Summary Purpose:  Recent evidence suggesting that some epilepsy surgery failures could be related to unrecognized insular epilepsy have led us to lower our threshold to sample the insula with intracerebral electrodes. In this study, we report our experience resulting from this change in strategy. Methods:  During the period extending from October 2004 to June 2007, 18 patients had an intracranial study including 10 with insular coverage. The decision to sample the insula with intracerebral electrodes was made in the context of (1) nonlesional parietal lobe‐like epilepsy; (2) nonlesional frontal lobe‐like epilepsy; (3) nonlesional temporal lobe‐like epilepsy; and (4) atypical temporal lobe‐like epilepsy. Results:  Intracerebral recordings confirmed the presence of insular lobe seizures in four patients. Cortical stimulation performed in 9 of 10 patients with insular electrodes elicited, in decreasing order of frequency, somatosensory, viscerosensory, motor, auditory, vestibular, and speech symptoms. Discussion:  Our results suggest that insular cortex epilepsy may mimic temporal, frontal, and parietal lobe epilepsies and that a nonnegligeable proportion of surgical candidates with drug‐resistant epilepsy have an epileptogenic zone that involves the insula.

Insular surgery is both safe and beneficial when it is well planned and performed with modern microsurgical techniques and good anatomical knowledge. Insulectomy is associated with little permanent morbidity and a high rate of seizure control. To the authors' knowledge, this is the first series of insulectomies predominantly performed for refractory epilepsy since those performed by Penfield.

Unruptured intracranial aneurysms are usually asymptomatic, detected incidentally on brain imaging. Larger unruptured aneurysms however can present with symptoms related to compression. Examples include chiasmatic compression by internal carotid or anterior communicating artery aneurysms, intracavernous aneurysms causing ophtalmoplegia and facial pain, and aneurysms of the posterior communicating artery producing third nerve palsy. We present three cases of middle cerebral artery (MCA) aneurysm who presented with bilateral paresthesiae and autonomic symptoms due to either epileptic activity or mass effect on the insular cortex. CASE SERIESCase 1: A 50-year-old female complained of dry mouth, throat constriction, palpitations and left arm paresthesiae for the previous three days. The paresthesiae progressed over the next five weeks to involve the left leg, perioral area and finally became bilateral, involving the four limbs. Her neurological exam was normal. Cardiac workup was normal. Cerebral magnetic resonance imaging (MRI) and angiography demonstrated a right MCA aneurysm measuring 11 mm lying ABSTRACT: Objective: To present a new semiological description of unruptured middle cerebral artery (MCA) aneurysms. Methods: We present a series of three MCA aneurysms presenting with progressive or paroxystic somatosensory symptoms in combination with visceral, motor, language or autonomic symptoms. Results: A surgical approach was proposed for two aneurysms, and both patients experienced complete resolution of their symptoms. The third aneurysm was successfully excluded by endovascular coiling but the symptoms persisted. Conclusions: To our knowledge this is the first description of unruptured aneurysms presenting with insular-related symptoms. RÉSUMÉ: Symptômes propres à l'insula comme symptômes d'appel d'anévrismes non rompus de l'ACM.Objectif : Nous présentons une nouvelle description séméiologique des anévrismes non rompus de l'artère cérébrale moyenne (ACM). Méthodes : Nous présentons une série de trois patients porteurs d'anévrismes de l'ACM dont les symptômes d'appel étaient des symptômes somesthésiques progressifs ou paroxystiques accompagnés de symptômes viscéraux, moteurs, du langage ou neuro-végétatifs. Résultats : Une approche chirurgicale a été proposée pour traiter deux des anévrismes et les symptômes ont disparu chez les deux patients. Le troisième anévrisme a été exclu avec succès par embolisation endovasculaire de microspires (coils), mais les symptômes ont persisté. Conclusions : Il s'agit, à notre connaissance, de la première description de patients porteurs d'anévrismes intacts dont les symptômes d'appel étaient des symptômes propres à l'insula.

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