Epilepsia partialis continua following metrizamide cisternography

Epilepsia partialis continua associated with levamisole

Epilepsia partialis continua is defined as a spontaneous regular or irregular clonic muscular twitching affecting a limited part of the body, occurring for a minimum of 1 hour and recurring at intervals of less than 10 seconds. Levamisole is used as an immunomodulating medication in patients with recurrent aphthous ulcers. Evidence suggests that it can induce multifocal inflammatory leukoencephalopathy. We describe the clinical neuroimaging and ictal electroencephalographic findings in an adolescent with epilepsia partialis continua caused by the administration of levamisole with cortical and subcortical lesions. To our knowledge, this is the first report that describes the association of epilepsia partialis continua cortical lesions detected by magnetic resonance imaging and levamisole that were not previously described.

Focal status epilepticus and epilepsia partialis continua in adults and children

Focal status epilepticus and epilepsia partialis continua (FSE-EPC) are most frequently seen with chronic focal progressive encephalitis of Rasmussen and Russian spring-summer encephalitis. FSE-EPC may be the presenting feature of nonketotic hyperglycemic diabetes mellitus but is more often noted as a late complication especially if there is a coexistent cerebral lesion such as cerebral infarction. FSE-EPC may be related to multiple sclerosis, primary or metastatic brain tumors, the MERRF-MELAS syndrome, benign epilepsy of childhood with rolandic spikes, and in some adults with acquired aphasia. The physiological origin of the myoclonic jerks seen in EPC is cortical and may be either spontaneous or provoked by the joint position of the affected limb. The treatment of FSE-EPC is influenced by the underlying disorder.

Clinical features, pathogenesis and management of drug-induced seizures

Many classes of pharmacological agents have been implicated in cases of drug-induced seizures. The list includes antidepressant drugs, lithium salts, neuroleptics, antihistamines (H1-receptor antagonists), anticonvulsants, central nervous system stimulants, general and local anaesthetics, antiarrhythmic drugs, narcotic and non-narcotic analgesics, non-steroidal anti-inflammatory drugs, antimicrobial agents, antifungal agents, antimalarial drugs, antineoplastic drugs, immunosuppressive drugs, radiological contrast agents and vaccines. For each of these classes of drugs, this article offers a revision of the literature and emphasises in particular the frequency of the adverse reaction, its clinical presentation, its presumed epileptogenic mechanism and the therapeutic strategy for the management of drug-induced seizures. An attempt is also made to distinguish seizures induced by standard dosages from those provoked by accidental or self-induced intoxication. For some classes of drugs such as antidepressants, neuroleptics, central nervous system stimulants (e.g. theophylline, cocaine, amphetamines) and beta-lactam antibiotics, seizures are a well recognised adverse reaction, and a large body of literature has been published discussing exhaustively the major aspects of the issue; sufficient data are available also for the other classes of pharmacological agents mentioned above. In contrast, several other drugs [e.g. allopurinol, digoxin, cimetidine, protirelin (thyrotrophin releasing hormone), bromocriptine, domperidone, insulin, fenformin, penicillamine, probenecid, verapamil, methyldopa] have not been studied thoroughly under this aspect, and the only source of information is the occasional case report. This review does not address the issue of seizures induced by drug withdrawal.

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.

Neurotoxicity of radiological contrast agents

The most important complications of intravascular administration of contrast agents include idiosyncratic (anaphylactoid) reactions, shock, congestive heart failure, cardiac arrhythmias, acute renal failure, and neurotoxic effects. The incidence of serious neurotoxic effects is low. Entry of contrast agents into the central nervous system normally is limited but may be increased by osmotic opening of the blood-brain barrier with cerebral arteriography or arch aortography. Most neurotoxic effects are thought to represent direct effects of the contrast agent on brain or spinal cord. Adverse effects with arteriography include seizures, transient cortical blindness, brain edema, and spinal cord injury. Most cases of focal brain deficit (other than cortical blindness) are attributed to embolism secondary to the catheter. Seizures may occur with intravenous administration, especially in patients with brain tumors or other processes disrupting the blood-brain barrier. The most important adverse effects observed with myelographic agents include acute and chronic meningeal reactions with iophendylate, and seizures and transient encephalopathy with metrizamide.