Total resection of presacral giant schwannoma via minimally invasive dorsal approach: illustrative case

BACKGROUND

Giant presacral schwannomas are extremely rare in neurosurgery. There are various approaches to the surgical treatment of symptomatic giant presacral schwannomas. The least traumatic is the one-stage surgery with a dorsal approach.

OBSERVATIONS

The authors describe a case of a 52-year-old male with pain in the sacral region and partial urinary dysfunction. A total tumor resection through a minimally invasive dorsal approach was performed, and anatomical and functional preservation of all sacral nerves with no postoperative complications was achieved.

LESSONS

The authors have shown the possibility of total tumor resection with a minimally invasive dorsal approach without the development of intra- and postoperative complications. Operative corridors that have been created by a tumor can be used and expanded for a minimally invasive dorsal approach to facilitate resection and minimize tissue disruption.

TRANS-ENDOSCOPIC TREATMENT OF CRANIOPHARYNGIOMA AND RECOVERY FROM BLINDNESS IN ADULT PATIENT - A CASE REPORT

We report a case of trans-endoscopic transventricular approach to a large cystic craniopharyngioma. Surgery was performed three days after visual acuity on both eyes deteriorated to blindness. Magnetic resonance imaging before surgery revealed a large lesion in the suprasellar region that severely compressed the optic chiasm and displaced the third ventricle upward. The lesion was operated through the trans-endoscopic transventricular approach, with the aim of urgent decompression of the optic apparatus. At first, wide ventriculo-cysto-cisternostomy was performed, and then tumor tissue was removed. Postoperatively, visual acuity significantly improved on one eye. Our case shows that this minimally invasive technique is safe and effective and can be an alternative treatment for large cystic craniopharyngiomas. The reported case also shows that loss of vision can still be recovered even after the 72-hour period in adults.

MINIMALLY INVASIVE TREATMENT OF IDIOPATHIC SYRINGOMYELIA USING MYRINGOTOMY T-TUBES: A CASE REPORT AND TECHNICAL NOTE

Syringomyelia is characterized by a fluid-filled cavity within the spinal cord. Expansion of the syrinx often results in the clinical course of progressive neurologic deficit. Surgery for syringomyelia generally aims to treat the underlying cause, if it is known. However, little is known about idiopathic syringomyelia, which requires specific management. In our paper, an alternative, minimally invasive treatment option for large symptomatic idiopathic cervicothoracic syrinx is described and discussed. We present a case of a 44-year-old male without a history of spinal cord trauma, infection, or other pathologic processes, who presented for thoracic pain. Due to progressive pain and left leg paresis, magnetic resonance imaging (MRI) was performed and revealed extensive septated syringomyelia from T5 to T7 and hydromyelia cranially. We applied minimally invasive technique for shunting the idiopathic syrinx into the subarachnoid space using two Richards modified myringotomy T-tubes. Postoperative MRI revealed significant decrease in the syrinx size and clinical six-month follow-up showed improvement of clinical symptoms. This minimally invasive treatment of syringomyelia was found to be an effective method for idiopathic septated syrinx, without evident underlying cause. However, long-term follow-up and more patients are necessary for definitive evaluation of this technique.

Endoscopic treatment of in utero diagnosed multiloculated interhemispheric cyst in a newborn: case report

Interhemispheric cysts, often associated with agenesis of corpus callosum, are rare lesions. The optimal treatment is still controversial. Placement of cystoperitoneal shunt and open microsurgery are traditional treatments. Neuroendoscopy in children is due to its minimal invasiveness a new emerging option. There have been a few published cases on neuroendoscopic treatment of interhemispheric cyst in children. The authors document the youngest reported child with multiloculated interhemispheric cyst that was treated with neuroendoscopy. The cyst was detected in a male fetus in 35th week of gestation and in utero magnetic resonance imaging was performed in 37th week of gestation. After delivery, progressive macrocrania with signs of raised intracranial pressure developed. Endoscopic cystoventriculocisternostomy was performed 28 days after the birth. There was a marked symptom relief. One month after the surgery, magnetic resonance showed shrinkage of the cyst and expansion of the brain parenchyma. After a 2-month follow up period, the child showed normal neurologic development and head circumference increased by only 0.5 cm. The created fenestrations enabled the brain to expand. Neuroendoscopic treatment,of interhemispheric cysts should be considered the operative technique of choice in newborns. Although the intracranial pressure and the size of the cyst have decreased, long-term follow up is necessary and future studies on more cases are needed.

Fetal cerebrovascular response to chronic hypoxia—implications for the prevention of brain damage

Fetal hypoxia is one of the leading causes of perinatal morbidity and mortality. One of the most severe sequels of fetal hypoxic insult is the development of perinatal brain lesions resulting in a spectrum of neurological disabilities, from minor cerebral disorders to cerebral palsy. One of the most important fetal adaptive responses to hypoxia is redistribution of blood flow towards the fetal brain, known as the 'brain sparing effect'. The fetal blood flow redistribution in favor of the fetal brain can be detected and quantified by the Doppler cerebral/umbilical ratio (C/U ratio = cerebral resistance index (CRI)/umbilical resistance index (URI)). Our studies on animal models and human fetuses have demonstrated clearly that this phenomenon cannot prevent the development of perinatal brain lesions in the case of severe or prolonged hypoxia. Fetal deterioration in chronic and severe hypoxia is characterized by the disappearance of the physiological cerebral vascular variability (vasoconstriction and vasodilatation), followed by an increase in cerebral vascular resistance. However, our latest study on growth-restricted and hypoxic human fetuses has shown that perinatal brain lesions can develop even before the loss of cerebrovascular variability. The fetal exposure to hypoxia can be quantified by using a new vascular score, the hypoxia index. This parameter, which takes into account the degree as well as duration of fetal hypoxia, can be calculated by summing the daily % C/U ratio reduction from the cut-off value 1 over the period of observation. According to our results, the use of this parameter, which calculates the cumulative, relative oxygen deficit, could allow for the first time the sensitive and reliable prediction and even prevention of adverse neurological outcome in pregnancies complicated by fetal hypoxia.

New Doppler index for prediction of perinatal brain damage in growth-restricted and hypoxic fetuses

OBJECTIVE

To evaluate the new vascular score, hypoxia index (HI), in the prediction of sonographically detected structural brain lesions in neonates within the first week after delivery of growth-restricted fetuses.

METHODS

This prospective study included 29 growth-restricted fetuses delivered between 31 and 40 gestational weeks. Doppler umbilical artery (UA) and middle cerebral artery (MCA) resistance indices (RI) were recorded at 48-h intervals for at least 2 weeks before delivery. The cerebroumbilical ratio (C/U ratio = MCA-RI/UA-RI) and the HI (the sum of the daily reductions in C/U ratio, i.e. percentage below the cut-off value of 1, over the period of observation) were calculated. After delivery, neonatal outcome was evaluated according to obstetric parameters and ultrasound examinations of the brain. Doppler indices, C/U ratio and HI, as well as neonatal clinical and biochemical parameters, were tested as potential predictors of brain lesions using the C4.5 data-mining algorithm.

RESULTS

Neonatal brain lesions were detected in 13 growth-restricted fetuses. Of all the parameters tested by the C4.5 data-mining algorithm, only HI was identified as a predictor of neonatal brain lesions. HI also showed better correlation with neonatal biochemical parameters, such as umbilical venous partial pressure of oxygen and umbilical venous pH, compared with the C/U ratio.

CONCLUSIONS

HI, which takes into account cumulative oxygen deficit, could significantly improve the prediction of a poor neurological outcome in pregnancies complicated by growth restriction and hypoxia.

Doppler Cerebro-Umbilical Ratio and Fetal Biophysical Profile in the Assessment of Peripartal Cardiotocography in Growth-Retarded Fetuses

OBJECTIVE

The aim of the study was to examine the value of the fetal biophysical profile (FBP) and the Doppler cerebro-umbilical ratio (C/U) in the assessment of peripartal cardiotocography (CTG) in growth-retarded fetuses.

METHODS

The prospective study included 58 pregnant women with singleton pregnancy from 28 to 42 weeks of gestation with clinically and ultrasonically verified late intrauterine growth retardation (IUGR). After assessment of the FBP, flow velocity waveforms from the umbilical and middle cerebral arteries were recorded and the C/U ratio was calculated. The C/U ratio and the FBP were assessed twice a week. The last peripartal CTG was used as an outcome parameter.

RESULTS

The FBP score was statistically significant when associated with peripartal CTG (p < 0.001). The mean value of the FBP was 7.77 +/- 0.28 for infants with a normal peripartal CTG, 6.13 +/- 0.41 for infants with a prepathological CTG and 4.40 +/- 0.60 for infants with a pathological peripartal CTG. There was also a statistically significant association between the C/U ratio > or =1 and normal CTG (p < 0.005), but there was no statistically significant difference between prepathological and pathological CTG in relation to C/U ratio values (p > 0.05). Normal and pathological peripartal CTG was correlated with the perinatal outcome, but prepathological CTG was not correlated with results of the perinatal outcome (p > 0.05).

CONCLUSIONS

Our results showed that both methods of fetal monitoring need to be used in perinatal monitoring of growth-retarded fetuses. The two methods can be used as important parameters in deciding to end pregnancies with IUGR when pathological values occur.

Somatosensory evoked potentials in children with brain ventricular dilatation

AIM

To determine possible nerve conduction changes in the somatosensory pathway in children with brain ventricular dilatation and to estimate the relation between the ventricular size and somatosensory evoked potentials (SEP).

METHODS

Twelve children with ventricular dilatation (frontal and occipital horn ratios >0.44) and 19 children without ventricular dilatation (control group), aged between 2 and 15 years, were included in the study. Somatosensory evoked responses to median nerve stimulation were recorded in both groups. Evoked potentials were recorded by silver/silver chloride cup electrodes from Erb's point in the supraclavicular fossa (wave N9), the cervical spine at the C7 vertebral prominence (wave N13), and the scalp above the contralateral sensory cortex at the point C3' or C4', 1 cm behind the C3 or C4 site in the standard 10-20 system (wave N19). Computed tomography scanning was performed to estimate ventricular dilatation.

RESULTS

The conduction time of the central somatosensory pathway (N19-N13 interwave latency) was significantly longer in the children with ventricular dilatation than in the control group (P = 0.046). A statistically significant but weak correlation was found between the frontal and occipital horn ratio values and the N19-N13 interwave latencies in the subjects with enlarged ventricles (r = 0.579, P = 0.045).

CONCLUSION

Ventricular dilatation is associated with prolonged conduction of the central part of the somatosensory pathway in children. Early detection and treatment of hydrocephalus could be useful in preventing long-term consequences of high intraventricular pressure.

Intracranial pressure and biochemical indicators of brain damage: follow-up study

AIM

To investigate the relation between metabolic parameters of the brain tissue, as direct indicators of real metabolic conditions within the brain, and intracranial pressure, as the consequence of pathophysiological changes.

METHODS

Twelve patients with closed head injuries were followed up for 24 hours after injury. A Codman parenchymal intracranial pressure and a Neurotrend electrode were inserted within 3 hours after injury to monitor parenchymal intracranial pressure, brain tissue partial oxygen pressure (P(br)O2), brain tissue partial carbon dioxide pressure (P(br)CO2), pH, and brain tissue temperature. Data detected at 8-hourly intervals were compared with repeated measures analysis of variance.

RESULT

At the initial observation, the mean value of intracranial pressure was 22.2 +/- 3.2 mm Hg. Although it increased at the second and decreased at the third measurement, the differences between the measurements were not significant (P = 0.320). The value of P(br)CO2 was increased from the beginning (63.3 +/- 6.0 mm Hg), whereas P(br)O2 was within the normal range at the first measurement (38.9 +/- 6.9 mm Hg), but significantly decreased after 8 hours (P = 0.004), remaining low at later time points.

CONCLUSION

After brain injury, changes in P(br)CO2 are visible earlier than those in P(br)O2. Improvement in intracranial pressure values did not necessary mean improvement in the brain tissue oxygenation. In addition to intracranial pressure, P(br)O2, P(br)CO2 and pH should also be monitored, as they directly reflect the real metabolic conditions within brain tissue and may be used in predictions about the outcome and possible therapeutic approaches.

Fetal biophysical profile and cerebro-umbilical ratio in assessment of brain damage in growth restricted fetuses

OBJECTIVE

To examine the relationship between fetal biophysical profile (FBP), Doppler cerebro-umbilical (C/U) ratio and neonatal neurosonography in growth restricted newborns.

STUDY DESIGN

This prospective study included 87 growth restricted fetuses from 28 to 42 weeks of gestation. The FBP and C/U ratio were assessed twice a week. Within 48h and on the seventh day after birth, neonatal neurosonography was performed as the outcome parameter.

RESULTS

Brain damage was detected, by neurosonography, in 34 newborns with intrauterine growth restriction (IUGR). Severe periventricular echodensities (PVE) were ultrasonographically verified in eleven infants. Intraventricular or intraparenchymal hemorrhage (severe intracranial hemorrhage ICH) was detected in seven infants, and subependymal hemorrhage (SEH) in nine infants with IUGR. Porencephalic cysts, as a result of chronic intrauterine hypoxia, were found in four infants, and brain atrophy was detected in one case. Nonspecific ultrasonographic changes were observed in two newborns. The FBP and C/U ratio were statistically significantly associated with neurosonographicaly verified neonatal brain lesions (P < 0.001).

CONCLUSIONS

The FBP and the C/U ratio represent the useful indicators for early detection and assessment of fetal hypoxia. They may also be parameters for the prediction of neonatal neurosonography findings in newborns with IUGR.

[Intrauterine hypoxia and sudden infant death syndrome]

Sudden infant death syndrome (SIDS) or crib or cot death are synonyms for the sudden, unexpected and unexplained death of an infant. The incidence of SIDS has been estimated to be from 1-2% to 3%. Protracted intrauterine hypoxia or recurrent hypoxic insults during fetal life undoubtedly influence the development of the central nervous structures as a tissue most susceptible to hypoxia, although well developed mechanisms of defense against hypoxia exist during the fetal life. The mechanisms underlying SIDS include neurologically compromised infants who are deprived of compensatory mechanisms during sleep, sustaining a hypoxic insult with alterations in neurotransmitter receptors within the regions involved in chemoreception and cardiovascular control. Changes in the brain result from perinatal prolonged hypoxia (persistent reticular pathways in the pons and medulla, astroglia in the brainstem, gliosis of brain nerve nuclei, defects in neurotransmitter receptors, neuronal apoptosis, microthrombosis, and hypoxic ischemic lesion). Hypoxic perinatal risk factors for SIDS included passive and active exposure to cigarette smoking in pregnancy, abuse of drugs, alcohol, coffee and medication in pregnancy, intrauterine growth retardation, perinatal hypoxia with or without resuscitation, preeclampsia, anemia in pregnancy, prematurity, multiparity, multiple pregnancy, pregnant women aged < 20 years and > 35 years, cardiocirculatory, pulmonary and endocrine diseases in pregnancy, and short time interval between two pregnancies. As cigarette smoking has been demonstrated to lead to fetoplacental insufficiency, which result in fetal hypoxia, it is concluded that hypoxia is a precondition for the occurrence of SIDS. Prenatal exposure to cigarette smoke decreases maternal red blood cell count, and concentrations of tyrosine and selenium, reduces fetal and neonatal cerebral blood flow, and increases maternal MCV, leukocytosis, especially neutrophils, monocytes and lymphocytes, maternal and fetal heart rate, systolic and diastolic blood pressure, resistance index in umbilical artery, fetal hemoglobin, cytokine, serotonine, dopamine, catecholamine, hypoxanthine, endorphin and interleukin-6. Pregnancy at a risk of hypoxia, especially in heavy smokers, is a major risk factor for SIDS, and such pregnancy requires close and intensive antenatal monitoring.

Fetal biophysical profile and cerebro-umbilical ratio in assessment of perinatal outcome in growth-restricted fetuses

AIM

To examine the value of the fetal biophysical profile (FBP) and the Doppler cerebro-umbilical ratio (C/U) in the assessment of perinatal outcome in growth-restricted and hypoxic fetuses.

STUDY DESIGN

The prospective clinical study included 87 pregnant women with singleton pregnancies at 28-42 weeks of gestation with clinically verified intrauterine growth restriction (IUGR). After assessment of FBP, flow velocity waveforms from the umbilical and middle cerebral arteries were recorded and the C/U ratio was calculated. The C/U ratio and FBP were assessed twice a week. At delivery, umbilical arterial pH, the occurrence of meconium-stained amniotic fluid (MAF), Apgar score at 5 min and the incidence of cesarean sections were used as outcome parameters.

RESULTS

The mean FBP value was 5.5 +/- 0.96 in cases with MAF, and 6.88 +/- 0.26 in cases without MAF. Also, there was no statistical significance in the relation between the C/U ratio and the appearance of MAF. At pH >7.2, the mean FBP value was 7.11 +/- 0.23, while it was 2.83 +/- 0.79 in newborns with acidosis. Both FBP and C/U values were statistically correlated with pH (p < 0.01). The mean umbilical arterial pH was 7.31 +/- 0.0 at a C/U ratio of >/=1 and 7.21 +/- 0.03 at a C/U ratio of <1. In cases with Apgar scores of 8-10, the mean FBP value was 7.28 +/- 0.23, at Apgar scores of 5-7 it was 3.9 +/- 0.52, while at Apgar scores of 0-4 the mean FBP value was 1.5 +/- 0.5. The mean Apgar score at 5 min was 9.54 +/- 0.09 at a C/U ratio of >/=1, and 8.12 +/- 0.49 at a C/U ratio of <1. The mean FBP value in cases of vaginal delivery was 7.55 +/- 0.31. In cesarean section deliveries, the mean FBP value was 5.97 +/- 0.37. Also, there was a high frequency of cesarean sections in growth-restricted fetuses with a C/U ratio of <1 (p < 0.05), i.e. slightly less than FBP.

CONCLUSIONS

FBP and C/U ratio were associated with low arterial pH, low Apgar score and the rate of cesarean sections (p < 0.05), but there was no association between FBP or C/U ratio and the appearance of MAF (p > 0.5). Due to their good predictive value the FBP and C/U ratio could be used in the prenatal monitoring of growth-retarded and hypoxic fetuses. These two methods can be used as important parameters in the decision to end pregnancies with IUGR, when pathological values occur. Thus a reduction in perinatal morbidity, mortality and the incidence of infants with poor neurologic outcome can be expected.

Modified fetal biophysical profile in the assessment of perinatal outcome

The aim of the study is the evaluation of variables of the biophysical profile in the assessment of perinatal outcome. The prospective study included 87 pregnant women with singleton pregnancy in the 28th to 42nd week of gestation with clinically and ultrasonically verified fetal growth retardation, where the fetal biophysical profile was assessed antenatally. Through the factor analysis of biophysical profile variables we obtained values indicating the contribution of individual variables to the predictability of perinatal outcome. 70% of the patients were examined in 15 minutes according to the principles of modified biophysical profile. The most sensitive variable of the biophysical profile in the prediction of perinatal outcome was the amniotic fluid volume, followed by fetal breathing movements, non-stress test and fetal movements, while the lowest prediction value was assigned to the fetal tone. The modified biophysical profiles need to be perfected on a larger number of pregnant women, which would advance the predictability of this method in detection of hypoxically endangered fetuses.