Neurosurgery
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Case Reports Randomized Controlled Trial Clinical Trial
Intrathecal octreotide for relief of intractable nonmalignant pain: 5-year experience with two cases.
Somatostatin is distributed in the substantia gelatinosa in the dorsal horn of the spinal cord, and its application has been found to produce an inhibitory effect on nociceptive neurons. Although intraspinal administration of somatostatin-14 produces pain relief in patients with cancer and in postoperative patients, its short half-life limits its clinical usefulness. ⋯ This article describes the 5-year clinical course of two patients receiving intrathecal octreotide for severe, intractable nonmalignant pain. Included in this description are the results of blinded, randomized "N of 1" trials conducted in each of these patients.
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Hyponatremia is frequently seen in neurosurgical patients and is often attributed to inappropriate secretion of antidiuretic hormone. A number of studies in recent years have shown that hyponatremia in many patients with intracranial disease may actually be caused by cerebral salt wasting, in which a renal loss of sodium leads to hyponatremia and a decrease in extracellular fluid volume. The appropriate treatment of cerebral salt wasting fluid and salt replacement, is opposite from the usual treatment of hyponatremia caused by inappropriate secretion of antidiuretic hormone. This review summarizes the evidence in favor of cerebral salt wasting in patients with intracranial disease, examines the possible mechanisms responsible for this phenomenon, and discusses methods for diagnosis and treatment.
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Comprehensive anatomic and clinical analyses of 39 patients with injuries involving the transverse atlantal ligament or its osseous insertions were performed to assess the morphology of the injured ligaments and the patients' capacity to heal. Injuries of the upper cervical spine were screened with plain radiographs, thin-section computed tomography, and magnetic resonance imaging studies. The injuries were classified as disruptions of the substance of the ligament (Type I injuries, n = 16) or as fractures and avulsions involving the tubercle for insertion of the transverse ligament on the C1 lateral mass (Type II injuries, n = 23). ⋯ Type II injuries, which rendered the transverse ligament physiologically incompetent even though the ligament substance was not torn, should be treated initially with a rigid cervical orthosis, because they had a 74% success rate nonoperatively. Surgery should be reserved for patients with Type II injuries that have nonunion with persistent instability after 3 to 4 months of immobilization. Type II injuries had a 26% rate of failure of immobilization; therefore, close monitoring is needed to detect patients who will require delayed operative intervention.
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Although histologically benign, one-third of all pituitary tumors will be invasive of surrounding structures. In this study, the relationship between the proliferative activity in pituitary adenomas and their invasiveness was investigated. Invasion was defined as gross, operatively or radiologically apparent infiltration of dura or bone. ⋯ The mean growth fraction of hormonally active pituitary adenomas (3.25 +/- 0.26%) was significantly higher than that for nonfunctioning adenomas (2.06 +/- 0.23%) (P = 0.03). Establishing a threshold labeling index of 3% served to distinguish invasive from noninvasive adenomas with 97% specificity and 73% sensitivity and was associated with positive and negative predictive values of 96 and 80%, respectively. Although invasive pituitary tumors exhibited significantly higher growth fractions than did noninvasive tumors, there were individual exceptions, indicating that in a subpopulation of invasive pituitary tumors, factors other than proliferative activity determine invasive potential.