodium salicylate (a cyclooxygenase inhibitor). Local application of sodium arachidonate decreased the activity in 17 of 28 warm-units and excited 12 of 16 cold-units, and the effects of arachidonate were blocked by sodium salicylate. The results are compatible with the view that one or more cyclooxygenase metabolites of arachidonic acid are involved in the IL-1 induced fever.

Responses of anterior hypothalamic-preoptic thermosensitive neurons to locally applied capsaicin

The effects of local application of capsaicin on the activity of single thermosensitive neurons in the anterior hypothalamic-preoptic area were studied in the urethane-anesthetized rat. Local injection of capsaicin through a cannula to the vicinity of the neurons increased the activity in 15 of 28 warm-units, decreased the activity in 2 of 4 cold-units and had no effect on 5 of 10 thermally-insensitive units. Electrophoretic application of capsaicin with the use of multibarrelled microelectrodes excited 16 of 27 warm-units, inhibited 12 of 17 cold-units and had no effect on 35 of 60 thermally-insensitive units. Progressive decreases in the responsiveness of the neurons to both capsaicin and the hypothalamic temperature were observed with repeated applications of capsaicin. Many neurons ceased firing after showing excitatory or inhibitory responses to single or repeated applications of capsaicin either by local injection or electrophoretic application. The results may explain the acute thermolytic response, as well as the subsequent decrease in responsiveness to the injection of capsaicin into the anterior hypothalamic-preoptic area, on the basis of changes in the activity of thermosensitive neurons in the anterior hypothalamic-preoptic area.

Bilateral suprascapular nerve entrapment syndrome associated with rotator cuff tear

A 51-year-old man had bilateral posterior aching of the shoulder and atrophy of the supraspinatus and infraspinatus muscles caused by suprascapular nerve entrapment syndrome associated with rotator cuff tears. Electromyography and a nerve conduction study revealed denervation potentials and delayed nerve conduction velocities. Cutting of the superior transverse scapular ligament and external neurolysis of the nerve on both sides followed by anterior acromioplasty brought diminished pain, weakness, and atrophy of the supraspinatus and infraspinatus muscles. Although suprascapular nerve entrapment syndrome is an infrequently recognized cause of disability in the shoulder region, awareness of its clinical presentation (referred shoulder pain with associated weakness and atrophy of the supraspinatus and infraspinatus muscles) can lead to a correct early diagnosis. So far a bilateral suprascapular nerve entrapment syndrome has rarely been described.1,3,5 To

Functional outcome of anterior transposition of the vascularized ulnar nerve for cubital tunnel syndrome

Anterior transposition of the ulnar nerve is a widely used treatment for cubital tunnel syndrome, but neurolysis performed at the time of surgery may impair the blood supply to the ulnar nerve. This study compared the results of intramuscular anterior transposition of the ulnar nerve with or without preserving the extrinsic vessels of the ulnar nerve in 35 patients. The postoperative nerve conduction velocity and the clinical results were better in the group in which the extrinsic vessels were presented.

Thermally-induced activities of the mesencephalic reticulospinal and rubrospinal neurons in the rat

Unit activities of 226 midbrain reticulospinal (mRfS) and non-mRfS neurons and 238 rubrospinal (RbS) and non-RbS neurons were investigated during changes in temperatures of midbrain (Tmb), preoptic and anterior hypothalamus (Thyp) and skin (Ts) in the urethane-anesthetized rat. Responsiveness to Tmb, Thyp and Ts were found in 43.5%, 41.6% and 51.5% of neurons of midbrain reticular formation (mRf), and in 35.2%, 32.7% and 17.6% of neurons of red nucleus (Rb). Higher incidence of responsiveness to remote temperatures was found among Tmb responsive neurons than Tmb unresponsive neurons in both mRf and Rb. The mRf contains significantly greater numbers of neurons having such multiple thermal responsiveness and also of neurons which were activated by falls in temperatures (cold-responsive neurons) than the Rb. These characteristics were more conspicuously seen among mRfS neurons, showing a high degree of convergence of cold signals from different sites of body. On the other hand, RbS neurons did not differ from non-RbS neurons regarding thermal characteristics and showed no particular combinations of responsiveness to temperatures of different sites. Microinjection of procaine and glutamate into the mRf just dorsolateral to the Rb, but not into the Rb, decreased and increased cold-induced increase in EMG activity and shivering without changes in cardiovascular and respiratory parameters and pilomotor activity. The results suggest that mRfS neurons are involved in the control of thermoregulatory muscle tone and shivering.

Subcutaneous Single Injection Digital Block with Epinephrine

The aim of this study was to investigate the anesthetic effect and risk of epinephrine for subcutaneous single injection digital block. Either 3.0 mL 1.0% Lidocaine or a 3.0 mL 1.0% Lidocaine with (1 : 100,000) epinephrine was injected into the subcutaneous space at the middle point of the palmar digital crease of the 18 middle fingers of 9 healthy volunteers. The SpO2 of the fingers decreased to a maximum of 97. No subjects showed any symptoms of ischemic injury. The time to anesthesia for the fingers was significantly shorter (P < 0.05), and the duration of anesthesia was significantly longer (P < 0.01) for the fingers in the epinephrine group. In conclusion, a subcutaneous single injection digital blocks with 3.0 mL of 1.0% Lidocaine and (1 : 100,000) epinephrine were safe, reducing the time to the onset of anesthesia, while also markedly prolonging the anesthesia.

CLINICAL CHARACTERISTICS OF NEUROPATHIC PAIN IN PATIENTS WITH CARPAL TUNNEL SYNDROME

The purpose of this study was to identify the clinical characteristics of neuropathic pain in patients with carpal tunnel syndrome. We retrospectively reviewed 143 hands in 127 patients with carpal tunnel syndrome. The neuropathic pain was determined by using the painDETECT as a self-administered psychometric questionnaire to distinguish neuropathic pain. There were no significant differences in the characteristics of the patients with and without neuropathic pain. However, there were significant differences in the pain scores between those with and without neuropathic pain (p < 0.01). Furthermore, there was a significant difference between the existence of night pain in these patients (p < 0.01). Based on the results of the current study, we conclude that it is important to be aware of, and consider the existence of neuropathic pain during the treatment of patients with carpal tunnel syndrome with night pain or a high score on the numerical rating scales of pain.

Neonate with calcinosis cutis following extravasation of calcium gluconate

Calcium gluconate has been widely used in the management of neonatal hypocalcemia. When extravasation of a calcium gluconate infusion occurs, there may be rapid and marked swelling, erythema, and signs of soft tissue necrosis or infection, with ensuing extensive local calcifi cation, called calcinosis cutis. In most cases, calcinosis cutis following extravasation of calcium gluconate can be treated conservatively without any special treatment. However, it is often diffi cult to make a proper diagnosis because the disease is rare in the orthopedic fi eld, there is a time discrepancy between the clinical symptoms and radiographic fi ndings, and most patients are neonates. There are only two reports of this disease in the orthopedic literature. This report describes a neonate with “calcinosis cutis” following extravasation of calcium gluconate. The patient’s family was informed that the data from this case would be submitted for publication, and they gave their consent.

THE EVALUATION OF PRE- AND POST-OPERATIVE CLASSIFICATION SYSTEM FOR CUBITAL TUNNEL SYNDROME

Pre- and post-operative classification systems for cubital tunnel syndrome are discussed in this study. Although there are several pre-operative evaluations, a suitable system should be easy to categorise, simple, reliable and reproducible. McGowans grading system has been widely used for these reasons; however, grade II included complicated cases. Accordingly, McGowans grade II is divided into two groups, such as grade II-A (relatively good prognostic group) and group II-B (relatively poor prognostic group). As far as the post-operative classification system is concerned, 4 grade (excellent, good, fair, and poor) classification is the most useful and easy to understand.

Multiple glomus tumors in the leg

Abstract Multiple regional glomus tumors are rare. A 61-year-old woman was presented with pain in the left leg and was diagnosed with multiple glomus tumors in the leg, and underwent surgery in 1996. Three bluish red subcutaneous masses on the fascia of the anterior and lateral side of the tibia were excised. Histological and immunohistochemical studies showed regional and solid type (positive for α-smooth muscle actin, vimentin, and type IV collagen and negative for desmin) multiple glomus tumors. The patient has experienced no pain and there has been no evidence of recurrence since the surgery.