Abstracts

RATIONALE: Alien-Limb syndromes are characterized by seemingly purposeful limb movements, which are subjectively experienced as alien induced and beyond the patient[scquote]s voluntary control. According to the localization of the underlying lesion, three subtypes of Alien-Limb syndromes have been described: (1) frontal type, (2) fronto-callosal type and (3) posterior type. Usually, Alien-Limb syndromes remain stationary but can also occur ictally as shown in our cases. The phenomenon is supposed to reflect a disconnection of interhemispheric pathways or unilateral projection fibers.
METHODS: Case 1: A 43-year-old patient with temporal lobe epilepsy due to left mesial temporal sclerosis suffered from episodic involuntary abduction movements of her alienized right arm. The episodes lasted only a few minutes while the patient tried to resist the movement by pulling back the arm with her unaffected left hand. Case 2: This 16-year-old patient with a focal epilepsy due to cortical dysplasia in the right cingulate gyrus experienced paroxysmal involuntary anteversion movements of his alienized left leg.
RESULTS: In both cases, video-EEG-monitoring revealed these episodic phenomena to be of ictal origin. Case 3: In this 16-year-old patient with left-sided tumoural parietal lobe epilepsy, paroxysmal Alien-Limb symptoms with involuntary movements and estrangement of his right arm could be elicited by electrical stimulation of the left postcentral cortex.
CONCLUSIONS: Epileptic seizures can cause a variety of focal neurologic symptoms by episodic activation or inhibition of cortical areas with certain functional eloquence. As our cases show, this is also true for complex phenomenona like the Alien-Limb syndromes. Analogous to the stationary types, we suspect a functional disconnection of sensory and motor cortex, limited to the duration of the seizure.