Parkinson Disease: Hashimoto T

Miziuno Y, Okuma Y, Kikuchi S, Kuno S, Hashimoto T, Hasegawa K, Mano Y, Miwa H, Murata M, Yamamoto M, Yokochi F, Okiyama R, Kanazawa A, Shinpo K, Chuma T, Higashi T, Maruyama T, Mizuta E, Yamazaki S, Anonymous00188. · Department of Neurology, Juntendo University School of Medicine, Tokyo, Japan · Rinsho Shinkeigaku. · Pubmed #12708433 No free full text.

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Yokoyama T, Hashimoto T, Itakura T, Tanaka K, Yamamoto T, Katayama Y, Kobayashi K, Fukaya C. · No affiliation provided · No Shinkei Geka. · Pubmed #15570883 No free full text.

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Hashimoto T. · No affiliation provided · No Shinkei Geka. · Pubmed #15148806 No free full text.

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Ikebe S, Harada T, Hashimoto T, Kanazawa I, Kuno S, Mizuno Y, Mizuta E, Murata M, Nagatsu T, Nakamura S, Takubo H, Yanagisawa N, Narabayashi H. · Department of Neurology, Juntendo University School of Medicine, 2-1-1 Hongo, Bunkyo, Tokyo 113-8421, Japan. · Parkinsonism Relat Disord. · Pubmed #12735915 No free full text.

Abstract: We report a consensus statement of the collaborative research group on the prevention and treatment of malignant syndrome (MS) in Parkinson's disease. The syndrome is quite similar to neuroleptic MS. Although sudden withdrawal of levodopa was the most frequent cause, many other precipitating events were found such as intercurrent infections, dehydration, hot weather, discontinuation of other anti-parkinsonian drugs, and "wearing off" phenomenon.Awareness of this syndrome is most important for its early detection and the prompt commencement of treatment. MS should be suspected whenever the body temperature rises above 38 degrees C without an apparent cause. Treatment consists of ample intravenous fluid, cooling the body, anti-parkinsonian drugs (particularly levodopa and bromocriptine), dantrolene sodium, and antibiotics if infection is present. Rhabdomyolysis, disseminated intravascular coagulation, and acute renal failure constitute serious complications.

Hashimoto T. · Third Department of Medicine(Neurology), Shinshu University School of Medicine. · Nippon Rinsho. · Pubmed #11068437 No free full text.

Abstract: Major parkinsonian motor symptoms, i.e., bradykinesia, muscular rigidity, and resting tremor, are due to abnormalities in the motor circuit of the basal ganglia caused by loss of nigrostriatal dopamine neurons. Bradykinesia results from increased activity with altered firing patterns of the output nuclei of the basal ganglia. Exaggerated long-latency reflex or decreased Ib inhibition of the spinal reflex network have been suggested to underlie rigidity, but the relationship between these reflex abnormalities and the altered activities of the basal ganglia in the parkinsonian state remains unclear. The central oscillator for parkinsonian tremor has been localized in the basal ganglia circuit, and the cerebellar system also participates in generation of the tremor. Dyskinesia and dystonia may develop from decreased activity with altered firing patterns of the output nuclei of the basal ganglia.

Hashimoto T, Tsuji S. · No affiliation provided · Ryoikibetsu Shokogun Shirizu. · Pubmed #10434592 No free full text.

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Vitek JL, Hashimoto T, Peoples J, DeLong MR, Bakay RA. · Emory University School of Medicine, Atlanta, Georgia, USA. · Mov Disord. · Pubmed #15300655 No free full text.

Abstract: High frequency (>100Hz) electrical stimulation in both the external (GPe) and internal (GPi) segments of the globus pallidus was effective in improving parkinsonian motor signs. Improvement generally occurred at short latency (<5-10 seconds) in both GPe and GPi but was often (50% of the time) delayed in GPi. Dyskinetic movements were observed during stimulation within GPe and GPi but were more frequent in GPe (20% vs. 9%). These findings suggest that electrical stimulation in both GPe and GPi may ameliorate parkinsonian motor signs. The mechanisms responsible for these observations, however, may differ. The tendency for delayed responses with GPi stimulation suggests a more complex spatial-temporal profile of stimulation on the electrical activity of GPi neurons and/or its effect on network activity in pallido-thalamo-cortical circuitry. The rarity of delayed effects with GPe stimulation suggests a more direct role of synaptic inhibition or normalization of neuronal activity of GPi either directly by means of activation of striatopallidal fibers passing through GPe (direct pathway), by means of activation of GPe-->GPi or GPe-->subthalamic nucleus projections (indirect pathway) or indirectly by means of the tonic activation of adjacent fiber pathways. These data provide a rationale for the exploration of electrical stimulation in GPe in patients with medically intractable Parkinson's disease and provide a basis on which to develop further investigations into the use of chronic electrical stimulation for the treatment of Parkinson's disease and other movement disorders.

Hayashi R, Hashimoto T, Tada T, Ikeda S. · Department of Medicine (Neurology), Shinshu University School of Medicine, Matsumoto, Japan. · Mov Disord. · Pubmed #12722165 No free full text.

Abstract: We studied the effects of unilateral pallidotomy on motor execution and reaction times in patients with moderately advanced Parkinson's disease (PD). Twelve consecutive patients (7 men, 5 women; all right-handed) underwent left-side microelectrode-guided pallidotomy. In addition to clinical rating, reaction time (RT) tests and repetitive movements of the contralesional hand/arm were carried out at baseline and 2 to 3 months after surgery while patients were on optimal medical regimens (on period). The initiation time in both simple reaction time (SRT) and choice reaction time (CRT) improved significantly after pallidotomy (P < 0.05), whereas no effect was observed on the choice processing time, which was calculated by subtracting the mean value of the onset of SRT from that of CRT. Pallidotomy resulted in significant improvement of repetitive movements such as hand pronation/supination and finger-tapping (P < 0.002, P < 0.005, respectively). Improvements in RT tests and repetitive movements suggest that pallidotomy may enhance attention and motor function. These effects are probably mediated through the pallido-thalamic-cortical neural circuitry.

Xu W, Russo GS, Hashimoto T, Zhang J, Vitek JL. · Department of Neurosciences, Lerner Research Institute of the Cleveland Clinic, Cleveland, Ohio 44195, USA. · J Neurosci. · Pubmed #19005057 links to  free full text

Abstract: Deep brain stimulation (DBS) in the subthalamic nucleus (STN) is an effective tool for the treatment of advanced Parkinson's disease. The mechanism by which STN DBS elicits its beneficial effect, however, remains unclear. We previously reported STN stimulation increased the rate and produced a more regular and periodic pattern of neuronal activity in the internal segment of the globus pallidus (GPi). Here we extend our observations to neurons in the pallidal [ventralis lateralis pars oralis (VLo) and ventralis anterior (VA)] and cerebellar [ventralis lateralis posterior pars oralis (VPLo)] receiving areas of the motor thalamus during STN DBS. Stimulation parameters that produced improvement in rigidity and bradykinesia resulted in changes in the pattern and power of oscillatory activity of neuronal activity that were similar in both regions of the motor thalamus. Neurons in both VA/VLo and VPLo tended to become more periodic and regular with a shift in oscillatory activity from low to high frequencies. Burst activity was reduced in VA/VLo, but was not significantly changed in VPLo. There was also a significant shift in the population of VA/VLo neurons that were inhibited during STN DBS, whereas VPLo neurons tended to be activated. These data are consistent with the hypothesis that STN DBS increases output from the nucleus and produces a change in the pattern and periodicity of neuronal activity in the basal ganglia thalamic network, and that these changes include cerebellar pathways likely via activation of adjacent cerebello-thalamic fiber bundles.

Hashimoto T, Nishi K, Nagasao J, Tsuji S, Oyanagi K. · Department of Neuropathology, Tokyo Metropolitan Institute for Neuroscience, Tokyo, Japan. · Brain Res. · Pubmed #18242592 No free full text.

Abstract: A study was conducted to clarify the effects of magnesium (Mg) administration in a rat Parkinson disease (PD) model involving culture of ventral mesencephalic-striatal cells with 1-methyl-4-phenylpyridinium (MPP+), based on recent evidence for significant loss of dopaminergic neurons exclusively in the substantia nigra of 1-year-old rats after exposure to low Mg intake over generations [Oyanagi, K., Kawakami, E., Kikuchi-Horie, K., Ohara, K., Ogata, K., Takahama, S., Wada, M., Kihira, T., Yasui, M., 2006. Magnesium deficiency over generations in rats with special references to the pathogenesis of the parkinsonism-dementia complex and amyotrophic lateral sclerosis of Guam. Neuropathology 26, 115-128.]. The results indicated that Mg might protect dopaminergic neurons in the substantia nigra from degeneration. The concentration of Mg in the culture medium varied from 0.8 mM, corresponding to the control condition, to 4.0 mM. Effects were estimated by counting the number of surviving dopaminergic neurons immunopositive for tyrosine hydroxylase and measuring the length of dopaminergic neurites. An increase in the concentration of Mg to 1.2 mM significantly inhibited the toxicity of MPP+, and a concentration of 4.0 mM completely prevented any decrease in the number of dopaminergic neurons. The length of dopaminergic neurites was significantly preserved in the presence of Mg at 1.2 and 4.0 mM. An increase in the concentration of Mg to 1.2 and 4.0 mM led to a significant amelioration in the length of dopaminergic neurites after MPP+ toxicity. This is the first report to document a significant and striking effect of Mg for prevention of neurite and neuron pathology, and also amelioration of neurite pathology in a PD model.

Oyanagi K, Hashimoto T. · Department of Neuropathology, Tokyo Metropolitan Institute for Neuroscience, 2-6 Musashidai, Fuchu, Tokyo 183-8526, Japan. · Brain Nerve. · Pubmed #17969347 No free full text.

Abstract: The amyotrophic lateral sclerosis (ALS) and parkinsonism-dementia complex (PDC) were the fatal neurological diseases, showing very high incidence during 1945-1965 and dramatic decrease after 1970 on Guam. Based on the findings obtained, it is proposed that (a) NFTs in ALS of Guam are merely a background feature widely distributed in this population, (b) Guam ALS occurs initially as classic ALS, (c) ALS-PDC mixed patient is a case combined with classic ALS and neurofibrillary degeneration, (d) thus a subtype of "Guam ALS" is not present, (e) PDC and ALS of Guam are basically different diseases, and (f) PDC is a discrete disease entity.

Hashimoto T. · Center for Neurological Diseases, Aizawa Hospital. · Rinsho Shinkeigaku. · Pubmed #17491332 No free full text.

Abstract: The rate model regarding the development of movement disorders of basal ganglia origin suggests that hyperkinetic and hypokinetic disorders occur as a result of changes in the firing rates in the GPi and SNr, which in turn suppress thalamocortical output. Dopamine depletion in Parkinson's disease increases basal ganglia output, then decreases thalamocortical output, leading to bradykinesia. This model, however, cannot explain a lack of deterioration of parkinsonian signs following thalamic coagulation surgery. Instead of the rate model, the beta oscillation hypothesis has been proposed, explaining that synchronized oscillation in the beta frequency in the basal ganglia disturbs initiation of voluntary movement. We observed that effective high-frequency STN stimulation in parkinsonian monkeys was associated with increase in the firing rate and the pattern shift from irregular burst firing to regular high-frequency firing in the projecting sites. High-frequency neural activation by deep brain stimulation is supposed to cancel lower frequency oscillation including beta oscillation, leading to improvement of bradykinesia. Our observation supports the significance of the neural activity pattern, rather than the tonic activity level, in the development of movement disorders. The rate model cannot explain the improvement of ballismus and chorea by pallidotomy because pallidotomy increases the disinhibition of the thalamocortical projection, which should increase the movements. We observed repetitive bursts or pauses of neuronal firing of the globus pallidus synchronized to ballistic movements in patients with hemiballism or chorea, suggesting that phasic neuronal driving in the basal ganglia is important as their pathophysiology.

Hashimoto T, Tada T, Ikeda S. · Center for Neurological Diseases, Aizawa Hospital, Matsumoto, Japan. · Stereotact Funct Neurosurg. · Pubmed #16741374 No free full text.

Abstract: OBJECTIVE: To evaluate presurgical factors affecting patient satisfaction with pallidal surgery. METHODS: Forty-one parkinsonian patients who underwent unilateral pallidal surgery replied to a questionnaire on general satisfaction with the outcome of surgery graded on a five-point scale. The contribution of age, disease duration, required activity level, Unified Parkinson's Disease Rating Scale Part II activity of daily living (ADL) score and presurgical to postsurgical ADL score change to the level of satisfaction was tested. The required activity level was defined as the physical activity level which the patients required to support their families. RESULTS: Multiple regression analysis revealed that age at surgery (p = 0.02), required activity level (p = 0.005), ADL score in the on phase at surgery (p = 0.001), and ADL score in the off phase at surgery (p = 0.0001) were significant contributors to satisfaction. CONCLUSIONS: The patients who were relatively young and required higher activity levels tended to have a higher degree of satisfaction with the outcome, while patients with advanced age tended to be less satisfied, independent of symptomatic improvement after the surgery.

Hagiwara N, Hashimoto T, Ikeda S. · Third Department of Medicine, Shinshu University, School of Medicine, Asahi, Matsumoto, Japan. · Mov Disord. · Pubmed #15077242 No free full text.

Abstract: We compared postural sway parameters during a 1-minute quiet stance in 28 patients with idiopathic Parkinson's disease (PD) in off phase with those in 17 age-matched normal subjects and investigated differences in the sway parameters before and after unilateral pallidotomy in 16 PD patients. The PD patients showed larger sway area (SA) and longer total sway path length (SPL) compared with normal subjects. Total SPL after subtraction of tremor effect did not differ from that in normal subjects. The shift of the mean center of foot pressure (CFP) position from the first 30 seconds to the last 30 seconds showed that the CFP tended to move forward in PD patients compared with normal subjects and to move laterally more in PD patients than normal subjects, especially in those with less severity (Unified Parkinson's Disease Rating Scale, motor score < 40). After the operation, there was little change in either SA or lateral movement of CFP, but forward movement of CFP and total SPL tended to be normalized, along with an improvement of major parkinsonian symptoms. From these results, it is concluded that SPL elongation significantly involves tremor effect, forward movement of CFP in PD derives from basal ganglia dysfunction, and SA enlargement and large lateral movement of CFP may be caused partly by compensatory movements or by dysfunction outside the basal ganglia circuitry.

Katai S, Maruyama T, Hashimoto T, Ikeda S. · Department of Neurology, Kakeyu Rehabilitation Centre and Clinic, Nagano, Japan. · J Neurol Neurosurg Psychiatry. · Pubmed #12754335 links to  free full text

Abstract: BACKGROUND: Patients with Parkinson's disease have been reported to have retrospective memory impairment, while prospective memory, which is memory for actions to be performed in the future, has not yet been investigated. OBJECTIVE: To investigate the prospective memory of patients with Parkinson's disease. METHODS: Twenty Parkinson's disease patients and 20 age matched normal controls were given event based and time based prospective memory tasks. In the event based prospective memory task, the subject was asked to perform an action whenever particular words were presented. In the time based prospective memory task, the subject was asked to perform an action at certain times. RESULTS: The Parkinson's disease patients were impaired on the event based prospective memory task but not on the time based prospective memory task. The impairment of the Parkinson's disease patients on the event based prospective memory task was not the result of their forgetting the content of the prospective memory instructions, but the result of their failure to retrieve it spontaneously when the target words appeared. CONCLUSIONS: These results suggest that event based prospective memory is impaired in patients with Parkinson's disease, presumably relating to frontal lobe dysfunction.

Takubo H, Harada T, Hashimoto T, Inaba Y, Kanazawa I, Kuno S, Mizuno Y, Mizuta E, Murata M, Nagatsu T, Nakamura S, Yanagisawa N, Narabayashi H. · Department of Neurology, Tokyo Rinkai Hospital, Tokyo, Japan · Parkinsonism Relat Disord. · Pubmed #12735913 No free full text.

Abstract: We report the results of a collaborative study on malignant syndrome (MS) that developed in patients being treated with levodopa and other anti-parkinsonian drugs. We analyzed clinical features, laboratory findings, precipitating events, and risk factors for poor outcome. The study was conducted in five centers in Japan. Patients who developed MS between January 1991 and December 1997 were included. The enrollment criteria used were the same as those for neuroleptic MS proposed by Levenson et al. (1985).A total of 99 episodes were encountered in 93 patients (72 with Parkinson's disease and 21 with secondary parkinsonism); one patient had four recurrences of MS and three patients had two recurrences. High fever was the most frequent clinical manifestation of MS followed by worsening of parkinsonism, and then altered levels of consciousness. Serum creatine kinase was abnormally elevated in all the patients studied. Life-threatening complications were rhabdomyolysis, disseminated intravascular coagulation, and acute renal failure.The most frequent precipitating event was discontinuation or dose reduction of anti-parkinsonian drugs, particularly levodopa. No drug was the exception in the precipitation of MS. Intercurrent infection was the next most common precipitating event. MS developed without drug withdrawal or infection in some patients. In five patients, severe "wearing off" phenomenon was the only event preceding the onset of MS. Hot weather and dehydration appeared to be the cause in three patients. Among the total of 99 episodes, patients recovered to the pre-MS state following 68 episodes (68.7%); in the remaining 31.3%, patients failed to recover to their previous state. Older age, higher Hoehn and Yahr stage during the symptomatic phase of MS, higher akinesia score, and the absence of wearing off phenomenon prior to developing MS were associated with poor outcome. The most frequently used treatments of MS were intravenous fluid, levodopa, dantrolene sodium, and intragastric bromocriptine. Early introduction of treatment is important. Any elevation of body temperature during the course of anti-parkinsonian drug treatment should be considered as MS until proved otherwise.

Hashimoto T, Tokuda T, Hanyu N, Tabata K, Yanagisawa N. · Third Department of Medicine, Shinshu University School of Medicine, 3-1-1 Asahi, Matsumoto 390-8621, Japan. · Parkinsonism Relat Disord. · Pubmed #12735912 No free full text.

Abstract: A symptom complex identical to neuroleptic malignant syndrome (MS) is known to develop in patients with idiopathic Parkinson's disease (PD) or other forms of parkinsonism on long-term treatment with anti-parkinsonian drugs. In order to clarify the risk factors for parkinsonian MS, the authors retrospectively reviewed charts of consecutive inpatients with PD in the neurological departments at the three hospitals and found 16 episodes of parkinsonian MS in 14 patients. A survey of health status preceding MS disclosed that deterioration of parkinsonian symptoms alone may induce MS, while association of major risk factors, i.e. rapid discontinuation of anti-parkinsonian drugs, dehydration or infection may precipitate or exacerbate MS. Cerebral vascular disorders, mechanical brain injury or physiological stress could be other risk factors leading to MS.

Morioka S, Sakata K, Yoshida S, Nakai E, Shiba M, Yoshimura N, Hashimoto T. · Department of Public Health, Wakayama Medical University, Japan. · J Epidemiol. · Pubmed #12462274 No free full text.

Abstract: To estimate an accurate annual incidence of Parkinson disease in Wakayama, a mail survey was conducted in 1998. A questionnaire was delivered to each clinic where Parkinson disease would be potentially diagnosed. The survey was conducted in February 1998 by the Research Committee on Parkinson disease of Wakayama. A total of 792 clinics and 87 hospitals were listed as candidates. Physicians in these 879 medical facilities were asked and instructed to register all newly diagnosed patients with Parkinson disease in 1997 according to the diagnostic criteria proposed by the Japanese Research Committee on Neuro-degenerative Diseases. Of 879 facilities, 873 ones including 81 hospitals replied (response rate: 99%). A total of 229 patients were reported as newly diagnosed cases in 1997. Of these cases, 183 cases were classified as Yahr I to III. The annual incidence rate was 16.9 per 100,000 population (95% confidence interval: 14.5-19.3). Male-to-female ratio was 1:1.4 as a whole, and the dominant age stratum was 70 to 79 years old. When Parkinson disease incidence was observed from northern part of Wakayama to south by district, crude rates (95% CIs) were 15.9(12.9-18.9), 18.1(12.0-24.2), and 19.3(13.4-25.2). After age-adjustment using the Japanese Model Population in 1985, differences of Parkinson disease incidence became attenuated and adjusted rates (95% CIs) turned to 10.8(9.1-12.7), 10.4(8.6-12.2), and 9.9(6.9-12.9), respectively.

Morita H, Shindo M, Morita S, Hashimoto T, Tada T, Ikeda S. · Clinical Neurophysiology Laboratory, Division of Neurology, Third Department of Medicine, Shinshu University School of Medicine, Asahi 3-1-1, Matsumoto, Japan. · Clin Neurophysiol. · Pubmed #12140013 No free full text.

Abstract: OBJECTIVES: The objective of this study is to clarify the participation of cortical motor control abnormality in the motor dysfunction of Parkinson's disease (PD), especially at the onset of movement. METHODS: Conditioning effects of transcranial magnetic simulation (TMS) on the soleus (SOL) H-reflex evoked with tibial nerve stimulation were examined in 19 patients with PD and 10 normal volunteers. Experiments were done at rest, during tonic plantarflexion (PF), and at PF onset. Stimulus intensity of TMS was maintained at less than 5% of the motor threshold in each situation. Seven patients underwent pallidotomy and were examined twice, once before and once after the operation. RESULTS: Short latency subthreshold TMS stimulation did not facilitate the SOL H-reflex neither during tonic PF nor at PF onset in the patients with PD, though it was evident in normal subjects. In some patients, paradoxical inhibition appeared at PF onset. The facilitation increase at PF onset, as compared to that at rest, was negatively correlated with the motor part of the unified Parkinson's disease rating scale and with the rigidity grade. Pallidotomy improved both modulation and the clinical scores. CONCLUSIONS: Cortical activity for the proper execution of reciprocal control between the agonist and antagonist seems to be disturbed in PD.

Hashimoto T, Yabe-Nishimura C. · Department of Pharmacology, Kyoto Prefecutural University of Medicine, Kawaramachi-Hirokoji, Kamikyoku, 602-8566, Kyoto, Japan. · Brain Res. · Pubmed #11897094 No free full text.

Abstract: 3,4-dihydroxyphenylacetaldehyde (DOPALD), an oxidative metabolite of dopamine (DA), induced dose-dependent DA release from pheochromocytoma (PC12) cells without affecting leakage of lactate dehydrogenase from the cells. DOPALD-induced DA release was independent of extracellular Ca2+ concentration and was not blocked by nifedipine, an L-type Ca2+ channel antagonist. These results indicated a novel intrinsic role of DOPALD in dopaminergic nerve terminals that may take part in the activation of dopamine neurons.

Hayashi R, Hashimoto T, Tada T, Ikeda S. · Department of Medicine (Neurology), Shinshu University School of Medicine, Matsumoto, Japan. · Clin Neurophysiol. · Pubmed #11595139 No free full text.

Abstract: OBJECTIVE: To study the effects of posteroventral pallidotomy on both the size of long-latency stretch reflex (LLR) and the muscle stiffness in the wrist flexor muscles. PATIENTS AND METHODS: Eleven consecutive patients (right-handed, 6 men and 5 women) underwent left-side microelectrode-guided pallidotomy. The LLR of the contralesional forearm was studied at baseline and 2-3 months after surgery while patients continued to take their optimal medical regimens ('on' period). Patients were instructed not to respond to the perturbation (passive mode) or to oppose the mechanical extensor perturbation (active mode). RESULTS: The stretch reflex evoked by extension perturbations of the wrist consisted of a short-latency reflex (M1) and an LLR (M2). Pallidotomy had no effects on the size of M1 components in both passive and active mode and on that of M2 component in the passive mode, however, it significantly reduced M2 component in the active mode (P<0.05). The inherent muscle stiffness over 60 ms period of mechanical stretch was not influenced by pallidotomy in any experimental condition (preoperative vs. postoperative or passive mode vs. active mode). The hand displacement following M2 component increased significantly after pallidotomy in both passive (P<0.005) and active mode (P<0.05). The inverted value of the displacement following M2 component correlated with the size of M2 component (r=0.60, P<0.001). CONCLUSIONS: Pallidotomy decreased the transcortical reflex gain, probably at cortical level, and consequently reduced muscle stiffness.

Hashimoto T, Shindo M, Yanagisawa N. · Third Department of Medicine (Neurology), Shinshu University School of Medicine, 3-1-1 Asahi, Matsumoto 390-8621, Japan. · Clin Neurophysiol. · Pubmed #11514243 No free full text.

Abstract: OBJECTIVES: To study the deficit of inhibition of excessive motor drive generated in the central nervous system in chorea. METHODS: Identical associated movements in the contralateral limb elicited by rapid hand squeezing were measured in 6 patients with Huntington's disease, 7 patients with peak-dose dyskinesia, 10 patients with Parkinson's disease, 8 patients with spinocerebellar degeneration and in 8 normal subjects. The intensity of associated movements was assessed by the EMG amplitude ratio of associated contractions to active contractions. RESULTS: The associated movement ratios were larger in Huntington's disease and peak-dose dyskinesia as compared to other groups. The ratios in akinetic "off" phase were smaller than those in dyskinetic "on" phase in all peak-dose dyskinesia patients. CONCLUSIONS: Enhanced associated movements support a possible common mechanism that chorea may result from failure in inhibition of phasic neural activity pathologically generated in the brain.

Hashimoto T, Izawa Y, Yokoyama H, Kato T, Moriizumi T. · Third Department of Internal Medicine, School of Medicine, Shinshu University, Asahi, Matsumoto, Japan. · J Neurosci Methods. · Pubmed #10522830 No free full text.

Abstract: Evaluation of the amount of overall animal movement is important for investigations of motor control mechanisms in the central nervous system. We describe a new method to quantify overall free movements of an animal without any markers using a video camera and a personal computer equipped with a video-capture board. The operating principle is that the amount of overall movement of an object can be expressed by the difference in total area occupied by the object in two consecutive picture frames. The software for this application operates in real-time. Using this method and with proper setting for the cage and recording view, we can estimate three-dimensional movements of animals. The major advantages are low cost, easy operation and high sensitivity. The experimental results indicate that this method can be applied to various fields of motion analysis.