Navita Choudhary - Academia.edu (original) (raw)
Papers by Navita Choudhary
CRC Press eBooks, Oct 17, 2012
Journal of epilepsy research, Dec 31, 2017
Refractory temporal lobe epilepsy (TLE) is commonly associated with imbalances in cardiovascular ... more Refractory temporal lobe epilepsy (TLE) is commonly associated with imbalances in cardiovascular (CV) parasympathetic and sympathetic functions, which are treated using TLE surgery. We investigated the effect of hemispheric lateralization of seizure foci on autonomic CV functions before and after TLE surgery. Methods: The study was conducted on patients with left TLE (LTLE, n = 23) and right TLE (RTLE, n = 30) undergoing unilateral TLE surgery. To assess the autonomic CV functions, changes in the heart rate (ΔHR) and blood pressure (BP) were measured using a standardized battery of autonomic reactivity tests before surgery and at 3 and 6 months after surgery. Results: Before surgery, ΔHR and the expiration to inspiration ratio (E:I) during the deep breathing test were higher in the LTLE group than in the RTLE group (both p < 0.001), but both outcomes were comparable between the groups at 3 and 6 months. ΔHR decreased at 3 and 6 months (p < 0.001 and 0.01, respectively) compared with preoperative values. The E:I at 3 months in the LTLE group was lower (p = 0.04) than the preoperative values. Decrease in systolic BP during the head-up tilt test was greater in the LTLE group than in the RTLE group (p = 0.002) before surgery. The maximum increase in diastolic BP during the cold pressor test was lower in the RTLE group at 6 months than that before surgery (p = 0.001) and in the LTLE group (p = 0.002). Conclusions: We found that hemispheric lateralization of seizure foci in the temporal lobe had a differential effect on autonomic CV functions before surgery. Before surgery, parasympathetic reactivity was higher in the LTLE group, and sympathetic reactivity was higher in the RTLE group. After surgery, autonomic CV functions were comparable between the groups, suggesting that TLE surgery stabilizes autonomic CV functions.
Epilepsy Research, Aug 1, 2012
Autonomic symptoms frequently occur during seizures. There are reports that the adult group of in... more Autonomic symptoms frequently occur during seizures. There are reports that the adult group of intractable epilepsy patients have different autonomic profile than the well controlled epilepsy, but there is no clear evidence in the children epilepsy group, therefore, we planned to study the autonomic profile in well controlled and refractory epilepsy children by recording the short-term heart rate variability (HRV). Methods: This cross sectional study was conducted in a tertiary care hospital between July 2008 and June 2009. Children with mean age of 9.1 ± 3.3 years were enrolled. Three groups of children, 40 in each group namely, refractory epilepsy, well controlled epilepsy and normal control children were included. Children who had chronic systemic diseases and were on drugs that cause autonomic dysfunction were excluded. All children underwent short term heart rate variability testing. Data was analyzed in time domain and frequency domain. Results: pNN50 was significantly lower in children with refractory epilepsy than the well control as well as healthy controls. Rest of the parameters of time domain and frequency domain were comparable between the groups. Conclusions: Our study showed that parasympathetic activity is lower in refractory epilepsy children. However, autonomic tone is comparable in well control versus healthy controls.
Journal of the Neurological Sciences, Oct 1, 2009
those which had interictal EEGs without abnormalities (9 patients) or with bilateral abnormalitie... more those which had interictal EEGs without abnormalities (9 patients) or with bilateral abnormalities (21 patients). In addition, video-EEG monitoring made it possible to rectify the diagnosis among 48 other patients. This approach allowed us to start our first experiment in term of epilepsy surgical treatment. Thirty five patients (19 with HS and 16 with mass lesion) have been operated with good outcomes in 28 cases. Non satisfying results were mostly obtained in patients with an association of secondary generalized seizures and interictal EEG abnormalities. Currently we try to improve our protocol while waiting for accessibility of invasive investigations in our country.
Journal of epilepsy research, 2017
Refractory temporal lobe epilepsy (TLE) is commonly associated with imbalances in cardiovascular ... more Refractory temporal lobe epilepsy (TLE) is commonly associated with imbalances in cardiovascular (CV) parasympathetic and sympathetic functions, which are treated using TLE surgery. We investigated the effect of hemispheric lateralization of seizure foci on autonomic CV functions before and after TLE surgery. The study was conducted on patients with left TLE (LTLE, n = 23) and right TLE (RTLE, n = 30) undergoing unilateral TLE surgery. To assess the autonomic CV functions, changes in the heart rate (ΔHR) and blood pressure (BP) were measured using a standardized battery of autonomic reactivity tests before surgery and at 3 and 6 months after surgery. Before surgery, ΔHR and the expiration to inspiration ratio (E:I) during the deep breathing test were higher in the LTLE group than in the RTLE group (both p < 0.001), but both outcomes were comparable between the groups at 3 and 6 months. ΔHR decreased at 3 and 6 months (p < 0.001 and 0.01, respectively) compared with preoperativ...
Clinical Applications, 2012
Seizure, 2010
Background The earliest known description of status epilepticus was in the 25th and 26th tablets ... more Background The earliest known description of status epilepticus was in the 25th and 26th tablets of the Sakikku cuneiform of the Neo-Babylonian era, written during 718-612 BC. 1 The operational definition of status epilepticus is an empirical compromise dictated by therapeutic needs, because treatment should not be delayed until patients are in established status epilepticus, when neuronal injury and time-dependent development of pharma-coresistance have occurred. 2 In its most severe form, refractory SE (RSE), continuous or repetitive seizures do not respond to benzodiazepines such as lorazepam and phenytoin-therapy. 3,4 Refractory status epilepticus (RSE) has been defined as seizures lasting >60 min, despite treatment with benzodiazepines (BZDs) and adequate antiepileptic medications (AEDs), or persistence of discrete seizures without return to baseline even with appropriate therapy. Randomized controlled trials comparing treatment strategies for RSE have not been performed to date, to our knowledge. RSE occurs in approximately 30% of patients with SE and is associated with increased hospital length of stay and functional disability and morbidity. 5 There should be no hesitation to intubate and severe arterial hypotension should be avoided because as it will curtail the cerebral blood flow. 2 However, in developing countries where facilities of intubation, adequate ventilation, Intensive Care Units and general anaesthesia are not always available, 6 need for an alternative AEDs which can abort the need for ventilation and buy time for transportation to a centre
Journal of the Neurological Sciences, 2009
those which had interictal EEGs without abnormalities (9 patients) or with bilateral abnormalitie... more those which had interictal EEGs without abnormalities (9 patients) or with bilateral abnormalities (21 patients). In addition, video-EEG monitoring made it possible to rectify the diagnosis among 48 other patients. This approach allowed us to start our first experiment in term of epilepsy surgical treatment. Thirty five patients (19 with HS and 16 with mass lesion) have been operated with good outcomes in 28 cases. Non satisfying results were mostly obtained in patients with an association of secondary generalized seizures and interictal EEG abnormalities. Currently we try to improve our protocol while waiting for accessibility of invasive investigations in our country.
Epilepsy Research, 2012
Autonomic symptoms frequently occur during seizures. There are reports that the adult group of in... more Autonomic symptoms frequently occur during seizures. There are reports that the adult group of intractable epilepsy patients have different autonomic profile than the well controlled epilepsy, but there is no clear evidence in the children epilepsy group, therefore, we planned to study the autonomic profile in well controlled and refractory epilepsy children by recording the short-term heart rate variability (HRV). Methods: This cross sectional study was conducted in a tertiary care hospital between July 2008 and June 2009. Children with mean age of 9.1 ± 3.3 years were enrolled. Three groups of children, 40 in each group namely, refractory epilepsy, well controlled epilepsy and normal control children were included. Children who had chronic systemic diseases and were on drugs that cause autonomic dysfunction were excluded. All children underwent short term heart rate variability testing. Data was analyzed in time domain and frequency domain. Results: pNN50 was significantly lower in children with refractory epilepsy than the well control as well as healthy controls. Rest of the parameters of time domain and frequency domain were comparable between the groups. Conclusions: Our study showed that parasympathetic activity is lower in refractory epilepsy children. However, autonomic tone is comparable in well control versus healthy controls.
Epilepsy Research, 2009
Epilepsy is associated with imbalance of sympathetic and parasympathetic activity which may lead ... more Epilepsy is associated with imbalance of sympathetic and parasympathetic activity which may lead to sudden unexplained death in epilepsy (SUDEP). Well-controlled (WcE) and intractable epilepsy (IE) subjects may present different autonomic profiles, which can be helpful in explaining the predisposition of the latter to SUDEP. To compare inter-ictal cardiovascular autonomic function in subjects with partial WcE and IE. Thirty WcE and 31 IE subjects underwent a battery of autonomic function tests: deep breathing, Valsalva maneuver, isometric exercise, cold pressor and tilt-table. Autonomic tone was assessed by heart rate variability (HRV). Their autonomic severity score and anxiety status was also assessed. IE subjects had elevated low frequency component (52.0 vs. 37.6, p=0.047) and decremented high frequency component (114 vs. 397, p=0.013) of HRV and higher diastolic BP (75.62+/-9.77 vs. 68.64+/-0.43, p=0.036). In deep breathing test, they had lesser HR changes (20+/-10.18 vs. 29.68+/-11.23, p=0.007) and lower E:I (1.29+/-0.16 vs. 1.43+/-0.21, p=0.008). IE subjects had higher dysautonomia (chi square 165.0, p&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;0.0001). We observed a higher vasomotor tone, higher sympathetic tone, lower parasympathetic tone, lower parasympathetic reactivity and more severe dysautonomia in the IE subjects. Refractoriness may lead to an alteration in cardiovascular autonomic regulation, which might be a predisposing factor for SUDEP.
Clinical EEG and Neuroscience, 2010
The phenomenon of temporal clustering of seizures is well known, but its effect on seizure locali... more The phenomenon of temporal clustering of seizures is well known, but its effect on seizure localization has not been rigorously analyzed. The aim of our study was to assess electrophysiological localization during Video EEG (VEEG) monitoring in patients with intractable epilepsy demonstrating a cluster of seizures. The study was conducted on 203 intractable epilepsy patients, aged 2 to 60 years (19.96 ± 10.87). Patients with unilateral temporal lobe epilepsy having clusters were compared with patients not having clusters, and the effect of clustering on concordance was addressed. Fully consistent localization was observed in 116 patients, partially consistent localization in 18 patients, and inconsistent localization in 19 patients. ANOVA did not reveal any significant difference in these groups (p = 0.65). A total of 770 seizures recorded from 149 patients was analyzed for clustering effect. Clustering was present in 603/770 seizures pairs (78.31%). In the cluster group, 483 (80.09...
The FASEB Journal
The effects of clonidine (C, sympatholytic drug) and lisinopril (L, ACE inhibitor) on thermoregul... more The effects of clonidine (C, sympatholytic drug) and lisinopril (L, ACE inhibitor) on thermoregulatory, cardiovascular, and autonomic responses to chronic (5 days, 2 times/day) exertional (ExHS) or non‐exertional (HS) heat stress were assessed in rats. ExHS and HS elicited increases in nocturnal core temperature (Tc) and heart rate (HR) in placebo (P) treated rats. This effect was blunted by C in the ExHS protocol and by both drugs in the HS‐only protocol. Nocturnal blood pressure (BP) increased more during the ExHS than the HS protocol. This hypertensive response to ExHS was blunted by both drugs. In P‐treated rats, baroreflex sensitivity decreased only during the ExHS protocol. L improved this impaired baroreflex function during exposure to ExHS more than C. In P‐treated rats, sympathetic modulation of cardiac and vascular function (low frequency HR and BP variability) was elevated in both protocols. Both drugs reduced this elevated sympathetic modulation of cardiovascular functio...
CRC Press eBooks, Oct 17, 2012
Journal of epilepsy research, Dec 31, 2017
Refractory temporal lobe epilepsy (TLE) is commonly associated with imbalances in cardiovascular ... more Refractory temporal lobe epilepsy (TLE) is commonly associated with imbalances in cardiovascular (CV) parasympathetic and sympathetic functions, which are treated using TLE surgery. We investigated the effect of hemispheric lateralization of seizure foci on autonomic CV functions before and after TLE surgery. Methods: The study was conducted on patients with left TLE (LTLE, n = 23) and right TLE (RTLE, n = 30) undergoing unilateral TLE surgery. To assess the autonomic CV functions, changes in the heart rate (ΔHR) and blood pressure (BP) were measured using a standardized battery of autonomic reactivity tests before surgery and at 3 and 6 months after surgery. Results: Before surgery, ΔHR and the expiration to inspiration ratio (E:I) during the deep breathing test were higher in the LTLE group than in the RTLE group (both p < 0.001), but both outcomes were comparable between the groups at 3 and 6 months. ΔHR decreased at 3 and 6 months (p < 0.001 and 0.01, respectively) compared with preoperative values. The E:I at 3 months in the LTLE group was lower (p = 0.04) than the preoperative values. Decrease in systolic BP during the head-up tilt test was greater in the LTLE group than in the RTLE group (p = 0.002) before surgery. The maximum increase in diastolic BP during the cold pressor test was lower in the RTLE group at 6 months than that before surgery (p = 0.001) and in the LTLE group (p = 0.002). Conclusions: We found that hemispheric lateralization of seizure foci in the temporal lobe had a differential effect on autonomic CV functions before surgery. Before surgery, parasympathetic reactivity was higher in the LTLE group, and sympathetic reactivity was higher in the RTLE group. After surgery, autonomic CV functions were comparable between the groups, suggesting that TLE surgery stabilizes autonomic CV functions.
Epilepsy Research, Aug 1, 2012
Autonomic symptoms frequently occur during seizures. There are reports that the adult group of in... more Autonomic symptoms frequently occur during seizures. There are reports that the adult group of intractable epilepsy patients have different autonomic profile than the well controlled epilepsy, but there is no clear evidence in the children epilepsy group, therefore, we planned to study the autonomic profile in well controlled and refractory epilepsy children by recording the short-term heart rate variability (HRV). Methods: This cross sectional study was conducted in a tertiary care hospital between July 2008 and June 2009. Children with mean age of 9.1 ± 3.3 years were enrolled. Three groups of children, 40 in each group namely, refractory epilepsy, well controlled epilepsy and normal control children were included. Children who had chronic systemic diseases and were on drugs that cause autonomic dysfunction were excluded. All children underwent short term heart rate variability testing. Data was analyzed in time domain and frequency domain. Results: pNN50 was significantly lower in children with refractory epilepsy than the well control as well as healthy controls. Rest of the parameters of time domain and frequency domain were comparable between the groups. Conclusions: Our study showed that parasympathetic activity is lower in refractory epilepsy children. However, autonomic tone is comparable in well control versus healthy controls.
Journal of the Neurological Sciences, Oct 1, 2009
those which had interictal EEGs without abnormalities (9 patients) or with bilateral abnormalitie... more those which had interictal EEGs without abnormalities (9 patients) or with bilateral abnormalities (21 patients). In addition, video-EEG monitoring made it possible to rectify the diagnosis among 48 other patients. This approach allowed us to start our first experiment in term of epilepsy surgical treatment. Thirty five patients (19 with HS and 16 with mass lesion) have been operated with good outcomes in 28 cases. Non satisfying results were mostly obtained in patients with an association of secondary generalized seizures and interictal EEG abnormalities. Currently we try to improve our protocol while waiting for accessibility of invasive investigations in our country.
Journal of epilepsy research, 2017
Refractory temporal lobe epilepsy (TLE) is commonly associated with imbalances in cardiovascular ... more Refractory temporal lobe epilepsy (TLE) is commonly associated with imbalances in cardiovascular (CV) parasympathetic and sympathetic functions, which are treated using TLE surgery. We investigated the effect of hemispheric lateralization of seizure foci on autonomic CV functions before and after TLE surgery. The study was conducted on patients with left TLE (LTLE, n = 23) and right TLE (RTLE, n = 30) undergoing unilateral TLE surgery. To assess the autonomic CV functions, changes in the heart rate (ΔHR) and blood pressure (BP) were measured using a standardized battery of autonomic reactivity tests before surgery and at 3 and 6 months after surgery. Before surgery, ΔHR and the expiration to inspiration ratio (E:I) during the deep breathing test were higher in the LTLE group than in the RTLE group (both p < 0.001), but both outcomes were comparable between the groups at 3 and 6 months. ΔHR decreased at 3 and 6 months (p < 0.001 and 0.01, respectively) compared with preoperativ...
Clinical Applications, 2012
Seizure, 2010
Background The earliest known description of status epilepticus was in the 25th and 26th tablets ... more Background The earliest known description of status epilepticus was in the 25th and 26th tablets of the Sakikku cuneiform of the Neo-Babylonian era, written during 718-612 BC. 1 The operational definition of status epilepticus is an empirical compromise dictated by therapeutic needs, because treatment should not be delayed until patients are in established status epilepticus, when neuronal injury and time-dependent development of pharma-coresistance have occurred. 2 In its most severe form, refractory SE (RSE), continuous or repetitive seizures do not respond to benzodiazepines such as lorazepam and phenytoin-therapy. 3,4 Refractory status epilepticus (RSE) has been defined as seizures lasting >60 min, despite treatment with benzodiazepines (BZDs) and adequate antiepileptic medications (AEDs), or persistence of discrete seizures without return to baseline even with appropriate therapy. Randomized controlled trials comparing treatment strategies for RSE have not been performed to date, to our knowledge. RSE occurs in approximately 30% of patients with SE and is associated with increased hospital length of stay and functional disability and morbidity. 5 There should be no hesitation to intubate and severe arterial hypotension should be avoided because as it will curtail the cerebral blood flow. 2 However, in developing countries where facilities of intubation, adequate ventilation, Intensive Care Units and general anaesthesia are not always available, 6 need for an alternative AEDs which can abort the need for ventilation and buy time for transportation to a centre
Journal of the Neurological Sciences, 2009
those which had interictal EEGs without abnormalities (9 patients) or with bilateral abnormalitie... more those which had interictal EEGs without abnormalities (9 patients) or with bilateral abnormalities (21 patients). In addition, video-EEG monitoring made it possible to rectify the diagnosis among 48 other patients. This approach allowed us to start our first experiment in term of epilepsy surgical treatment. Thirty five patients (19 with HS and 16 with mass lesion) have been operated with good outcomes in 28 cases. Non satisfying results were mostly obtained in patients with an association of secondary generalized seizures and interictal EEG abnormalities. Currently we try to improve our protocol while waiting for accessibility of invasive investigations in our country.
Epilepsy Research, 2012
Autonomic symptoms frequently occur during seizures. There are reports that the adult group of in... more Autonomic symptoms frequently occur during seizures. There are reports that the adult group of intractable epilepsy patients have different autonomic profile than the well controlled epilepsy, but there is no clear evidence in the children epilepsy group, therefore, we planned to study the autonomic profile in well controlled and refractory epilepsy children by recording the short-term heart rate variability (HRV). Methods: This cross sectional study was conducted in a tertiary care hospital between July 2008 and June 2009. Children with mean age of 9.1 ± 3.3 years were enrolled. Three groups of children, 40 in each group namely, refractory epilepsy, well controlled epilepsy and normal control children were included. Children who had chronic systemic diseases and were on drugs that cause autonomic dysfunction were excluded. All children underwent short term heart rate variability testing. Data was analyzed in time domain and frequency domain. Results: pNN50 was significantly lower in children with refractory epilepsy than the well control as well as healthy controls. Rest of the parameters of time domain and frequency domain were comparable between the groups. Conclusions: Our study showed that parasympathetic activity is lower in refractory epilepsy children. However, autonomic tone is comparable in well control versus healthy controls.
Epilepsy Research, 2009
Epilepsy is associated with imbalance of sympathetic and parasympathetic activity which may lead ... more Epilepsy is associated with imbalance of sympathetic and parasympathetic activity which may lead to sudden unexplained death in epilepsy (SUDEP). Well-controlled (WcE) and intractable epilepsy (IE) subjects may present different autonomic profiles, which can be helpful in explaining the predisposition of the latter to SUDEP. To compare inter-ictal cardiovascular autonomic function in subjects with partial WcE and IE. Thirty WcE and 31 IE subjects underwent a battery of autonomic function tests: deep breathing, Valsalva maneuver, isometric exercise, cold pressor and tilt-table. Autonomic tone was assessed by heart rate variability (HRV). Their autonomic severity score and anxiety status was also assessed. IE subjects had elevated low frequency component (52.0 vs. 37.6, p=0.047) and decremented high frequency component (114 vs. 397, p=0.013) of HRV and higher diastolic BP (75.62+/-9.77 vs. 68.64+/-0.43, p=0.036). In deep breathing test, they had lesser HR changes (20+/-10.18 vs. 29.68+/-11.23, p=0.007) and lower E:I (1.29+/-0.16 vs. 1.43+/-0.21, p=0.008). IE subjects had higher dysautonomia (chi square 165.0, p&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;0.0001). We observed a higher vasomotor tone, higher sympathetic tone, lower parasympathetic tone, lower parasympathetic reactivity and more severe dysautonomia in the IE subjects. Refractoriness may lead to an alteration in cardiovascular autonomic regulation, which might be a predisposing factor for SUDEP.
Clinical EEG and Neuroscience, 2010
The phenomenon of temporal clustering of seizures is well known, but its effect on seizure locali... more The phenomenon of temporal clustering of seizures is well known, but its effect on seizure localization has not been rigorously analyzed. The aim of our study was to assess electrophysiological localization during Video EEG (VEEG) monitoring in patients with intractable epilepsy demonstrating a cluster of seizures. The study was conducted on 203 intractable epilepsy patients, aged 2 to 60 years (19.96 ± 10.87). Patients with unilateral temporal lobe epilepsy having clusters were compared with patients not having clusters, and the effect of clustering on concordance was addressed. Fully consistent localization was observed in 116 patients, partially consistent localization in 18 patients, and inconsistent localization in 19 patients. ANOVA did not reveal any significant difference in these groups (p = 0.65). A total of 770 seizures recorded from 149 patients was analyzed for clustering effect. Clustering was present in 603/770 seizures pairs (78.31%). In the cluster group, 483 (80.09...
The FASEB Journal
The effects of clonidine (C, sympatholytic drug) and lisinopril (L, ACE inhibitor) on thermoregul... more The effects of clonidine (C, sympatholytic drug) and lisinopril (L, ACE inhibitor) on thermoregulatory, cardiovascular, and autonomic responses to chronic (5 days, 2 times/day) exertional (ExHS) or non‐exertional (HS) heat stress were assessed in rats. ExHS and HS elicited increases in nocturnal core temperature (Tc) and heart rate (HR) in placebo (P) treated rats. This effect was blunted by C in the ExHS protocol and by both drugs in the HS‐only protocol. Nocturnal blood pressure (BP) increased more during the ExHS than the HS protocol. This hypertensive response to ExHS was blunted by both drugs. In P‐treated rats, baroreflex sensitivity decreased only during the ExHS protocol. L improved this impaired baroreflex function during exposure to ExHS more than C. In P‐treated rats, sympathetic modulation of cardiac and vascular function (low frequency HR and BP variability) was elevated in both protocols. Both drugs reduced this elevated sympathetic modulation of cardiovascular functio...