László Novák

The relative exposure of the operating room staff to sevoflurane during intracerebral surgery.

BACKGROUND: Our primary aim in this study was to investigate whether escape of the volatile anesthetic sevoflurane from the surgical site during craniotomy for tumor resection increases the exposure of the neurosurgeon to the anesthetic when compared with the anesthesiologist. METHODS: Initially, the release of sevoflurane from the surgical site was measured during 35 tumorectomies starting from opening to closure of the dura. Volatile anesthetic absorbers were placed at three detection sites: 1) the surgeon’s breathing zone, 2) the anesthesiologist’s breathing zone, and 3) the farthest corner of the operation room. In the second sampling series that included 16 patients, the detector that had been in the corner of the operating room in the first series was now placed in the vicinity of the patient’s mouth (within 5 cm). Sevoflurane captured by the absorbers was quantified by an independent chemist using chromatography. RESULTS: Absorbers in the surgeon’s breathing zone (0.24 ± 0.04 ppm) captured a significantly lower amount of sevoflurane compared with absorbers in the anesthesiologist’s breathing zone (1.40 ± 0.37 ppm) and comparable with that in the farthest corner of the operation room (0.25 ± 0.07 ppm). There was no correlation between the amount of absorbed sevoflurane and the size of craniotomy window, even when adjusting for the variation in duration of surgery. In the second series of sampling, absorbers in the proximity of the patient’s mouth captured the highest amount of sevoflurane (1.54 ± 0.55 ppm), followed by the anesthesiologist’s (1.14 ± 0.43 ppm) and the surgeon’s (0.15 ± 0.05 ppm) breathing zones. CONCLUSIONS: The close proximity of the surgeon’s breathing zone to the craniotomy window does not appear to be a source of increased exposure to sevoflurane. The observed higher exposure of the anesthesiologist to sevoflurane in the operating room environment warrants further exploration.

Cerebrovascular Reserve Capacity Many Years After Vasospasm Due to Aneurysmal Subarachnoid Hemorrhage: A Transcranial Doppler Study With Acetazolamide Test

BACKGROUND AND PURPOSE Vasospasm in aneurysmal subarachnoid hemorrhage results in proliferative vasculopathy. Systemic hypertension also causes vascular hypertrophy. Both of these histological changes can lead to rigidity of the cerebrovascular system, reducing its autoregulatory capacity. METHODS Blood flow velocity (BFV) in the middle cerebral artery at rest and cerebrovascular reserve capacity (CVRC) (percent rise in BFV after acetazolamide stimulation) measured by means of transcranial Doppler sonography were studied many years after aneurysmal subarachnoid hemorrhage in patients with proven cerebral vasospasm (mean BFV > 160 cm/s). The BFV under resting conditions and the CVRC values of the ipsilateral and the contralateral hemispheres were measured in 29 patients (mean age, 43 years; mean follow-up, 4.6 years) and compared with those of control subjects. RESULTS Persistent high BFV (> 120 cm/s) was found in three patients in the peripheral branch of the ipsilateral middle cerebral artery. In the main trunks of the arteries of the anterior circle of Willis, BFV was normal in all cases. CVRC was normal in all patients (ipsilateral, 52 +/- 21%; contralateral, 56 +/- 17%); values did not differ significantly from each other or from the control value (45 +/- 18%). The higher value of CVRC on the contralateral side was found to be statistically significant in selected groups (hypertensive patients and patients with residual infarct on late CT). CONCLUSIONS Proliferative vasculopathy developed at the time of vasospasm must have resolved and did not reduce late vasoreactivity. Comorbidity with hypertension also did not seem to influence the late vasoreactivity toward normalization.

Regional cerebral 18FDG uptake during subarachnoid hemorrhage induced vasospasm

Abstract Objectives: The aim was to elucidate whether aneurysmal subarachnoid hemorrhage (SAH)-induced vasospasm induces changes of regional glucose uptake in surgically treated, asymptomatic cases. Methods: 18FDG uptake (standardized uptake value, SUV) was analysed with PET in eight surgically treated aneurismal patients with a mean middle cerebral artery flow velocity >120 cm/seconds measured with transcranial Doppler ultrasound. Data were compared with a healthy control group using Statistical Parametric Mapping (SPM99b). Results: Six of the eight patients had no focal neurological signs. The inhomogeneous bilateral increase in SUV (p<0.0001) was asymmetrical, with an almost 70% larger volume on the operated side. Reduced glucose uptake was found in the frontal and temporobasal regions of the two patients with neurological deficits (p<0.0001); the affected volume was 40% larger on the operated side. Discussion: SAH-induced vasospasm results in widespread increase of glucose uptake—probably reflecting increased glycolysis. This was earlier than neurological focal signs appear. Decreased glucose uptake can be detected in severe cases of vasospasm reflected by neurological deficit. Although the changes are more prominent where surgery had taken place our results suggest that not only the surgery, but also subarachnoid blood might have resulted in our findings.

Correlation between central somatosensory conduction time, blood flow velocity, and delayed cerebral ischemia after aneurysmal subarachnoid hemorrhage.

In this retrospective study of 67 aneurysmal patients, the predictive role of central conduction time (CCT) on vasospasm occurrence evaluated by means of transcranial Doppler sonography (TCD) and the correlation of CCT to blood flow velocity measured simultaneously in postoperative course were studied.Data about the clinical state of patients at the time of admission (Hunt Hess scale), severity of subarachnoidal hemorrhage on initial CT scan (Fisher grade), timing of surgery (acute or delayed), outcome (Glasgow Outcome Scale), severity of vasospasm graded by highest mean blood flow velocity (BFV) during the entire clinical course, and CCT values measured at admission (preoperatively), then post-operatively (one day after surgery) and simultaneously with later TCD investigations were collected from the files. Interhemispheric difference of CCT was also calculated.The results showed that CCT at admission was not predictive for vasospasm. CCT measured either at admission or on the first postoperative day did not differ significantly in the different grades of vasospasm. Similar results were obtained in the acute and in the late operated group of patients. The results also suggest that increased CCT and interhemispheric difference at the time of admission indicate a worse prognosis, but this can be related to higher surgical risk rather than to a higher incidence of late ischemic deterioration. Simultaneous CCT and TCD examinations demonstrated that coincident and statistically significant (p < 0.01) increase of actual CCT (6.7 msec) was found only in the severe grade of vasospasm (BFV < 200 cm/s). The authors discuss the role of CCT and TCD monitoring in the management of aneurysmal subarachnoid hemorrhage.

A single preoperative dose of diclofenac reduces the intensity of acute postcraniotomy headache and decreases analgesic requirements over five postoperative days in adults: A single center, randomized, blinded trial☆

OBJECTIVE Postcraniotomy headache causes considerable pain and can be difficult to treat. We therefore tested the hypothesis that a single 100-mg preoperative dose of diclofenac reduces the intensity of postcraniotomy headache, and reduces analgesic requirements. METHODS 200 patients having elective craniotomies were randomly assigned to diclofenac (n = 100) or control (n = 100). Pain severity was assessed by an independent observer using a 10-cm-long visual analog scale the evening of surgery, and on the 1st and 5th postoperative days. Analgesics given during the first five postoperative days were converted to intramuscular morphine equivalents. Results were compared using Mann-Whitney-tests; P < 0.05 was considered statistically significant. RESULTS Baseline and surgical characteristics were comparable in the diclofenac and control groups. Visual analog pain scores were slightly, but significantly lower with diclofenac at all times (means and 95% confidence intervals): the evening of surgery, 2.47 (1.8-3.1) vs. 4. 37 (5.0-3.7), (P < 0.001); first postoperative day, 3.98 (3.4-4.6) vs. 5.6 (4.9-6.2) cm (P < 0.001) and 5th postoperative day: 2.8 (2.2-3.4) vs. 4.0 ± (3.3-4.7) cm (P = 0.013). Diclofenac reduced systemic analgesic requirements over the initial five postoperative days (mean and 95% CI): 3.3 (2.6-3.9) vs. 4.3 (3.5-5.1) mg morphine equivalents (P < 0.05). CONCLUSIONS Preoperative diclofenac administration reduces postcraniotomy headache and postoperative analgesic requirements - a benefit that persisted throughout five postoperative days.

Clinical and genetic characteristics of craniosynostosis in Hungary

Craniosynostosis, the premature closure of cranial sutures, is a common craniofacial disorder with heterogeneous etiology and appearance. The purpose of this study was to investigate the clinical and molecular characteristics of craniosynostoses in Hungary, including the classification of patients and the genetic analysis of the syndromic forms. Between 2006 and 2012, 200 patients with craniosynostosis were studied. Classification was based on the suture(s) involved and the associated clinical features. In syndromic cases, genetic analyses, including mutational screening of the hotspot regions of the FGFR1, FGFR2, FGFR3, and TWIST1 genes, karyotyping and FISH study of TWIST1, were performed. The majority (88%) of all patients with craniosynostosis were nonsyndromic. The sagittal suture was most commonly involved, followed by the coronal, metopic, and lambdoid sutures. Male, twin gestation, and very low birth weight were risk factors for craniosynostosis. Syndromic craniosynostosis was detected in 24 patients. In 17 of these patients, Apert, Crouzon, Pfeiffer, Muenke, or Saethre–Chotzen syndromes were identified. In one patient, multiple‐suture craniosynostosis was associated with achondroplasia. Clinical signs were not typical for any particular syndrome in six patients. Genetic abnormalities were detected in 18 syndromic patients and in 8 relatives. In addition to 10 different, known mutations in FGFR1,FGFR2 or FGFR3, one novel missense mutation, c.528C>G(p.Ser176Arg), was detected in the TWIST1 gene of a patient with Saethre–Chotzen syndrome. Our results indicate that detailed clinical assessment is of paramount importance in the classification of patients and allows indication of targeted molecular testing with the highest possible diagnostic yield.

Achondroplasia with multiple-suture craniosynostosis: a report of a new case of this rare association.

We report on a female patient with an exceedingly rare combination of achondroplasia and multiple‐suture craniosynostosis. Besides the specific features of achondroplasia, synostosis of the metopic, coronal, lambdoid, and squamosal sutures was found. Series of neurosurgical interventions were carried out, principally for acrocephaly and posterior plagiocephaly. The most common achondroplasia mutation, a p.Gly380Arg in the fibroblast growth factor receptor 3 (FGFR3) gene, was detected. Cytogenetic and array CGH analyses, as well as molecular genetic testing of FGFR1, 2, 3 and TWIST1 genes failed to identify any additional genetic alteration. It is suggested that this unusual phenotype is a result of variable expressivity of the common achondroplasia mutation.

Does increased 18FDG uptake reflect malignant transformation of a low-grade glioma? A diagnostic dilemma

Benign gliomas of the brain show decreased uptake of 18F fluorodeoxyglucose (FDG) on positron emission tomography (PET). Malignant transformation is usually manifested by an increase of 18FDG uptake. A 45-year-old female has been followed up since 1987 by means of 18FDG-PET for a right hemispheric World Health Organization Grade II oligoastrocytoma. In 1996, increased epileptic activity was accompanied by increased 18FDG uptake within the temporal part of the tumor. After surgery, the epileptic seizures diminished. Histological examination of the resected tumor showed no change in the pathology when compared with the first biopsy. Localized temporal increase of 18FDG uptake was not associated with malignant progression. The decrease of seizure frequency might shed light on a putative connection of hyperglycolysis and epileptic discharges.

Endotracheal tube cuff inflation with and without a pressure gauge to minimise sevoflurane pollution during intermittent positive pressure ventilation.

Editor,Possible health hazards from exposure to trace concentrations of inhalational anaesthetics cannot yet be definitively excluded.1 We have previously reported that the concentrations of the commonly used volatile anaesthetic sevoflurane were significantly higher in the proximity of the intubate

Bilateral transtentorial herniation and isolated fourth ventricle: a scientific note.

Three morphological types of PVL described in the literature[5] are as follows: type I, most common, showing focal necrosis centered on the ventricles or the subcortical zone; type II, with linear diffuse necrosis, is quite rare and resembles a fungal mycelium microscopically, as seen in this case, with large areas of hemorrhagic necrosis; and type III, which has variegated necroses. Valsiuk et al.[6] have described 4 cases of PVL, wherein the basophilic fibers were mimicking as fungal hyphae, which are damaged non-myelinated axons with mineralization. In conclusion, this case highlights the gross and microscopic lesions of PVL as rare fungal mimickers; and the need for awareness of this resemblance to avoid misinterpretation.