Abstracts

Rationale: An overview of the electrical brain stimulation (EBS) reports is missing from the current literature. Such an overview would provide useful information about symptomatogenic zones in the brain of patients with epilepsy. Methods: Using PUBMED, we searched for publications containing the keywords human , brain , stimulation", or epilepsy , which resulted in 9272 reports. We scanned the abstract of all reports and selected 109 reports that were published in English and dealt with EBS in human subjects. We also searched for relevant papers in the references provided in each of these publications and reviewed additional books and magazine articles. Results: An abridged summary of the general themes of our findings is as follows: 1. Frontal Lobe: eye movements, change of posture and tone, oroalimentary automatisms, emotional facial expression and laughter, reaching, grasping, and nonconscious movements; retrosternal pain or discomfort, disequilibrium, somatic sensations; speech arrest, reading, singing problems, palilalia; dysautonomia. 2. Insula: sensation of suffocation, bilateral pain, warmth and or cooling sensation, vertigo, nausea, feeling of falling; automatisms. 3. Parietal Lobe: somatotopic sensation, vestibular and sensorimotor responses and visual disturbances, urge to move or illusion of moving body parts, out of body experience, hemispatial neglect, somatosensory and vestibular sensations, anomia, speech arrest and conduction aphasia, finger agnosia and acalculia. 4. Occipital Lobe: Mostly in calcarine, occipitoparietal and occipitotemporal areas: simple visual sensations such as seeing simple patterns, geometric shapes, phosphenes, colors, movement; visual hallucinations such as seeing people and or movements, visual illusions such as slowing down of actual movements. 5. Temporal Lobe: Feeling of unreality or familiarity; emotional feelings and recall of past experiences; auditory hallucinations, pain or automatisms; visual hallucinations; disruption in reading, comprehension, naming and or identification (left inferior). 6. Subcortical Areas: (STN or internal capsule): transient acute depression, hypomania; motor responses such as crying, psychomotor retardation, exaggerated facial and gag reflexes; language impairments; autonomic changes; and eye apraxia. Conclusions: This review was an attempt to bring to light some of the classic EBS studies, classify the evidence in a systematic way, and provide details about the parameters used in each reported study. Findings of EBS studies must be interpreted cautiously in the light of variables such as the location of the brain target verified or presumed, the strength of electrical charge delivered, and the mode of electrical stimulation (i.e., bipolar or unipolar).