Toshiya Tomioka

Anesthesia for Patients with Congenital Insensitivity to Pain and Anhidrosis: A Questionnaire Study in Japan

UNLABELLED We investigated the anesthetic management of patients with congenital insensitivity to pain and anhidrosis (CIPA) in Japan. CIPA is a rare inherited disease characterized by a lack of pain sensation and thermoregulation. Although lacking pain sensation, some patients do have tactile hyperesthesia. Thus, anesthetics are a necessity during operations. We also determined that because patients with CIPA have problems with thermoregulation, temperature management is a concern during the perioperative period and sufficient sedation is necessary to avoid accidental fractures. Additionally, it was found that the use of muscle relaxants does not present a problem, malignant hyperthermia is not associated with CIPA, and that the possibility of abnormalities in the autonomic nervous system must be taken into consideration. Therefore, patients with CIPA can be safely managed with anesthesia. IMPLICATIONS We investigated the anesthetic management of patients with congenital insensitivity to pain and anhidrosis. We clarified the following three important points: anesthesia is necessary, temperature management must be maintained, and there must be sufficient perioperative sedation in the anesthetic management of patients with congenital insensitivity to pain and anhidrosis.

Using the intact hand for objective assessment of phantom hand‐perception

After amputation, most patients experience a phenomenon known as a phantom limb (PL). A variety of PL experiences appear to be associated with neural plasticity within the CNS. However, due to the subjective nature of PL experiences, there was no definitive way to reliably assess PL experiences other than using patients’ direct reports. Here, we were able to obtain patients’ indirect responses to PL experiences, for a more objective evaluation. First, we conducted a study with normals and 17 non‐PL patients experiencing pathological pain in one hand. We took digital photographs of their affected and unaffected hands, altered the sizes of the images digitally, and then asked each subject to choose the image that most closely matched the actual size of their own hands (from a series of images presented on a video screen). Subjective size perceptions of the hands were homologous, regardless of the pathological condition of one hand (p < 0.0001, Spearman R2= 0.82). Next, we used the same method for total 19 patients with a phantom hand. The intact hand‐size perception was linearly correlated with phantom hand‐size perception (weighted linear regression analysis: p < 0.0001, R2 = 0.75, adjusted R2 = 0.73, F‐value = 50.1, degree of freedom = 18). Thus, without requiring a subjective description about PL, the patients’ evaluation of the intact hand‐size precisely but indirectly indicated whether the PL was perceived to be telescoped (shrunken), normal or enlarged. This more objective evaluation of PL phenomena could become a key tool for disentangling the neural mechanisms involved.

The importance of tail temperature monitoring during tail-flick test in evaluating the antinociceptive action of volatile anesthetics.

Background:  Tail‐flick (TF) latency can be influenced by tail‐skin temperature (TT), and treatments that raise TT can mimic hyperalgesia on a TF test. As volatile anesthetics can raise TT via heat redistribution, their antinociceptive action can be hidden or obscured in a TF test. We tested the hypothesis that TT monitoring improves the efficiency of TF tests in evaluating the antinociceptive action of volatile anesthetics.

Post-herpetic neuralgia in a patient with congenital insensitivity to pain and anhidrosis.

Congenital insensitivity to pain and anhidrosis (CIPA) is an inherited disease. CIPA is characterized by episodes of unexplained fever, systemic analgesia, anhidrosis, and mental distress. These symptoms occur because of an abnormality of the trkA gene, a receptor tyrosine kinase of nerve growth factor (NGF) [1]. Patients with CIPA often experience trauma, fracture, and even osteomyelitis because of their insensitivity to pain. We experienced a patient who had been diagnosed with CIPA who complained of itching as a sequela of Herpes zoster infection. We believe that this itching was a symptom of post-herpetic neuralgia. Post-herpetic neuralgia is defined as persistent pain that follows a Herpes zoster infection; however, the mechanism of post-herpetic neuralgia is not known. We present a report of this patient and discuss the mechanism of postherpetic neuralgia in this individual.

Oral Local Anesthesia Successfully Ameliorated Neuropathic Pain in an Upper Limb Suggesting Pain Alleviation through Neural Plasticity within the Central Nervous System: A Case Report.

Neural blockades are considered an alternative to pharmacotherapy for neuropathic pain although these blockades elicit limited effects. We encountered a patient with postbrachial plexus avulsion injury pain, which was refractory to conventional treatments but disappeared temporarily with the administration of the local anesthetic lidocaine around the left mandibular molar tooth during dental treatments. This analgesic effect on neuropathic pain by oral local anesthesia was reproducible. Under conditions of neuropathic pain, cerebral somatotopic reorganization in the sensorimotor cortices of the brain has been observed. Either expansion or shrinkage of the somatotopic representation of a deafferentated body part correlates with the degree of neuropathic pain. In our case, administration of an oral local anesthetic shrank the somatotopic representation of the mouth, which is next to the upper limb representation and thereby expanded the upper limb representation in a normal manner. Consequently, oral local anesthesia improved the pain in the upper limb. This case suggests that pain alleviation through neural plasticity within the brain is related to neural blockade.

Pressure sore as a possible complication of lower central neuraxial blockade

minutes after the first epidural bolus injection, an epidural infusion of plain 1% mepivacaine was started at a rate of 6ml·h 1. Throughout the operation, the patient was in the lithotomy position. To prevent pressure sores, the operating table was covered with silicon jelly pads. The operative area was sterilized with 0.2% chlorhexidine gluconate. Surgery lasted about 4h and 30 min. The patient was in the lithotomy position for 5h. During surgery her systolic blood pressure varied between 90 and 110 mmHg, and her general condition was stable. The bladder temperature did not decrease below 36°C. The total blood loss was 320ml, and we did not give a blood transfusion. At the end of surgery, we checked the condition of the whole body surface of the patient. Although the disinfectant, chlorhexidine gluconate, flowed along her sides a little, there was no change in her sacral skin. Postoperatively, an epidural infusion was started with 0.25% bupivacaine 2ml·h 1 and fentanyl 15 μg·h 1. The patient could move her legs when the continuous epidural infusion was started. She remained hemodynamically stable throughout the first postoperative night. The morning after surgery, 24 hr after the beginning of surgery, a large erythema was discovered on her sacral skin. The erythema was 6 4 cm in size and was tinged with violet (Fig. 1). There were no skin lesions on her body except for the sacral area. The patient did not complain of pain on her sacral skin. A dermatologist confirmed the diagnosis of pressure sore. We informed her about the sacral skin lesion, and she consented to treatment with ointments containing disinfectant and anti-decubitus ulcer drugs. All of the erythema had completely disappeared uneventfully by the fourth postoperative week.

Complex Regional Pain Syndrome Revived by Epileptic Seizure Then Disappeared Soon during Treatment with Regional Intravenous Nerve Blockade: A Case Report

We present a case of complex regional pain syndrome (CRPS), in which symptoms, including burning pain and severe allodynia, were alleviated by using a regional intravenous nerve blockade (Bier block) combined with physiotherapy, but reappeared following an epileptic seizure. Symptoms disappeared again following control of epileptic discharges, as revealed by single-photon emission computed tomography (SPECT) and electroencephalography (EEG) results. Although systemic toxicity of a local anesthetic applied by Bier block was suspected as a cause of the first seizure, the patient did not present any other toxic symptoms, and seizures repeatedly occurred after Bier block cessation; the patient was then diagnosed as having temporal symptomatic epilepsy. This case suggests that symptoms of CRPS may be sustained by abnormal brain conditions, and our findings contribute to the understanding of how the central nervous system participates in maintaining pain and allodynia associated with CRPS.

Is the current perception threshold test affected by circadian changes? A study of healthy volunteers

AbstractThe effect of circadian changes on the Current Perception Threshold (CPT) and Pain Tolerance Threshold (PTT) values were examined in a group of 11 healthy volunteers. Three frequencies, 5 Hz, 250 Hz, and 2000 Hz, were used to stimulate nerve fibers during each test. No significant circadian changes of CPT or PTT, tested with all the frequencies, were found. This means that the time of day is not important for pain measurements.