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George H. Weiss and William F. Caveness

✓ A group of 356 patients who received head injuries in the Korean War during 1951–1953 have been reviewed with special concern for the prognostic indicators in posttraumatic epilepsy. Factors that operate in the occurrence of seizures after craniocerebral trauma are degree of brain destruction, length of coma, and, to a lesser extent, site of injury. None of these factors is related to the persistence of attacks once they have begun. For the latter, the most useful prognostic factors are derived from the time of onset and frequency of seizures.

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William T. Couldwell, Peter Kan and Martin H. Weiss

✓ The most common nonendocrine complication after transsphenoidal surgery is cerebrospinal fluid (CSF) leak. Many neurosurgeons have advocated the routine reconstruction of the floor of the sella turcica using autologous fat, muscle, fascia, and either cartilage or bone after transsphenoidal surgery to prevent postoperative CSF fistulas. However, the use of autologous grafting requires a second incision, prolongs operative time, and adds to the patient's postoperative discomfort. In addition, the presence of sellar packing may interfere with the interpretation of postoperative images. To avoid these disadvantages, the authors suggest that routine sellar reconstruction or closure after transsphenoidal surgery is unnecessary unless an intraoperative CSF leak is encountered. The incidence of postoperative CSF leakage in the patients reported on in this series is no higher than that reported by others, and no other complications such as pneu-matocele have been encountered in approximately 2700 patients in whom no intraoperative CSF leak was encountered. The authors conclude that routine closure of the floor of the sella turcica or sphenoid is unnecessary in the absence of intraoperative CSF leak.

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William T. Couldwell and Martin H. Weiss

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William T. Couldwell, Parakrama T. Chandrasoma and Martin H. Weiss

✓ A case of prostatic carcinoma metastasis to the pituitary gland is reported. The presentation and rarity of such a lesion is addressed. The literature review yielded only isolated case reports of symptomatic brain metastases unassociated with bone disease from adenocarcinoma of the prostate. The management options of such a lesion are discussed.

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John H. Schneider, Martin H. Weiss and William T. Couldwell

✓ The Los Angeles County General Hospital has played an integral role in the development of medicine and neurosurgery in Southern California. From its fledgling beginnings, the University of Southern California School of Medicine has been closely affiliated with the hospital, providing the predominant source of clinicians to care for and to utilize as a teaching resource the immense and varied patient population it serves.

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Mark D. Krieger, William T. Couldwell and Martin H. Weiss

Object. The criteria for remission of acromegaly following transsphenoidal adenoma resection are in evolution. In the present study the authors evaluate the utility of predicting long-term remission by reference to a single fasting growth hormone (GH) level on the 1st postoperative day.

Methods. A retrospective analysis was conducted on 181 patients with acromegaly who underwent transsphenoidal resection between 1973 and 1990 and completed a 5-year follow-up period. Fasting serum GH levels were obtained in all patients on the 1st postoperative day in the absence of exogenous glucocorticoids. All patients participated in a follow-up evaluation lasting at least 5 years, which included measurements of serum insulin-like growth factor—I (IGF-I) levels as an index of acromegalic activity.

Among the 181 patients, GH levels ranged from 0 to 8 ng/ml in 131 (72%) on the 1st postoperative day, suggesting biochemical remission. This group included 107 (84%) of the 127 patients with microadenomas, but only 24 (44%) of the 54 with macroadenomas. Nevertheless, 15 (11%) of the 131 patients who initially had attenuated GH levels displayed recurrent acromegaly within the first 2 years (with elevated levels of IGF-I in all cases, and abnormalities appearing on magnetic resonance images in nine cases). Only one of 116 patients in whom the initial postoperative GH level was lower than 2 ng/ml experienced a recurrence, whereas 14 (93%) of the 15 patients with postoperative GH levels between 2.2 and 8 ng/ml subsequently displayed biochemical evidence of acromegaly.

Conclusions. The findings indicate that a fasting morning serum GH level lower than 2 ng/ml on the 1st postoperative day portends long-term biochemical remission of acromegaly, whereas higher levels are a significant marker for recurrent disease.

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William T. Couldwell, Martin H. Weiss and Edward R. Laws Jr

Background

Whether the withdrawal of treatment in patients with nontumoral hyperprolactinemia, microprolactinomas, or macroprolactinomas is safe and effective has been unclear. We performed an observational, prospective study of cabergoline (a dopamine-receptor agonist) withdrawal in such patients.

Methods

The study population included 200 patients—25 patients with nontumoral hyperprolactinemia, 105 with microprolactinomas, and 70 with macroprolactinomas. Withdrawal of cabergoline was considered if prolactin levels were normal, magnetic resonance imaging (MRI) showed no tumor (or tumor reduction of 50 percent or more, with the tumor at a distance of more than 5 mm from the optic chiasm, and no invasion of the cavernous sinuses or other critical areas), and if follow-up after withdrawal could be continued for at least 24 months.

Results

Recurrence rates two to five years after the withdrawal of cabergoline were 24 percent in patients with nontumoral hyperprolactinemia, 31 percent in patients with microprolactinomas, and 36 percent in patients with macroprolactinomas. Renewed tumor growth did not occur in any patient; in 10 female patients (22 percent) and 7 male patients (39 percent) with recurrent hyperprolactinemia, gonadal dysfunction redeveloped. In all diagnostic groups, prolactin levels at the time of recurrence were significantly lower than at diagnosis (p < 0.001). The Kaplan–Meier estimated rate of recurrence at five years was higher among patients with macroprolactinomas and those with microprolactinomas who had small remnant tumors visible on MRI at the time of treatment withdrawal than among patients whose MRI scans showed no evidence of tumor at the time of withdrawal (patients with macroprolactinomas, 78 percent vs. 33 percent, P = 0.001; patients with microprolactinomas, 42 percent vs. 26 percent, P = 0.02).

Conclusions

Cabergoline can be safely withdrawn in patients with normalized prolactin levels and no evidence of tumor. However, because the length of follow-up in our study was insufficient to rule out a delayed increase in the size of the tumor, we suggest that patients be closely monitored, particularly those with macroprolactinomas, in whom renewed growth of the tumor may compromise vision.

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William T. Couldwell, Thomas C. Chen, Martin H. Weiss, Takanori Fukushima and William Dougherty

✓ The authors describe the use of a porous polyethylene Flexblock implant for cosmetic cranioplasty. The implant may be used to cover any small- or medium-sized (< 8 cm) cranial defect, offering similar cosmetic results to standard alloplast cranioplasty while decreasing operation time. The porous implant design permits ingrowth of soft tissue and bone to increase implant strength and decrease the risk of infection. The Flexblock alloplast has been utilized in 25 cases with excellent cosmetic results and no implant-related complications.

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James K. Liu, Kaushik Das, Martin H. Weiss, Edward R. Laws Jr and William T. Couldwell

✓ Initial attempts at transcranial approaches to the pituitary gland in the late 1800s and early 1900s resulted in a mortality rate that was generally considered prohibitive. Schloffer suggested the use of a transsphenoidal route as a safer, alternative approach to the sella turcica. He reported the first successful removal of a pituitary tumor via the transsphenoidal approach in 1906. His procedure underwent a number of modifications by interested surgeons, the culmination of which was A. E. Halstead's description in 1910 of a sublabial gingival incision for the initial stage of exposure. From 1910 to 1925, Cushing, combining a number of suggestions made by previous authors, refined the transsphenoidal approach and used it to operate on 231 pituitary tumors, with a mortality rate of 5.6%. As he developed increasing expertise with transcranial surgery, however, Cushing reduced his mortality rate to 4.5%. With the transcranial approach, he was able to verify suprasellar tumors and achieve better decompression of the optic apparatus, resulting in better recovery of vision and a lower recurrence rate. As a result he and most other neurosurgeons at the time abandoned the transnasal in favor of the transcranial approaches.

Norman Dott, a visiting scholar who studied with Cushing in 1923, returned to Edinburgh, Scotland, and continued to use the transsphenoidal procedure while others pursued transcranial approaches. Dott introduced the procedure to Gerard Guiot, who published excellent results with the transsphenoidal approach and revived the interest of many physicians throughout Europe in the early 1960s. Jules Hardy, who used intraoperative fluoroscopy while learning the transsphenoidal approach from Guiot, then introduced the operating microscope to further refine the procedure; he thereby significantly improved its efficacy and decreased surgical morbidity. With the development of antibiotic drugs and modern microinstrumentation, the transsphenoidal approach became the preferred route for the removal of lesions that were confined to the sella turcica. The evolution of the transsphenoidal approaches and their current applications and modifications are discussed.