Annals of neurology
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Annals of neurology · Apr 1995
Cerebral oxygen supply and utilization during infant cardiac surgery.
The survival of infants with congenital heart disease has improved dramatically. However, the incidence of neurological injury in infants surviving cardiac surgery remains considerable. These neurological sequelae are attributable at least in part to hypoxia-ischemia/reperfusion, which inevitably accompanies infant heart surgery with deep hypothermia, cardiopulmonary bypass, and circulatory arrest. ⋯ These findings demonstrate a paradoxical dissociation of changes in intravascular and mitochondrial oxygenation during hypothermic cardiopulmonary bypass; a pronounced decrease of mitochondrial oxygenation is established during induction of hypothermia and a delay in recovery of mitochondrial oxygenation occurs following circulatory arrest. These effects were more pronounced in infants older than 2 weeks than in younger infants. The data suggest potentially deleterious impairments of intrinsic mitochondrial function or of delivery of intravascular oxygen to the mitochondrion or both, effects previously undetected and apparently influenced by cerebral maturation.
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Annals of neurology · Mar 1995
Case ReportsDetection of silent cerebellar lesions by increasing the inertial load of the moving hand.
In a previous study, we analyzed the hypermetria of wrist flexion movements in patients with a cerebellar syndrome. We found that hypermetria augmented when the inertial load of the moving hand was artificially increased. ⋯ In all of these patients, the addition of a mass to the moving hand caused the appearance of a hypermetria. This lack of adaptation of fast and accurate movements to an increased inertia thus appears as a new diagnostic tool enabling the detection of silent cerebellar lesions.
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Annals of neurology · Mar 1995
Experimental pneumococcal meningitis: cerebrovascular alterations, brain edema, and meningeal inflammation are linked to the production of nitric oxide.
We investigated whether treatment with the nitric oxide synthase inhibitor N-nitro-L-arginine (L-NA) and the free radical scavenger superoxide dismutase influences cerebral blood flow changes, brain edema, and cerebrospinal fluid pleocytosis in early experimental pneumococcal meningitis. Compared to untreated infected rats, superoxide dismutase given 3 hours after infection significantly attenuated the increase of brain water content, intracranial pressure, and cerebrospinal fluid white blood cell count, but did not modulate the increase in regional cerebral blood flow. N-Nitro-L-arginine treatment (5 mg/kg intravenously, followed by 5 mg/kg/hour) reversed the increase in regional cerebral blood flow; prevented an increase in brain water content, intracranial pressure, and cerebrospinal fluid nitrite concentrations; and reduced cerebrospinal fluid white blood cell count. ⋯ When the effective dose was increased twofold, the effects of N-nitro-L-arginine became more pronounced but resulted in the death of 4 of 5 rats, probably due to hemodynamic side effects. In primary cultures of rat cerebral endothelial cells, nitrite concentrations increased after pneumococcal stimulation, which could be prevented by N-nitro-L-arginine and cycloheximide. These data suggest that (a) nitric oxide accounts for regional cerebral blood flow changes and pial arteriolar dilatation in the early phase of experimental pneumococcal meningitis; (b) both superoxide radical and nitric oxide are involved as mediators of brain edema and meningeal inflammation; and (c) cerebral endothelial cells can be stimulated by pneumococci to release nitric oxide presumably via the inducible nitric oxide synthase.
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Annals of neurology · Feb 1995
Randomized Controlled Trial Clinical TrialTopical lidocaine gel relieves postherpetic neuralgia.
Postherpetic neuralgia (PHN) following herpes zoster is a common and disabling neuropathic pain syndrome. In a double-blind, three-session study, 5% lidocaine gel or vehicle was applied simultaneously to both the area of pain and to the contralateral mirror-image unaffected skin. In the local session, lidocaine gel was applied to the painful skin area. ⋯ Remote lidocaine application to mirror-image skin was no different from placebo. No systemic adverse effects were reported and blood levels did not exceed 0.6 microgram/ml. Topical application of 5% lidocaine gel relieves PHN pain by a direct drug action on painful skin.
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Drunkenness and senility were recognized early as the basis of a staggering gait. To these were added venereal excesses, hence syphilis. Medical and scientific concerns began to be focused on "locomotor ataxia" in the 19th century with the systematic development of neuroanatomy and physiology. ⋯ Failures of input and output, of conduction and central coordination were invoked and explained, among them the vestibular apparatus, as well as the causation by neoplasms, demyelination, degeneration, and infarction affecting even the frontal lobe, thalamus, and basal ganglia. Clinical testing was brought up to 20th-century standards essentially by Sherrington and Bárány, followed by Dandy, the neurosurgeon who showed how to replace ventricular fluid by air, more recently made obsolete by modern roentgenographic procedures. And tabes dorsalis, once the chief culprit, has practically become a medical anachronism thanks to penicillin.