Lumbar myelography with metrizamide

Myelography with iohexol (Omnipaque); a clinical report with special reference to the adverse effects

One thousand myelographies (370 cervical, 77 thoracic and 553 lumbar examinations) with iohexol (Omnipaque) were performed in 922 patients. No convulsions were seen. Transient hallucinations were reported in one patient. Headache occurred in 38%. The highest frequency of headache (52%) was reported following cervical myelography with lumbar puncture technique, placing the patient horizontally after the examination. The lowest frequency (20%) occurred following cervical myelography with the C1-C2 puncture technique, placing the patient in bed with the head end elevated 20 degrees. Lumbar myelography was performed on an out-patient basis in 243 patients. The frequency of headache was slightly higher (49%) in this group than in the other lumbar myelography patients (34-44%), but no serious complications were seen.

Side effects after diagnostic lumbar puncture and lumbar iohexol myelography

A prospective, controlled study was performed to compare side effect incidences after lumbar iohexol myelography (n = 97) and diagnostic lumbar puncture (n = 85). No significant side effect incidence differences (iohexol vs. controls) were found regarding number of patients with any side effect (63 vs. 73%), headache (44 vs. 54%), nausea, dizziness, visual, auditory, or psychic symptoms. Early-onset headache occurred significantly more often in the iohexol group (17 vs 5%), while postural headache occurred most frequently after lumbar puncture (25 vs. 41%). These results suggest that apart from the slight early-onset headache, most side effects after lumbar iohexol myelography are related to the puncture per se, not to the contrast agent.

Lumbar myelography with Omnipaque (iohexol)

Lumbar myelography with iohexol (Omnipaque) was performed in 103 consecutive adult patients with low back pain or sciatica. The patients were observed for 48 h with registration of possible adverse reactions. Mild or moderate transient side effects were recorded in 24 patients. No serious adverse reactions were noted, and EEG recorded in 25 patients showed no changes.

EEG changes 24 hours after myelography with metrizamide

A prospective study of EEG changes following metrizamide myelography was made on 34 patients aged 17-79 years. EEGs were recorded just before and 22-26 hours after myelography. Usually 8-10 ml of metrizamide was injected by either lumbar or lateral cervical puncture. The concentration of metrizamide was relatively high. EEGs were abnormal in 15 out of the 20 patients whose baseline EEGs were normal. EEGs deteriorated in 10 of the 14 patients whose control tracings were abnormal. High voltage delta activity and/or a great deal of theta activity were common abnormalities. Three patients showed triphasic waves. No relationships were found between the EEG changes and clinical variables. But central nervous system involvements by metrizamide tended to be accompanied by a severe EEG slowing.

A double-blind clinical trial of iopamidol versus metrizamide for lumbosacral myelography

A double-blind study was performed to compare metrizamide with the new iodinated water-soluble nonionic contrast medium, iopamidol, for conventional and computerized tomography lumbosacral myelography. Both contrast agents were used in 30 patients, and were equivalent in terms of image quality and clinical accuracy. Headaches and nausea were less severe using iopamidol. The most striking difference was found in adverse neurobehavioral reactions and associated electroencephalographic abnormalities, which were noted in 17% of the metrizamide group but were not seen with the use of iopamidol. Iopamidol appears to be superior to metrizamide for intrathecal applications. An explanation of the differential neurotoxicity is provided.

Myelography with iopamidol, a nonionic water-soluble contrast medium: incidence of complications

A review of immediate and delayed side effects noted in a consecutive series of 1,138 myelograms made with Iopamidol in the Services of Neuroradiology of various hospitals and university clinics at Pavia, Perugia, Vicenza, and Parma (all in Italy). The contrast was administered by lumbar spinal route at iodine concentrations of 200, 300 and 370 mg/ml, in amounts varying from 5 to 20 ml depending on segments being examined and extant clinical indications. The incidence and characteristics of complications (headache, nausea, vomiting, evidence of radicular irritation, etc.) were assessed in relation to examination technics, segments of spine being explored, iodine concentrations, and amounts of contrast injected.

Asterixis and encephalopathy following metrizamide myelography: investigations into possible mechanisms and review of the literature

Marked asterixis occurred in two patients following metrizamide myelography. One also suffered generalized seizures and the other had severe stuttering speech for seven days. The spectrum of toxic manifestations of metrizamide is reviewed with emphasis on the unusual lethargy and other depressive effects seen with this relatively safe agent. The hypothesis that metrizamide exerts a ouabain-like effect on the cortical surface was tested. Metrizamide in concentrations as high as 20 mM had no inhibitory effect on rat cerebral K+-para-nitrophenylphosphatase, a partial reaction of (Na+K+)-adenosine triphosphatase. Because metrizamide is a 2-deoxyglucose analogue, a competitive inhibition of hexokinase at the first step in glycolysis was also postulated. Metrizamide was found to competitively inhibit commercial (microbial) hexokinase. The Michaelis constant for glucose rises from 0.13 to 0.25 to 0.33 to 0.91 mM in the presence of 0, 0.4, 1.0, and 2.0 mM metrizamide, respectively. Since the concentration of metrizamide over the cerebral cortex after routine myelography may be approximately 50 mM compared with a glucose concentration of only 3.6 mM (65 mg/dl), it is postulated that impaired brain glucose metabolism may be responsible for some of the toxic effects of metrizamide.

Confusion, dysphasia, and asterixis following metrizamide myelography

A patient exhibited confusion, dysphasia, and striking asterixis 18 hours after metrizamide myelography. The symptoms lasted for a day and a half. While metrizamide is a useful contrast medium, side effects are not unusual and can, on occasion, be quite severe.

Metrizamide lumbar epidurography with Seldinger Technique through the sacral notch and selective nerve root injection

Lumbar epidurography serves as an important radiographic procedure in the evaluation of patients with equivocal myelography and confusing or non-diagnostic physical findings. It is particularly valuable in patients with a wide ventral epidural space secondary to previous surgery, arachnoiditis or on a congenital basis. Several techniques and various contrast agents have been employed for the procedure. A pure Seldinger technique with a caudal approach through the sacral hiatus and injection of metrizamide gives excellent visualization of the epidural space and nerve root sleeves. The proper concentration of metrizamide is crucial for optimal results. Lateral, AP, and AP oblique radiographs, occasionally combined with lateral, complex motion tomography, clearly demonstrate the root sleeves and ventral epidural space. CT scanning, with present technology, does not provide the necessary detail for evaluating the epidural space.

Absorption of a non-ionic contrast agent from cerebrospinal fluid to blood

Intrathecal injection of a non-ionic contrast agent in the lumbar area of rabbits resulted in: (1) a rapid rise in blood iodine level with a maximum after 23-46 min; (2) low concentrations in cisterna magna during the observation period (24 h); and (3) complete or almost complete disappearance of visible contrast medium on the radiographs within 30 min. This indicates that after injection in the lumbar area of the rabbit most of the contrast medium absorption takes place from the lumbar area. Similar injections in cisterna magna showed the following: (1) a slow rise in blood level with a maximum after 150-275 min; (2) little or no disappeared of visible contrast medium on the radiographs within the first hour. This indicates that in the rabbit the absorption from the subarachnoid space of the spine takes place at different rates dependent on the level at which the injection has been made and the area of deposition of contrast medium.

The effect of metrizamide on the electroencephalogram: a prospective study in 61 patients

A prospective study was made of changes in the electroencephalogram after the use of metrizamide for myelography and posterior fossa cisternography in 61 patients (62 studies). The EEG changed in 21 patients (34%); 3 of these had had previously abnormal records, and the abnormalities were accentuated on the second recording. Eight developed paroxysmal activity, including spike and wave in 1. EEG changes appeared 24 to 48 hours after the use of metrizamide in 6 patients whose intervening EEGs were normal. The percentage of records that changed tended to increase as metrizamide was brought to more rostral levels. Symptoms following the use of metrizamide were reviewed in 58 patients. Although there were no seizures in the present series, seizures did occur with subsequent use of metrizamide in 3 other patients at our institution. Previous reports may have underestimated the frequency of EEG changes after metrizamide since these may require 24 to 48 hours to develop. The appearance of such activity suggests that the use of metrizamide in patients with known seizure disorders, the anatomical level to which metrizamide is brought during radiography, removal of contrast medium, and further investigation of premedication with anticonvulsants all require careful consideration when use of metrizamide is being contemplated.

Cervical metrizamide myelography by lumbar puncture

Cervical myelography with metrizamide administered by a lumbar puncture is described. Diagnostic information in the cervical region was obtained in 8 of the 8 patients studied. No major complications were encountered.

Clinical evaluation of metrizamide for neuroradiology in chilren

Metrizamide is a nonionic water-soluble contrast medium for neuroradiological studies that is less irritating to the nervous system than other water-soluble agents. Studies in adults have shown that metrizamide has advantages over currently available media, but experience with children has been limited. Sixty-two children have had myelography or ventriculography using metrizamide. The children ranged in age from 11 days to 22 years. Technically satisfactory studies were obtained in every patient. No major complications were encountered. Minor side-effects included headache in 11 children (18%), mild nausea or vomiting in 16 children (26%), and fever in 4 children (6%). Seizures did not occur. One infant in the study subsequently died of unrelated problems; there was no evidence of arachnoiditis at postmortem examination. Metrizamide is a safe, effective contrast medium for neuroradiological use in children.

Experimental evaluation of watersoluble contrast media for myelography

An experimental method for testing contrast media for myelography was developed and used to compare three watersoluble contrast media, iocarmate meglumine, iothalamate meglumine and metrizamide after suboccipital myelography in 120 rabbits. A further 71 rabbits served as controls. Iocarmate and iothalamate caused vigorous convulsions; metrizamide did not. Examination of the CSF revealed an acute pleocytosis after installation of the contrast media and after cisternal puncture with injection of hypertonic saline. Histological examination of the spinal cord, nerve roots and meninges revealed pathological changes in 1 or 32 unoperatec controls (3%). Leucocyte infiltrations were found in the meninges, nerve roots and spinal cord of about 20% of the animals after myelography, after cisternal puncture without injection or with injection of hypertonic saline. There were no significant quantitative differences between the experimental groups. Degenerative changes were seen only after myelography. No meningeal fibrosis was demonstrated. An abnormal leucocyte count in the primary CSF influenced the incidence of histological changes, indicating that only rabbits with CSF cell counts within normal limits should be used in future experiments.

A clinical trial of Amipaque in lumbar myelography

Three hundred lumbar myelographies using a new water-soluble, non-electrolytic contrast medium, Amipaque, were assessed with reference to: 1) the correlation between radiological and operative diagnosis; 2) the side-effects during and after the myelography. Myelograms of the same reliability as those obtained with other water-soluble contrast media were obtained. However, arachnoiditis as sequelae to previous myelography with oil-soluble and earlier water-soluble contrast media prevented the correct evaluation in some cases. Spinal anaesthesia was not necessary. There was no case of muscle spasms or other serious complication. Eight patients who were re-examined with Amipaque more than two months later revealed no evidence of arachnoiditis as sequelae to the first Amipaque myelography.