In EEG type of wave seen in metabolic encephalophathy

Ans. is 'cl' i.e., Delta E.E.G. changes in metabolic encephalopathy In metabolic encephalopathy changes are typically nonfocal E.E.G. has been widely used to evaluate metabolic encephalopathy. The E.E.G .findings are abnormal in acute encephalopathic stages. It is difficult to establish a diagnosis of metabolic encephalopathy with ceainity through E.E.G. There is generalized slowing of the E.E.G with an excess of the delta and theta waves with suppression of normal alpha and beta wave activity and occasionally bilateral spikes and waves complexes occurring in absence of seizure activity". In metabolic encephalopathies, the E.E.G evolution correlates well with the severity of encephalopathy. o However EEG has little specificity in differentiating etiologies in metabolic encephalopathy. For example, though triphasic waves are most frequently mentioned in hepatic encephalopathy, they can also be seen in uremic encephalopathy or even in aged psychiatric patients treated with lithium. o Spikes and waves may appear in hypo or hyperglycemia uremic encephalopathy or vitamin deficiencies. Common principles of EEG changes in metabolic encephalopathy are : - Varied degrees of slowing Associated mixtures of epileptic discharge High incidence of triphasic waves Reversibility after treatment of underlying causes Metabolic encephalopathy EEG rythm Grade I (almost normal) Dominant activity is alpha rhythm with minimal teta activity Grade II (mildly abnormal) Dominant teta background with some alpha and delta activities. Grade II (moderately abnormal) Continuous delta activity predominates, little activity of faster frequencies Grade IV (severely abnormal) Low-amplitude delta activity or suppression-burst pattern Grade V (extremely abnormal) Nearly"flat" tracing or electrocerebral inactivity.