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Stephen A. Hill, James M. Falko, Charles B. Wilson and William E. Hunt

✓ Hyperthyroidism due to thyrotrophin (TSH)-secreting pituitary tumors is rare. Four cases are described, with the features that allow preoperative diagnosis. In all the patients, thyroid hormone production was consistently elevated despite antithyroid therapy, and TSH levels were inappropriately elevated. All patients were treated with both surgery and irradiation. Each patient had recurrent tumor with suprasellar, intrasphenoidal, or intraorbital spread. The combination of a recurrent, aggressive tumor complicated by thyrotoxicosis makes this a complex and difficult surgical problem.

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W. George Bingham, Harold Goldman, Stewart J. Friedman, Sharon Murphy, David Yashon and William E. Hunt

✓ The authors used indicator fractionation techniques to determine blood flow in normal and bluntly traumatized spinal cords of Macaca rhesus monkeys. Normal flow rates were determined for several levels of spinal cord as well as differential values for white and gray matter from representative areas. Flow rates in traumatized tissue, obtained at several different time intervals up to 4 hours after injury, demonstrated marked differences in regional perfusion of the white matter and gray matter after trauma. Gray matter perfusion was nearly obliterated while white matter blood flow persisted and in fact was higher than uninjured controls. The findings do not support the concept of ischemia as a factor in white matter failure. If toxic pathobiochemical alterations are induced by trauma, it may be possible to reverse these changes by exploiting the preserved white matter blood flow for chemotherapeutic intervention.

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William E. Hunt, J. N. Meagher, A. Friemanis and C. W. Rossel

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Calvin B. Early, Richard C. Dewey, Heinz P. Pieper and William E. Hunt

✓ Pressure-flow data are presented for the brain vascular bed in the rhesus monkey. These data are obtained at fixed levels of vasomotor tone. Resultant flow curves are called the “dynamic pressure-flow relationships” (DPFR). In the experimental model, arterial pressures are oscillated with a sinusoidal pump at frequencies exceeding the vasomotor response lag time. The resultant DPFR curves are discussed. A model is presented to show that changes in vasomotor tone cause a vertical shift of the DPFR. Changes in vascular bed resistance cause a change in the slope of the DPFR (▵P/▵F).

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David Yashon, W. George Bingham Jr., Edward M. Faddoul and William E. Hunt

✓ Identification of central nervous system edema is based on increased water content in relation to nonvolatile residue per unit weight. Nonvolatile residue in spinal cord tissue following impact trauma was determined to ascertain the magnitude and persistence of edema. High and low thoracic laminectomies were carried out on each of 17 rhesus monkeys. The lower exposed cord was traumatized with a calibrated blow of 300 gm cm. All upper exposed cords and the lower exposed cord in one monkey served as nontraumatized controls. At time intervals of 5 minutes to 20 days after trauma, cord segments were removed and assayed for water content. Increased tissue water was evident within 5 minutes and persisted for 15 days. By the 20th day it had essentially subsided. Increased tissue water content in the traumatized segment reached a maximum of 7.4% over control values at 5 days and then gradually diminished. These findings support the concept that edema following spinal trauma is unrelated to secondary effects of ischemia after 18 hours. The protracted course of increased water content (15 to 20 days) was unexpected and may indicate that edema-reducing measures should be continued for 2 to 3 weeks following spinal cord trauma with severe neurological dysfunction.

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David Yashon, W. Michael Vise, Richard C. Dewey and William E. Hunt

✓ The temperature of the spinal cord parenchyma during local hypothermia was recorded in 18 dogs with and without a 300 to 500 gm-cm spinal cord injury. Other variables included opening the dura, location of the inflow stream, and the use of alcohol bath cooling. In nontraumatized cord, the temperature varied between 5.4° and 23.5°C depending on the location of the inflow stream; the variable range of 10–15 minutes of perfusion to reach these levels was unexpected. Temperatures of the injured cord fell to those of the reservoir (1.0° to 3.8°C) within 2½ minutes. The fact that the temperature of nontraumatized areas two segments cephalad to the injury was also reduced showed the capacity of the cord for thermal conduction. Opening the dura or use of an alcohol bath had little effect on cord temperature. Lack of heat transport due to ischemia is postulated as the primary cause of the rapid reduction of temperature in the injured cord to that of the surrounding environment.

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S. Sam Finn, Sigurdur A. Stephensen, Carole A. Miller, Laura Drobnich and William E. Hunt

✓ Thirty-two patients with aneurysmal subarachnoid hemorrhage (SAH) were managed according to a protocol based on pain control and hemodynamic manipulation, monitored by an arterial line and Swan-Ganz catheter. Hemodynamic parameters were adjusted to four clinical situations. 1) For the unoperated patient with no neurological deficit, the regimen aims to maintain pulmonary wedge pressure (PWP) at 10 to 12 mm Hg, and the cardiac index (CI) and blood pressure (BP) at normal levels. 2) For the unoperated patient presenting with or developing neurological deficit, the PWP is increased until the deficit is reversed or the CI falls; the CI is high, and the BP normal. 3) For the postoperative patient with no neurological deficit, the PWP is maintained at 12 to 14 mm Hg, the CI is a high normal, and the BP is normal. 4) For the postoperative patient developing neurological deficit but showing no surgical complication on the computerized tomography scan, the PWP is increased until the deficit is reversed or the CI falls; the CI is high and the BP is increased with vasopressors if necessary.

Fourteen patients developed neurological deficits either preoperatively, postoperatively, or both. Neurological deficits were repeatedly reversed by increasing the PWP, as measured hourly. In several patients an optimal wedge pressure was determined, below which deficits would reappear. In one patient whose neurological deficit was reversed on several occasions by increasing the PWP, the optimal PWP rose after each episode until it reached 22 mm Hg.

Detailed event-related analysis of these patients' course illustrates these phenomena well. The optimal PWP varied from patient to patient, but ranged most frequently from 14 to 16 mm Hg. Meticulous monitoring of the patients' neurological status coupled with prompt correction of low PWP (assuming an adequate CI) has proven to be an effective way to prevent and reverse neurological deficits following aneurysmal SAH.

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Carole Miller, Thomas V. Lloyd, John C. Johnson and William E. Hunt

✓ The authors present an unusual case of eosinophilic granuloma arising in the region of the foramen rotundum.

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Pediatric neck injuries

A clinical study

Stephen A. Hill, Carole A. Miller, Edward J. Kosnik and William E. Hunt

✓ This review of pediatric neck injuries includes patients admitted to Children's Hospital of Columbus, Ohio, during the period 1969 to 1979. The 122 patients with neck injuries constituted 1.4% of the total neurosurgical admissions during this time. Forty-eight patients had cervical strains; 74 had involvement of the spinal column; and 27 had neurological deficits. The injuries reached their peak incidence during the summer months, with motor-vehicle accidents accounting for 31%, diving injuries and falls from a height 20% each, football injuries 8%, other sports 11%, and miscellaneous 10%.

There is a clear division of patients into a group aged 8 years or less with exclusively upper cervical injuries, and an older group with pancervical injuries. In the younger children, the injuries involved soft tissue (subluxation was seen more frequently than fracture), and tended to occur through subchondral growth plates, with a more reliable union than similar bone injuries. In the older children, the pattern and etiology of injury are the same as in adults. The entire cervical axis is at risk, and there is a tendency to fracture bone rather than cartilaginous structures.

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Eric Zimmerman, John Grant, W. Michael Vise, David Yashon and William E. Hunt

✓ Two patients with bursting fractures of the atlas vertebra are presented. The use of a halo apparatus as an effective alternative to bedrest and cervical traction in these patients is discussed. Polytomography was helpful in establishing an accurate diagnosis.