Presynaptic prostaglandin E2 EP1-receptor facilitation of cerebral nitrergic neurogenic vasodilation.

Background And Purpose: Prostaglandin E(2) (PGE(2)) modulates autonomic transmission in the peripheral circulation. We investigated the role of endogenous PGE(2) and its presynaptic EP(1) receptor subtype in modulating the autonomic neurotransmission in cerebral vasculature.

Methods: The standard in vitro tissue-bath technique was used for measuring changes in isolated porcine basilar arterial tone.

Effect of phospholipase C blockade on cerebral vasospasm.

Background: Delayed cerebral ischemia due to cerebral vasospasm remains a major cause of morbidity and mortality following subarachnoid hemorrhage. Oxyhemoglobin (OxyHb) and vasoconstrictor prostanoids have been suggested as putative spasmogens. We have previously reported a synergistic vasoconstrictive action between thromboxane A(2) (TXA(2)) and OxyHb.

Transsulcal microsurgical approach for subcortical small brain lesions: technical note.

We describe a transsulcal microsurgical approach for removal of small subcortical brain lesions, guided by frameless stereotaxy. This technique of simultaneous stereotactic localization of the subcortical lesion and its adjacent sulcus, before surgical approach, results in optimal surgical planning, leading to minimal brain tissue loss and excellent surgical outcome.

EP1- and EP3-receptors mediate prostaglandin E2-induced constriction of porcine large cerebral arteries.

Prostaglandin E2 (PGE2) has been shown to dilate and constrict the systemic vascular beds, including cerebral vessels. The exact mechanism of PGE2-induced cerebral vasoconstriction, however, is less clarified. The authors' preliminary studies showed that PGE2 exclusively constricted the adult porcine basilar arteries.

Radiological evaluation of cerebral aneurysms in selected clinical presentations.

Background And Purpose: Cerebral aneurysms have different presenting features and, to some extent, a variable clinical course based on the pattern of subarachnoid hemorrhage, the circumstance of their discovery, and the anatomy. Thus, the neuroimaging workup must be tailored accordingly to provide accurate diagnosis and optimal follow-up.

Method: The authors suggest neuroradiological evaluation of patients in the emergency room and in cases of perimesencephalic subarachnoid hemorrhage, aneurysmal pattern of subarachnoid hemorrhage with normal angiography, vascular infundibula, unruptured/incidental aneurysms, infectious aneurysms, dissecting aneurysms, dolichoectatic/fusiform aneurysms, intracavernous aneurysms, and traumatic aneurysms.

Diagnosis and management of spontaneous cerebrospinal fluid-middle ear effusion and otorrhea.

Objectives/hypothesis: Spontaneous leak of cerebrospinal fluid (CSF) into the middle ear can occur in adults without a history of temporal bone trauma or fracture, meningitis, or any obvious cause. Therefore, clues may be lacking that would alert the otolaryngologist that fluid medial to an intact eardrum, or fluid emanating from an eardrum perforation, is likely to be CSF fluid. A review of relevant medical literature reveals that herniation of the arachnoid membrane through a tegmen defect may be congenital, or CSF leak may occur when dynamic factors (i.

Role of single photon emission computed tomography and transcranial Doppler ultrasonography in clinical vasospasm.

This report presents our experience with Transcranial Doppler (TCD) ultrasonography and Single Photon Emission Computed Tomography (SPECT) in the assessment of patients with aneurysmal subarachnoid haemorrhage (SAH). It was designed to evaluate clinical vasospasm with both TCD and SPECT and determine their diagnostic value. Twenty-eight consecutive patients were examined with both TCD and SPECT, performed within 24 hours of each other.

Transsphenoidal meningoencephalocele in adults.

Background: Transsphenoidal meningoencephalocele is a rare congenital anomaly, reported only in 14 adult patients. It may be subdivided into intrasphenoidal, extending into the sphenoid sinus, and true transsphenoidal, traversing the floor of the sinus and protruding into the nasal cavity or nasopharynx.

Methods: We present the eighth case of true transsphenoidal meningoencephalocele reported in an adult.

Brain pH monitoring during ischemia.

Background: Brain tissue acidosis can result from ischemia when cerebral blood flow reduction reaches a critical value. The portable, battery-operated Khuri pH monitor has been used previously in a large number of patients undergoing cardiopulmonary bypass surgery to monitor the intramyocardial pH during aortic clamping. It was found to be easy to use, reliable, and a strong predictor of myocardial preservation.

SPECT imaging in cerebral vasospasm following subarachnoid hemorrhage.

Unlabelled: Cerebral vasospasm is a frequent complication after subarachnoid hemorrhage and contributes to overall morbidity and mortality. Arteriography is the standard test for determining the presence of vasospasm. A retrospective review of 16 patients with cerebral aneurysm was undertaken to assess the sensitivity and specificity of SPECT for diagnosis of vasospasm.

Lymphocytic hypophysitis.

A male patient with lymphocytic hypophysitis is reported on. Lymphocytic hypophysitis is a rare disease that may mimic pituitary adenoma and occurs mostly in women in the peripartum period. Only six other cases have been reported in men.

Subintimal dissection of the vertebral artery in subluxation of the cervical spine.

The vertebral arteries appear to be particularly susceptible to injury in trauma of the cervical spine because of their close anatomical relationship to the spine; however, traumatic subintimal dissection of the vertebral artery is rare judging from the paucity of cases reported in the literature. The case of a patient who developed a visual field defect secondary to a fracture-subluxation of the cervical spine is reported. Angiography demonstrated an intimal dissection of the vertebral artery at the site of the fracture-subluxation resulting in thrombus formation and subsequently in emboli occluding the posterior temporal branch of the posterior cerebral artery.

Grading and outcome prediction of cases of aneurysmal subarachnoid haemorrhage by bedside xenon cerebral blood flowmetry.

Ninety-six patients with aneurysmal subarachnoid haemorrhage underwent serial measurement of regional cerebral blood flow throughout the period of their treatment over the period of 5 years (1983 to 1988). A portable bedside xenon cerebral blood flow machine was used in this study and the initial slope index (ISI) values showed a clear relationship between reduction of cerebral blood flow and deteriorating clinical grade. Furthermore, serial measurements showed a statistically significant relationship between drop of cerebral blood flow, at anytime during the course of the disease, and fatal or less than satisfactory outcome.

Synovial cyst of the cervical spine.

A case of acute posttraumatic myelopathy resulting from hemorrhage into synovial cysts bilaterally at the C-6, C-7 facet joints is presented. The pathogenesis of synovial cysts remains unclear, although reports in the literature have implicated trauma leading to cyst enlargement. Hemorrhage into the cavity of the synovial cysts resulted in epidural compression of the spinal cord in this patient.

Temporary vascular occlusion during aneurysm surgery.

Premature rupture of a cerebral aneurysm during operation is a serious hazard. Direct pressure and suction may not always be effective in controlling the hemorrhage, and hasty dissection under such circumstances can cause serious injury to vital structures. In facing this risk, elective temporary arterial occlusion of parent vessels can be an advantage.

Comparison of fast flow and initial slope index values for cerebral blood flow following subarachnoid haemorrhage.

Forty five patients with subarachnoid haemorrhage proved by lumbar puncture underwent serial measurements of cerebral blood flow and central conduction time. When the initial slope index (ISI) value for cerebral blood flow is considered there is a clear relationship between reduction of cerebral blood flow and deteriorating clinical grade. This relationship is not so clearly demonstrated using the fast flow (f1) value for cerebral blood flow.

Mean hemispheral cerebral blood flow changes after craniotomy. Significance and prognostic value.

The effects of craniotomy on cerebral haemodynamics remains controversial from a study of the literature. This report represents our experience with respect to CBF changes within 10 days of surgery. Our objective was twofold, first to study the effect of craniotomy on the cerebral circulation and second to determine whether the CBF pattern at different post-operative intervals could provide useful prognostic information.

A comparative study of the portable regional CBF monitor and the portable mean hemispheral CBF monitor: advantages and disadvantages in clinical practice.

CBF determination can provide additional valuable information which can be used in clinical practice to enhance our capabilities in patient evaluation. The initial techniques requiring intraarterial injections have been largely replaced by the noninvasive inhalation and intravenous methods. The recent refinement of microcomputers and the development of portable CBF monitors have made CBF determination a nontraumatic, dependable and easily repeatable examination at the patient's bedside.

Anterior sacral meningocele. Current diagnosis.

One hundred fifty cases of anterior sacral meningocele have been reported in the world literature. This rare pathologic entity was first recognized and described by Bryant in 1837. We report a patient with an incidental anterior sacral meningocele.

Decerebrate posturing with the syndrome of inappropriate secretion of antidiuretic hormone.

Decerebrate and/or decorticate posturing have not yet been described as possible features of the syndrome of inappropriate secretion of antidiuretic hormone. Cerebral edema and loss of brain electrolytes are contributing factors resulting in altered excitability of the neural membrane. We describe a patient who, on the eighth day after a head injury, presented with decerebrate posturing, which coincided with the development of the syndrome of inappropriate secretion of antidiuretic hormone, and which rapidly reversed with the correction of the hyponatremia.