Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0030567 (Parkinson's disease)
 63,064 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We elicited motor evoked potentials (MEPs) using transcortical magnetic stimulation in 150 control subjects aged 14 to 85 years and 275 patients with a variety of diseases. There were no significant side effects. Cortex-to-target muscle latencies measured 20.2 +/- 1.6 ms (thenar), 14.2 +/- 1.7 ms (extensor digitorum communis), 9.4 +/- 1.7 ms (biceps), and 27.2 +/- 2.9 ms (tibialis anterior). Central motor delay between the cortex and the C-7 and L-5 measured 6.7 +/- 1.2 ms and 13.1 +/- 3.8 ms, respectively. Mean spinal cord motor conduction velocity measured 65.4 m/s. MEP amplitude expressed as a percentage of the maximum M wave was never less than 20% of the M wave. A value of less than 10% is considered abnormal. MEP latency increases linearly with age and central motor delay is longer in older subjects. Compound muscle action potentials and absolute MEP amplitudes decreased linearly with age. In multiple sclerosis (MS), MEP latency and central delay were often very prolonged. The MEP was more sensitive than the SEP in MS. In amyotrophic lateral sclerosis, MEP latencies were only modestly prolonged; the characteristic abnormality was reduced amplitude. When pseudobulbar features predominated MEPs were often absent. The MEP was of normal latency in Parkinson's disease, but age-related amplitude was often increased. MEP latency and amplitude were normal in Huntington's disease. Abnormal MEPs persisted several months after stroke despite good functional recovery. The MEP could be used to advantage to demonstrate proximal conduction slowing and block in demyelinating neuropathies. In plexopathy, ability to elicit an MEP several days after onset of paresis was good evidence of neuronal continuity in motor fibers.
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PMID:AAEM minimonograph #35: Clinical experience with transcranial magnetic stimulation. 793 34

Motor evoked potentials (MEPs) to transcranial stimulation (TCS) and somatosensory evoked potentials to median nerve stimulation (MN-SEPs) were examined in 74 patients affected by multiple sclerosis (MS = 49 cases), amyotrophic lateral sclerosis (ALS = 9 cases), cervical cord lesions (7 cases), Parkinson's disease (PD = 5 cases), Huntington's chorea (HC = 2 cases), Wilson's disease (WD = 1 case), subacute combined degeneration (SCD = 1 case). MN-SEPs were altered in 38% of arms in MS with a higher incidence in clinically affected than in clinically 'silent' arms (= 77.8% vs. 27.5%). MEP alterations were found in 54% of examined arms, mostly because of a prolongation of the motor CCT. This index was invariably altered in the affected arms, whilst it was involved in 40% of the 'silent' ones. Twelve out of 18 arms displayed abnormal MEPs in ALS. These were mainly due to an absent response, even if moderate motor CCT prolongation and 'giant' MEPs were also encountered. MN-SEPs were altered in 3/18 arms. By recording MEPs from proximal and distal upper limb muscles, cues on the level of abnormal propagation were obtained in patients suffering from 'focal' lesions of the spinal cord. Combining SEP records enhanced the diagnostic yield in this field. Both MEPs and SEPs were normal in patients with PD and HC, whilst abnormally prolonged CCTs were found in the case with WD. MEP and SEP recording revealed central propagation abnormalities coupled to a severe clinical picture of the peripheral nerve involvement (as in the case of SCD).
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PMID:Neurophysiological evaluation of the central nervous impulse propagation in patients with sensorimotor disturbances. 245 26

Diagnosis of Parkinson's disease is not yet possible with neurophysiological methods. Therefore we investigated the median somatosensory and visually evoked potentials (SEP and VEP) to single and double stimulation, VEP using a special stimulation technique and motor evoked potentials (MEP) employing spinal and transcranial stimulation. In Parkinson's disease the absolute and relative refractory periods of cortical N1 peak of SEP did not differ from that of normal subjects. After single stimulation the cortical N20 latencies were only in 2 of 17 cases delayed. In 8 of 10 cases central conduction time was normal. Also the SEP peaks of brain stem were normal and there was no correlation between symptomatology and SEP results. The data of motor evoked potentials (MEP) demonstrated in all patients a normal central motor conduction time of 5.0 msec. In 30% of patients the VEP data showed a significant delay of P2 latency, independently of clinical status or age. But there were no more P2 alterations after special visual stimulation techniques. In contrast to a good clinical effect in 14 of 19 patients with end-off-dose akinesia, an improvement of P2 delay could not be noticed during a chronic L-dopa and deprenyl therapy.
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PMID:Somatosensory, motor and special visual evoked potentials to single and double stimulation in "Parkinson's disease" an early diagnostic test? 348 Sep 40

In five patients with initial idiopathic Parkinson disease AEPs (early and late components of auditory evoked potentials), SEPs (somatosensory evoked potentials) and arm ballistic movements (abduction of the humerus) were studied. Experimental sessions were conducted before starting treatment (L-Dopa plus Carbidopa) and at two and six month intervals. Before treatment evoked potential abnormalities were found in four out of five patients; EMG patterns underlying ballistic arm abduction movements were altered in all patients; corresponding prolonged duration of initial movements and low mean velocities were found. After treatment AEP and SEP showed a reduction of previously observed abnormalities and both EMG patterns and kinematic variables consistently improved. It is suggested that the electrophysiological investigations employed in this preliminary study may be a useful tool in clinical and pharmacological researches on Parkinson disease.
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PMID:Auditory and somatosensory evoked potentials (AEPs and SEPs) and ballistic movements in Parkinson disease. 406 68

Among early cortical median nerve SEPs the frontal N30 potential is known to show amplitude reduction during execution of voluntary movements and to be abnormally reduced in parkinsonian patients. However, it is not clear whether N30 abnormalities are related to the severity of motor disability in Parkinson's disease. To address this question we studied median nerve SEPs, using a 16-channel montage, in 7 patients chronically treated with subcutaneous (s.c.) injections of apomorphine hydrochloride for spontaneous "on-off" motor fluctuations. We observed no significant changes in the latency, amplitude or scalp topography of early SEPs when comparing traces and maps obtained in the "off" condition and during the "on" phase induced by s.c. injection of apomorphine. The absence of any SEP changes, despite a clear-cut relief of the akinetic-rigid syndrome, suggests that early cortical SEPs, and in particular the frontal N30 potential, at least when recorded in a subject at rest, are not usable as an objective means to assess the severity or the fluctuations of motor disability in Parkinson's disease.
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PMID:Apomorphine-induced relief of the akinetic-rigid syndrome and early median nerve somatosensory evoked potentials (SEPs) in Parkinson's disease. 768 79

Magnetic stimulation (MS) was performed in 9 patients with clinically diagnosed corticobasal degeneration (CBD), 10 patients with Parkinson's disease (PD) (under L-dopa therapy) and 10 age-matched healthy subjects (HS). Motor evoked potentials (MEPs) were recorded from the abductor pollicis brevis muscle (APB) in response to cortical stimulation and cervical stimulation (C7). In all patients with CBD, the duration of inhibitory period (IP), which was a transient suppression of muscle action potentials following MEPs by cortical stimulation, was significantly shorter than that in PD and HS. In 4 patients with CBD who presented with focal and distal myoclonus of one limb, long latency reflexes following electrical stimulation of the median nerve showed C-reflex, which had a latency of about 40 ms, but a giant SEP and a jerk-locked cortical potential were not demonstrated. With cervical MS, these 4 patients also showed long-latency (about 30 ms) evoked potentials (LEPs), which were much greater in latency from cervical stimulation-induced MEPs (cervical MEPs). LEPs may be mediated via a transcortical loop, because the sum of the latency of C-reflex and compound muscle action potential approximates that of LEP and cervical MEP. In patients with CBD, these findings suggest disturbance within the basal ganglia-thalamocortical motor circuit and a damage of the motor cortices including the primary motor cortex, premotor cortex and supplementary motor cortex.
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PMID:[A study of magnetic stimulation in patients with clinically diagnosed corticobasal degeneration]. 950 65

Analysis of scalp-recorded potentials (EEG or evoked potential examination) is of great importance for studying bioelectrical processes in the human brain both in normal and pathological cases. Investigating potential distributions in the relation to individual topography of the cortex is helpful in treatment and surgery planning. We developed a method providing visual presentation of electrical potentials measured in EEG examination superimposed on a patient's cortex surface computed from MRI data. Analysis of such images contributes into diagnostics of common neurological disorders (for example: epilepsy, Parkinson's disease, any mechanical damage). Integration of EEG and MRI data sets requires their alignment. This paper focuses on applying a new registration technique for the alignment of these two data sets. The method does not require any external fiducial markers to be fixed on a patient's head, what makes it convenient for numerous examinations performed in clinic. Alignment bases on geometrical features derived from intrinsic data of an image or an object. To show the example of usage of the technique for assisting in neurological diagnostics we present results of SEP (sensory evoked potential) examinations performed for one pathological case and a control group.
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PMID:Presentation of brain electrical activity distribution on its cortex surface derived from MR images. 983 65

Although deep brain stimulation (DBS) is a clinically effective therapy for patients with advanced Parkinson's disease (PD), its physiological effects on the brain and possible actions on non-motor functional systems remain largely unknown. This study evaluated the effects of DBS of the subthalamic nucleus (STN) on neurophysiological variables and on cardiovascular physiology. Nine patients affected by PD undergoing chronic DBS of the STN have been studied. We performed electroencephalography (EEG), somatosensory (SEPs) and visual evoked potentials (VEPs), exteroceptive masseteric silent period and sympathetic skin response (SSR) studies with DBS ON and OFF. To assess the effects of stimulation on the cardiovascular system the tilt test and plasma renin activity were studied. When we turned the DBS OFF, both SEP N20 and the VEP P100 component increased significantly in amplitude whereas the SSR decreased in amplitude and increased in latency. Although plasma renin activity tended to increase with DBS OFF, its modification induced by postural changes and blood pressure values did not significantly differ with DBS ON and OFF. We conclude that DBS of the STN in PD, besides inducing a clinical improvement, induces several non-motor effects.
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PMID:Non-motor effects of deep brain stimulation of the subthalamic nucleus in Parkinson's disease: preliminary physiological results. 1148 14

Prevalence of restless legs syndrome (RLS), a clinically defined disorder, varies from 2.5 to 15% among populations. In the French adult population, prevalence is estimated to be 8.5%. RLS is often secondary to a variety of disorders. Neurological conditions usually associated with RLS are neuropathies and Parkinson's disease. There are few studies of its association with multiple sclerosis (MS). The aim of this study was to estimate RLS prevalence in a population of French MS patients. During one month, 17 neurologists from the G-SEP group prospectively recruited 242 patients who fulfilled the Mc Donald criteria for MS. Each patient underwent a standardised questionnaire to verify the international criteria of RLS. We collected date of birth, gender, MS course (relapsing remitting, primary progressive and secondary progressive) and MS duration. Forty-one subjects (18%) met the criteria for RLS. Comparing the RLS group with the group without RLS, no significant differences were found in age, gender and MS duration. RLS was more prevalent in the relapsing remitting MS group. Prevalence of RLS seems to be doubled in MS patients compared to the general population. This finding warrants further study. Identification of this syndrome in MS patients might lead to specific treatments.
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PMID:[High prevalence of restless legs syndrome in multiple sclerosis]. 1880 67

There are nine subfamilies of TAARs. They are predominantly intracellular, located in the central nervous system and peripherally. They have a role in homeostasis and rheostasis, and also in olfaction. They demonstrate significant cross-talk with the monoamine system and are involved in the regulation of cAMP signalling and K+ channels. There is evidence to suggest that TAAR1 may be a promising therapeutic target for the treatment of schizophrenia, psychosis in Parkinson's disease, substance use disorders, and the metabolic syndrome and obesity. TAAR1 expression may also be a prognostic biomarker for cancers. A number of TAAR modulators have been identified, including endogenous ligands and new chemical entities. Some of these agents have shown efficacy in animal models of addiction behaviours, depression and anxiety. Only one agent, SEP-363856, has progressed to randomised clinical trials in humans; however further, larger studies with SEP-363856 are required to clarify its suitability as a new treatment for schizophrenia spectrum disorders. SEP-363856 is an agonist of TAAR1 and 5HT1A and it is not clear to what extent its efficacy can be attributed to TAAR1 rather than to other drug targets. However, current research suggests that TAAR1 has an important role in human physiology and pathophysiology. TAAR1 modulators may become an important new drug class for the management of a wide array of mental disorders in the future.
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PMID:Trace Amine-Associated Receptor 1 (TAAR1): A new drug target for psychiatry? 3303 17


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