OPHTHALMOLOGICAL SYNOPSES CLINICAL ELECTRO-ENCEPHALOGRAPHY. H EEG Reporting

EEG reporting is difficult because of the quantity of information in a record and also because of changes in the patient's level of arousal which may be hard to assess (see "Difficulties of EEG" in Part I: Brit. J. Ophthal. (1968), 52, 426). The report consists of a descriptive and an interpretative part. The background rhythms are described: their amplitude and frequency; symmetry between the hemispheres which usually behave similarly; the form of any discrete phenomena such as sharp waves or bursts of spikes and waves; and the location and occurrence of focal abnormalities as indicated by "phase reversal". The interpretation of these phenomena in relation to the clinical situation is then carried out, bearing in mind that the EEG is but one physical sign which like others must be taken in relation to the whole clinical picture. Value of the EEG There are many different situations in which this investigation may be of value, e.g. in patients with anoxic brain damage following cardiac arrest, in those with hepatic encephalopathy, and in children with phenyl-ketonuria. It is of par- Type of Activity Waveform Remark