Experimental neurology
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Experimental neurology · Jun 2010
Clinical TrialDescending volleys generated by efficacious epidural motor cortex stimulation in patients with chronic neuropathic pain.
Epidural motor cortex stimulation (EMCS) is a therapeutic option for chronic, drug-resistant neuropathic pain, but its mechanisms of action remain poorly understood. In two patients with refractory hand pain successfully treated by EMCS, the presence of implanted epidural cervical electrodes for spinal cord stimulation permitted to study the descending volleys generated by EMCS in order to better appraise the neural circuits involved in EMCS effects. Direct and indirect volleys (D- and I-waves) were produced depending on electrode polarity and montage and stimulus intensity. ⋯ The descending volleys elicited by bipolar EMCS are close to those elicited by transcranial magnetic stimulation using a coil with posteroanterior orientation. Different pathways are activated by EMCS according to stimulus intensity and electrode montage and polarity. Special attention should be paid to these parameters when programming EMCS for pain treatment.
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Experimental neurology · Jun 2010
Effects of Aquaporin-4 on edema formation following intracerebral hemorrhage.
Intracerebral hemorrhage (ICH) constitutes 10% to 15% of all strokes and is associated with high morbidity and mortality. To date, little is known about the role of AQP4 (Aquaporin-4), which is abundantly expressed in pericapillary astrocyte foot processes and in edema formation after intracerebral hemorrhage. The purpose of this study was to examine the role of AQP4 in edema formation after ICH by using AQP4(-/-) mice. ⋯ These results suggest that AQP4 deletion increases ICH damage, including edema formation, blood-brain barrier damage and neuronal death/TUNEL-positive cells. Further studies on the protective role of activated AQP4 expression following ICH may provide useful therapeutic target for ICH-induced brain injury.