Earlier Tachycardia Onset in Right then Left Medial Temporal Lobe Seizures

Epilepsy News From: Wednesday, October 15, 2014

In the September 5, 2014, articles published ahead of print in the journal Neurology, Doctors Kato and colleagues from the Department of Epileptology, Neurology and Neurosurgery at the Tohoku University Graduate School of Medicine in Sendai, Japan, present a fascinating analysis assessing tachycardia and how it relates to either right or left temporal lobe seizures. 

  • The particular objective of this paper was to clarify whether the presence and timing of peri-ictal heart rate change is a seizure lateralizing sign in patients with medial temporal lobe epilepsy. 

How was the study conducted?

  • The investigators reviewed long-term video monitoring in 21 people, 7 men and 14 women, between the ages of 13 to 67 years, diagnosed with medial temporal lobe epilepsy with MRI lesions in the medial temporal structures, (i.e., hippocampal sclerosis or amygdala hypertrophy). 
  • Investigators reviewed 77 partial seizures without secondary generalization. 
  • The investigators then looked at the peri-ictal or around seizure heart rate change and compared them between the people with left and right seizure.

What did the study find?

  • The researchers found that heart rate abruptly increased in all 29 right seizures and in 42 of 48 left temporal seizures. The onset time of heart rate increase in relation to the seizure onset was earlier in right seizures than in left seizures.
  •  The time of maximum heart rate was significantly earlier in the right than the left by 36 seconds vs. 58 seconds. The maximum heart rate changes from baseline showed no significant difference between the right and left seizures.
  •  The researchers conclude that earlier increases in pulse rate in right medial temporal lobe seizures more than the left support previous ideas the right cerebral hemisphere is dominant in the network that controls heart rate or sympathetic system.

Authored by

Joseph I. Sirven MD

Reviewed Date

Wednesday, October 15, 2014

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