Evidence of a suffocation alarm system within the periaqueductal gray matter of the rat.

Dyspnea, hunger for air, and urge to flee are the cardinal symptoms of panic attacks. Patients also show baseline respiratory abnormalities and a higher rate of comorbid and antecedent respiratory diseases. Panic attacks are also precipitated by infusion of sodium lactate and inhalation of 5% CO2 in predisposed patients but not in healthy volunteers or patients without panic disorder. Accordingly, Klein [Klein (1993) Arch Gen Psychiatry 50:306-317] suggested that clinical panic is the misfiring of an as-yet-unidentified suffocation alarm system. In rats, selective anoxia of chemoreceptor cells by potassium cyanide (KCN) and electrical and chemical stimulations of periaqueductal gray matter (PAG) produce defensive behaviors, which resemble panic attacks. Thus, here we examined the effects of single or combined administrations of CO2 (8% and 13%) and KCN (10-80 µg, i.v.) on spontaneous and PAG-evoked behaviors of rats either intact or bearing electrolytic lesions of PAG. Exposure to CO2 alone reduced grooming while increased exophthalmus, suggesting an arousal response to non-visual cues of environment. Unexpectedly, however, CO2 attenuated PAG-evoked immobility, trotting, and galloping while facilitated defecation and micturition. Conversely, KCN produced all defensive behaviors of the rat and facilitated PAG-evoked trotting, galloping, and defecation. There were also facilitatory trends in PAG-evoked exophthalmus, immobility, and jumping. Moreover, whereas the KCN-evoked defensive behaviors were attenuated or even suppressed by discrete lesions of PAG, they were markedly facilitated by CO2. Authors suggest that the PAG harbors an anoxia-sensitive suffocation alarm system which activation precipitates panic attacks and potentiates the subject responses to hypercapnia.

Association of plasma levels of human immunodeficiency virus type 1 RNA and oropharyngeal Candida colonization.

The pathophysiology of oropharyngeal candidiasis in patients infected with human immunodeficiency virus (HIV) type 1 is poorly understood. Association between oropharyngeal yeast carriage and various clinical factors in HIV-1-infected patients was studied in 83 patients with no clinical evidence of thrush and no recent antifungal use. Of the clinical factors measured, the only correlate of yeast colonization was with plasma HIV-1 RNA levels (P=.001), whereas the correlation with CD4 cell count was poor (P=.36). By multivariable regression modeling, plasma HIV-1 RNA was the only parameter that correlated with the extent of colonization with Candida infection (P=.003). These data indicate that the presence and amount of asymptomatic oropharyngeal yeast carriage in persons with HIV-1 infection is more significantly correlated with plasma HIV-1 RNA levels than with CD4 cell count. Further studies on the effect of HIV-1 on oropharyngeal yeast colonization, infection, and local immunity are warranted.

In vitro and in vivo efficacy of the triazole TAK-187 against Cryptococcus neoformans.

Multiple isolates of Cryptococcus neoformans, including those with fluconazole resistance, were tested to assess the in vitro activity of the new triazole TAK-187. MICs of TAK-187 were at least eightfold lower than those of fluconazole, and fungicidal concentrations for most isolates were 4 microg/ml or less. TAK-187 also was evaluated as intermittent therapy using two dosages in a rabbit model of experimental cryptococcal meningitis. Compared to daily treatment with fluconazole, as little as two doses of TAK-187 given 7 days apart were found to be effective. Plasma and cerebrospinal fluid TAK-187 concentrations were many times higher than MICs and fungicidal concentrations. Based upon its therapeutic efficacy and long half-life in the rabbit model, TAK-187 should be investigated for intermittent dosing in treatment or suppression of cryptococcal infections in humans.

Chronic spinal subdural hematoma.

A 55-year-old woman with chronic spinal subdural hematoma, diagnosed by magnetic resonance (MR) is presented. There was no coagulation defect, anticoagulant therapy, or trauma.

[Turcot syndrome: a report of 2 cases]. / Síndrome de Turcot. Relato de dois casos.

The authors describe two patients with the association of polyposis-coli and central nervous system tumor (Turcot's syndrome). Clinical, genetic and therapeutic aspects are discussed.

Encapsulated spinal epidural hematoma in an octogenarian.

An 88-year-old man was found at laminectomy to have an encapsulated spinal epidural hematoma. The surgical result was gratifying and reinforced a recent statement that spinal surgical procedures in the very elderly should not be withheld on the basis of age alone. Moreover, the rarity of this pathology in this age group and the clear identification of the lesion on the computed tomography scan of this case are to be noted.

Vasospasm after acoustic neuroma removal.

A case of a acoustic neuroma with a two-stage removal due to severe bleeding is presented. The patient remained drowsy after the second operation and by the 8th day deteriorated quickly with progressive right hemiplegia and aphasia. The cerebrospinal fluid was bloody, vasospasm was shown in the angiograms, and an ischemic area was disclosed in the computed tomography scan. The outcome and the neuroradiologic examinations suggested that blood in the basal cisterns caused the vasospasm and the brain ischemia. A review of the literature disclosed only one similar case.

[Incidental syringohydromyelography: report of a case]. / Siringohidromielografia incidental: registro de um caso.

The radiological findings of syringomyelography are described in a five years old patient who underwent a percutaneous injection of opaque contrast medium (Lipiodol) into the intraspinal syringomyelic cavity. The clinical picture, the usual diagnostic methods and the place of syringomyelography for the diagnosis of syringomielia are discussed.

[Neuroenteric cyst: report of a case]. / Cisto neuroentérico: registro de um caso.

The case of 15 years old boy with an enterogenous cyst causing compression of the spinal cord at T-2 is reported. The diagnosis was made by thoracic laminectomy and confirmed by histological examination. The motor disorders improved progressively after surgery.

[Computed tomography in the follow-up of patients with intracranial tumors]. / Tomografia computadorizada no seguimento de pacientes com tumores intracranianos.

Computed Tomography (CT) has been very useful in the follow-up of patients with brain tumors. Soon after the craniotomy, CT would show any residual tumor if an incomplete excision was done. CT has been essential when one needs to evaluate any deterioration in the patient's neurological status post operatively. In such instances, CT may detect brain edema, hematoma, hydrocephalus and the presence of air. CT findings are more accurate than those obtained from conventional neuroradiology or from intracranial pressure monitoring, being also more innocuous than those methods. Later in the post operative follow-up, CT allows, besides precocious diagnosis of tumor recurrences, a good evaluation of the results obtained by chemiotherapy or radiotherapy. When hydrocephalus is accompanying the primary pathology, ventricular size can be rapidly evaluated by CT. Difficulties may arise when one wishes to differentiate CT images of radionecrosis from tumor recurrences at least in the initial stages.

[Tumoral form of cerebral cysticercosis: diagnosis by computerized tomography]. / Forma tumoral da cisticercose cerebral: diagnóstico pela tomografia computadorizada.

Solitary granulomatous lesions due to cysticercosis in the brain were found by computed tomography in six patients. The CT images were in all cases very similar to those from brain neoplasms. The cerebrospinal fluid complement fixation test for cysticercosis was negative in all of the cases. The definite etiological diagnosis could only be made by craniotomy in this series.

[Computerized tomography in ventral and lateral prone position in the differential diagnosis of subdural hematoma and cortical atrophy]. / Tomografia computadorizada em decúbito ventral e lateral no diagnóstico diferencial entre hematoma subdural e atrofia cortical.

The differential diagnosis between brain atrophy versus subdural effusion in children has shown some difficulties in a few cases, mainly when the frontal subarachnoid space is very large on computed tomography. We think that a simple procedure, that is, CT scans in the lateral and prone position following the standard examination, may be worth to clarify those cases of doubtful diagnosis.

[Calcified papilloma of the choroid plexus. Report of a case]. / Papiloma calcificado do plexo coroide. Registro de um caso.

A case of calcified choroid plexus papilloma in a 7 years old child is reported. The radiologic findings are discussed.

[Use of the inflated balloon catheter in the treatment of carotid-cavernous fistula]. / Uso de cateter com balão inflável no tratamento da fístula car¿otido-cavernosa.

In the vast majority of techniques used to treat carotid-cavernous fistulas the carotid artery has been occluded. Occlusion of the fistula with preservation of carotid blood flow is achieved by new techniques as those proposed by Parkinson, Serbinenko and Mullan. However the sophisticated equipments and surgical acts which are needed for these methods has not allowed its general use. The use of Fogarty type balloon catheters has had a place in the treatment of carotido-cavernous fistulas. The carotid artery has to be occluded too, but the procedure is much safer and easier. Our results in a series of 6 cases are reported. Considerations about indications and the technical aspects are made. The results were good and the procedure may be used with conventional equipment.

[Microsurgical cerebral revascularization]. / Revascularização cerebral microcirurgica

Techniques of microsurgical revascularization are reviewed. A series of 5 cases, submitted to 6 anastomosis of the superficial temporal artery is presented.