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We report on the effects of bilateral neurostimulation of the ventral intermediate thalamic nucleus (VIM) in a patient with medically intractable and progressing inherited myoclonus dystonia syndrome (IMDS). Postoperatively, the patient improved by approximately 80% on the modified version of a myoclonus score without any significant change in the dystonic symptoms. This suggests that neurostimulation of the VIM may be an effective treatment for myoclonus in pharmacologically intractable IMDS.

We evaluated the response of cerebral arterioles to angiotensin II (ANG II) in anesthetized rats equipped with a closed cranial window. Topical application of 10(-10)-10(-5) M ANG II induced dose-dependent arteriolar vasodilation. Maximum vasodilation of 24 +/- 2.2% (+/- SE) was attained at a concentration of 10(-6) M ANG II. The dilation in response to ANG II was blocked by 3 micrograms/ml indomethacin, a cyclooxygenase inhibitor, and was reversed to minimal vasoconstriction by 10(-5) M methylene blue, a substance that has been reported to eliminate endothelium-dependent vasodilation. Coapplication of indomethacin with methylene blue reduced the arteriolar response to ANG II to a similar extent as the application of indomethacin alone. Indomethacin or methylene blue did not inhibit the vasodilation induced by 10(-5) M adenosine, which is not endothelium and cyclooxygenase dependent. Mercury light illumination of the pial vessels after intravenous injection of fluorescein dye, a technique that has been used by others to functionally damage endothelial cells, reversed ANG II (10(-6) M)-induced vasodilation into a -14.2 +/- 2.3% constriction while not affecting the response to adenosine. Our data suggest that ANG II produces vasodilator responses of rat cerebral arterioles by the release of a factor that is derived from the endothelium and may be generated through a cyclooxygenase-dependent mechanism.

Summary:We investigated the temporal profile of the changes in regional CBF (rCBF) and intracranial pressure (ICP) during the early phase of pneumococcal meningitis in the rat. rCBF, as measured by laser-Doppler flowmet ry, and ICP were continuously monitored during 6 h post infection (pj.). Brain edema formation was assessed by brain water content determinations. Meningitis was in duced by intracisternal injection of 75 IJ-l of 107 colony forming units/ml pneumococci (n = 7). In control animals (n = 6), saline was injected. There was no change in the rCBF or ICP of controls throughout the experiment. However, there was a dramatic increase in rCBF and ICP associated with brain edema formation in untreated men ingitis animals. rCBF increased to 135.3 ± 33.8% (mean ± SD) in the untreated animals at I h pj. and reached 211.1 ± 40.5% at 6 h pj. (p < 0.05 compared with con trols). ICP increased from 2.9 ± 1.4 to 10.4 ± 4.7 mm Hg at 6 hpj. (p < 0.05 compared with controls). Brain water content was significantly elevated (79.69 ± 0.24 com pared with 78.94 ± 0. 16% in the control group, p < 0.05).