Controversies in the Management of Central Nervous System Coccidioidomycosis

Central nervous system infection with Coccidioides spp is fatal if untreated, and complications occur even when therapy is directed by experienced clinicians. We convened a panel of clinicians experienced in the management of coccidioidal meningitis to summarize current controversies and provide consensus for the management of this difficult infection.

Intrathecal amphotericin in the management of coccidioidal meningitis

Coccidioidal meningitis is lethal in the absence of treatment. The advent of the azoles has not led to cure, causing many clinicians to revert to intra-cerebrospinal fluid (CSF) amphotericin as part of the treatment regimen, desiring the influence of the latter regimen's ability to clear infection more completely and rapidly. Intra-CSF amphotericin therapy is, however, far more toxic than oral azoles and requires much more clinical management to achieve success and avoid toxicity. This management task increasingly, for insurance reasons or geographic reasons, falls on clinicians unfamiliar with the disease. We delineate our experience in the medical and surgical management of this form of therapy, including procedural details that we have found useful, for the benefit of our colleagues who may wish to use them. As ours is a teaching institution, we have found this material also useful for physicians in training, who are learning about the treatment of these patients.

An improved stereotactic technique for cyst cannulation

Stereotactic techniques for cannulation of cystic structures, within the brain, are well known. Superimposed structures (vessels, ventricles, etc.) may make this problematic as does the need to approach the cystic structure perpendicular to its tangent plane (rather than "glancing") as with a craniopharyngioma cyst. To facilitate a three-dimensional visualization of the trajectory, we have employed digital holography. Transparent holographic images of cystic structures, ventricles, and sulci are rendered from T2-weighted MR data. Holographic images of vascular structures are rendered from CT or MR angiographic data. Vascular holograms are superimposed over the brain holograms, demonstrating the spatial relationships of these structures with regard to each other. Holographic images of the skull are rendered from CT slices. A Laitinen stereotactic frame (Sandstrom) is placed on the patient prior to obtaining the CT. The skull, pre-existing shunt catheters, and the stereotactic frame are all readily visible. The brain and vascular holograms are superimposed on these. The resulting image clearly demonstrates cystic structures, ventricles, vessels, pre-existing catheters, all within the skull and stereotactic frame. Using this holographic image as a "phantom", the actual Laitinen stereotactic frame is placed within its holographic image. The optical trajectory is then chosen, and the articulated arm of the stereotactic device is so adjusted. Subsequently, the frame is used to effect stereotactic placement of the cannula, in the usual manner. The major advantages of this technique are twofold. The first advantage lies with the fact that the surgeon can readily visualize the entire trajectory of the needle, and easily appreciate all structures which may be encountered by the needle on its passage from the skull to the target. Presumably, the surgeon's knowledge of anatomy would unable such knowledge to be apparent, but in complex cases the "safe" corridor may be rather small, and its limits may not be intuitively obvious. This is all the more the case, when obstacles along the pathway are pathologically distorted, or when they are not of tissue origin (shunt catheters, etc.). Employing this technique, we have successfully cannulated cystic structures in six patients, three of which presented with complex trajectory problems.

Herpes simplex virus type I from a patient with radiculoneuropathy

Herpes simplex virus type I was isolated from the CSF of a patient with atypical lumbosacral pain. The features of this case are unusual and important in light of the current understanding of herpes-simplex-virus-associated neurologic disease.

Cardiac arrhythmias resulting from experimental head injury

The cardiovascular events resulting from experimental head injury were studied to determine the incidence of cardiac arrhythmias and to define the autonomic mechanisms responsible for these changes. Electrocardiograms and arterial blood pressure were recorded in anesthetized monkeys before and after the animals were subjected to temporoparietal head impact. Cardiac arrhythmias and hypotension occurred immediately following impact in every animal studied. Various atrioventricular nodal and ventricular arrhythmias were seen. Cholinergic blockage was found to prevent arrhythmias induced by head injury whereas adrenergic blockage was found to be ineffective.

High-speed angiography of experimental head injury

✓ Cineangiograms were performed at 1000 frames/sec in anesthetized rhesus monkeys during 4 meters/sec impact head injuries. Impacts that did not fracture the skull resulted in rapid transient movements of intracranial arteries. Lateral blows distorted the ipsilateral middle cerebral artery and reversibly displaced the anterior cerebral artery across the midline. Occipital blows distorted the peripheral branches of the middle and posterior cerebral arteries, and produced marked stretching of extracranial vessels. These data indicate that most of the intracranial movements hypothesized as etiological in brain injury occur in the first milliseconds following trauma. This technique makes possible quantitative measurement of these intracranial events and so may aid in the understanding of brain injury.