Transient encephalopathy and asterixis following metrizamide myelography. Case report

Asterixis: a study of 103 patients

In 1949, asterixis was first described in patients with hepatic encephalopathy. It was quickly recognized that this phenomenon also occurs in other generalized encephalopathies and sometimes results from structural brain lesions. This paper is a study of asterixis in the general neurology clinic and on the inpatient neurology consultation service. The neurologists recorded the findings on inpatients and clinic patients for 12 consecutive months. Of the 1,109 inpatients with adequate examination, asterixis was documented in 97. Eighteen of the 97 cases were unilateral (18.6%) and 79 cases were bilateral (81.4%). Of the 614 outpatient visits with well documented examination, 6 (1%) individuals had asterixis. Since a small number of patients were examined more than once, the study yielded 103 individuals with adequate data for analysis. Asterixis resulted from varied causes: medications, renal disorder, hepatic dysfunction, pulmonary insufficiency, stroke and other brain lesions (including malignancy, subdural hematoma, and epidural abscess). Asterixis occurred in various patterns: in some cases it was easier to elicit in the upper extremities, in some it was easier to elicit in the lower limbs, and some it was solely or predominantly unilateral. The findings are discussed in light of the literature on asterixis with regard to its varied causes, patterns and presentations. Lastly, asterixis is examined from a historical perspective and the terminology is elucidated.

Incidental intrathecal injection of meglumine diatrizoate

Introduction:

Myelograghy is a process of instilling contrast medium to the subarachnoid space for evaluating the spinal column by radiography. There are various contrast solutions for different radiographic studies but not all of them are suitable for spinal column evaluation.

Case Presentation:

Our patient was a 60-year-old man who developed severe pain, tonic clonic convulsions and cardiopulmonary arrest after intrathecal injection of 14 mL of meglumine diatrizoate during an elective myelography procedure. Many of these cases would die or suffer from permanent sequelae if appropriate treatment is not received.

Conclusions:

Our subject recovered completely without any sequelae after receiving appropriate treatment in a multidisciplinary intensive care unit.

Malignant Cerebral Edema following CT Myelogram Using Isovue-M 300 Intrathecal Nonionic Water-Soluble Contrast: A Case Report

Lumbar myelogram utilizing nonionic contrast is a commonly performed procedure to identify spinal pathology. Complication rates are low. Cerebral edema has been shown to occur following intrathecal injection of ionic contrast; however, no current literature has documented this complication relating to the ubiquitously used nonionic contrast medium. We report a case of a patient who developed malignant cerebral edema following a lumbar myelogram with Isovue-M 300 nonionic water-soluble intrathecal contrast. We believe this is the first reported case of cerebral edema resulting from the use of a nonionic contrast.

Clinical experience with iomeprol in myelography and myelo-CT: clinical pharmacology and double-blind comparisons with iopamidol, iohexol, and iotrolan

RATIONALE AND OBJECTIVES

To evaluate iomeprol, a new nonionic iodinated contrast medium, as a contrast agent for myelography and to compare it with iopamidol, iohexol, and iotrolan.

METHODS

An extensive clinical program was conducted on more than 600 patients to assess iomeprol's pharmacokinetics, tolerability, safety, and efficacy after intrathecal injection.

RESULTS

Pharmacokinetics study results showed that after intrathecal administration iomeprol is completely absorbed from the cerebrospinal fluid compartment; once absorbed into the systemic circulation, it is rapidly excreted, unmetabolized, by glomerular filtration. Dose-finding studies showed that the opacification produced by iomeprol depends on the injected dose. Although a dose-dependent increase in efficacy was observed, no differences in neurotolerability and safety were detected between the doses tested. Doses of iomeprol greater than 3 g I did not cause a greater incidence of adverse events and produced significantly better contrast efficacy. Comparative clinical trials showed that iomeprol and iopamidol, iohexol, and iotrolan always provided adequate opacification of the subarachnoid space, both in conventional myelography and myelo-CT, with adequate delineation of normal structures and pathologic processes. No serious adverse events occurred up to a total dose of 4.5 g I. No differences between the agents with regard to tolerance, adverse events, and effects on vital signs, physical examination, and neurologic examination were observed.

CONCLUSIONS

Iomeprol is safe and effective and can be recommended for myelography and myelo-CT.

Case report: Pontine haemorrhage following iohexol lumbar myelography

A case of pontine haemorrhage following lumbar myelography using iohexol is described. Stress, inducing transient hypertension during the procedure, with superimposed neurotoxicity from contrast medium (iohexol) is suggested as a possible mechanism. No brain stem lesion was seen on the initial brain CT scan, possibly because of the high attenuation of the contrast medium in the subarachnoid space. A delayed CT brain scan demonstrated the pontine haemorrhage and was necessary to confirm the diagnosis.

Serial EEG recordings following intrathecal metrizamide administration

EEG recordings were obtained before and after intrathecal metrizamide injection in 50 consecutive patients who underwent metrizamide myelography or cisternography. EEG tracings were recorded daily until the pattern returned to baseline. One patient (2%) developed seizures. The most frequent EEG abnormality was generalized slowing of various degrees. In 15 patients (30%), the EEG record was normal throughout the study. In 4 patients (8%), EEG disturbances were seen up to the fifth day after the procedure. Patients who had undergone cervical myelography and cisternography had a marginally higher frequency of EEG disturbances than patients who underwent lumbar myelography. The causes inducing these time-related disturbances are discussed, as compared to pharmacokinetics of intrathecally administered metrizamide.

Metrizamide and the EEG: three case reports and a review

Three patients are described who developed cerebral complications and an EEG abnormality for several days after metrizamide myelography. Clinically, the patients showed a fluctuating confusional state with dysphasia and retrograde amnesia, while their EEGs were dominated by runs of slow wave activity interspersed with frequent spikes. The runs appeared either continuously or in paroxysmal bursts. The clinical symptoms and the EEG are compatible with complex partial status epilepticus and are similar to the symptomatology of ten patients described in the literature. This rare clinical entity should be distinguished from a more common complication of metrizamide--non-specific slow wave abnormality of variable degree in the EEG with or without clinical signs. Clinical manifestations may include transient aphasia and weakness of the limbs with pyramidal signs.

Formed visual hallucinations after metrizamide myelography

About 12 hours after 77-year-old woman underwent metrizamide myelography of the posterior fossa to elucidate the cause of downbeat nystagmus, she developed formed visual hallucinations consisting primarily of brightly colored geometric shapes, cloud formations, and human figures. Her white blood cell count was 26,000/mm3 and her serum creatine phosphokinase level was markedly increased to 438 units/liter. Two days later, the hallucinations had subsided, the white blood cell count had decreased to 17,000/mm3, and the serum creatine phosphokinase level had decreased to 105 units/liter. The hallucinations were probably caused by penetration of the metrizamide into the temporal lobe and visual association cortex.