Tetsuya Yokoyama

Effects of Dorsal Column Spinal Cord Stimulation (DCS) on Reversibility of Neuronal Function—Experience of Treatment for Vegetative States

We have reported that DCS (dorsal column stimulation) improves the clinical symptoms of cases in persistent vegetative states. Since then, we have accumulated 23 cases who have been treated by DCS. We describe the clinical EEG, rCBF, and biochemical changes in cerebrospinal fluid (CSF) caused by DCS in patients in persistent vegetative states; (1) eight of these cases showed good clinical improvement; (2) most patients were young and the CTscan did not show large, diffuse, definite or bilateral low density areas in cortex, brainstem of thalmus; (3) neurostimulation increased rCBF (cerebral blood flow) in many parts of the brain in cases with vegetative states; blood flow increased in the cerebrum, cerebellum and brainstem; (4) neurostimuiation enhanced the metabolism of catecholamines in CSF, NE, DA, DOPAC, HVA, and 5H1AA increased, but 3MT and 5HT decreased in CSF. DCS increased rCBF, enhanced the metabolism of catecholamines in CSF, and improved the EEG in patients in persistent vegetative states.

Dorsal column stimulation in persistent vegetative state.

Objectives.  The problem of treating patients in a vegetative state remains grossly unresolved, and spinal cord stimulation (SCS) had seemed promising in some studies, suggesting, to us, further study.

CLINICAL USEFULNESS OF 3-D CT ENDOSCOPIC IMAGING OF CEREBRAL ANEURYSMS

Usefulness of endoscopic imaging of cerebral aneurysms is presented. 3D-luminal images were obtained using a new processing technique which extracts CT numbers in the boundary region between the vessel wall and contrast media filling in the vascular lumen. Clinical application of this technique to complicated large cerebral aneurysms showed that, with this 3D-CT endoscopic images and MRA, anatomical details of cerebral aneurysms such as the orifice of the aneurysm, intraluminal thrombus, and calcification of the wall could be clearly demonstrated. We operated on two large, complicated aneurysms after obtaining 3D-CT endoscopy images of the aneurysms. Such information was found to be very useful when operating on difficult and complicated cerebral aneurysms.

Neurostimulation for patients in vegetative status.

Dorsal column stimulation has been used in four patients who were in a persistent vegetative state. There was improvement of the EEG in four patients and clinical improvement in three patients. Stimulation was for 12 hours per day at 100 Hz, 5 to 8 volts, and with a pulse width of 0.12 msec. The mechanism of improvement may involve changes in cerebral blood flow.

Deep hypothermia cardiopulmonary bypass and direct surgery of two large aneurysms at the Vertebro-Basilar junction

SummaryThis paper highlights two interesting cases of radial clipping of large aneurysms at the vertebro-basilar junction accompanied by a vascular anomaly, consisting of fenestration of the split basilar artery at its origin. Description of the inner and outer surface of the aneurysm were obtained pre-operatively, from analysis by 3D CT and 3D CT endoscopy of the form of the neck, parent vessels of the vertebral arteries on both sides, basilar artery and split basilar artery, as well as other details of branching. The neck exhibited a broad base in both cases. The height of the neck extended to the internal acoustic meatus, and it was possible to expose the circumference of the aneurysmal neck, peripheral basilar artery and both vertebral arteries proximally with an anterior transpetrosal approach. Based on the size of the aneurysm and the site being the anterior surface of the brain stem, clipping (consisting of interruption of the occluded portion and reconstruction of the parent vessels) was performed. In the first case it was achieved protecting the brain by hypothermia and barbiturates under deep hypothermia with extracorporal circulation, and in the second case, a state of circulatory arrest was used. This paper documents the report of two cases along with other cases treated so far.