Effect of stimulation of the dorsal aspect of the cervical spinal cord on local cerebral blood flow and EEG in the cat.
Currently there is considerable interest in electrical stimulation of the dorsal aspect of the cervical spinal cord as a potentially effective therapy for persistent vegetative patients. The authors assessed change in the local cerebral blood flow (LCBF) and electroencephalogram (EEG) in the cat following spinal cord stimulation (SCS). In 31 adult cats under isoflurane anesthesia, an electrode for SCS was introduced epidurally to the midline of the C2-C3 segment. Stimulation was performed at 25 Hz and 0.1 msec for 30 min. These animals were divided into five groups by the voltage: (1) 2V (n = 7), (2) 4V (n = 7), (3) 6V (n = 7), (4) 4V with intravenous injection of muscarinic cholinergic agents--atropine sulfate (n = 5), and (5) sham-operated control (n = 5) without stimulation. LCBF was measured by laser Doppler flowmetry through bilateral small burr holes at the parietal area during and 60 min after stimulation. At 2V, LCBF increased only during SCS, then returned to the pre-stimulated level, while the increase continued until the end of the experiment at 4V and 6V. The increase in LCBF was not affected by atropine sulfate. EEG showed spike and wave or polyspikes after SCS in two animals of the 6V group, but not in the 2V and 4V groups, and moreover a moderate increase of the background activity at only 4V. The present data suggested that SCS at 4V can provide the appropriate microcirculatory enhancement with less harmful influence which continues to increase 30 min after SCS, although the exact mechanism should be elucidated continuously. Within the limitation of animal experiments, this study could provide the logical basis for determining the condition of SCS.
Inoue
M
M
Department of Neurosurgery, Nara Medical University, Japan.
Nakase
H
H
Hirabayashi
H
H
Hoshida
T
T
Sakaki
T
T
D000109:Acetylcholine / Q000502:physiology; D000818:Animals; D001285:Atropine / Q000494:pharmacology; D001784:Blood Gas Analysis; D001794:Blood Pressure / Q000502:physiology; D002245:Carbon Dioxide / Q000494:pharmacology; D002415:Cats; D002560:Cerebrovascular Circulation / Q000187:drug effects / Q000502:physiology*; D002574:Cervical Vertebrae; D004558:Electric Stimulation; D004569:Electroencephalography; D005260:Female; D017078:Laser-Doppler Flowmetry; D008297:Male; D018727:Muscarinic Antagonists / Q000494:pharmacology; D013116:Spinal Cord / Q000502:physiology*
D018727:Muscarinic Antagonists; D002245:Carbon Dioxide; D001285:Atropine; D000109:Acetylcholine