Prolonged Confusion due to Absence Status Following Metrizamide Myelography

Absence Status following Metrizamide Myelography: Management of Nonresponders

“…Some cases may present urinary incontinence and focal or generalized myoclonus. The latency period between myelography and the presenta tion of the first symptom was less than 3 h in the cases where myelography included the entire cervical spine [4,6,10], and more than 5 h in the patients, in whom myelography did not involve the entire cervical spine [3,5,7], All the patients presented persistent alterations of their EEG tracings, except case 2 of Russel et al [3] and case 2 of Bergvall et al [7] who presented EEG tracings that permit the diagnosis of complex partial status [13] (by control EEG in case 2 of Russel et al and the ictal EEG in case 2 of Bergvall et al), all the other cases meet the current criteria of absence status [12], No patient presented the EEG pattern associated with typi cal absence status represented by regular 3-Hz spike wave activity. The pattern of absence status following MM is similar to those previously reported elsewhere for absence status of other etiologies, generally in adults [ 12].…”

“…Until recently, these patients were con sidered as having metrizamide-induced toxic encepha lopathy. In 1980, 2 cases with acute confusional state were reported to have EEGs characteristic of complex partial status [3], More recently, 2 other cases [4,5] were reported to have EEGs characteristic of absence status. None of these reported cases were previously epileptic.…”

“…It has been pos tulated that it might be due to a direct neurotoxic effect of the contrast agent, which might interfere with glucose metabolism and/or other metabolic pathways [1], The literature emphasizes the need to perform an EEG recording of all patients who present with an acute confusional state following MM to establish the differ ential diagnosis between toxic encephalopathy and nonconvulsive status [5]. However, our case shows that EEG monitoring during treatment and the following days is warranted for adequate management of cases who fail to respond to a single dose of diazepam or clonazepam, but who are likely to respond to a higher dose.…”

“…The frequency of convulsive seizures varies from 0 to 0.6% as reported in the larger series [1]. However, the nonconvulsive seizures seem to be rare since only 2 cases of complex partial status [3] and, more recently, 3 cases of absence status have been reported [4][5][6]. These cases can only be differentiated from toxic encephalopathy by EEG, since the acute confusional state in these patients is non specific [5].…”

“…However, the nonconvulsive seizures seem to be rare since only 2 cases of complex partial status [3] and, more recently, 3 cases of absence status have been reported [4][5][6]. These cases can only be differentiated from toxic encephalopathy by EEG, since the acute confusional state in these patients is non specific [5]. Various cases have been reported with mental changes and epileptiform activity on the EEG [7][8][9][10][11] but no specific classification of the epileptic disturbance was done.…”