Current approaches to hypothalamic-pituitary radiology

Currently computed tomography (CT) is the primary imaging modality for pituitary and hypothalamic lesions, although it is probable that NMR will supersede it. The range of size of the normal pituitary is considerable, with relatively larger glands occurring in adolescence and females of childbearing age. Asymptomatic microadenomas and cysts are not infrequent so that small low-density lesions in a gland on the borderline of enlargement can only be assessed in relation to clinical presentation. Patients presenting with clinical or biochemical evidence of abnormal pituitary hormone secretion or with an enlarged sella but without evidence of any neurological abnormality are likely to have either a small pituitary tumour or an empty sella and are investigated by thin section high resolution CT to produce coronal and sagittal images. Visual defects, paralysis of ocular muscles or hypothalamic disturbances, in the absence of clinical evidence of hypersecretion of pituitary hormones, may be due to a variety of pathologies. These cases are elucidated by plain plus contrast-enhanced CT, supplemented as necessary by angiography and computed cysternography after injection of non-ionic contrast media. Hypothalamic disturbances may occasionally complicate cerebral malformations which are also elucidated by cranial CT.

Documentation of a new contrast medium for the subarachnoid space. Demands, design and results from the first multicentre trial with iohexol

The first clinical trial with the non-ionic contrast medium iohexol (Omnipaque) in lumbar myelography was performed as a multicentre investigation of a total of 88 included patients. The design of the comprehensive clinical trial program is presented and the necessity of using such an extensive clinical trial program in the early stage of the investigation is discussed. This comprehensive monitoring did not reveal any serious or persistent side effects. The documentation on the safety of the drug encourages further clinical trials.

Clinical trial of iohexol in lumbar myelography

Iohexol containing 180 mg I/ml was used in 20 patients for lumbar myelography. By using an adequate volume up to a maximum of 15 ml, satisfactory films were obtained in all cases. Minor or moderate adverse effects occurred in 4 patients. There were no changes in vital signs or neurologic examination related to the examinations. No patient had difficulty with concentration, personality changes or seizures. Later encephalographies performed in all patients before and during 24 h after the iohexol injections, showed no seizure or abnormal activity or any significant change. Repeated lumbar puncture was performed in 9 patients 24 h after the injection of iohexol. One of these, a patient with symptoms due to disc prolapse, whose CSF was abnormal before the myelography, had a slightly increased cellular response. There was no significant change in any of the other patients. Iohexol is a very satisfactory contrast medium for myelography and compared favorably with other non-ionic contrast media.

Clinical trial of iohexol for lumbar myelography

Iohexol containing 180 mg I/ml was used in 80 patients for myelography by lumbar injection. By using an adequate volume, between 10 and 20 ml, satisfactory films were obtained in all cases. Minor adverse effects occurred in 12 patients (15%) and were more frequent in women than men; they were headache (5), nausea (3), vomiting (2), back or limb pain (5), and skin rash (1) and were of minor degree in 10 cases, moderate in the other two and lasted more than 24 h in only one case. There was no change in vital signs or neurological examination related to the studies. No patient suffered difficulty with concentration, personality change or seizures. Electroencephalograms performed on 21 patients before and during the 24 h after iohexol showed no seizure or focal activity or any significant change. Repeat lumbar punctures were performed on ten patients during the 24 h following myelography. One of these, a patient with symptoms due to disc prolapse, whose CSF was abnormal prior to the myelogram, showed a slightly increased cellular response. There was no significant change in any other case. Iohexol is a very satisfactory contrast medium for myelography and compares favourably with other non-ionic contrast media.

Diagnosis of masses presenting within the ventricles on computed tomography

The radiological and clinical features of 90 histologically verified intraventricular masses were reviewed. Computed tomography (CT) and plain X-rays were available in all and angiograms in over half the cases. The localisation, effects on the adjacent brain substance and the presence and degree of hydrocephalus was evident on CT. Two-thirds of colloid cysts presented as pathognomonic anterior third ventricular hyperdense masses and the other third were isodense; an alternative diagnosis should be considered for low density masses in this situation. Plexus papillomas and carcinomas mainly involved the trigone and body of a lateral ventricle of young children and caused asymmetrical hydrocephalus; the third ventricle was occasionally affected also in children and the fourth ventricle more frequently and usually in adults. Two-thirds were hyperdense, one-third of mixed or lower density. The meningiomas were dense trigonal tumours of adults generally arising in the choroid plexus, but two tentorial meningiomas passed through the choroidal fissure and caused a predominantly intraventricular mass. Gliomas frequently thickened the septum and generally involved the frontal segments of the lateral ventricles. They may be supplied by perforating as well as by the choroidal arteries, which supply most other vascularised masses within the ventricles. Only 10% of our cases did not fall into one of the former categories; these included low density non-enhancing dermoid or epidermoid tumours and higher density enhancing metastatic or angiomatous masses.

Results of treatment of arteriovenous fistulae with the Debrun technique

In a series of 54 caroticocavernous fistulae and eight vertebrovertebral fistulae, clinical cures were obtained in 46 of the caroticocavernous fistulae and in all of the vertebrovertebral fistulae using the Debrun coaxial catheter detachable balloon technique. Most low vertebrovertebral and about half of the posteriorly opening caroticocavernous fistulae were successfully treated by the safe transvenous approach. Technical difficulties were not infrequent but were overcome in most cases. In nine cases the artery was occluded with the fistula and in two others minimal residual shunt persisted, progressing in one to a symptomatic aneurysm. Five caroticocavernous fistulae in which the balloon could not be satisfactorily sited were not closed, and another caroticocavernous fistula closed spontaneously after a failed transvenous approach. Displacement of balloons during detachment reopened two caroticocavernous fistulae. One of these had to be closed by transcranial surgery; the other balloon embolized the middle cerebral artery, was surgically removed, and a mild hemiparesis persisted. Premature balloon detachment in a grossly atheromatous artery caused the only other major complication and contributed to the death of an 87-year-old patient. The most frequent complications were transient ophthalmoplegias. Minor modifications to the catheter system should reduce the incidence of such catastrophes and complications.

Cord shape and measurements in cervical spondylotic myelopathy and radiculopathy

A combined clinical myelographic and computed myelographic study was performed in 30 patients with cervical spondylotic myelopathy; computed myelography was also performed in 16 control patients. Good correlation was found between degree of deformity of cross-sectional shapes of the cord and the outcome of surgery, and measurements of anteroposterior diameter and area of the cord seemed helpful in this preliminary study. There was also reasonably good correlation between the clinical features when grouped according to specific tract involvement, and the pattern of deformity shown by the abnormal cross-sectional cord shapes.

Subarachnoid-pleural fistula-case report and review of literature

The investigation and surgical closure of a subarachnoid pleural fistula following direct trauma to the dorsal spinal theca and spinal cord are described and a review of the literature on spinal subarachnoid-pleural fistula is presented.

Whipple's disease confined to the nervous system

Whipple's disease confined to the nervous system occurred in a 36-year old woman who presented with grand mal seizures and dementia. There was no evidence of extracerebral involvement and the jejunal biopsy was negative before treatment. Multiple enhancing lesions on CT scan progressed despite therapy with minocycline and prednisone, but resolved on treatment with tetracycline. The dementia did not progress while she was on antibiotic therapy. Whipple's disease should be considered as a treatable cause of progressive dementia even in the absence of an abnormal jejunal biopsy.

Benign communicating hydrocephalus in children

A review was performed of the computed tomograms (CTs) of 500 children which had been reported as showing widening of the supratentorial subarachnoid spaces with normal cerebral substance. On the basis of this a radiological diagnosis of cerebral atrophy had been made in all but five, who were said to have megalencephaly. From these, the children with large or abnormally enlarging heads, but normal or only slightly enlarged ventricles, were selected; there were 40 such cases (8%). The clinical condition either improved or remained stable over a period of 2 years; in the majority the scan abnormality regressed (22.5%) or remained static (67.5%). In three cases there was slight progression of the CT changes before stabilisation, but only one case developed classical communicating hydrocephalus necessitating a shunt procedure. This condition is a generally benign and mild form of communicating hydrocephalus, for which an aetiological factor was apparent in about two-thirds of the cases studied.

Clinical features, investigation and treatment of post-traumatic syringomyelia

Thirteen patients who sustained spinal cord trauma causing persisting disability, developed new symptoms, the chief one of which was severe pain unrelieved by analgesics. The clinical diagnosis of post traumatic syringomyelia was confirmed in each case by means of myelography, as well as endomyelography in seven patients. In every case exploration of the spinal cord syrinx was performed. Ten patients were troubled by severe pain while three patients were mainly subject to altered sensation in the upper limbs. Of the six patients who had initially sustained complete cord transections, three were treated by cord transection and three were treated by syringostomy. The seven patients who sustained incomplete cord lesions were all treated by syringostomy. The patients who initially sustained incomplete sensory motor spinal cord damage had a better symptomatic response to surgery than hose who had sustained a complete spinal cord lesion. The ten patients whose main symptom was severe pain were completely relieved of their symptoms by surgery.

Percutaneous transvenous balloon occlusion of arteriovenous fistula

The closure of arteriovenous fistulas, using a balloon catheter introduced through the vein draining the fistula, is discussed. The application of this method to the closure of an iatrogenic vertebrovertebral fistula is described.