Thomas H. Shawker

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The mechanisms previously proposed for the progression of syringomyelia associated with Chiari I malformation of the cerebellar tonsils are controversial, leave many clinical observations unexplained, and underlie the prevalence of different operations currently used as initial treatment. To explore the mechanism of syringomyelia progression in this(More)
Focal hepatosplenic candidiasis has been recognized with increasing frequency in recent years. We reviewed the cases of eight patients seen between 1982 and 1985, and information on 60 patients whose cases have been reported in the world literature. The characteristics of focal hepatosplenic candidiasis include persistent fever in a neutropenic patient(More)
To facilitate the noninvasive preoperative localization of islet cell tumors less than 15 mm in diameter, the authors examined the use of calcium as an insulin secretagogue in an arterial stimulation venous sampling (ASVS) technique. In four patients with episodic hypoglycemia, calcium gluconate (0.01-0.025 mEq Ca2+/kg) was injected directly into branches(More)
The purpose of the present study was to evaluate prospectively the value of intraoperative ultrasound scanning (IOUS) in localizing islet cell tumors by comparing results of IOUS to those of palpation during 44 consecutive laparotomies for gastrinoma (36) or insulinoma (8). All patients had preoperative radiographic imaging studies and selective venous(More)
OBJECT Syringomyelia causes progressive myelopathy. Most patients with syringomyelia have a Chiari I malformation of the cerebellar tonsils. Determination of the pathophysiological mechanisms underlying the progression of syringomyelia associated with the Chiari I malformation should improve strategies to halt progression of myelopathy. METHODS The(More)
Intraoperative ultrasonography has not been used previously to locate an insulinoma that was not surgically palpable or that could not be seen by selective arteriography. In this report we described a patient with an insulinoma localized to the pancreatic head identified by transhepatic portal venous sampling but not by selective arteriography or palpation.(More)
Patients with recurrent or persistent primary hyperparathyroidism have increased operative risk because of scarring in the operative field and the frequent presence of an ectopic gland. Preoperative imaging studies will identify the hyperfunctioning parathyroid gland in the majority of circumstances. The best types or combination of imaging tests has not(More)
Eight immunocompromised cancer patients with tissue-proved candidiasis underwent serial abdominal ultrasound (US) and computed tomography (CT). At US, four patterns of hepatic and splenic candidiasis were recognized, one of which the authors call a "wheels-within-wheels" pattern. In addition, periportal linear areas of increased attenuation, possibly(More)
Management of patients with biochemical evidence of insulinoma and negative preoperative imaging studies (occult) tumors is controversial, varying from primarily medical management to aggressive, blind nearly total pancreatectomy to extirpate the tumor. Since 1982, 12 consecutive patients with occult insulinoma underwent preoperative portal venous sampling(More)
Using noninvasive real-time ultrasound, tongue movement was visualized during single swallowing in eight normal subjects and one neurologically impaired patient with dysphagia and chronic aspiration. In normals, a clearly defined muscular wave of the tongue, traveling at approximately 15 cm/sec, carried a 5-cc test water bolus posteriorly. In the patient(More)