metrizamide and Seizures

The pharmacology, side effects, and possible drug interactions of metrizamide, a water-solulbe contrast medium for myelography, are reviewed. Metrizamide concentration in the brain reaches maximal levels two to six hour after lumbar injection, depending on dose and patient positioning, and is largely (55-96%) excreted from the body after 24 hours. Its lower neurotoxicity, compared with other water-soluble contrast agents, can be attributed in part to its undissociated, non-ionic nature. Common side effects, which include headache, nausea, and vomiting, occur to the same degree as with other myelographic contrast media. Reported data suggest that convulsions, which have occurred in a very small percentage of patients, are related to the amount of contrast medium reaching the brain which, in turn, is largely a factor of dose and examination technique. Although the risk of seizures is small, it is recommended that drugs that lower the seizure threshold (phenothiazine derivatives, butyrophenones, tricyclic antidepressants, and MAO-inhibitors) should be avoided 48 hours before metrizamide administration (if possible), should not be used to control nausea, and should not be resumed for 24 to 48 hours after the myelographic procedure. The value of premedication (e.g., with diazepam) to prevent seizures has not been established and is not recommended.

Topics: Antiemetics; Antipsychotic Agents; Behavior; Drug Interactions; Humans; Metrizamide; Myelography; Phenothiazines; Premedication; Psychotropic Drugs; Seizures

In contradistinction to all currently available water-soluble contrast media, metrizamide (Amipaque) is not a salt, but a substituted amide and therefore does not dissociate in solution. This unique property results in solutions of high iodine content yet with low osmolality. Metrizamide probably has a lower neurotoxicity than any other known water-soluble contrast agent. A clinical trial of metrizamide lumbar myelography in 201 patients in three clinical centres represents the first clinical assessment of this new contrast medium in the United Kingdom. The technique of the radiological procedure and the adverse reactions encountered are presented and discussed. There were no serious adverse effects: no muscle spasm or epilepsy. Minor adverse reactions--headache, vomiting and nausea occur with approximately the same frequency as with meglumine iocarmate: 43 percent of patients complained of headache. In 118 patients, the lower dorsal subarachnoid space was also examined with no increase in toxic reactions. It is concluded that metrizamide is a safe contrast medium for lumbar and lower dorsal myelography. Water-soluble media will probably largely replace oil products for these investigations. Further clinical trials are being extended to include examination of the upper dorsal and cervical subarachnoid space.

Topics: Arachnoiditis; Clinical Trials as Topic; Headache; Humans; Iodobenzoates; Metrizamide; Myelography; Nausea; Seizures

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.

Topics: Female; Humans; Male; Metrizamide; Middle Aged; Myelography; Needles; Punctures; Seizures; Spinal Cord Diseases; Spinal Cord Injuries; Vertebral Artery

Topics: Adult; Diagnosis, Differential; Humans; Injections, Spinal; Isoflurane; Male; Malignant Hyperthermia; Metrizamide; Myelography; Postoperative Complications; Seizures; Succinylcholine; Syndrome

The effect of fluid (5% dextrose in water or lactated Ringer's solution) administered intravenously on the development of seizures after cervical myelography with metrizamide was studied in 10 dogs. In a crossover experimental design, 8 dogs were used twice. Urine output was measured during the second part of the study to determine whether diuresis was a factor affecting seizure development. Dogs given 5% dextrose in water had significantly (P less than 0.05) fewer seizures than did dogs given lactated Ringer's solution. This was attributed to an increase in CSF glucose concentration and was not associated with diuresis.

Topics: Animals; Dog Diseases; Dogs; Glucose; Injections, Intravenous; Isotonic Solutions; Metrizamide; Myelography; Ringer's Lactate; Seizures

We examined the influence of various anesthetic drug combinations on the frequency of seizures in dogs after cervical myelography with metrizamide. Over a 12-month period, 78 dogs admitted to the teaching hospital for cervical myelography were assigned randomly to 1 of 6 anesthetic protocols. Myelography was performed, and the dogs were observed for signs of seizure activity after recovery from anesthesia. The person making the decision as to whether or not a dog had had a seizure was unaware of the anesthetic protocol that had been used. Preanesthetic treatment with pentobarbital (5.0 mg/kg) and maintenance of anesthesia with methoxyflurane significantly reduced the frequency of seizures (P less than 0.05). No reduction in seizure frequency was seen with any anesthetic protocol using halothane as the maintenance agent.

Topics: Anesthesia, General; Animals; Dog Diseases; Dogs; Metrizamide; Myelography; Seizures

We conducted a prospective study to examine the effect of pentobarbital administration on the development of seizures in dogs that had undergone cervical myelography with metrizamide while anesthetized with halothane. Thirty dogs scheduled for cervical myelography were assigned to 3 groups. Dogs in group 1 received no pentobarbital. Those in group 2 were administered pentobarbital (5 mg/kg, IM) before induction of anesthesia, and those in group 3 received pentobarbital at the end of the procedure when the anesthetic vaporizer was turned off. Anesthesia was induced with thiamylal sodium in all dogs and was maintained with halothane. Dogs that underwent surgery immediately after the myelography were not included in the study. A significant difference was not found among the 3 groups in terms of number of dogs that had seizures, mean body weight of the dogs, duration of anesthesia after injection of metrizamide, time from extubation to first seizure, volume of metrizamide injected, or clinician performing the myelography.

Topics: Anesthesia, General; Animals; Body Weight; Dog Diseases; Dogs; Halothane; Metrizamide; Myelography; Pentobarbital; Premedication; Prospective Studies; Seizures

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%).

Topics: Animals; Diuresis; Dog Diseases; Dogs; Female; Glucose; Male; Metrizamide; Myelography; Seizures

Topics: Cervical Vertebrae; Humans; Male; Metrizamide; Middle Aged; Myelitis; Myelography; Seizures; Spinal Osteophytosis; Substance-Related Disorders

A case of neurologic sequelae from intrathecal metrizamide is presented. The patient had a convulsion, became comatose, and transiently developed mutism and hemiparesis, with eventual full recovery. Metrizamide is generally safe, but side effects do occur, and they may require clinical attention and follow-up.

Topics: Adult; Coma; Conversion Disorder; Diagnosis, Differential; Female; Hemiplegia; Humans; Metrizamide; Mutism; Myelography; Seizures

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.

Topics: Cerebrospinal Fluid Rhinorrhea; Electroencephalography; Epilepsy, Tonic-Clonic; Female; Humans; Metrizamide; Middle Aged; Myelography; Risk; Seizures

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.

Topics: Adult; Brain Diseases; Headache; Humans; Male; Metrizamide; Middle Aged; Myelography; Nervous System Diseases; Seizures; Vomiting

Equimolar doses of iohexol and metrizamide (0.48 mmol/kg body weight = 185 mg I/kg), administered in solutions iso- and hyperosmolar to the CSF, were injected subarachnoidally into rabbits under pentobarbital anaesthesia. No excitative effects of iohexol were observed in the behaviour of the rabbits during a 3-h period immediately after the injection. Metrizamide caused significant, severe excitative effects, ranging from hyperexcitability to repeated generalized seizures. The frequency and severity of excitative effects were independent of the osmolality of the metrizamide solutions injected.

Topics: Anesthesia; Animals; Contrast Media; Female; Injections; Iodobenzoates; Iohexol; Male; Metrizamide; Muscles; Nervous System; Osmolar Concentration; Pentobarbital; Rabbits; Seizures; Subarachnoid Space; Triiodobenzoic Acids

Adverse neurobehavioral reactions have not been emphasized as a complication of metrizamide myelography. We encountered six such reactions in approximately 250 metrizamide myelograms. All reactions followed either cervical myelography or panmyelography via lumbar puncture. We also treated a single case of tonic-clonic seizure after intracranial spill of metrizamide in a patient without a history of seizure disorder, and a case of myoclonus following a thoracic metrizamide myelogram that showed a highgrade block. Metrizamide should not be used if an intrathecal block is suspected, or if the location to be studied makes intracranial spill difficult to avoid.

Topics: Adult; Aged; Electroencephalography; Extravasation of Diagnostic and Therapeutic Materials; Female; Humans; Mental Disorders; Metrizamide; Middle Aged; Myelography; Myoclonus; Seizures

Topics: Anesthetics; Central Nervous System; Humans; Metrizamide; Radiography; Seizures

Topics: Adolescent; Adult; Aphasia; Central Nervous System Diseases; Electroencephalography; Epilepsies, Myoclonic; Female; Humans; Iopamidol; Iothalamic Acid; Male; Metrizamide; Middle Aged; Myelography; Seizures; Time Factors

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.

Topics: Drug Interactions; Electroencephalography; Headache; Humans; Methotrimeprazine; Metrizamide; Myelography; Nausea; Sciatica; Seizures; Time Factors

Topics: Humans; Metrizamide; Myelography; Seizures

Detailed analysis of complications in 363 patients undergoing myelography with metrizamide is presented. Patients have been separated into three groups: those who had lumbar myelograms via lumbar puncture; patients who had cervical myelograms via lumbar route and patients who had cervical myelograms via cervical puncture (lateral C1/C2. approach). Analysis has revealed that the incidence of minor complications like headaches, nausea, and vomiting is higher than that associated with myodil myelography. Nevertheless, it is concluded that because of lack of long term disability of arachnoiditis, and because of greater diagnostic accuracy, metrizamide represents the best contrast medium for myelography currently available.

Topics: Adolescent; Adult; Aged; Arachnoiditis; Drug Evaluation; Female; Headache; Humans; Male; Metrizamide; Middle Aged; Myelography; Nausea; Seizures; Spinal Puncture; Vomiting

Topics: Adolescent; Adult; Aged; Brain Diseases; Cerebral Ventriculography; Child; Convulsants; Electroencephalography; Female; Humans; Iothalamic Acid; Male; Meglumine; Metrizamide; Middle Aged; Myelography; Seizures; Sorbitol

Selective left vertebral angiography was carried out in 25 rabbits comparing the toxic effects of iohexol and metrizamide (Amipaque). The iodine concentration for iohexol was 280 and 350 mg/ml and for metrizamide 350 mg/ml. Short general convulsions were seen in many of the animals with iohexol in the concentration of 350 mg iodine/ml. Cardiovascular reactions were seen with both contrast media, but were more marked with iohexol than with metrizamide in the concentration of 350 mg iodine/ml. Both iohexol and metrizamide are far less toxic than the ionic contrast medium metrizoate, but metrizamide seems to be less toxic than iohexol in vertebral angiography.

Topics: Animals; Bradycardia; Contrast Media; Female; Iodobenzoates; Iohexol; Male; Metrizamide; Paralysis; Rabbits; Radiography; Seizures; Spine; Triiodobenzoic Acids

Topics: Animals; Brain; Contrast Media; Depression, Chemical; Dose-Response Relationship, Drug; Injections, Spinal; Iodobenzoates; Iohexol; Iopamidol; Iothalamic Acid; Metrizamide; Rabbits; Seizures; Subarachnoid Space; Triiodobenzoic Acids

Topics: Adult; Epilepsies, Myoclonic; Female; Humans; Metrizamide; Myelography; Seizures; Spinal Diseases

To avoid disantvantages and possible late reactions of oily contrast medium we performed 18 Meatocisternographies using the watersoluble contrast medium Metrizamide (Amipaque). Anti-convulsive premedication and clinical observance over a period of 24 h are necessary due to adverse reactions.

Topics: Adult; Cerebellar Neoplasms; Cerebellopontine Angle; Cisterna Magna; Dizziness; Dysarthria; Electroencephalography; Electronystagmography; Female; Headache; Humans; Injections, Spinal; Male; Metrizamide; Middle Aged; Nausea; Paresthesia; Radiography; Seizures; Vomiting

Metrizamide is a water-soluble, nonionic radiocontrast medium that penetrates better into narrow subarachnoid spaces than do oily contrast media or gas. We performed metrizamide optic nerve thecography on five cats with iatrogenic orbital lesions. Optic thecograms successfully demonstrated displacement of the optic nerve, obstruction of the optic nerve sheath subarachnoid space, and extravasation of the contrast medium from a punctured optic nerve sheath. Metrizamide-induced seizures could be prevented by intramuscular preadministration of diazepam.

Topics: Animals; Cats; Diazepam; Metrizamide; Optic Nerve; Optic Nerve Injuries; Orbit; Radiography; Seizures

Topics: Adult; Aged; Aphasia; Cognition Disorders; Contrast Media; Female; Humans; Male; Metrizamide; Middle Aged; Movement Disorders; Myelography; Nervous System Diseases; Seizures

Metrizamide, a new, water-soluble contrast agent, was clinically evaluated as a myelographic agent in 17 dogs. Nine dogs were given lumbar subarachnoid injections and six were given cisternal injections. Two dogs were given cisternal and lumbar injections; in one dog, both injections were given on the same day. The dosage ranged from 0.3 to 0.57 ml/kg of body weight, using an isotonic solution of metrizamide. Of eight dogs given cisternal injections, two experienced convulsive activity requiring diazepam treatment during the anesthetic recovery period. The lumbar injections did not cause convulsions. Satisfactory radiographic density persisted up to 45 minutes after injection, allowing time for several views to be obtained. In general, metrizamide appeared to be an adequate myelographic agent in the dog.

Topics: Anesthesia; Animals; Cisterna Magna; Dog Diseases; Dogs; Female; Injections; Lumbar Vertebrae; Male; Metrizamide; Myelography; Seizures; Spinal Cord Compression; Spinal Cord Diseases

A new water-soluble myelographic contrast agent with more hydrophilic properties than metrizamide was developed and tested in the primate (Macaca mulatta) and the cat. A new animal model that allows study of the convulsive effects of intrathecally administered contrast agents in the awake monkey was designed. With this sensitive model the new contrast agent was shown to have a remarkable reduced convulsive effect when compared with metrizamide and other media. Intrathecal hypertonic solutions in the cat depress the evoked cortico-spinal responses whereas the neurotoxic effects of the iodinated water-soluble contrast media increase them. The net effect is a combination of the two actions.

Topics: Animals; Cats; Cerebral Cortex; Haplorhini; Hypertonic Solutions; Iothalamate Meglumine; Macaca mulatta; Metrizamide; Myelography; Reflex; Seizures; Spinal Cord

We have taken myelograms of six patients with grave post-tuberculous thoracic gibbus of the spine and gross deformity of the thoracic cage. Two of these patients suffered violent convulsions and fracture of the neck of the femur. In one patient the myelogram was taken with Conray Meglumine and in another with Dimer X. We suggest that a grave deformity of the thoracic cage is a relative contraindication for lumbar myelography with these water-soluble contrast media. We assume that the reduced tissue oxygenation in these patients results in a lower threshold for convulsions.

Topics: Femoral Neck Fractures; Humans; Iothalamate Meglumine; Metrizamide; Myelography; Seizures; Spinal Diseases; Spine

Selective left vertebral angiography was carried out in 21 rabbits comparing the toxic effects of meglumine iothalamate (Conray meglumine), meglumine metrizoate (Isopaque Cerebral) and metrizamide (Amipaque). The iodine concentration for all 3 media was 280 mg/ml. General convulsions were seen in many of the animals with all 3 media. The convulsions occurred at higher doses and were milder with metrizamide than with the 2 other contrast agents. Bradycardia was also seen with all 3 media and there was no statistical significant difference between them in this respect. The mortality was approximately 50% with both meglumine iothalamate and meglumine metrizoate, while no animals died following angiography metrizamide.

Topics: Angiography; Animals; Bradycardia; Contrast Media; Female; Injections, Intra-Arterial; Iodobenzoates; Iothalamate Meglumine; Male; Metrizamide; Metrizoic Acid; Rabbits; Seizures; Vertebral Artery

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.

Topics: Animals; Cerebrospinal Fluid; Contrast Media; Iodobenzoates; Iothalamate Meglumine; Iothalamic Acid; Leukocyte Count; Metrizamide; Myelography; Paralysis; Rabbits; Reflex, Abnormal; Seizures

Two-hundred-fifteen patients were evaluated with metrizamide, a new water-soluble contrast agent for use in the subarachnoid spaces. Side effects were reported in 67% of these; 39% were moderate or severe. Cervical injections monitored by fluoroscopy provide the most precise positioning of the medium. The benefits of metrizamide use outweigh its risk.

Topics: Cerebrospinal Fluid; Contrast Media; Headache; Humans; Iodobenzoates; Metrizamide; Myelography; Nausea; Seizures; Vomiting

Experiments conducted on rabbits confirmed that chlorpromazine potentiates the weak epileptogenic action of Amipaque (metrizamide). Chlorpromazine withdrawal for a period of 48 h suppresses this potentiating effect in the rabbit. Neuroleptic drugs should therefore be avoided in patients examined with Amipaque. In patients under chronic treatment, neuroleptics ought to be discontinued at least 48 h before examination with Amipaque. With the doses and methods used in the present study, diazepam was not as effective as phenobarbital in preventing epilepsy produced by Amipaque. When premidication is needed or when convulsions occur after Amipaque examinations, combined diazepam and phenobarbital therapy ought to be instituted in order to achieve the best control of epileptic reactions.

Topics: Animals; Chlorpromazine; Contrast Media; Diazepam; Drug Synergism; Iodobenzoates; Metrizamide; Phenobarbital; Rabbits; Seizures; Tranquilizing Agents

The adverse effects in a series of 50 lumbar myelographies with Amipaque were compared with those in a corresponding series, examined with Dimer-X. Side effects occurred in 58% of the cases examined with Amipaque and in 68% of the Dimer-X series. No seizures occurred in 58% of the cases examined with Amipaque and in 68% of the Dimer-X series. No seizures occurred in either series but slight fibrillations of fasciculations appeared in 2 Dimer-X patients. Hyperreflexia of the legs was recorded in 22% of the Amipaque and in 36% of the Dimer-X cases. Other adverse reactions to the media were mild to moderate. Some burst activity, but no definite paroxysmal abnormality was noted in EEG recordings in 2 Amipaque cases. The low epileptogenicity of Amipaque has ensured a wider safety margin of lumbar myelography.

Topics: Adult; Aged; Brain; Diazepam; Drug Evaluation; Electroencephalography; Female; Fever; Headache; Humans; Iodobenzoates; Iothalamate Meglumine; Iothalamic Acid; Lumbosacral Region; Male; Metrizamide; Middle Aged; Myelography; Nausea; Pain; Premedication; Seizures

An investigation was made of the use of a new water-soluble contrast material (metrizamide) for posterior-fossa radiography in the baboon. The experiments showed that the concentration of metrizamide needed to produce adequate radiographs from sub-occipital injections into the posterior fossa always produced generalized seizures. Intraventricular injection produced excellent radiographs from metrizamide concentrations, which did not result in either clinical or EEG seizure activity. Seizures, when they occurred, were easily controlled with pentobarbitone and phenytoin. In all the experiments, ECG changes were found, which disappeared after some hours.

Topics: Animals; Electrocardiography; Electroencephalography; Haplorhini; Injections, Intraventricular; Iodobenzoates; Metrizamide; Papio; Pentobarbital; Phenytoin; Seizures; Skull; Tomography, X-Ray

In a comparative study between Dimer X and Amipaque (metrizamide) for lumbar myelography it was found that there is a little higher frequency of monor, but unimportant side effects after Amipaque. Amipaque has also been used for thoracocervical myelography with excellent results and without greater discomfort than after myelography in the lumbar region. A new puncture technique was used for the eximation of the cervical region alone: lateral puncture on the neck between the laminae of C1 and C2 under TV control. In more than 75 reinvestigations no arachnoid changes were observed.

Topics: Adult; Aged; Female; Fever; Headache; Humans; Iodobenzoates; Iothalamate Meglumine; Iothalamic Acid; Lumbosacral Region; Male; Metrizamide; Middle Aged; Myelography; Nausea; Neck; Seizures; Subarachnoid Space; Surveys and Questionnaires; Urination Disorders; Vomiting

Technical problems in myelography with the water-soluble contrast medium, metrizamide are analysed and a technique used for examination of the entire spinal subarachnoid space is described. The choice of gas or water-soluble contrast medium for myelography is also discussed.

Topics: Adult; Aged; Contrast Media; Female; Headache; Humans; Iodobenzoates; Lumbosacral Region; Male; Metrizamide; Middle Aged; Myelography; Nausea; Osmolar Concentration; Pneumoradiography; Posture; Seizures; Solubility

Topics: Animals; Cats; Contrast Media; Electroencephalography; Injections, Intraventricular; Iothalamate Meglumine; Metrizamide; Seizures; Solubility; Water