Shino Shigemori

Changes in regional cerebral blood flow in the thalamus after electroconvulsive therapy for patients with complex regional pain syndrome type 1 (preliminary case series)

Background and Objectives The aim of the present case series was to examine whether changes in regional cerebral blood flow (rCBF) induced by electroconvulsive therapy (ECT) in the thalamus are related to the efficacy of ECT. Four chronic pain patients with complex regional pain syndrome (CRPS) type-1 (age, 33 to 58 years) who had failed to respond to standard pain treatments received a course of ECT. To investigate the possible mechanisms of the analgesic effect of ECT on chronic CRPS type-1, we measured significant changes in the rCBF of the thalamus using technetium-99m ethyl cysteinate dimer single photon emission computed tomography (99mTc ECD SPECT), before and after ECT and compared these values between responders and nonresponders. Results Two of 4 (50.0%) patients responded to ECT treatment (response defined as a reduction of at least 60% on the visual analog scale [VAS]). 99mTc ECD SPECT showed that the mean contralateral thalamus-to-cerebellum ratio increased 11.5% after ECT compared with the ratio before ECT in the 2 responders, but remained unchanged in nonresponders. Conclusions The results from the SPECT suggest that normalization of the balance of rCBF in the thalamus may be related to the analgesic efficacy of the ECT on CRPS Type-1.

Chronic pain with beneficial response to electroconvulsive therapy and regional cerebral blood flow changes assessed by single photon emission computed tomography

Background Recent neuroimaging studies suggested that chronic neuropathic pain may be largely sustained by a complex neuronal network involving the thalamus. Although recent studies have demonstrated the efficacy of electroconvulsive therapy (ECT) in the treatment of a variety of types of chronic neuropathic pain, the effects of ECT on regional cerebral blood flow (rCBF) have not been studied. Objectives and Methods We present a 50-year-old female postsurgical chronic pain patient whose pain had failed to respond to standard pain treatment, but was resolved by ECT. To investigate the potential role of rCBF in ECT’s analgesic effect, we measured significant changes in the rCBF in the thalamus before and after a course of bilateral ECT using technetium-99m ethyl cysteinate dimer (99mTc-ECD) single photon emission computed tomography (SPECT). Results 99mTc-ECD SPECT showed a significant bilateral decrease in the thalamus on the side of the pain, and this decreased rCBF in the thalamus increased after ECT. Conclusions The results from the SPECT suggest that ECT increases abnormally decreased thalamus activity in chronic neuropathic pain.

Dissociation between lactate accumulation and acidosis in middle cerebral artery-occluded rats assessed by 31P and 1H NMR metabolic images under A 2-T magnetic field

The relationships among tissue edema, lactate accumulation, and intracellular pH in middle cerebral artery (MCA)-occluded rats were investigated with multiecho 1H magnetic resonance imaging and spatially resolved metabolic images constructed by 1H and 31P nuclear magnetic resonance (NMR) chemical shift imaging (CSI). For the effective and sensitive detection of NMR signals from the brain, outer volume suppression (OVS), reduced k-space sampling and proton irradiation were incorporated into the CSI sequences. The consecutive three measurements of calculated T2 image, lactate image, and pH image which were required for 3.75 h were repeated for four cycles of 1-16 h after MCA occlusion. Tissue edema and lactate accumulation in the infarcted region were gradually and consistently increased during the 15-h observation period. In contrast, severe acidosis was already detected on the first pH image (2-4.7 h after MCA occlusion); thereafter, the degree of acidosis became milder and showed no further progression. The dissociation between the time courses of the lactate accumulation and pH decrease was clearly demonstrated by the NMR metabolic images. Acid-base balance in cerebral infarction might be affected not only by lactate production but also by complicated interactions with tissue edema and some other factors.

The effects of halothane and isoflurane on the phosphoenergetic state of the liver during hemorrhagic shock in rats : An in vivo 31P nuclear magnetic resonance spectroscopic study

We studied the effects of halothane versus isoflurane on the phosphoenergetic state and intracellular pH (pHi) of the rat liver using in vivo31 P nuclear magnetic resonance (NMR) spectroscopy during and after hemorrhagic shock.Seventeen rats were anesthetized with 1 minimum alveolar anesthetic concentration of halothane or isoflurane. The mean arterial blood pressure was reduced to 40 mm Hg and maintained at this level for 45 min by withdrawing blood from the common carotid artery. The shed blood was then returned slowly. In vivo31 P NMR spectra were consecutively collected throughout the study. The phosphoenergetic state of the liver was evaluated from the changes in adenosine triphosphate (ATP) and inorganic phosphate (Pi) levels. pHi was calculated from the chemical shifts of Pi and alpha-ATP peaks. During hemorrhagic shock, beta-ATP decreased to 35% and 45%, and Pi increased to 300% and 230% of their initial values in the halothane and isoflurane groups, respectively. Intracellular acidosis was more severe in the halothane group. The recoveries of beta-ATP and Pi were better in the isoflurane group. Halothane showed a more detrimental effect than isoflurane on the hepatic phosphoenergetic level during and after hemorrhagic shock. (Anesth Analg 1997;85:347-52)

Central pain associated with low thalamic blood flow treated by electroconvulsive therapy

table central poststroke pain throughout his right hemibody, mostly in the upper and lower extremities, had lasted for almost 3 years. Three years after the event, he was referred to the pain clinic of the Department of Anesthesiology, Shiga University of Medical Science, in order to receive a course of ECT treatment for his persistent pain. Visual analogue scale (VAS) levels for pain were rated as 8–10 (0, no pain; 10, maximal pain). He was unable to resume walking because of the persistent pain. The patient was informed about the treatment protocol, which was approved by the Hospital Ethical Committee, and about the possible benefits and side-effects of ECT. Informed oral and written consent was obtained before ECT. Medication at that time consisted of 30mg·day 1 nortriptyline and 300mg·day 1 carbamazepin. The ECT was conducted by brief-pulse stimulus (frequency 60Hz, pulse width 1 ms, current 0.7 A, stimulus duration 2.8 s) once a week over 8 weeks unilaterally using a Thymatron DGX (Somatics) and seizure was assured by EEG monitoring and by viewing cuffed-limb seizures. The unilateral ECT application was to the nondominant hemisphere and ipsilateral to the cerebral vascular accident. Hypnosis was induced with a bolus injection of thiopental (2–3 mg·kg 1), and muscle relaxation was achieved by succinylcholine (1–1.5 mg·kg 1 IV). Ventilation was assisted using a facemask with 100% oxygen, and nicardipine (0.5–1.5mg IV) was injected to attenuate acute cardiovascular side-effects. A course of eight unilateral ECT treatments resulted in a reduction in pain. After ECT treatment, the patient still had some occasional pain, but was able to tolerate it. VAS levels for pain after ECT were rated 2–5. His mental state and daily activities improved, and he could enjoy walking. He suffered retrograde and anterograde memory impairments transiently, but recovered within 2 months. One and half years after the ECT treatment, the reduction in central poststroke pain has persisted.

Relationship between gluconeogenesis and phosphoenergetics in rat liver assessed by in vivo 13C and 31P NMR spectroscopy.

The relationship between the phosphoenergetic state and gluconeogenesis in the liver after ischemic damage was investigated using living rats. The ATP level was determined with in vivo 31P nuclear magnetic resonance spectroscopy, and gluconeogenesis was evaluated with in vivo 31C NMR spectroscopy using L‐[3‐13C]alanine as a tracer. These two measurements were alternated repeatedly. The rats were divided into three groups: without ischemia (group A); with 10 min ischemia (group B); and with 30 min ischemia (group C). ATP was depleted to 20% of the preischemic state after 10 min ischemia and this level was maintained during 30 min ischemia. After reperfusion, the ATP level was partially restored, but the recovery was smaller in group C. Infusion of [3‐13C]alanine was started immediately after the reperfusion. In vivo 13C NMR disclosed changes in the alanine C3, glutamine/glutamate C2 and C3, glucose C1–6, and glycogen C1 signals in the liver. After 60 min infusion of [3‐13C]alanine, the ATP level correlated negatively with the signal intensity of alanine (r=0.664, p=0.008) and positively with those of glucose and glyogen (r=0.586, p=0.023, and r=0.643, p=0.011, respectively). These results suggest that the ATP level participates in gluconeogenesis and glycogenesis in the liver. Such multinuclear in vivo NMR observations might uncover new aspects of the metabolic function of the liver in the in vivo state.

Phantom pain with beneficial response to electroconvulsive therapy (ECT) and regional cerebral blood flow (rCBF) studied with Xenon-CT

AbstractWe present a phantom limb pain patient whose ongoing pain was resolved after electroconvulsive therapy (ECT). Before ECT, regional cerebral blood flow (rCBF) on the ipsilateral side of the anterior cingulate cortex (BA32) and insula increased, compared to the pain on the patients contralateral side. These asymmetries in the anterior cingulate cortex and insula were normalized after ECT, when the phantom limb pain subsided. There were no abnormalities or significant right-left differences of rCBF in the thalamus. Our results suggest that the rCBF of the anterior cingulate cortex and insula were related to the analgesic efficacy of the ECT.

Chronic neuropathic pain with beneficial response to electroconvulsive therapy (ECT) and regional cerebral blood flow changes assessed by SPECT

AbstractWe present two patients with type-1 complex regional pain syndrome (CRPS) and one patient with post-herpetic neuralgia (PHN) patients whose pain had failed to respond to standard pain treatment, but was resolved by electroconvulsive therapy (ECT). To investigate the potential role of regional cerebral blood flow (rCBF) involved in ECTs analgesic effect, we measured significant changes in the rCBF in the thalamus before and after a course of bilateral ECT using technetium-99m ethyl cysteinate dimer (99mTc ECD) single photon emission computed tomography (SPECT). SPECT showed significantly decreased rCBF in the thalamus which increased after ECT. The results of SPECT suggest that ECT increases abnormally decreased thalamus activity in chronic neuropathic pain. Our results from the SPECT suggest that these rCBF changes may be related to the analgesic efficacy of ECT.

Evaluation of thalamic neural function in chronic neuropathic pain patients by proton MR spectroscopy: a correlative study with rCBF by SPECT

AbstractThe thalamus has been implicated in having an important role in pain processing in chronic neuropathic pain patients in recent imaging studies. The purpose of this study was to examine the correlation of the N-acetylaspartate to creatine (NAA/Cr) ratio measured by proton magnetic resonance spectroscopy (1H-MRS), which reflects neural function, with regional cerebral blood flow (rCBF) in the thalamus of chronic neuropathic pain patients. We performed 1H-MRS with a 1.5T MR system on a 2×2×2 cm voxel in the thalamus bilaterally in six patients with chronic neuropathic pain (CRPS type-1, 4; central post-stroke pain; 2). We compared NAA/Cr ratios measured by 1H-MRS to rCBF measured by 99mTc ECD SPECT. The asymmetry index of the NAA/Cr ratio, which was defined as contralateral/ipsilateral ratio, was significantly positively correlated with the asymmetry index of rCBF (r = 0.94; p < 0.05). Our results using 1H-MRS show that neural function of the thalamus may be associated with rCBF.

A case of central post-stroke pain with beneficial response to electroconvulsive therapy: a proton magnetic resonance spectroscopy study

Abstract We present a 58-year-old male chronic post-stroke central pain patient, whose pain resulted from left thalamic hemorrhage, and whose pain had failed to respond to standard pain treatment, but was resolved by electroconvulsive therapy (ECT). To investigate the potential role of neural function in ECTs analgesic effect, the patient underwent a proton magnetic resonance spectroscopy (1H-MRS) on a 2 × 2 × 2 cm voxel in the thalamus bilaterally before and after a course of unilateral ECT.The N-acetylaspartate-to-creatine (NAA/Cr) ratio, which reflects neural function, was calculated on the voxel of the thalamus. Before ECT, the left to right thalamus NAA/Cr ratio was 62.3%. The NAA/Cr ratio of the left thalamus increased 32.0% after ECT,compared to the ratio before ECT.The results from the 1H-MRS suggest that improvement of neural dysfunction in the thalamus may be related to the analgesic efficacy of ECT.