Rare cause of delirium and hypoxemia after coronary bypass surgery: transdermal lidocaine patch-associated methemoglobinemia.

We present a case of a patient administered parasternal transdermal lidocaine patch therapy as part of a multimodal analgesic regime designed to diminish opioid-associated delirium after coronary bypass surgery. The patient presented with delirium and severe methemoglobinemia (41%) that responded to discontinuation of lidocaine therapy, oxygen administration, and methylene blue administration. The clinical contributors and medicolegal implications of this degree of lidocaine-associated methemoglobin-mediated delirium are presented in the hope of avoiding similar complications in the postoperative setting after coronary bypass surgery.

Diagnosis and medical and surgical management of cervical spondylotic myelopathy.

Cervical spondylotic myelopathy is a complex condition with subtle history and examination findings that mimic other conditions. Primary care physician assistants often are the first providers to evaluate these patients. This article describes cervical spondylotic myelopathy, its diagnosis and management, and recent data that offer strong evidence that patients who undergo surgical decompression show significant improvement over patients who are treated conservatively.

Hemicraniectomy and durotomy upon deterioration from infarction-related swelling trial: randomized pilot clinical trial.

Background And Purpose: Hemicraniectomy and Durotomy Upon Deterioration From Infarction-Related Swelling Trial (HeADDFIRST) was a randomized pilot study to obtain information necessary to design a Phase III trial to evaluate the benefit of surgical decompression for brain swelling from large supratentorial cerebral hemispheric infarction.

Methods: All patients with stroke were screened for eligibility (age 18-75 years, National Institutes of Health Stroke Scale≥18 with Item 1a<2 [responsive to minor stimulation], and CT demonstrating unilateral, complete middle cerebral artery territory infarction by specific imaging criteria). All enrolled patients were treated using a standardized medical treatment protocol.

Nitric oxide synthase inhibition depresses the height of the cerebral blood flow-pressure autoregulation curve during moderate hypotension.

Variations in the height of the CBF response to hypotension have been described recently in normal animals. The authors evaluated the effects of nitric oxide synthase (NOS) inhibition on these variations in height using laser Doppler flowmetry in 42 anesthetized (halothane and N2O) male Sprague-Dawley rats prepared with a superfused closed cranial window. In four groups (time control, enantiomer control, NOS inhibition, and reinfusion control) exsanguination to MABPs from 100 to 40 mm Hg was used to produce autoregulatory curves.

Variability in the magnitude of the cerebral blood flow response and the shape of the cerebral blood flow-pressure autoregulation curve during hypotension in normal rats [corrected].

Background: The maintenance of constant cerebral blood flow (CBF) as mean cerebral perfusion pressure (CPP) varies is commonly referred to as CBF-pressure autoregulation. The lower limit of autoregulation is the CPP at which the vasodilatory capacity is exhausted and flow falls with pressure. We evaluated variability in the magnitude of percent change in CBF during the hypotensive portion of the autoregulatory curve.

Functional outcome after repair of unruptured intracranial aneurysms.

Object: Repair of unruptured aneurysms is a reasonable course of action if their expected natural history is worse than the predicted risks of treatment. The purpose of this study was to examine the presenting symptoms of unruptured aneurysms and to test the hypothesis that unruptured intracranial aneurysms can be repaired without significant functional worsening. A second hypothesis was also examined--that is, that the experience of the surgeon, the aneurysm size, and the patient age can be used to predict functional outcome.

Nuances of middle cerebral artery aneurysm microsurgery.

Middle cerebral artery aneurysms, a common source of subarachnoid hemorrhage, occur predominantly at the main bifurcation of the middle cerebral artery. Microsurgical clipping is the most effective treatment of these aneurysms because of their peripheral location, wide necks, and straightforward surgical anatomy. Despite the moderate technical requirements of this type of surgery, patients with ruptured aneurysms often have poor outcomes because of the high incidence of intracerebral hematomas.

Inflammation and intracranial aneurysms.

Objective: An intracranial aneurysm is an important acquired cerebrovascular disease that can cause a catastrophic subarachnoid hemorrhage. Despite modern therapy, most patients die or are left disabled as a direct result of a severe initial hemorrhage. The development of more effective treatment strategies depends on understanding the fundamental biology of cerebral aneurysms.

Detachable balloon embolization: concomitant use of a second safety balloon.

We describe a relatively unusual case of carotid cavernous fistula in association with a persistent trigeminal artery, presumably related to aneurysm rupture near the carotid origin of the vessel. We emphasize the use of a second, nondetachable balloon solely for the purpose of stabilizing placement of the first device at the time of detachment.

Cortical NOS inhibition raises the lower limit of cerebral blood flow-arterial pressure autoregulation.

The maintenance of constant cerebral blood flow (CBF) as arterial blood pressure is reduced, commonly referred to as CBF-pressure autoregulation, is typically characterized by a plateau until the vasodilatory capacity is exhausted at the lower limit, after which flow falls linearly with pressure. We investigated the effect of cortical, as opposed to systemic, nitric oxide synthase (NOS) inhibition on the lower limit of CBF-pressure autoregulation. Forty-four Sprague-Dawley rats were anesthetized with halothane and N2O in O2.

The ciliospinal reflex in pentobarbital coma.

Object: This study was conducted to delineate the ciliospinal reflex (CSR), which is defined as pupillary dilation caused by a noxious stimulus to the face or head. The authors anecdotally observed that patients in a pentobarbital coma have a CSR that can mimic pathological conditions. A pentobarbital coma obscures the results of the neurological examination in patients with potentially life-threatening cerebral edema; pupil size and reactivity are the only readily monitored signs.

Vascular extracellular matrix remodeling in cerebral aneurysms.

Object: The occurrence of cerebral aneurysms has been linked to alterations in the extracellular matrix and to matrix-degrading proteases. The purpose of the present study was to determine whether active extracellular matrix remodeling occurs within cerebral aneurysms.

Methods: Aneurysm tissue was collected from 23 patients (two of whom had a ruptured aneurysm and 21 of whom had an unruptured aneurysm) and compared with 11 control basilar arteries harvested at autopsy.

Identification of a serum gelatinase associated with the occurrence of cerebral aneurysms as pro-matrix metalloproteinase-2.

Background And Purpose: Subarachnoid hemorrhage from intracranial aneurysm rupture produces a severe form of stroke. Extracellular matrix remodeling is associated with cerebral aneurysms and may play a role in the formation or rupture of these lesions. We previously reported a 3-fold increase in a 72-kDa serum gelatinase in a subgroup of aneurysm patients.

Increasing hospital admission rates for intracerebral hemorrhage during the last decade.

Background: The incidence and mortality of all types of strokes, including intracerebral hemorrhages, declined during the 1970s. However, some evidence exists that these trends stabilized or reversed during the 1980s. In the present study, a large North American population was observed from 1981 to 1989 to assess changes in the annual hospital admission rates of intracerebral hemorrhage.

Rare lesions of the posterior fossa with initial retrocochlear auditory and vestibular complaints.

Objective: To catalog a series of rare lesions of the posterior fossa that appeared with unusual initial retrocochlear symptoms and signs and to make the reader more aware of these unusual lesions with a view to improving initial assessment and treatment planning.

Study Design: The study was a retrospective case review of seven patients.

Setting: Multidisciplinary team evaluation in a tertiary hospital referral center.

Gelatinase activity and the occurrence of cerebral aneurysms.

Background And Purpose: Cerebral aneurysms are associated with decreased arterial collagen content; however, whether this deficiency results from impaired collagen synthesis or enhanced collagen degradation is unknown. This study tested the hypothesis that enhanced collagen degradation, not impaired collagen synthesis, is associated with the occurrence of cerebral aneurysms.

Methods: Cultured skin fibroblasts and serum samples were studied in patients with angiographic evidence of aneurysm (n = 31) and control subjects (n = 14).

Prevention of chronic cerebral vasospasm in dogs with milrinone.

Objective: Delayed cerebral ischemia resulting from vasospasm is a major cause of morbidity and death in patients with aneurysmal subarachnoid hemorrhage. Milrinone, because it inhibits Type IV cyclic adenosine monophosphate-specific phosphodiesterase enzyme in both cardiac and vascular smooth muscle, is a powerful inotrope and vasodilator, but it has little effect on heart rate or blood pressure. Because of these properties, milrinone is an attractive potential therapy after subarachnoid hemorrhage.

Normal pressure perfusion breakthrough after resection of arteriovenous malformation.

Unlabelled: Objectives. The syndrome of normal pressure perfusion breakthrough (NPPB) follows the surgical resection of a small fraction of cerebral arteriovenous malformations (AVM). Although intraoperative hyperemia occurs in NPPB, the relationship and temporal profile of vasomotor paralysis to NPPB are unknown.

Specific repression of the preproendothelin-1 gene in intracranial arteriovenous malformations.

Cerebrovascular arteriovenous malformations (AVMs) display abnormal vascular development and dysautoregulation of blood flow. Genetic mechanisms that contribute to the pathogenesis and phenotype of cerebral AVMs are unknown. As a first step in understanding the pathophysiology of AVMs, the authors investigated the hypothesis that endothelial dysfunction-specifically, deregulation of endothelin-1 (ET-1) secretion-contributes to the abnormal vascular phenotype and the lack of hemodynamic autoregulation elaborated by these lesions.

Is image subtraction necessary in the clinical interpretation of single-day split-dose stress cerebral perfusion single-photon emission tomography using technetium-99m compounds?

The aim of this study was to validate a simplified semiquantitative method of evaluating a single-day stress cerebral perfusion test to obtain cerebrovascular reserve capacity (CVRC) for routine clinical uses. A split-dose protocol was tested in 36 pairs of technetium-99m hexamethylpropylene amino oxime baseline (low dose) and acetazolamide (high dose) stress brain single-photon emission tomographic (SPET) studies from 16 patients with cerebrovascular disease. The images were displayed on a semiquantitative color scale with (corrected) and without (uncorrected) image subtraction, dose adjustment, and decay correction.