Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:Q16637 (SMA)
 8,107 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

It has been suggested that the underactivity of mesial frontal structures induced by dopamine depletion could constitute one of the main substrates underlying akinesia in Parkinson's disease. Functional imaging and movement-related potential recordings indicate an implication of the frontal lobes in this pathological process, but the question has not yet been investigated at a cellular level using single unit recording. We therefore compared neuronal activity in both the presupplementary motor area (pre-SMA) and the supplementary motor area proper (SMAp) of the Macaca mulatta monkey during a delayed motor task, before and after MPTP treatment. In the pre-SMA, which receives strong inputs from the prefrontal cortex, the baseline firing frequency and the percentage of neurons responding to visual instruction cues decreased in lesioned monkeys. In the SMAp, which sends direct outputs to the primary motor cortex, not only was the response to visual cues impaired, but the percentage of SMAp neurons responding to intracortical microstimulation fell and the threshold of response rose. Neuronal activity after the Go signal diminished sharply in both structures in the symptomatic animal and the discharge pattern became more irregular; in the SMAp neuronal activity remained modified longer. Most of these changes could already be observed in the presymptomatic animal presenting no clinical signs of parkinsonism. These data would indicate that, at the moment when dopamine depletion has impaired the ability of cortical neurons to operate the focused selection of incoming information giving instructions for movement, pre-SMA and SMAp neurons are also in a state of severe hypoactivity. The conjunction of these phenomena could play a critical role in the genesis of akinesia.
 ...
PMID:Disruption of information processing in the supplementary motor area of the MPTP-treated monkey: a clue to the pathophysiology of akinesia? 1247 99

We present the case of a floppy neonate with marked and generalized weakness, respiratory insufficiency and fetal akinesia deformation sequence. The infant showed multiple joint contractures, two bone fractures and needed mechanical ventilation from birth to death at 16 days of age. Electrophysiological assessment showed electrically unexcitable motor and sensory nerves. Muscle biopsy showed diffuse atrophy of type I and type II fibers. Necropsy confirmed the diagnosis of infantile spinal muscular atrophy (SMA) with severe loss of motor neurons in anterior horns and motor nuclei of brainstem. There were also neuronal loss, gliosis, chromatolysis, ballooned cells, empty cell beds and neuronophagia figures in other brainstem and brain nuclei. Genetic analysis of the patient revealed homozygous deletions of survival motor neuron gene 1 (SMN1) and a single copy of SMN2 in region 5q13. This case confirms that the loss of spinal motor neurons underlies the muscular atrophy in severe cases of 5q SMA. This case also shows that the presence of multiple joint contractures, bone fractures and respiratory insufficiency in SMA in the neonatal period does not necessarily exclude the occurrence of classical deletions in the SMA 5q13 region. Rather, these atypical clinical findings show the extreme severity and prenatal onset of the disease in these SMA cases, which may be related with the occurrence of a single copy of SMN2 gene. More reports of clinically, pathologically and genetically well-documented cases are essential to define the different types of this disease.
 ...
PMID:Neonatal spinal muscular atrophy with multiple contractures, bone fractures, respiratory insufficiency and 5q13 deletion. 1496 68

We treated a patient with levodopa-resistant akinesia with motor cortex stimulation (MCS), and she showed dramatic improvement more than 1 year. On admission, the patient presented severe akinesia and gait disturbance without tremor and rigidity, and did not respond to levodopa test. The patient was suspected pure akinesia and progressive supranuclear palsy. First, high-frequency rTMS of primary motor cortex was examined, and showed the dramatic improvement. Next, chronic subdural electrodes were implanted over the motor cortex bilaterally. One year after surgery, the Unified Parkinson's Disease Rating Scale had improved remarkably, and she could walk four times faster than before. The H2 15O PET study showed a significant increase of rCBF in the left SMA and right dorsolateral prefrontal cortex after bilateral MCS. MCS may be an alternative treatment for patients with akinesia, including those with PD, and particularly for levodopa-resistant patients, who respond well to rTMS.
 ...
PMID:Motor cortex stimulation for levodopa-resistant akinesia: case report. 1755 43

The supplementary motor area (SMA-proper) is important for the programming and execution of motor, speech, and other elaborative functions. SMA is frequently involved by brain tumors (particularly WHO grade II gliomas). Surgery in this area can be followed by the 'SMA syndrome', characterised by contralateral akinesia and mutism. We present a case of Falcine meningioma in the region of the right SMA which developed SMA syndrome. Our patient showed complete recovery of neurological function but the process was slow with a specific pattern.
 ...
PMID:Post-operative Supplementary Motor Area Syndrome: A Case Report. 2858 86