The Insertion of Electrodes in the Brain for Electrophysiological Recording or Chronic Stimulation Is Not Associated With Any Biochemically Detectable Neuronal Injury

OBJECTIVE

The aim of this study was to evaluate the degree of brain tissue injury that could be potentially induced by the introduction of a) microrecording electrodes, b) macrostimulation electrodes, or c) chronic stimulation electrodes. We aimed to evaluate whether the use of five simultaneous microrecording tracks is associated with any brain injury not detectable by conventional imaging such as CT or MRI.

MATERIALS AND METHODS

The study included 61 patients who underwent surgery for implantation of 121 DBS leads. In all cases, five simultaneous tracts were utilized for microelectrode recordings. All patients underwent measurements of serum S-100b at specific time points as follows: a) prior to the operation, and b) intraoperatively at specific stages of the procedure: 1) after opening the burr hole, 2) after the insertion of microrecording electrodes, 3) during macrostimulation, 4) at the end of the operation, and 5) on the first postoperative day.

RESULTS

The levels of serum S-100B protein remained within the normal range during the entire period of investigation in all patients with the exception of two cases. In both patients, the procedure was complicated by intraparenchymal hemorrhage visible in neuro-imaging. The first patient developed a small intraparenchymal hemorrhage, visible on the postoperative MRI, with no neurological deficit. The second patient experienced a focal epileptic seizure after the insertion of the right DBS chronic lead and the postoperative CT scan revealed a right frontal lobe hemorrhage.

CONCLUSION

These results strongly indicate that the insertion of either multiple recording electrodes or the implantation of chronic electrodes in DBS does not increase the risk of brain hemorrhage or of other intracranial complications, and furthermore it does not cause any biochemically detectable brain tissue damage.

Assessment of both serum S-100B protein and neuropeptide-Y levels in childhood breath-holding spells

OBJECTIVE

Breath-holding spells are common paroxysmal events in children. Although the spells have a benign prognosis in the long term, they may be complicated by loss of consciousness, tonic-clonic movements, and occasionally seizures. Hence, this study aimed to measure the levels of serum S-100B proteins and neuropeptide-Y in the blood of children who experience breath-holding spells.

METHODS

The study groups consisted of 45 patients (13 females, 32 males) with breath-holding spells and a control group of 32 healthy individuals (12 females, 20 males). The serum S-100B levels were measured using commercially available ELISA kits. The neuropeptide-Y levels in the serum were measured with RayBio® Human/Mouse/Rat Neuropeptide Y ELISA kits.

RESULTS

The mean serum S-100B protein level of the breath-holding spells group was 56.38 ± 13.26 pg/mL, and of the control group, 48.53 ± 16.77 pg/mL. The mean neuropeptide-Y level was 62.29 ± 13.89 pg/mL in the breath-holding spells group and 58.24 ± 12.30 pg/mL in the control group. There were significant differences between the groups with respect to serum S-100B protein levels (p = 0.025), while there was no statistically significant difference in neuropeptide-Y levels between the breath-holding spells group and the control group (p = 0.192).

CONCLUSIONS

The findings of this study suggest that frequent and lengthy breath-holding may lead to the development of neuronal metabolic dysfunction or neuronal damage which is most likely related to hypoxia. In light of these findings, future studies should be conducted using biochemical and radiological imaging techniques to support these results.

Prognostic value of brain injury biomarkers in acute encephalitis/encephalopathy

BACKGROUND

Acute encephalitis/encephalopathy (AEE) is a devastating cause of severe neurodevelopmental sequelae or death in children. Assessing ongoing brain injury and predicting outcomes using bedside point-of-care testing is expected to be extremely valuable.

METHODS

For this study, three brain injury markers, S-100B, glial fibrillary acidic protein (GFAP), and tau protein, were measured in early cerebrospinal fluid samples of children with AEE. Subjects comprised three groups: Group 1 (non-AEE control, n = 27); Group 2 (AEE with normal resolution or mild sequelae, n = 13); and Group 3 (AEE with severe sequelae or death, i.e. "poor outcome," n = 10).

RESULTS

All marker levels were significantly higher in Group 3 than in Group 1 or 2. In Group 3, only S-100B was significantly higher in non-survivors than in survivors. For scoring assessment (range: 0-3 points), the predictive accuracies of 3 points for poor outcomes in children with AEE (i.e. Group 2 and 3, n = 23) were 91% (21/23) for S-100B, 74% (17/23) for GFAP, and 78% (18/23) for tau. When the scores were summed up for S-100B, GFAP, and tau (range: 0-9 points), and for S-100B and tau (range: 0-6 points), the patients with poor outcomes were identified more accurately using the respective thresholds of 6 points and 4 points (96% [22/23] and 100% [23/23], respectively).

CONCLUSION

Our findings suggest that combined measurement and scoring assessment of the markers, especially S-100B and tau, show promise as predictors of clinical outcomes in children with AEE.