Neurology
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Deep brain stimulation (DBS) is an effective treatment for several movement disorders. However, its mechanism of action is largely unknown. Both lesioning and DBS of the ventralis intermedius (VIM) nucleus of thalamus improve essential tremor. Although DBS was initially thought to inhibit the target neurons, recent studies suggest that DBS activates neurons. ⋯ Because the ventralis intermedius (VIM) projects directly to the motor cortex, the high motor evoked potential amplitude with deep brain stimulation ON suggests that VIM DBS activates rather than inhibits the target area.
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Presented is a pedigree with infancy-onset benign hereditary chorea (BHC) caused by a novel nonsense mutation in exon 3 (523G-->T, E175X) of the TITF-1 (Nkx2.1) gene. Four confirmed mutation carriers showed the typical movement disorder of BHC and congenital hypothyroidism. Surprisingly, treatment with levodopa improved gait dramatically and reduced chorea in two patients. Dopaminergic drugs should be considered a useful therapeutic option in BHC.
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In 1968, publication of the Harvard committee's report concerning "irreversible coma" established a paradigm for defining death by neurologic criteria (brain death [BD]). Five years earlier, Dr. ⋯ To put those events into present-day perspective, the author reviewed the proceedings of a Ciba Symposium held in London in 1966 at which Alexandre introduced his pioneering view, obtaining information and documents from Alexandre and others who attended that meeting. Comparing Alexandre's approach with the Harvard report and later advances helps in understanding how both defining death by brain criteria and transplanting organs from a brain-dead donor have become morally tolerable today.