Electroencephalographic Changes

In adult humans exposed to elevated levels of Pb, EEG recordings have shown a slowing of the alpha rhythm and increases in the amount of slow wave activity in the theta and delta range, diffuse irregular patterns, and focal pairoxysmal discharges. Saito reported increased activity in theta and decreased activity at higher frequences. These EEG abnormalities can be reversed by chelation therapy.  

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Reversible electroencephalographic changes, probably due to progestogenic effects (143), have been observed in 25-60% of oral contraceptive users. 

Of the six reviewed patients, two died in coma the other four had neuropsychological problems that did not improve after 6 months and up to 2 years. They had comparable electroencephalographic changes. During coma there was hypokalemia and hypocalcemia combined with increased lipolysis this may have accounted for the permanent cerebral changes. 

Interestingly, some endpoints, such as temporal perception, were initially impaired by low-dose soman treatment, but led to tolerance later on, whereas others, such as nociceptive sensory and perceptual thresholds, became and remained elevated throughout the course of treatment (Russell et al., 1986). In nonhuman primates treated with subtoxic doses of sarin (Burchfiel et al, 1976) as well as humans with symptomatic but limited exposure to nerve agents (Duffy et al, 1979 Metcalf and Hohnes, 1969 Wadia et al, 1974), electroencephalographic changes were significant and persisted many months after exposure. 

High concentrations of busulfan in the cerebrospinal fluid have been correlated with development of myoclonic epilepsy and/or other electroencephalographic changes after high-dose busulfan conditioning regimens for acute leukemia (9). 

Epilepsy occurs rarely and can be accompanied by electroencephalographic changes (68-70). 

Metrizamide was the first non-ionic contrast medium and became widely used for myelography and ventriculography. It was much less neurotoxic than iocarmate, although electroencephalographic changes lasting up to... 

In comparative trials, iopamidol and iohexol produced fewer adverse effects than metrizamide and they do not so far appear to have given rise to the psychosjmdrome, but slight electroencephalographic changes can occur even with the newer media. Seizures and clonic jerks have been reported when relatively large doses of iopamidol have been used in myelography (SEDA-7, 455) (SEDA-13, 436). 

Of 18 German patients undergoing lumbar myelography with metrizamide, six had an organic psychosis, characterized by impaired memory and depression, but it was demonstrable only by psychometric tests and disappeared within 5 days (109). In four of the 18 patients there was hyporeflexia or areflexia and in three there were electroencephalographic changes there was no correlation between these various types of effect. 

Electrocardiographic and electroencephalographic changes have been reported as rare adverse effects of oxamniquine (SEDA-11, 598) (2). 

In uremic patients an inverse correlation has been observed between nerve conduction velocity and the blood level of myoinositol (Rll). Uremic nerve tissue has been shown to contain increased levels of myoinositol (N6). In hemodialyzed patients, however, there is no correlation between nerve conduction times, the degree of clinical neuropathy or electroencephalographic changes, and the levels of plasma or cerebrospinal fluid myoinositol (B24, Rll). Thus, there is little convincing evidence of an etiological role of myoinositol in the development of neuropathy. 

Brown HW Electroencephalographic changes and disturbance of brain function following human organophosphate exposure. Northwestern Medicine 70 845-846,1971 Bullman TA, Kang HK The effects of mustard gas, ionizing radiation, herbicides, trauma, and oil smoke on US military personnel the results of veteran studies. Annu Rev Public Health 15 69-90, 1994... 

Yaar I, Ron E, Modan B, et al Long term electroencephalographic changes caused by low therapeutic x-radiation doses to the scalp in childhood a power spectral study (abstract). Electroencephalogr Clin Neurophysiol 43 494,1977... 

Chalupa B, Synkova J, Sevcik M The assessment of electroencephalographic changes and memory disturbances in acute intoxications with industrial poisons. British Journal of Industrial Medicine 17 238-241,1960 Cherry N, Venables H, Waldron HA, et al Some observations on workers exposed to methylene chloride. British Journal of Industrial Medicine 38 351-355, 1981 Crystal HA, Schaumburg HH, Grober E, et al Cognitive impairment and sensory loss associated with chronic low-level ethylene oxide exposure. Neurology 38 567-569, 1988... 

Thiopental exhibits enantioselectivity in its EEG effects [199,200]. After the continuous infusion of thiopental enantiomers administered separately to rats [199], the lethality anesthetic potency ratio of doses was significantly lower for S-thiopental (2.1) than for antipode (3.2). The authors also found that initial electroencephalographic changes were greater for... 

Different results were found concerning neuro-physiological changes and neurological diseases. Electroencephalographic changes and a slight decrease in cerebral blood flow of paint industry workers was noted by Oerbaek et al. and there were occasional cases of... 

In rats imipenem - - dlastin provoked convulsions dose dependently, with characteristic electroencephalographic changes [21 ]. Audiogenic stimulation did not by itself provoke seizures in untreated rats but did after pretreatment with imipenem however, these seizures were not accompanied by electroencephalographic changes. The authors proposed that imipenem-induced seizures involve neuronal networks in the cortex whereas audiogenic seizures involve networks in the brainstem. 

Diagnostic difficulties arise in subacute sclerosing encephalitis, although as a rule its course is more rapid and electroencephalographic changes are typical. Other virus encephalitides show unequivocally faster progression than ML. 

Records were normal in nine of ten controls with various anemias not of megaloblastic type. The electroencephalographic changes in pernicious anemia do not seem to be due to anemia. Perhaps they are due to a specific defect in cerebral metabolism caused by deficiency of vitamin B12. 

Endoh F, Kobayashi K, Hayashi Y, Shibata T, Yoshinaga H, Ohtsuka Y. Efficacy of topiramate for intractable childhood generalized epilepsy with epileptic spasms with special reference to electroencephalographic changes. Seizure September 2012 21(7) 522-8. 

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