Brain activation during ideomotor praxis: imitation and movements executed by verbal command.

BACKGROUND: Ideomotor apraxia is a disorder of both imitation movements and movements executed by verbal command. Lesion studies have identified the left parietal lobe as the neural correlate for ideomotor praxis (IP), although there are opposing views. OBJECTIVES: To localise the neural substrates for IP using functional magnetic resonance imaging. Brain regions activated by both imitation and verbal command movements were tested against a simple self paced movement. METHODS: Twenty two young, right handed, healthy subjects were examined. Functional and anatomical data were acquired. The experiment comprised three motor conditions (imitation, movements executed by verbal command, and finger bending/unbending) and a rest condition. All motor tasks were performed using the left hand. Eighteen drawings of left hand postures were presented for the imitation condition. Identical postures were instructed verbally for the verbal command condition. The finger bending/unbending movement was self paced. Blood oxygenation level dependent (BOLD) signal increases were compared during two kinds of IP (imitation and verbal command movements) and during finger bending/unbending movements. RESULTS: The depth of the posterior part of the left intraparietal sulcus and bilateral precunei were activated during both imitation and verbal command movements. The difference in BOLD signal between imitation and verbal command movements was localised in the dorsal and ventral occipital areas. BOLD signal differences for movements executed by verbal command against imitation were observed in the superior temporal areas. CONCLUSIONS: The depth of the posterior part of the left intraparietal sulcus and bilateral precunei are the neural substrates for IP.

[A case of ischemic dilated cardiomyopathy, mitral regurgitation and congestive heart failure successfully treated by Batista operation, coronary artery bypass grafting and mitral valve replacement; usefulness of myocardial scintigraphy].

A 75-year-old man diagnosed as having ischemic dilated cardiomyopathy, congestive heart failure and mitral regurgitation underwent left ventricle volume reduction operation (Batista), coronary bypass grafting and mitral valve replacement because myocardial infarction had developed at lateral, inferior and small area of apex wall, not at interventricular septum. Left ventricular endodiastolic volume index and left ventricular endosystolic volume index decreased from pre-operative values of 155, and 128 ml/m2 to post-operative values of 113, and 82 ml/m2, respectively. Left ventricular ejection fraction increased from a pre-operative value of 17% to a post-operative value of 27%. This evaluation was performed by myocardial scintigraphy (quantitative gated spect: QGS). This method was bloodless and useful for determination of indication of left ventricle volume reduction surgery including Batista operation and pre- and post-operative evaluation of this type of surgery. Today, Batista operation is, generally speaking, performed for non-ischemic dilated cardiomyopathy. In this case, however, Batista operation was applied to ischemic dilated cardiomyopathy and was very effective.

Proton magnetic resonance spectroscopy in disturbances of cortical development.

Proton magnetic resonance spectroscopy(1H-MRS) can be used for looking at cerebral metabolites in vivo. However, measurement of concentrations of cerebral metabolites in patients with disturbances of cerebral development have not been successful. Our purpose was to measure the concentrations of cerebral metabolites in such patients. We carried out quantitative 1H-MRS in eight patients with cortical dysplasia, four with lissencephaly and three with heterotopic grey matter and six age-matched normal controls. Regions of interest for 1H-MRS were set over the affected cortex in the patients and the occipital cortex in controls. The calculated concentration of N-acetylaspartate ([NAA]) was significantly lower in the affected cortex in patients with cortical dysplasia (P < 0.05), lissencephaly (P < 0.01), and heterotopia (P < 0.05) than in controls, idnicating a decreased number and/or immaturity or dysfunction of neurones in the affected cortex. The concentration of choline ([Cho]) was significantly lower in patients with lissencephaly (P < 0.01) than in controls, indicating glial proliferation and/or membrane abnormality.

Abnormality of the myocardial sympathetic nervous system in a patient with Becker muscular dystrophy detected with iodine-123 metaiodobenzylguanidine scintigraphy.

PURPOSE: This study was performed to determine whether I-123 metaiodobenzylguanidine (MIBG) scintigraphy can depict myocardial sympathetic nerve abnormalities in Becker muscular dystrophy. MATERIALS AND METHODS: A 34-year-old man with Becker muscular dystrophy underwent Tl-201 and I-123 MIBG scintigraphy sequentially before and 4 months after the beginning of oral administration of enalapril maleate, an angiotensin-converting enzyme inhibitor. RESULTS: Before and during treatment, stress Tl-201 scintigraphy revealed nonreversible myocardial perfusion defects in the anterior, inferoposterior, and apical walls, and I-123 MIBG scintigraphy depicted a region with decreased sympathetic nerve function or innervation. Before treatment, the I-123 MIBG heart count- mediastinum count (H:M) ratio was 2.1 and the washout rate was 21% on delayed images obtained 4 hours after the injection of I-123 MIBG, indicating hyperactivity of the sympathetic nervous system in the myocardium. During treatment, the H:M ratio was 3.0 and the washout rate was 15%. CONCLUSION: With I-123 MIBG scintigraphy it is possible to evaluate an abnormality of the myocardial sympathetic nervous system and the efficacy of administration of an angiotensin-converting enzyme inhibitor in this disease.

Validation of CBF measurement with non-invasive microsphere method (NIMS) compared with autoradiography method (ARG).

The purpose of this study is to examine the correlation of measured regional cerebral blood flow (rCBF) by means of a new microsphere method (non-invasive microsphere method), to the autoradiography (ARG) method, which is an established quantification method for 123I-IMP brain SPECT. The non-invasive microsphere (NIMS) method and ARG method were simultaneously applied to 30 patients, and quantified rCBF maps were calculated with each method. A significant correlation (r = 0.70: p < 0.001) was detected between mCBF values calculated with the NIMS and ARG methods. This new method seems to reliably quantify rCBF with brain SPECT.

Proton magnetic resonance spectroscopy of Sjögren-Larsson syndrome heterozygotes.

A deficit of fatty alcohol:NAD+ oxidoreductase complex (FAO) activity has been detected in patients with the Sjögren-Larsson syndrome (SLS). A moderate decrease in FAO activity has also been reported in heterozygote SLS subjects. Abnormal peaks were detected with proton magnetic resonance spectroscopy (1H-MRS) in homozygote SLS subjects. The purpose of this study was to examine whether 1H-MRS can be used to detect metabolic and/or pathological abnormalities in heterozygote SLS subjects. Four SLS heterozygotes were examined using 1H-MRS. A moderate decrease in FAO activity was demonstrated in two of the four heterozygotes. Abnormal peaks were detected at 0.9 ppm in the spectrum from cerebral hemispheres of every heterozygote. 1H-MRS was able to detect an abnormal accumulation of fatty alcohols and lipids, which is expected to increase due to an decrease in FAO activity or dysmyelination in heterozygote SLS subjects. Thus, 1H-MRS is suggested to be a powerful tool in the screening of SLS heterozygotes.

[A case of orbital MALT lymphoma in which 67Ga scintigraphy was useful for evaluating the radiation therapy response].

A 67-year-old man was hospitalized at our institution complaining with epiphora and exophthalmos on the left side. Magnetic resonance imaging (MRI) showed an ill demarcated retrobulbar mass in the left orbit. 67Ga scintigraphy revealed avid uptake in the left orbital region. The patient was treated with radiation therapy. One month after the radiation therapy, the size of the mass decreased remarkably on MRI. 67Ga planar imaging after treatment showed no uptake, but 67Ga SPECT showed slightly increased uptake in the left orbital region. One year after the radiation therapy, MRI showed residual mass in the left orbital region. Both 67Ga planar imaging and SPECT showed no uptake in the left orbital region. 1.8 years after the radiation therapy, MRI showed the residual mass with no interval change in size. Both 67Ga planar imaging and SPECT showed no uptake in the left orbital region. The patient remains well with no evidence of local recurrence. 67Ga scintigraphy is useful in assessing the response to radiation therapy of MALT lymphoma in this case.

Multiple myeloma showing increased accumulation of Tc-99m hexamethylpropylene amine oxime on brain SPECT.

The authors report a case of multiple myeloma with increased accumulation of Tc-99m hexamethylpropylene amine oxime (HMPAO) on brain SPECT. Tc-99m HMPAO is a lipophilic compound that freely passes through the intact blood-brain barrier and cell membrane and is rapidly converted to a hydrophilic form by glutathione and then retained in the neuron for several hours. In general, Tc-99m HMPAO shows decreased accumulation in brain tumors. However, some reports of increased accumulation in brain tumors, such as meningioma, glioblastoma multiforme, high-grade astrocytoma, pituitary adenoma, and multiple myeloma, have been published. The Tc-99m HMPAO uptake in these tumors has been attributed to tumor blood flow or glutathione contents within the tumor. With regard to uptake to Tc-99m HMPAO in multiple myeloma, the tumor size is considered to be an additional factor.

Activation of supplementary motor area during imaginary movement of phantom toes.

To evaluate changes in the human cerebral cortex after lower limb amputation, we studied repetitive toe movements using functional magnetic resonance imaging. The subject did not experience any phantom pain but had a vivid sensation of the phantom limb's presence and was able to imagine the movement of her phantom toes and ankle. Actual movement of her normal limb activated the contralateral supplementary motor area (SMA), the primary motor cortex (M1), and the primary somatosensory cortex (S1). Movement of her phantom limb activated the contralateral SMA and the M1. Imaginary movement of her normal toes without actual movement activated the contralateral SMA. The slice level that was activated by the movement of the phantom limb was shifted 8 mm caudally, suggesting that cortical reorganization had occurred after the lower limb amputation.

Proton MR spectroscopy of Sjögren-Larsson's syndrome.

We performed single-voxel proton MR spectroscopy (1H-MRS) in two children with Sjögren-Larsson's syndrome (SLS). Both patients showed two abnormal spectral peaks at 1.3 ppm and 0.9 ppm that were obtained with short echo times. These two abnormal spectral peaks were seen in high-intensity areas on T2-weighted images and also in basal ganglia of normal intensities. 1H-MRS may be useful for establishing the diagnosis and investigating the natural history of SLS, and for evaluating the efficacy of therapeutic approaches to SLS.

Functional magnetic resonance imaging localization of tactile reading phonograms in Japanese subjects.

Functional magnetic resonance imaging (fMRI) is used to investigate the neural basis for tactile reading of Japanese phonograms (kana) with the left hands of six normal right-handed Japanese subjects. Both the tactile reading and recognition tasks activated the areas surrounding the left and right central sulci in all subjects. The region surrounding the left intraparietal sulcus was activated during the tactile reading task in all subjects, whereas the region was activated during the tactile recognition task in only two subjects. These results suggest the bilateral central sulcus areas participate in the manipulatory movement of the left hand and processing of the somatosensory information, and the left intraparietal sulcus area participates inevitably, in the tactile reading of Japanese phonograms. Our experiments support the essential role of the intraparietal sulcus area in the phonogram-reading process.

Hydraulic analysis of the functional properties of saline-jet aspiration thrombectomy catheters.

The purpose of this paper is to clarify the functional properties of a saline-jet aspiration thrombectomy catheter based on hydraulics. This catheter, developed by the authors, aspirates intravascular thrombi by means of the effect of a high-speed jet. We have derived the relationships between Qs, Qa, and p(n), where Qs is the water supply rate, Qa is the water aspiration rate and p(n) is the negative pressure created in the distal lumen of the catheter. The relationships are represented by simple equations using c1 and c2, where c1 and c2 are coefficients proper to the catheter. We have obtained c1 and c2 experimentally for three types of catheter with different distal shapes. Two practical conclusions are derived from this study. First, making a short taper at the distal end increases the negative pressure created and is advantageous for thrombus aspiration. Second, making the diameter of the inner tube and nozzle smaller is essential for improving the aspiration ability of the catheter.

Hemodynamic changes around cerebral arteriovenous malformation before and after embolization measured with PET.

To estimate the changes in regional cerebral blood flow (rCBF) around cerebral arteriovenous malformation (AVM) before and after embolization, 6 patients with AVM were sequentially examined with positron emission tomography (PET). PET depicted the remodeling of rCBF in the ipsilateral hemisphere of AVM after embolization. Decrease of rCBF in the ipsilateral hemisphere was also detected in patients with focal symptoms before embolization, and improvement of clinical symptoms after embolization corresponded to disappearance of rCBF decrease. PET can detect hemodynamic changes after embolization, and has a possibility to estimate the effect of embolization in patients with AVM.

[1H-NMR spectroscopy of a patient with pachygyria].

1H-NMR spectroscopy was performed on a 6-month-old boy with pachygyria. A MRI study demonstrated an abnormally thick cortex localized in the right occipital lobe. 1H-NMR spectrums were collected from the lesion and the contralateral cortex that appeared normal on MRI. The N-acetylaspartate (NAA)/Cre (creatine) ratio was markedly lower in the abnormal cortex than in the contralateral cortex and the occipital cortex. NAA localizes to neurons, axons, dendrites and synaptic connections and increases with maturation of neurons. Its decrease is considered to represent the decrease in the number of these structures and/or disturbance of neuronal maturation. We conclude that NAA/Cre can be an important index that reflects the pathogenesis of pachygyria.

3 beta-p-hydroxybenzoyldehydrotumulosic acid from Poria cocos, and its anti-inflammatory effect.

The structure of a new triterpene derivative isolated from Poria cocos was determined to be 3 beta-p-hydroxybenzoyldehydrotumulosic acid by spectral and chemical methods. 3 beta-p-hydroxybenzoyldehydrotumulosic acid showed marked inhibitory activity against 12-O-tetradecanoylphorbol-13-acetate (TPA)- and arachidonic acid (AA)-induced ear inflammation in mice. The 50% inhibitory doses of 3 beta-p-hydroxybenzoyldehydrotumulosic acid were 0.27 and 1.25 mg per ear on TPA- and AA-induced inflammation, respectively.