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Singh V, Grewal KS, Vibha D, Singh RK, Ramanujam B, Nehra A, Chandra SP, Gaikwad S, Babu I, Tripathi M. Cortico-limbic disruption, material-specificity, and deficits in cognitive-affective theory of mind. Brain Commun 2023; 5:fcad100. [PMID: 37101833 PMCID: PMC10123397 DOI: 10.1093/braincomms/fcad100] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Revised: 12/20/2022] [Accepted: 04/18/2023] [Indexed: 04/28/2023] Open
Abstract
The Theory of Mind deficit due to cognitive-affective disintegration is a poorly understood cognitive consequence of cortical and subcortical disruption in right temporal lobe epilepsy. Following Marr's trilevel approach, we used the material-specific processing model to understand the Theory of Mind deficit in drug-resistant epilepsy (N = 30). We examined pre- and post-surgery changes in first-order (somatic-affective, non-verbal component) and second-order Theory of Mind (cognitive-verbal component) in three groups formed using: (i) seizure side (right versus left), (ii) right temporal epilepsy (right temporal lobe epilepsy versus non-right temporal lobe epilepsy), and (iii) right temporal lobe epilepsy with amygdalohippocampectomy (right temporal lobe epilepsy versus left temporal lobe epilepsy amygdalohippocampectomy versus non-amygdalohippocampectomy). We observed a marked deficit in the first-order Theory of Mind in the right temporal lobe amygdalohippocampectomy group; we mapped this deficit to decline in the non-verbal component of Theory of Mind (somatic-affective component). Preliminary results support using a material-specific processing model to understand the Theory of Mind deficits in right temporal lobe epilepsy amygdalohippocampectomy. Malleability of verbal processing in presence of deterioration of non-verbal processing might have clinical relevance for post-surgery recovery in right temporal lobe epilepsy amygdalohippocampectomy. Documenting the material-specific nature of deficits (verbal versus non-verbal) in non-western, linguistically, and socioeconomically diverse country enables us to understand the problem of heterogeneity in post-surgery cognitive consequences in the right amygdalohippocampectomy.
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Affiliation(s)
- Varsha Singh
- Psychology, Department of Humanities and Social Sciences, Indian Institute of Technology Delhi (IIT), New Delhi, 110016, India
| | - Kirat S Grewal
- Department of Neurology, Neurosciences Centre, All India Institute of Medical Sciences, Delhi (AIIMS), Delhi, New Delhi 110029, India
| | - Deepti Vibha
- Department of Neurology, Neurosciences Centre, All India Institute of Medical Sciences, Delhi (AIIMS), Delhi, New Delhi 110029, India
| | - Rajesh K Singh
- Department of Neurology, Neurosciences Centre, All India Institute of Medical Sciences, Delhi (AIIMS), Delhi, New Delhi 110029, India
| | - Bhargavi Ramanujam
- Department of Neurology, Neurosciences Centre, All India Institute of Medical Sciences, Delhi (AIIMS), Delhi, New Delhi 110029, India
| | - Ashima Nehra
- Neuropsychology, Neurosciences Centre, All India Institute of Medical Sciences (AIIMS), Delhi, New Delhi 110029, India
| | - Sarat P Chandra
- Department of Neurosurgery, All India Institute of Medical Sciences (AIIMS), Delhi, New Delhi 110029, India
| | - Shailesh Gaikwad
- Department of Neuroimaging Interventional Neuroradiology, All India Institute of Medical Sciences (AIIMS), Delhi, New Delhi 110029, India
| | - Indupriya Babu
- The UQIDAR Joint Ph.D. program, Indian Institute of Technology Delhi (IIT), New Delhi 110016.India
| | - Manjari Tripathi
- Correspondence to: Manjari Tripathi Room no 705, 7th Floor Department of Neurology AIIMS, New Delhi, Delhi, 110029, India E-mail:
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Chou P, Kuo CC. Anticonvulsant vs. Proconvulsant Effect of in situ Deep Brain Stimulation at the Epileptogenic Focus. Front Syst Neurosci 2021; 15:607450. [PMID: 34408632 PMCID: PMC8366291 DOI: 10.3389/fnsys.2021.607450] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Accepted: 07/05/2021] [Indexed: 11/20/2022] Open
Abstract
Since deep brain stimulation (DBS) at the epileptogenic focus (in situ) denotes long-term repetitive stimulation of the potentially epileptogenic structures, such as the amygdala, the hippocampus, and the cerebral cortex, a kindling effect and aggravation of seizures may happen and complicate the clinical condition. It is, thus, highly desirable to work out a protocol with an evident quenching (anticonvulsant) effect but free of concomitant proconvulsant side effects. We found that in the basolateral amygdala (BLA), an extremely wide range of pulsatile stimulation protocols eventually leads to the kindling effect. Only protocols with a pulse frequency of ≤1 Hz or a direct current (DC), with all of the other parameters unchanged, could never kindle the animal. On the other hand, the aforementioned DC stimulation (DCS), even a pulse as short as 10 s given 5 min before the kindling stimuli or a pulse given even to the contralateral BLA, is very effective against epileptogenicity and ictogenicity. Behavioral, electrophysiological, and histological findings consistently demonstrate success in seizure quenching or suppression as well as in the safety of the specific DBS protocol (e.g., no apparent brain damage by repeated sessions of stimulation applied to the BLA for 1 month). We conclude that in situ DCS, with a novel and rational design of the stimulation protocol composed of a very low (∼3% or 10 s/5 min) duty cycle and assuredly devoid of the potential of kindling, may make a successful antiepileptic therapy with adequate safety in terms of little epileptogenic adverse events and tissue damage.
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Affiliation(s)
- Ping Chou
- Institute of Physiology, National Taiwan University College of Medicine, Taipei, Taiwan
| | - Chung-Chin Kuo
- Institute of Physiology, National Taiwan University College of Medicine, Taipei, Taiwan.,Department of Neurology, National Taiwan University Hospital, Taipei, Taiwan
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