Abstracts

Rationale: Alien hand phenomena (AHP) has been reported to occur in association with various neurological conditions, such as cerebral vascular accident, brain tumor, corticobasal degeneration, and surgical transaction of the corpus callosum for intractable epilepsy. Although the concept of AHP comprises a variety of clinical conditions, the condition has not been consistently defined. Most clinical manifestations of AHP are reported to have either gradually disappeared over the course of 6-12 months or remained persistent, while ictal AHP has been rarely noted. Herein, we present 2 cases of ictal AHP associated with partial seizures in patients with epilepsy.Methods: We carefully collected the clinical history of the present patients and also investigated their clinical records, including cranial MRI and SPECT findings.Results: Case 1: Alien hand sign A 25-year-old right-handed female was involved in a traffic accident at 7 years old. Her first convulsion occurred 1 year later and epileptiform discharges were reported to be seen in the right frontal lobe at the age of 9 years. At the most recent examination, no epileptiform discharge was recorded. During her habitual seizures, the patient retains consciousness, but experiences auditory disturbance and transient mild stiffness of the left upper limb for no more than 1 minute. Only during the ictus of the seizure, the affected limb shows uncooperative involuntary movements. Interictal technetium -99m ECD brain SPECT showed an area of relative hypoperfusion in the frontal lobes, especially on the left side, while there was no apparent abnormality found in cranial MRI of the frontal lobes. Case 2: Compulsive manipulation of tools A 59-year-old right-handed male experienced his first generalized tonic-clonic seizure at the age of 14 years. His habitual seizures since that time include loss of consciousness and grinning for several seconds. Secondary generalizations are rare. At 50 years old, he developed a sudden onset of paroxysmal auditory disturbance and speech difficulty. Only during the ictus of the seizure, his right hand involuntarily reaches out to grasp chopsticks or a spoon if placed in front of him, then moves by its own volition and attempts to bring the chopsticks or spoon toward his mouth. Cranial MRI revealed an infarction in the left parietal lobe.Conclusions: The following features of AHP seen in our patients have led us to speculate that they are caused by epileptic mechanisms. (1) The phenomena are paroxysmal and repeatedly emerge for only short periods. (2) The phenomena have not caused permanent impairment. (3) The phenomena appear at the same time as evident epileptic seizures. The mechanisms related to development of AHP remain mostly unknown and additional investigations are needed in order to explain the phenomena in Case 1. As for Case 2, the left anterior cingulated gyrus as well as supplementary motor area are assumed to malfunction due to the influence of epileptic discharges occurring in the left parietal lobe. This condition may cause dysfunction of the mechanism related to right hand movement inhibition, which would be expected to result in compulsive manipulation of tools.