Adil Harroud1, Olivier Boucher2, Thi Phuoc Yen Tran3, Louis Harris4, Jeffery Hall1, François Dubeau1, Ismail Mohamed5, Alain Bouthillier6, Dang Khoa Nguyen7. 1. Montreal Neurological Institute and Hospital, McGill University, Montreal, Québec, Canada. 2. Departement of Psychology, Université de Montréal, Montreal, Canada. 3. Department of Internal Medicine, Hue University of Medicine and Pharmacy, Hue, Vietnam. 4. Division of Neurology, CHUM Notre-Dame, Université de Montréal, Montreal, Canada. 5. Division of Pediatric Neurology, UAB School of Medicine, AL, United States. 6. Division of Neurosurgery, CHUM Notre-Dame, Université de Montréal, Montreal, Canada. 7. Division of Neurology, CHUM Notre-Dame, Université de Montréal, Montreal, Canada. Electronic address: d.nguyen@umontreal.ca.
Abstract
OBJECTIVE: The precuneus is a complex and highly connected structure located in the medial portion of the superior parietal lobule. The clinical presentation of precuneal epilepsy is poorly characterized, mostly because these patients have seldom been distinguished from those with other types of parietal lobe epilepsy. The present study aims to improve the understanding of precuneal epilepsy by detailing its clinical features and surgical outcomes. METHODS: Six previously unreported cases of drug-resistant precuneal epilepsy investigated between 2002 and 2014 were retrospectively studied. Seizure focus was confirmed by presence of a lesion, intracranial monitoring, or post-operative seizure control when applicable. RESULTS: Seizures arising from the precuneus have heterogeneous presentations, including body movement sensation, visual auras, eye movements, vestibular manifestations, and complex motor behaviors. Two patients with an anterior precuneus lesion described body movement sensations whereas two others with a posterior precuneus lesion experienced visual symptoms. Two of the five patients who underwent epilepsy surgery achieved good seizure control (Engel IA). One patient underwent gamma knife surgery with an Engel IV outcome. Surgical complications included contralateral visual field impairment, limb hypoesthesia and hemispatial neglect. One patient developed late-onset epilepsia partialis continua from a Rolandic subdural grid-related contusion. SIGNIFICANCE: In absence of a clear precuneal epileptogenic lesion, recognition of a precuneal focus is challenging. Magnetoencephalography may sometimes localize the generator but invasive EEG remains in well-selected cases necessary to identify the seizure focus. Surgical failures may be explained by the widespread connectivity of the precuneus with distant and adjacent structures. Different ictal manifestations of precuneal epilepsy in this series provide a clinical correlate to the described functional subdivisions of the precuneus.
OBJECTIVE: The precuneus is a complex and highly connected structure located in the medial portion of the superior parietal lobule. The clinical presentation of precuneal epilepsy is poorly characterized, mostly because these patients have seldom been distinguished from those with other types of parietal lobe epilepsy. The present study aims to improve the understanding of precuneal epilepsy by detailing its clinical features and surgical outcomes. METHODS: Six previously unreported cases of drug-resistant precuneal epilepsy investigated between 2002 and 2014 were retrospectively studied. Seizure focus was confirmed by presence of a lesion, intracranial monitoring, or post-operative seizure control when applicable. RESULTS:Seizures arising from the precuneus have heterogeneous presentations, including body movement sensation, visual auras, eye movements, vestibular manifestations, and complex motor behaviors. Two patients with an anterior precuneus lesion described body movement sensations whereas two others with a posterior precuneus lesion experienced visual symptoms. Two of the five patients who underwent epilepsy surgery achieved good seizure control (Engel IA). One patient underwent gamma knife surgery with an Engel IV outcome. Surgical complications included contralateral visual field impairment, limb hypoesthesia and hemispatial neglect. One patient developed late-onset epilepsia partialis continua from a Rolandic subdural grid-related contusion. SIGNIFICANCE: In absence of a clear precuneal epileptogenic lesion, recognition of a precuneal focus is challenging. Magnetoencephalography may sometimes localize the generator but invasive EEG remains in well-selected cases necessary to identify the seizure focus. Surgical failures may be explained by the widespread connectivity of the precuneus with distant and adjacent structures. Different ictal manifestations of precuneal epilepsy in this series provide a clinical correlate to the described functional subdivisions of the precuneus.
Authors: Francisco Javier Fuentealba-Villarroel; Josué Renner; Arlete Hilbig; Oliver J Bruton; Alberto A Rasia-Filho Journal: Front Synaptic Neurosci Date: 2022-01-11
Authors: Josef Parvizi; Rodrigo M Braga; Aaron Kucyi; Mike J Veit; Pedro Pinheiro-Chagas; Claire Perry; Clara Sava-Segal; Michael Zeineh; Eric Klaas van Staalduinen; Jaimie M Henderson; Matthew Markert Journal: Proc Natl Acad Sci U S A Date: 2021-07-20 Impact factor: 12.779