Bilateral sequential inferior petrosal sinus sampling with corticotrophin-releasing hormone stimulation in the diagnosis of Cushing's disease.

OBJECTIVE: The demonstration of a central to peripheral ACTH gradient in a hypercortisolaemic patient is diagnostic of Cushing's disease. We tried to determine whether single blood samples for ACTH obtained sequentially from each of the inferior petrosal sinuses following human corticotrophin-releasing hormone (hCRH) stimulation can reliably establish such a gradient. DESIGN: Prospective study. PATIENTS: Seventeen patients with clinical and biochemical features of Cushing's syndrome. METHODS: After the administration of hCRH, the patients underwent bilateral sequential inferior petrosal sinus sampling, with a single blood sample obtained from each of the inferior petrosal sinuses sequentially, along with a peripheral venous sample. The petrosal sinus catheter was withdrawn immediately after obtaining a blood sample. Patients did not require indwelling catheters in the petrosal sinuses, nor heparinisation. RESULTS: Bilateral sequential inferior petrosal sinus sampling correctly identified a pituitary source of ACTH, as shown by a central to peripheral ACTH ratio >2, in all patients in whom the procedure was successfully carried out. All patients underwent transsphenoidal pituitary surgery resulting in remission. CONCLUSIONS: The simplified method of inferior petrosal sinus sampling, using a single sequential sample from each of the inferior petrosal sinuses, following initial hCRH stimulation, is as accurate as the more complex test using multiple bilateral simultaneous inferior petrosal sinus samples. It avoids the use of indwelling cerebral venous catheters and is therefore unlikely to cause brain stem damage.

Shrinkage of thyrotrophin secreting pituitary adenoma treated with octreotide.

Thyrotrophin secreting pituitary adenomas are a rare cause of recurrent thyrotoxicosis. We report on a 47 year old woman with an 8-year history of this condition. In this case the somatostatin analogue, octreotide, normalized thyroid hormone levels. It was associated with marked tumour shrinkage, with striking reduction of the suprasellar extension and improved appearances in the region of the left cavernous sinus shown by high resolution computerized tomography. Following surgery she developed a biochemical relapse which responded to the reinstitution of octreotide. On long term treatment she developed stomach cramps and gallstones. Octreotide was discontinued. We review previous reports of this condition and discuss the role of octreotide in its management.

Thin section computed tomography in the evaluation of naso-ethmoidal trauma.

We reviewed the computed tomography (CT) appearances, plain film radiographs and clinical findings of 17 patients who suffered fractures of the naso-ethmoidal complex. Six patients (35%) with diplopia were noted on CT to have lateral displacement of medial orbital wall fragments into the orbit (medial wall 'blow-in' fractures) leading to displacement of the globe or extra-ocular muscles. Medial displacement of ethmoid bone fragments (medial wall 'blow-out' fractures) with medial rectus entrapment was noted in a further two cases (11%) also. Multiple associated facial fractures were seen in all but one case with CT evidence of frontal bone fracture and intracranial injury in 12 (70%) patients. CT was judged to add valuable information to clinical findings and plain film radiography and was especially helpful where marked soft tissue swelling precluded detailed physical examination of the naso-orbital region. The CT features of naso-ethmoidal trauma are illustrated and discussed and the advantages of CT in the pre-operative evaluation of such injuries are emphasised.

Diagnostic and counselling difficulties using a fully comprehensive screening protocol for families at risk for tuberous sclerosis.

Tuberous sclerosis (TS) results from an autosomal dominant gene which exhibits variable expression and reduced penetrance. Although there are well established diagnostic criteria for TS, examination of first degree relatives can cause diagnostic criteria for TS, examination of first degree relatives can cause diagnostic problems with consequent difficulties in genetic counselling. Using an extensive, non-invasive protocol consisting of skin examination with Wood's lamp, cranial CT scan, specialist ophthalmological and dental examination, skeletal survey, and echocardiography, we have examined 56 first degree relatives of persons with TS. These consisted of 40 parents and seven sibs from 25 sporadically affected families and nine persons from seven multigeneration families. In seven of the apparently sporadically affected families, three mothers had echocardiographical findings consistent with one or more rhabdomyoma. In another, the mother's renal ultrasound showed evidence of single cysts in both kidneys. In a fifth family, the father had suggestive but not diagnostic features of TS on the cranial CT scan and skeletal survey. In the sixth family, the mother was found to have atypical calcification on CT scan. In a seventh instance a sib from a two generation family had echocardiographical evidence of a rhabdomyoma. Even though the proband in three of the sporadically affected families presented with fits, developmental delay, and depigmented patches, and therefore did not strictly fulfil the diagnostic criteria for TS, two mothers were found to have evidence of rhabdomyomata on echocardiography and the brother of the third had typical depigmented patches. Although the presently accepted diagnostic criteria for TS may not allow one to make a definitive diagnosis of TS in these relatives, we recommend that an extensive screening protocol be used to examine first degree relatives and that caution be used in counselling apparently unaffected members of families at risk for TS.

Identical twins with idiopathic external hydrocephalus.

Monozygotic twins with idiopathic external hydrocephalus are reported. Characteristic computerised tomographic features were associated with early gross motor delay and rapid improvement. A genetic basis for the syndrome is supported by its occurrence in identical twins.

Seizures after intravenous contrast media for cranial computed tomography.

Patients who had contrast medium-induced seizures were reviewed retrospectively in a consecutive series of 15,226 contrast-enhanced head CT examinations. An incidence of 0.19% was found. There was a strong association with a history of spontaneous seizure and with the presence of a structural intracranial abnormality. The contrast medium-induced seizures were short-lived and self-limiting or readily controlled with small doses of intravenous diazepam. They were clinically benign.

Iohexol vs. iopamidol for myelography.

Three hundred sixty-three patients undergoing myelography were examined on a random basis with either iohexol (179) or iopamidol (184). All patients underwent neurologic or psychological assessment before and after the examination; 100 patients also submitted to cardiovascular and hematologic tests. Sixty patients were examined with electroencephalography before and after myelography. Incidence and severity of side effects were carefully evaluated in all patients and, wherever possible, by an independent observer, who was not told which contrast medium had been used. Radiographic quality was independently estimated and graded and was equally adequate with both media. Both iohexol and iopamidol will, in competent hands, provide myelograms of good radiographic quality without producing any permanent adverse sequelae. Incidence and severity of adverse side effects were slightly but significantly less with iohexol than with iopamidol. Three patients of the 25 examined with iopamidol showed EEG evidence of neuronal excitability following myelography. None of the 35 examined with iohexol showed this change.

Cerebral embolism due to non-bacterial thrombotic endocarditis following pregnancy.

A case is reported of cerebral embolism with two very unusual features. Two bilaterally symmetrical haemorrhagic infarcts occurred, due to non-bacterial thrombotic cardiac valvular vegetations precipitated by the puerperium in a previously healthy young woman.

Myelography with lopamidol.

Two hundred patients who underwent myelography with iopamidol were independently assessed as to film quality and adverse side effects. Comparison was made with a similarly assessed group of 1,000 patients who underwent myelography with metrizamide. Diagnostic quality was generally excellent with both contrast media. The incidence of side effects, notably vomiting and headache, was significantly less with iopamidol but remains appreciable. More severe side effects may occasionally occur with either contrast medium.

Conservative management of pituitary prolactinomas; evidence for bromocriptine-induced regression.

Thirty-six women with sustained hyperprolactinaemia, 29 showing radiological abnormality of the pituitary fossa, were managed conservatively; 28 accepted bromocriptine treatment which controlled hyperprolactinaemia in all and was associated with improvement in the radiological appearance of the pituitary in 4 cases. Two of the 8 patients who did not accept bromocriptine showed radiological extension of the pituitary lesion; one showed radiological improvement. Bromocriptine should be regarded as a drug to control the pituitary tumour, not merely one which inhibits the endocrine effects.

Intracranial venous thrombosis in the first trimester of pregnancy.

We describe a fatal case of intracranial venous thrombosis occurring in early pregnancy. Such thrombosis usually occurs in late pregnancy or the puerperium but rarely during the first trimester of pregnancy. Computerized axial tomography suggested massive cerebral venous infarction. Necropsy findings showed not only cerebral venous thrombosis but also extensive pelvic and iliac vein thromboses. The relationship of cerebral venous thrombosis and pregnancy is discussed and the literature reviewed.

Angiography with Amipaque.

Amipaque (metrizamide) has proved considerably less uncomfortable than Urografin 310 M in 42 patients submitted to selective or subselective external carotid, subclavian, and spinal angiography. Two out of five patients undergoing selective spinal arteriography developed transient neurological complications during the injection of Urografin 310 M. On repeat examination with Amipaque no complications were encountered.