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This study reviewed the technical complication of 112 cases of lateral C1-2 puncture myelography for cervical spinal cord disorders. Spinal cord puncture and contrast injection, puncture between the occiput and C1, and blood vessel puncture were the main complications. These principally depended on the positioning of the patient's neck (hyperextension) and misdirection of the x-ray beam. For preventing major arterial puncture, the authors also reviewed 164 vertebral angiograms and determined the pathway of the vertebral arteries and the incidence of anomaly.

This study was conducted to determine whether prescribed ambulation in post-myelography patients injected with metrizamide would significantly decrease the incidence of post-myelography headache. Eighty patients undergoing metrizamide lumbar myelography were assigned to two groups of 40 patients each. The control group was restricted to complete bedrest for the immediate 24-hour period following myelography. The experimental group participated in a prescribed regimen of ambulation every four hours following myelography. Data were collected during the immediate 24 hours post-myelography. Subjects were assessed as to the presence or absence of headache at four-hour intervals during data collection. At the end of the 24-hour period post-myelography, the Visual Analogue Pain Intensity Scale was administered to subjects with documented subjective complaints of headache pain. The nonambulatory group had a 62.5% incidence of headache while the ambulatory group revealed only a 42.5% incidence of post-myelography headache. The z test was used to test the first research hypothesis that there would be a higher incidence of post-myelography headache in the nonambulatory group than in the ambulatory group. The calculated z = 1.79, p less than .05; therefore, it was possible to conclude that the number of nonambulatory patients with headache was significantly higher than the number of ambulatory patients with headache. The second research hypothesis, that the severity of post-myelography headache would be greater in the nonambulatory group than in the ambulatory group, was tested using the Student's t test. The calculated t = .6492, p greater than .05. The subjects' self-perception of the severity of headache was not significantly different in the nonambulatory than in the ambulatory subjects.

Two hundred and fifty-six myelograms in 192 patients were following by repeat myelography using a water-soluble contrast medium. The films of these re-examinations were analysed for signs of meningeal changes. Adhesive arachnoiditis had developed in five of 46 cases after methiodal sodium, in 24 of 96 cases after iothalamate meglumine, in seven of 12 cases after iocarmate meglumine, in seven of ten cases after iodophendylate, but in none of 90 cases after metrizamide. Dose of contrast medium, observation time and protein concentration of the CSF were found to be factors of importance for the development of adhesive arachnoiditis.

A series of lumbar myelographies -- 105 in 98 patients - was carried out with water-soluble Metrizamid (Amipaque R) in a concentration of 170 mg I/ml and showed side-effects in 32% and a quality of contrast similar to that of other water-soluble contrast media used before. The side effects were mild, of short duration and needed no treatment. There were no epileptic fits, tonic or clonic carried out 1 - 12 months later showed no signs of arachnoiditis. Dangers of more serious complications appeared to increase, the higher the level of injection into the spinal canal. A short survey of contrast media used in myelography and earlier experience of experimental or clinical side effects caused by Medtrizamid in myelography follows.

The use of water-soluble contrast media for the thoracic myelography has become possible with the introduction of Metrizamide (Amipaque). A modification of the technique used with oily contrast media results in excellent demonstration of detail of intraspinal structures and of pathological changes. The medium is well tolerated and does not cause irritation of the spinal cord; the results must be regarded as excellent.

To test the validity of our impression that in the absence of objective clinical evidence of nerve-root impingement there is a disproportionately high incidence of complications associated with myelography, the results in 248 patients were reviewed retrospectively and those in 110 were studied prospectively. Of all 358 patients, 53 per cent had complications after myelography with injection of metrizamide, of which headache and nausea and vomiting were the most frequent. The incidence of complications in the 112 patients whose objective clinical and myelographic findings were consistent was compared with that in the 180 patients who had only subjective complaints and normal myelographic findings. The incidence of complications was 30 per cent in the former group and 70 per cent in the latter group, an almost twofold difference (p greater than 0.05). The 110 patients in the prospective study were asked to grade the intensity of their headache after myelography. Of the thirty-one patients with positive objective clinical and myelographic findings, ten complained of headache, which was mild in seven (70 per cent) and severe in three. Of the sixty patients with only subjective complaints, thirty-eight complained of headache, which was mild in twelve (32 per cent) and severe in twenty-six.

Diuresis by IV administration of 5% dextrose in a balanced electrolyte solution (BES) reduced the frequency of occurrence of postmyelographic seizures in dogs. In the first study, a single myelogram was obtained in 8 dogs without dextrose diuresis. Two of these dogs weighed greater than 15 kg and both had seizures after metrizamide myelography. The remaining 6 dogs weighed less than 15 kg and only 2 had seizures. Greater body weight may have increased the risk of postmyelographic convulsions. In a crossover study, myelograms were obtained in 12 dogs weighing 20 to 31 kg. Six dogs were given 5% dextrose in BES (20 ml/kg of body weight/hr [diuresed]) and 6 were given BES alone (10 ml/kg/hr [not diuresed]). When myelography was repeated 10 days later, the 6 dogs that had been given 5% dextrose in BES were given BES only and the 6 dogs that had been given BES alone were given 5% dextrose in BES. The frequency of convulsions after metrizamide myelography was lower when dogs were given dextrose (33%) than when they were not (100%).

Complex partial status epilepticus developed in two patients following myelography with metrizamide. The status epilepticus was manifested by confusion and complex motor symptoms, and electroencephalograms (EEGs) showed ictal activity alternating independently over both hemisphere. Immediate clinical improvement occurred with antiepileptic treatment, and to date no sequelae have been observed. Neither patient had a previous history of epileptic seizures, but both had preexisting EEG abnormalities.

A series of myelographies performed with a smaller than customary dose (3.75 g) of metrizamide was compared with a series using the larger customary dose. While little decrease in the incidence of headache and vomiting resulted from the decreased dose, there was a heartening drop in the incidence of psychoneurologic side effects. Little difference in diagnostic quality between the two series resulted when the contrast agent was injected close to the site of main interest, but total spinal canal myelography performed with the low dose is often inadequate.

When cervical myelography is required, the highest incidence of adverse effects usually supervenes. These effects are particularly important in patients with metastatic disease, post-cervical trauma and out-patients. Low dose hydrosoluble CT myelography imaging (300-500 mg I, total dose) can be accomplished by injecting the contrast medium when the patient is in the CT scanner via C1-2 puncture with a small needle (e.g. 25 gauge). Our method of accomplishing this was to use C-arm fluoroscopy performed with the patient either supine or prone and to transfer the patient with the needle in situ to the scanner. This was done with the patient on a portable exchangeable CT table top. Remarkably few adverse effects (transient mild headache in 2 of 22 patients) would appear to render this technique safe and useful.

Metrizamide, a major contrast agent for myelographic procedures, has rarely been reported to cause irreversible neurologic complications. The major transient neurologic alterations include neuropsychological reactions, generalized tonic-clonic seizures, and headaches. Two cases of irreversible spinal neurologic deficits resulting from metrizamide myelography are reported, and the factors that may increase the risks of complications in metrizamide myelographic studies are discussed, including preexisting dehydration, patient positioning, and the concentration of contrast agent.

We measured several F- and averaged F-response variables before and after lumbar myelography with metrizamide and iohexol in order to evaluate possible effects of these contrast agents upon proximal motor nerve conduction and motor neurone exitability. Averaged F-response onset latency increased while both duration and amplitude decreased after iohexol myelography. These changes were interpreted as signs of minor neural depression but they were slight and without clinical significance in the individual patient. F-response variables were not affected after metrizamide myelography.

Water-soluble contrast media, which have been employed in the examination of the lumbar spinal canal for 30 years, can sometimes result in severe complications, such as arachnoiditis, epileptic seizures, and myoclonic spasm. These complications have been seen less frequently since the advent of metrizamide, a new non-ionic water-soluble contrast medium. However, a further neurological complication has now arisen--mental disorder, varying in kind and degree; for example, organic psychosis and perceptual disturbance. Some characteristic cases are described. A series of 75 patients, all of whom received varying amounts of metrizamide for the purpose of cervical, thoracic and lumbar myelography, has been studied. Seven patients were found to have a pronounced organic psychosis and three patients had visual illusions or hallucinations. It is suggested that there is some degree of correlation between the total amount of iodine received and patient age. By careful enquiry and examination, similar disturbances were also found some 4-8 h after myelography with other water-soluble contrast media.

Cervical myelography by means of lumbar application of metrizamide was performed on 110 patients. The exploration technique, the results, the quality of the myelograms, and the side effects observed are discussed. The most frequent complaint was headache. There were also cases of vertigo, vomitus, pain in the back and legs, and one case of tachycardia. Complications of a more serious nature, in particular epileptic seizures, did not occur.

The adverse reactions from aqueous myelography in 88 primates were reviewed to determine what factors increase the risk of complications. Seventy-four iocarmate (Dimeray) myelograms were obtained on 41 animals, and 90 metrizamide (Amipaque) myelograms were obtained on 47 animals. The risk of seizures and death from iocarmate myelography was higher than from metrizamide myelography. In animals that had previous myelograms or showed evidence of arachnoiditis, the risk of complications from aqueous myelography was higher. Additional precautions may be indicated if aqueous myelography is performed in patients with arachnoiditis.

The relationship between various technical factors and the incidence of side effects, particularly headache, following metrizamide myelography has been investigated in 203 patients. The higher incidence of side-effects which has been demonstrated in females was of statistical significance, whilst the higher incidence which followed cervical myelography via lateral C1-2 puncture was not. None of the other parameters considered (needle size, weight of iodine injected, or patient's age) had any influence. The greater frequency of side-effects in women cannot be readily explained, though it may reflect the higher incidence of headaches which is said to occur in females following diagnostic lumbar puncture. The results of this study suggest that metrizamide is no more likely to produce headache than other myelographic contrast agents, or indeed, diagnostic lumbar puncture.

Differences in frequency of postmyelographic adverse reactions were analyzed with respect to sex and age in a prospective study including 1026 patients injected with metrizamide and 739 injected with iohexol. Regardless of the type of contrast medium or myelography, all types of adverse reactions were 1.4-3.8 times as frequent in women as in men. Most of the differences were statistically significant. Headache was more frequent, while vomiting and dizziness were less frequent in both women and men aged 26-50 years compared with those over 50 years of age. Dizziness and increased low back pain were consistently reported spontaneously by the patients less frequently than emerged via formal interview. The large differences between the sexes suggest that further research on contrast media toxicity would be best performed with separation of the data by gender.

In patients with lumbago-sciatica levomepromazine is a potent supplement to analgetics in pain treatment. The hypothesis that neuroleptics increase the risk of epileptic seizures after metrizamide myelography was not confirmed in a series of 77 patients, 26 with and 51 without levomepromazine medication, before and after lumbar metrizamide myelography. No differences existed between the groups with regard to the appearance of EEG abnormalities such as slow waves or spikes. Mild side effects were more frequent in the levomepromazine group, except nausea and vomiting. Lumbar metrizamide epidurography in 30 patients did not cause any abnormal EEG.

Metrizamide is a water-soluble contrast medium used as a diagnostic tool in myelography and cisternography. Despite its accepted safety, its use has been associated with generalized motor seizures, and several cases of this toxicity have been reported. Risk factors include phenothiazine ingestion, seizure history, and large doses of the contrast material. Abnormal electroencephalographic wave patterns, as well as seizure activity, are less frequent after cisternography than myelography. A case of a metrizamide-induced generalized motor seizure following cisternography is reported in a patient with none of the above risk factors. The need for a thorough medication history and the use of prophylactic anticonvulsants in selected patients is discussed.

Sixty-three myelographies were performed with Amipaque. Remyelography after an interval of longer than 2 months showed that in one case there was progression of an arachnoiditis which had already been present during the first Amipaque study. In one other case there were minimal, unilateral nerve root changes caused by an intervening operation. Altogether 269 remyelographies without secondary late reactions are registered. Two cases of increased arachnoid changes from a previous myelography with another contrast medium hardly can be due to Amipaque.

The effect of dehydration on the incidence of side effects from metrizamide myelography was studied. One hundred consecutive patients scheduled for myelography fasted overnight and were then randomly divided into two groups. Group I received 2 liters of fluid intravenously just prior to myelography; Group II did not. Both groups were studied in the standard manner, using 170 mg l/ml of metrizamide. Side effects were recorded 24 and 48 hours after the procedure. Headaches, vomiting, and some other side effects were less common and less severe in the hydrated group. Clear liquids given orally or intravenous fluids are recommended prior to myelography to minimize side effects.

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.

The frequency of adhesive arachnoiditis following lumbar radiculography with methiodal sodium (95 patients), methylglucamine iocarmate (20 examinations in 18 patients), and metrizamide (77 examinations in 73 patients) was found to be 29% in patients who were not operated on between methiodal studies and 48% in those who were operated on. With both methylglucamine iocarmate and metrizamide the frequency was very low. No changes indicating adhesive arachnoiditis were seen with these media in patients who were not operated on between radiographic examinations.

Diagnostic quality of radiographs and adverse reactions associated with the use of metrizamide and iohexol as contrast agents in lumbar myelography were compared in a prospective randomized double blind study in 350 patients at seven centers. The contrast media were administered in comparable volumes at a concentration of 180 mg I per ml. Overall quality of radiographic visualization was graded good or excellent in 95% of 175 metrizamide studies and in 98% of 175 iohexol studies. Ninety-three patients examined using metrizamide (53%) and 130 patients examined using iohexol (74%) experienced no discomfort during or after myelography. Postmyelographic headache was associated with 38% of metrizamide examinations and 21% of iohexol examinations. Nausea and vomiting were also more common with metrizamide. Five patients examined using metrizamide (3%) experienced transient confusion and disorientation following lumbar myelography. No such reactions were observed following iohexol myelography.

The myelographic contrast agent, metrizamide, causes a temporary confusional state in many patients. Since metrizamide is a 2-deoxyglucose analogue, it was tested for inhibitory effects on glucose metabolism. The Michaelis constant (Km) of human brain hexokinase for glucose rose from 0.039 to 0.24 and 0.47 mM with final metrizamide concentrations of 0, 16 and 32 mM, respectively. The maximal velocity did not change. Since metrizamide is injected into the human CSF in concentrations of up to 780 mM, impairment of brain glucose metabolism can be expected. These effects could be largely counteracted if metrizamide were injected in a 100 mM glucose solution.

Two patients seen after lumbar myelography with metrizamide demonstrated transient confusion and asterixis. Metabolic etiologies were excluded. To our knowledge, these are the first reported cases of asterixis following myelography with metrizamide.

A prospective investigation of the adverse effects of myelography with metrizamide was performed in a series of 250 examinations in infants, children and adolescents. Adverse reactions occurred in 58 per cent of all cases. The majority of these were mild, and seemed to be due to the lumbar puncture alone. The frequency of the moderate and marked reactions was directly related to the total amount of metrizamide given and to the cranial extension of the examination in the spinal canal. No other circumstances around the procedure had any impact on the occurrence of adverse reactions.

One single clinical complication of grand mal seizures in conjunction with the subarachnoid administration of the new non-ionic contrast medium metrizamide is reported in a patient who had been taking chlorpromazine. An interaction between the contrast medium and phenothiazine derivatives is considered probable.

This prospective study of 90 patients after lumbar metrizamide myelography indicates that the semiupright position at 45 degrees in bed or early ambulation reduces postprocedure vomiting but does not reduce the frequency of headache. Ambulatory patients have less frequent nausea than patients kept in bed.

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.