Cardiovascular autonomic functions in well-controlled and intractable partial epilepsies.
BACKGROUND
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.


OBJECTIVE
To compare inter-ictal cardiovascular autonomic function in subjects with partial WcE and IE.


METHODS
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.


RESULTS
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<0.0001).


CONCLUSIONS
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.
Mukherjee
Shalini
S
Dept. of Neurology, UT Southwestern Medical Center at Dallas, 5323 Harry Hines Blvd, Dallas, TX, United States. shalini mukherjee@yahoo.com
Tripathi
Manjari
M
Chandra
Poodipedi S
PS
Yadav
Rajeev
R
Choudhary
Navita
N
Sagar
Rajesh
R
Bhore
Rafia
R
Pandey
Ravindra Mohan
RM
Deepak
K K
KK
D000293:Adolescent; D000328:Adult; D000927:Anticonvulsants / Q000627:therapeutic use*; D001341:Autonomic Nervous System / Q000503:physiopathology*; D001794:Blood Pressure / Q000187:drug effects; D002320:Cardiovascular Physiological Phenomena; D002648:Child; D002675:Child, Preschool; D003080:Cold Temperature; D004351:Drug Resistance; D004562:Electrocardiography; D004828:Epilepsies, Partial / Q000188:drug therapy* / Q000503:physiopathology* / Q000523:psychology; D005260:Female; D018737:Hand Strength / Q000502:physiology; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D015656:Respiratory Mechanics / Q000502:physiology; D014636:Valsalva Maneuver / Q000502:physiology; D055815:Young Adult
D000927:Anticonvulsants