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Spencer ER, Chinappen D, Emerton BC, Morgan AK, Hämäläinen MS, Manoach DS, Eden UT, Kramer MA, Chu CJ. Source EEG reveals that Rolandic epilepsy is a regional epileptic encephalopathy. Neuroimage Clin 2022; 33:102956. [PMID: 35151039 PMCID: PMC8844714 DOI: 10.1016/j.nicl.2022.102956] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Revised: 01/10/2022] [Accepted: 02/03/2022] [Indexed: 01/15/2023]
Abstract
Children with RE have fewer spindles but they have typical time–frequency features. Spindle deficits extend to multiple cortical regions in Rolandic epilepsy. Cognitive deficits are predicted by spindle rate in Rolandic epilepsy. Regional spindle rate predicts motor deficits better than Rolandic spindle deficit. Spindle features in RE identify a regional thalamocortical epileptic encephalopathy.
Rolandic epilepsy is the most common form of epileptic encephalopathy, characterized by sleep-potentiated inferior Rolandic epileptiform spikes, seizures, and cognitive deficits in school-age children that spontaneously resolve by adolescence. We recently identified a paucity of sleep spindles, physiological thalamocortical rhythms associated with sleep-dependent learning, in the Rolandic cortex during the active phase of this disease. Because spindles are generated in the thalamus and amplified through regional thalamocortical circuits, we hypothesized that: 1) deficits in spindle rate would involve but extend beyond the inferior Rolandic cortex in active epilepsy and 2) regional spindle deficits would better predict cognitive function than inferior Rolandic spindle deficits alone. To test these hypotheses, we obtained high-resolution MRI, high-density EEG recordings, and focused neuropsychological assessments in children with Rolandic epilepsy during active (n = 8, age 9–14.7 years, 3F) and resolved (seizure free for > 1 year, n = 10, age 10.3–16.7 years, 1F) stages of disease and age-matched controls (n = 8, age 8.9–14.5 years, 5F). Using a validated spindle detector applied to estimates of electrical source activity in 31 cortical regions, including the inferior Rolandic cortex, during stages 2 and 3 of non-rapid eye movement sleep, we compared spindle rates in each cortical region across groups. Among detected spindles, we compared spindle features (power, duration, coherence, bilateral synchrony) between groups. We then used regression models to examine the relationship between spindle rate and cognitive function (fine motor dexterity, phonological processing, attention, and intelligence, and a global measure of all functions). We found that spindle rate was reduced in the inferior Rolandic cortices in active but not resolved disease (active P = 0.007; resolved P = 0.2) compared to controls. Spindles in this region were less synchronous between hemispheres in the active group (P = 0.005; resolved P = 0.1) compared to controls; but there were no differences in spindle power, duration, or coherence between groups. Compared to controls, spindle rate in the active group was also reduced in the prefrontal, insular, superior temporal, and posterior parietal regions (i.e., “regional spindle rate”, P < 0.039 for all). Independent of group, regional spindle rate positively correlated with fine motor dexterity (P < 1e-3), attention (P = 0.02), intelligence (P = 0.04), and global cognitive performance (P < 1e-4). Compared to the inferior Rolandic spindle rate alone, models including regional spindle rate trended to improve prediction of global cognitive performance (P = 0.052), and markedly improved prediction of fine motor dexterity (P = 0.006). These results identify a spindle disruption in Rolandic epilepsy that extends beyond the epileptic cortex and a potential mechanistic explanation for the broad cognitive deficits that can be observed in this epileptic encephalopathy.
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Affiliation(s)
- Elizabeth R Spencer
- Graduate Program in Neuroscience, Boston University, Boston, MA 02215; Department of Neurology, Massachusetts General Hospital, Boston, MA 02114
| | - Dhinakaran Chinappen
- Graduate Program in Neuroscience, Boston University, Boston, MA 02215; Department of Neurology, Massachusetts General Hospital, Boston, MA 02114
| | - Britt C Emerton
- Department of Psychiatry, Massachusetts General Hospital, Boston, MA 02114
| | - Amy K Morgan
- Department of Psychiatry, Massachusetts General Hospital, Boston, MA 02114
| | - Matti S Hämäläinen
- Harvard Medical School, Boston, MA 02115; Athinoula A. Martinos Center for Biomedical Imaging, Charlestown, MA 02129; Massachusetts General Hospital, Department of Radiology, Boston, MA 02114
| | - Dara S Manoach
- Department of Psychiatry, Massachusetts General Hospital, Boston, MA 02114; Harvard Medical School, Boston, MA 02115; Athinoula A. Martinos Center for Biomedical Imaging, Charlestown, MA 02129
| | - Uri T Eden
- Department of Mathematics and Statistics, Boston University, Boston, MA 02215; Center for Systems Neuroscience, Boston University, Boston, MA 02215
| | - Mark A Kramer
- Department of Mathematics and Statistics, Boston University, Boston, MA 02215; Center for Systems Neuroscience, Boston University, Boston, MA 02215
| | - Catherine J Chu
- Department of Neurology, Massachusetts General Hospital, Boston, MA 02114; Department of Psychiatry, Massachusetts General Hospital, Boston, MA 02114.
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Mader EC, Xiang XM, Olejniczak PW, Miller D. Ictal Hypersalivation and Salivary Gland Enlargement in a Patient With Acquired Frontal Lobe Epilepsy. Cureus 2021; 13:e15319. [PMID: 34221768 PMCID: PMC8238497 DOI: 10.7759/cureus.15319] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Hypersalivation is a well-known ictal semiology of benign Rolandic epilepsy and other childhood epilepsy syndromes. There are also occasional reports of adults with temporal, parietal, or frontal lobe epilepsy in which hypersalivation is a prominent seizure manifestation. Notably lacking are reports linking salivary gland enlargement to ictal hypersalivation. A 33-year-old man with frontal lobe epilepsy due to a ruptured aneurysm presented with focal seizures and facial swelling. The only seizures he had in the past were generalized tonic-clonic seizures. Eight days prior to admission, he started having focal seizures characterized by pronounced hypersalivation, speech arrest, impaired awareness, and left upper extremity posturing or automatism. Seizure frequency increased from five to 30 per day. Four days prior to admission, his face started to swell up, and his family thought he had mumps. Computed tomography (CT) of the head showed encephalomalacia in the inferomedial cortex of the right frontal lobe, the same lesion seen in his old CT images. Maxillofacial CT revealed enlargement of the parotid and submandibular glands. Although electroencephalography (EEG) showed seizure onset in the right frontal region, the initial ictal discharge on the scalp may represent seizure propagation from a focus near the zone of encephalomalacia. After seizure freedom was achieved with antiepileptic drugs, the patient’s salivary glands decreased in size and returned to normal.
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Affiliation(s)
- Edward C Mader
- Neurology, Louisiana State University Health Sciences Center, New Orleans, USA
| | - Xinran M Xiang
- Pediatric Neurology, Oregon Health & Science University, Portland, USA
| | - Piotr W Olejniczak
- Neurology, Louisiana State University Health Sciences Center, New Orleans, USA
| | - Daniella Miller
- Pediatric Neurology, Louisiana State University Health Sciences Center, New Orleans, USA
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