Electroencephalogram (EEG) Registry Practice Exam

The finding of attenuation of background activity in the left hemisphere on the EEG of an aphasic patient with a subdural hematoma is particularly significant. Aphasia, which is a language disorder often associated with lesions in the left hemisphere, can manifest as a reduction in the overall electrical activity of the brain in that area due to the presence of a subdural hematoma, which can disrupt normal brain function.

The subdural hematoma may lead to increased intracranial pressure and cause focal brain damage or dysfunction, particularly in regions related to language processing, such as Broca's area or Wernicke's area—both located in the left hemisphere for most right-handed individuals. As a result, the EEG can reveal an attenuation of the normal background rhythm, indicating impaired neuronal activity in that area, which correlates well with the aphasic condition observed.

This finding underscores the relationship between structural brain changes due to a subdural hematoma and their impact on EEG readings, which can help medical professionals assess the functional consequences of such traumatic injuries.