Nonconvulsive status epilepticus following metrizamide myelography

Triphasic Waves: Historical Overview of an Unresolved Mystery

SUMMARY

Triphasic waves are a fascinating and mysterious EEG feature. We now have to accept that, at times, epileptiform discharges may have a blunted "triphasic morphology," and that there may be great difficulty in distinguishing between these often similar forms. The aim of this review was to describe the evolution in our understanding of triphasic waves that has occurred regarding the pathophysiology of triphasic waves, their most frequent causes, and the diagnostic difficulties involved in interpretation and differentiation from nonconvulsive status epilepticus.

Causes of status epilepticus

Status epilepticus (SE) is the most extreme form of epilepsy. It describes a prolonged seizure that may occur in patients with previous epilepsy or in acute disorders of the central nervous system. It is one of the most common neurologic emergencies, with an incidence of up to 41 per 100,000 per year and an estimated mortality is 20%. The three major determinants of prognosis are the duration of SE, patient age, and the underlying cause. Common and easily recognized causes of SE include cerebrovascular disorders, brain trauma, infections, and low antiepileptic drug levels in patients with epilepsy. Less common causes present a clinical and diagnostic challenge, but are major determinants of prognosis. Among them, inflammatory causes and inborn errors of metabolism have gained wide interest; recent insights into these causes have contributed to a better understanding of the pathophysiology of SE and its appropriate treatment. This review focuses on the different etiologies of SE and emphasizes the importance of prompt recognition and treatment of the underlying causes.

[Prolonged confusion syndrome in the course of cyclosporine treatment: a state of confusion?]

Cyclosporine is a potent immunosuppressant that is more and more widely used, particularly after organ transplantations. Many neurological side effects, including convulsions, that could be related to this drug, have been previously observed, most often with high blood concentrations. We report, for the first time, a case of prolonged confusion where a non convulsive status epilepticus may be discussed. It occurred in a 64-year-old woman, 17 days after a liver transplantation. The whole blood cyclosporine value was 230 micrograms/l (normal range: 100-200 micrograms/l) at the beginning of the status epilepticus. The cyclosporine imputability and the part of other factors that could have facilite are discussed.

Absence, myoclonic, and atonic seizures

This article describes the typical absence attack, as well as the typical manifestations of myoclonic and atonic seizures. It reviews the usual treatment, including pharmacology, and gives the prognosis for these entities.

Nonconvulsive status epilepticus following cerebral angiography

A 64-year-old man developed lethargy and aphasia immediately following cerebral arteriography with iothalamate meglumine. An electroencephalogram showed continuous epileptiform activity. The patient was treated with intravenous phenytoin with complete resolution of clinical symptoms and electroencephalographic epileptiform abnormalities. The diagnosis of nonconvulsive status epilepticus should be considered in cases of altered consciousness following cerebral arteriography.

Absence status epilepticus with computed tomographic brain changes following metrizamide myelography

Absence status epilepticus following metrizamide myelography was associated with computed tomographic scan evidence of a high concentration of the dye in brain gray matter. We suggest that absence status epilepticus is due to the direct effect of metrizamide on the cortex and that this clinically treatable condition may have escaped diagnosis in previous reports.

Influence of the spread and period of retention of Iotrolan in the subarachnoid space on the side effects rate in myelography

Fifty patients underwent myelography with the newly developed CSF-isotonic, dimeric, non-ionic contrast medium Iotrolan. Repeat spinal and cranial computerised tomographic studies with measurement of the attenuation values were conducted to demonstrate the administered contrast medium in the spinal canal and intracranial subarachnoid space. The patients were examined neurologically, observed clinically and asked about concomitant symptoms. The period of retention and the spread of the contrast medium in the subarachnoid space was not found to have any influence on the side effects rate. In particular, no association was confirmed between intracranially demonstrable contrast medium and the occurrence of side effects.

Multiple subcortical haemorrhages following lumbar metrizamide myelography

The case is presented of a patient showing multiple subcortical haemorrhages after lumbar metrizamide myelography. This complication after intrathecally administered metrizamide contrast medium appears not to have been reported before. Several different possible explanations are proposed for the phenomena observed in this case.