Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0003635 (apraxia)
 2,817 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We report a 53-year-old right handed woman with a 5-year history of slowly progressive clumsiness of her right hand. Neurologic symptoms was otherwise unremarkable except for mild dysarthria. Brain CT and MRI revealed a focal atrophic change in the left precentral gyrus. She was thought to have the primary progressive limb-kinetic apraxia. Electrophysiological studies were performed to explore physiologic mechanism of her apraxia. Surface EMG revealed co-contraction of antagonistic muscles in her right upper extremity with rhythmic myoclonic discharges. C-reflex was positive after median nerve stimulation only on the affected side. SEPs elicited by the median nerve stimulation were not enlarged and the SEP recovery curves showed no abnormal facilitation or inhibition. In addition, the premyoclonus spike was demonstrated by Jerk-locked averaging. Transcranial magnetic stimulation using double pulse paradigm revealed a decrease in the level of cortico-cortical inhibition on the motor cortex in the affected side. Median nerve stimulation given prior to the transcortical magnetic stimulation on the size of the magnetic evoked potential (MEP) revealed abnormal facilitations on the affected side, especially at conditioning-test interval of 60-80 ms. Therefore, our results indicate increase in the excitability of motor cortical neurons in primary progressive limb-kinetic apraxia, likely due to a decreased excitability of cortico-cortical inhibitory mechanism as a result of focal degeneration of cortical neurons.
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PMID:[Primary progressive limb-kinetic apraxia: a case report with an electrophysiological study]. 1039 51

We investigated the association between clinical and neurophysiological characteristics in patients with a clinical diagnosis of probable corticobasal degeneration (CBD), and searched for neurophysiological features supporting the diagnosis in life. Ten patients with clinically probable CBD underwent comprehensive neurological evaluation and brain MRI. Long latency reflexes (LLR), upper limb somatosensory (SEP) and motor evoked (MEP) potentials were recorded. The mini-mental state examination (MMSE), the phonemic verbal fluency test (PVFT) and the De Renzi ideomotor apraxia test were also performed. Polygraphic EEG was performed in the six patients with myoclonus. The SEP N30 frontal component was absent bilaterally in four patients, was absent on the left side in one, and had increased latency in other three. MEPs were abnormal in four patients (three had prolonged central motor conduction time, one of whom also had increased MEP threshold, and one had increased MEP threshold). All six patients with myoclonus had enhanced LLRs at rest, which were also of abnormally increased amplitude during motor activation; latencies were generally shorter than in classic cortical reflex myoclonus. On back-averaging, no EEG spikes time-locked to EMG activity were found in any myoclonus patient. Five patients were demented by MMSE, eight had ideomotor apraxia scores in the ideomotor apraxia range and five had defective verbal fluency. Brain MRI revealed asymmetric cortical atrophy in all patients, particularly evident frontoparietally. Neurophysiological techniques, particularly LLR, can assist CBD diagnosis especially in patients with myoclonus. Patients with evident parkinsonism had greater SEP N30 (frontal) abnormalities, while most patients with marked paresis had slower MEP times.
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PMID:Neurophysiological features in relation to clinical signs in clinically diagnosed corticobasal degeneration. 1275 52