Technical aspects and results of surgery for craniosynostosis.

BACKGROUND: The timing and extent of surgery continue to be a matter of discussion in current craniosynostosis management. PATIENTS AND METHODS: We retrospectively reviewed the first 159 children seen from 1996 to 2000 of a total of 243 patients presenting with suspected craniosynostosis. We did not establish a surgical indication in 74 children (47%), either because their malformations were of different origin without associated craniosynostosis (11/7%) or they presented with only mild clinical manifestations of sutural synostosis (63/40%). In 85 cases (53%), we established a surgical indication. Parents did not follow our recommendation in two cases (1%). In 83 cases, we performed diagnosis-related remodeling at the age of 4-12 months. Demographic data, clinical follow-up findings, and regular photo documentation were analyzed. RESULTS: After a mean follow-up of 3 years and 8 months, the results were satisfactory in 68 cases (82%). Of 15 cases (18%) with only limited improvement, two children were submitted to a second intervention. Another two children had to be reoperated on immediately for insufficient hemostasis. In the largest subgroup of children (47) with sagittal synostosis, there was no difference in outcome between surgery performed before and after 6 months of age. DISCUSSION: Surgical indication and assessment of results are based on subjective criteria which limit the comparison with the literature. Our results correspond to those of similar published series. Most of the unfavorable results could be attributed either to inadequate adaptation of the surgical technique to the individual form of the malformation or to a significant secondary loss of correction in multi-sutural synostosis. CONCLUSIONS: The overall results of surgery within the first year of life were satisfactory in 82%. Standard procedures need to be adapted carefully to the individual form of craniosynostosis to avoid unfavorable results. We therefore propose a new surgical technique based on a statistically averaged modular system of skull models to replace freehand remodeling.

Spontaneous intracerebral hemorrhage and multiple infarction in Williams-Beuren syndrome.

A 7-year-old boy diagnosed with Williams-Beuren syndrome was admitted for spontaneous right hemispheric intracerebral hemorrhage. Cerebral angiography did not reveal any source of bleeding. After a short period of clinical improvement under conservative treatment, the boy deteriorated rapidly. CT showed the beginning of a complete infarction of both hemispheres. Operative evacuation of the bleeding and bilateral osteoclastic decompression had no perceptible influence on the clinical course. To the present day, the boy has remained in a vegetative state. Reports in the literature suggest that Williams syndrome with cerebral infarction is associated with a markedly poorer prognosis when there is additional intracerebral bleeding.

Intracranial compliance as a bed-side monitoring technique in severely head-injured patients.

A recently developed monitoring technology makes an on-line assessment of intracranial compliance (ICC) possible. Aims of our research: 1. Course and values of ICC (critical threshold: < 0.5 ml/mmHg) in episodes of pathological intracranial pressure (ICP) (> 20 mmHg) and reduced cerebral oxygenation (brain tissue PO2 (PtiO2) < 10 mmHg). 2. Mean ICC in different ages. 3. Relationship between ICC and outcome. 4. Evaluation of ICC as routine monitoring parameter by calculation of s.c. time-of-good-data-quality (TGDQ). Computer data assessment of 7 patients with severe closed head-injury was performed providing 830 hours of data. TGDQ resulted from the formula: TGDQ (%) = artifact free time (min) x 100 (%)/total monitoring time (min). Outcome was assessed 6 months posttrauma (Glasgow Outcome Score (GOS). 1. Analysis revealed 43 episodes of pathologically elevated ICP and 39 of critical ICC. In 17 cases overlapping periods were found. In 9 of these ICC preceded ICP. Reduced cerebral oxygenation was neither related with high ICP nor low ICC. 2. ICC was found to be age-related. At a cut-off-point of 20 mmHg in ICP, ICC in children (< or = 16 years) was 0.9, in adults (17-60 years) 0.7 and in elderly (> 60 years) 0.6 ml/mmHg. 3. Adverse outcome was indicated best by high ICP (up to 45% of monitoring time) followed by low ICC (up to 41% of monitoring time). 4. TGDQ in ICC was 72% compared to 95% in ICP and 98% in PtiO2. In predicting adverse outcome, ICP was equal to ICC. The different ICC in each age class points to the need of age-adjusted thresholds. Further refinements of ICC technology are needed to improve ICC data quality and therefore become a useful tool in neuromonitoring.

Detection of secondary insults by brain tissue pO2 and bedside microdialysis in severe head injury.

We evaluated bedside cerebral on-line microdialysis for early detection of cerebral hypoxia in patients with traumatic brain injury. 24 severely head injured patients (Glasgow Coma Score < or = 8) were studied. Patients underwent continuous brain tissue PO2 (PtiO2) monitoring using the LICOX (GMS mbH, Germany) microcatheter device. The catheter was placed into the non-lesioned frontal white matter within 32.2 (7-48) hrs post injury. The microdialysis catheter (CMA 100, Sweden) was placed close to the PtiO2 probe via a 2- or 3-way skull screw, connected to a pump and perfused with Ringer solution (0.3 microliter/min). The microdialysis samples were collected hourly and analyzed at the bedside for glucose, lactate, lactate-pyruvate-ratio and glutamate (CMA 600, Sweden). We identified 252 episodes of impending hypoxia (PtiO2 < 15 mm Hg; 11,810 minutes) and 38 episodes of cerebral hypoxia (PtiO2 < 10 mm Hg; 1996 minutes). Before cerebral hypoxia, glucose decreased significantly. Glutamate was unchanged when no hypoxia or impending hypoxia occurred but increased 3-4 fold before a hypoxic episode appeared. We conclude that early metabolic detection of cerebral hypoxia before a critical decrease in brain tissue PtiO2 is seen and possibly allows earlier changes in treatment (e.g. reduction of hyperventilation therapy).

Temporal profiles of extracellular nitric oxide metabolites following aneurysmal subarachnoid hemorrhage.

The temporal profile of nitric oxide metabolite concentrations i.e. nitrite and nitrate (NOx) was investigated in brain parenchyma of patients following aneurysmal subarachnoid hemorrhage (SAH). In a subset of ten patients (7F/3M, age: 47 +/- 14 yrs) included in a prospective clinical trial on neurochemical intensive-care monitoring, microdialysis (MD) probes (CMA70, Sweden) were implanted at time of aneurysm surgery. Samples from patients clipped electively (n = 3) were considered "normal" in regard to SAH patients (n = 7). MD was performed for 162 +/- 63 hrs. NOx was measured off-line using a highly sensitive, fluorometric assay (2-3-diaminonaphtalene, DAN). NOx concentrations determined from electively operated patients averaged 36.7 +/- 9.6 microM (n = 59, pooled data). Regardless of the development of delayed ischemic neurological deficits (DIND), SAH patients showed a specific temporal profile of NOx consisting of an initial peak followed by an exponential decay. In detail, NOx decreased from initial values of 46.2 +/- 34.8 microM to 23.5 +/- 9.0 microM on day 6-7 after SAH (p < 0.05). Following SAH extracellular concentrations of NO metabolites decrease over time. This is in agreement with hypothetical NO scavenging by products of hemolysis. However, subsequent development of DIND cannot be explained by a lack of vasodilatory NO alone.

Decompressive craniectomy following traumatic brain injury: ICP, CPP and neurological outcome.

Decompressive craniectomy is often the final option in the management of posttraumatic intracranial hypertension. Aim of this study was to investigate the effect of secondary decompression on intracranial pressure (ICP), cerebral perfusion pressure (CPP) and neurological outcome. 62 patients decompressed after severe head injury were included in the retrospective study. Decompression was performed when ICP could not be controlled by non-surgical treatment. Mean age was 36.6 yrs, 77.4% were male. Initial Glasgow Coma Score (GCS) was 6. Outcome was determined 6 months after trauma according to the Glasgow Outcome Scale (GOS) and the functional Barthel-Index (BI). In the last hour before decompression ICP was 40.5 +/- 1.6 mmHg and CPP was 65.3 +/- 2.1 mmHg (being maintained, if necesary, by catecholamines). ICP was significantly reduced to 9.8 +/- 1.3 mmHg by surgery and CPP improved to 78.2 +/- 2.3 mmHg. 12 hrs following decompression mean ICP rose to 21.6 +/- 1.7 mmHg again (CPP: 73.6 +/- 1.7 mmHg), but in the following period ICP could be kept below 25 mmHg in the majority of patients. 6 months after trauma 22.5% of the patients had died (except one all these patients were aged more than 50 yrs). 48.4% of patients survived with an unfavourable outcome (GOS 2 + 3), while 29.1% had a favourable outcome (GOS 4 + 5). Decompressive craniectomy is highly effective to treat otherwise uncontrollable intracranial hypertension and improves CPP. A satisfactory outcome, however, is only achieved under strict consideration of negative predictors (e.g. age).

Fluorescent tracer in pilocarpine-treated rats shows widespread aberrant hippocampal neuronal connectivity.

Neuronal fibres of the hippocampal formation of normal and chronic epileptic rats were investigated by fluorescent tracing methods using the pilocarpine model of limbic epilepsy. Two months after onset of spontaneous limbic seizures, hippocampal slices were prepared and maintained in vitro for 10 h. Small crystals of fluorescent dye [fluorescein (fluoro-emerald) and tetramethylrhodamine (fluoro-ruby)] were applied to different hippocampal regions. The main findings were: (i) in control rats there was no supragranular labelling when the mossy fibre tract was stained in stratum radiatum of area CA3. However, in epileptic rats a fibre network in the inner molecular layer of the dentate gyrus was retrogradely labelled; (ii) a retrograde innervation of area CA3 by CA1 pyramidal cells was disclosed by labelling remote CA1 neurons after dye injection into the stratum radiatum of area CA3 in chronic epileptic rats; (iii) labelling of CA1 neurons apart from the injection site within area CA1 was observed in epileptic rats but not in control animals; and (iv), a subicular-hippocampal projection was present in pilocarpine-treated rats when the tracer was injected just below the stratum pyramidale of area CA1. The findings show that fibre rearrangement in distinct regions of the epileptic hippocampal formation can occur as an aftermath of pilocarpine-induced status epilepticus.

Relation of cerebral energy metabolism and extracellular nitrite and nitrate concentrations in patients after aneurysmal subarachnoid hemorrhage.

In a prospective clinical investigation on neurochemical intensive care monitoring, the authors' aim was to elucidate the temporal profile of nitric oxide metabolite concentrations-that is, nitrite and nitrate (NO(x))--and compounds related to energy-metabolism in the cerebral interstitium of patients after aneurysmal subarachnoid hemorrhage (SAH). During aneurysm surgery, microdialysis probes were implanted in cerebral white matter of the vascular territory most likely affected by vasospasm. Temporal profiles of NO(x) were analyzed in a subset of 10 patients (7 female, 3 male, mean age = 47 +/- 14 years). Microdialysis was performed for 152 +/- 63 hours. Extracellular metabolites (glucose, lactate, pyruvate, glutamate) were recovered from the extracellular fluid of the cerebral parenchyma. NO(x) was measured using a fluorometric assay. After early surgery, SAH patients revealed characteristic decreases of NO(x) from initial values of 46.2 +/- 34.8 micromol/L to 23.5 +/- 9.0 micromol/L on day 7 after SAH (P < 0.05). Decreases in NO(x) were seen regardless of development of delayed ischemia (DIND). Overall NO(x) correlated intraindividually with glucose, lactate, and glutamate (r = 0.58, P < 0.05; r = 0.32, P < 0.05; r = 0.28, P < 0.05; respectively). After SAH, cerebral extracellular concentrations of NO metabolites decrease over time and are associated with concomitant alterations in energy-or damage-related compounds. This could be related to reduced NO availability, potentially leading to an imbalance of vasodilatory and vasoconstrictive factors. On the basis of the current findings, however, subsequent development of DIND cannot be explained by a lack of vasodilatory NO alone.

Treatment of a cavernous sinus dural arteriovenous fistula by deep orbital puncture of the superior ophthalmic vein.

In a patient with progressive ophthalmological problems, including uncontrolled intraocular pressure related to a cavernous sinus dural arteriovenous fistula, urgent intervention may be necessary to prevent permanent visual loss. We report a case in which inadequate transarterial embolisation and lack of access for transvenous catheterisation, including a direct approach through the superior ophthalmic vein, preceded percutaneous puncture of the superior ophthalmic vein deep within the orbit, permitting venous occlusion without complications. This case demonstrates that deep orbital puncture of the vein is feasible for occlusion of a cavernous sinus dural arteriovenous fistula.

Secondary insults in severe head injury--do multiply injured patients do worse?

OBJECTIVES: To study the occurrence of secondary insults and the influence of extracranial injuries on cerebral oxygenation and outcome in patients with closed severe head injury (Glasgow Coma Scale score < or =8). DESIGN: Two-year prospective, clinical study. SETTING: Two intensive care units in a level III trauma center. PATIENTS: We studied 119 patients. Eighty patients had severe head injury and were divided into two categories: "isolated" severe head injury patients (n = 36, Injury Severity Score <30), and severe head injury patients with associated extracranial injuries (n = 44, Injury Severity Score >29). Thirty-nine patients with extracranial injuries and no head injury served as the control group. INTERVENTIONS: After patients were admitted to the intensive care unit, we began continuous multimodal cerebral monitoring of intracranial pressure, mean arterial blood pressure, cerebral perfusion pressure, end-tidal Co2, brain tissue Po2 (Licox), jugular bulb oxyhemoglobin saturation in severe head injury patients, and mean arterial blood pressure in the control group. Targets of management included intracranial pressure <20 mm Hg, cerebral perfusion pressure >60 mm Hg, Paco2 > 30 mm Hg, control of cerebral oxygenation, and delayed surgery for non-life-threatening extracranial lesions. MEASUREMENTS AND MAIN RESULTS: Data were analyzed for critical thresholds. The occurrence of secondary insults (intracranial pressure >20 mm Hg, mean arterial blood pressure <70 mm Hg, cerebral perfusion pressure <60 mm Hg, end-tidal Co2 <30 torr, brain tissue Po2 <10 torr, jugular bulb oxyhemoglobin saturation <50%) was comparable in patients with isolated severe head injury and those with severe head injury with associated extracranial lesions (Abbreviated Injury Scale score < or =5). The duration of intracranial hypertension and arterial hypotension significantly correlated with an unfavorable outcome, independent of the Injury Severity Score. In patients with severe head injury, 1-yr outcome was 29% dead or vegetative, 17% severely disabled, and 54% moderate or good outcome. This was similar to patients with severe head injury and extracranial injuries (31% dead or vegetative, 14% severely disabled, and 56% moderate or good outcome) and was independent of the Injury Severity Score. Patients with no head injury had less secondary insults (mean arterial blood pressure <70 mm Hg, p <.01) and a better outcome compared with both severe head injury groups (p <.044). CONCLUSIONS: In patients with severe head injury who have targeted management including intracranial pressure- and cerebral perfusion pressure-guided therapy and delayed surgery for extracranial lesions, the occurrence of secondary insults in the intensive care unit and long-term neurological outcome were comparable and independent of the presence of extracranial lesions (Abbreviated Injury Severity level < or =5). A severe head injury is still a major contributor predicting an unfavorable outcome in multiply injured patients.

Role of bedside microdialysis in the diagnosis of cerebral vasospasm following aneurysmal subarachnoid hemorrhage.

OBJECT: Ischemia due to vasospasm is a feared complication in patients following aneurysmal subarachnoid hemorrhage (SAH). Cerebral online microdialysis monitoring may detect the metabolic changes in the extracellular fluid associated with ischemia. The aims of the present study were to correlate clinical course, microdialysis-recorded data, transcranial Doppler (TCD) ultrasonography findings, and angiographic findings in patients with SAH. METHODS: In 60 patients a microdialysis catheter was inserted into the brain parenchyma that is most likely to be affected by vasospasm directly after aneurysm clipping. Hourly analyses of glucose, pyruvate, lactate, and glutamate levels were performed using a bedside device. Blood-flow velocities were obtained using serial TCD measurements. Cerebral angiography was routinely performed on Day 7 after aneurysm clipping or earlier in cases of clinical deterioration (30 patients). In all patients the results of microdialysis monitoring, TCD ultrasonography, and angiography were correlated. The mean duration of monitoring was 7.3+/-2.5 days. In patients with acute ischemic neurological deficits (18 patients) immediate microdialysis-recorded alterations were observed if the probe was placed close to the malperfused region. In 13 of 15 patients with symptomatic vasospasm (delayed ischemic neurological deficit [DIND]), the microdialysis-recorded values revealed secondary deterioration. In terms of confirming DIND, microdialysis had the highest specificity (0.89, 95% confidence interval [CI] 0.78-1) compared with TCD ultrasonography (0.63, 95% CI 0.46-0.8) and angiography (0.53, 95% CI 0.35-0.7). For microdialysis, the positive likelihood ratio was 7.8, whereas this was significantly lower for TCD ultrasonography (1.7) and angiography (2.1). CONCLUSIONS: Although angiography also demonstrates vessel narrowing in asymptomatic patients, online microdialysis reveals characteristic metabolic changes that occur during vasospasm. Thus, online microdialysis may be used to confirm the diagnosis of vasospasm.

Secondary abscess formation in pituitary adenoma after tooth extraction. Case report.

The presence of an abscess in a pituitary tumor is a very rare finding. The authors report the case of a 69-year-old man with a pituitary adenoma confirmed by neuroimaging results, in whom a high fever, meningismus, and left-sided ophthalmoplegia developed 4 days after tooth extraction. The results of serial cranial magnetic resonance imaging were highly indicative of an abscess formation within the pituitary adenoma. During surgery the tumor was approached transsphenoidally and removed. Histological examination confirmed the presence of an abscess formation within the pituitary adenoma. It is most likely that the tooth extraction caused a bacteremia, which led to an inflammation with abscess formation within the pituitary adenoma. The authors conclude that invasive dental procedures should be avoided before planned resection of a pituitary adenoma.

Ibn Sina (Avicenna). Historical note.

Ibn Sina (often known by his last name in Latin, Avicenna; 980-1037 A.D.) was the most famous physician and philosopher of his time. His Canon of Medicine, one of the most famous books in the history of medicine, surveyed the entire medical knowledge available from ancient and Muslim sources and provided his own contributions. In this article the authors present a unique picture of the neurosurgical technique of Ibn Sina and briefly summarize his life and work.

Alterations of neuronal connectivity in area CA1 of hippocampal slices from temporal lobe epilepsy patients and from pilocarpine-treated epileptic rats.

PURPOSE: Neuronal network reorganization might be involved in epileptogenesis in human and rat limbic epilepsy. Apart from aberrant mossy fiber sprouting, a more widespread fiber rearrangement in the hippocampal formation might occur. Therefore, we studied sprouting in area CA1 because this region is most affected in human temporal lobe epilepsy. METHODS: In slices from hippocampi of patients operated on for temporal lobe epilepsy (n = 134), from pilocarpine-treated rats (n = 74), and from control rats (n = 15), viable neurons were labeled with fluorescent dextran amines. RESULTS: In human hippocampi as well as in pilocarpine-treated rats, the degree of nerve cell loss varied. In 67 of 134 slices from human specimens with distinct Ammon's horn sclerosis and in 23 of 74 slices from pilocarpine-treated rats, a severe shrunken area CA1 presented with a similar picture: few damaged neurons were labeled, and aberrant fiber connections were not visible. This was in contrast to human resected hippocampi and hippocampi from pilocarpine-treated rats with no or moderate loss of neurons. In these cases, pyramidal cells remote from the injection site were labeled (human tissue, n = 59 of 134; pilocarpine-treated rats, n = 39 of 74). In human resected hippocampi without obvious pathology and in control animals, no pyramidal neurons were labeled apart from the injection site. CONCLUSIONS: Axon collaterals of CA1 pyramidal cells are increased in human temporal lobe epilepsy and in pilocarpine-treated rats. Adjacent CA1 pyramidal cells project via aberrant collaterals to the stratum pyramidale and the stratum radiatum of area CA1. This network reorganization can contribute to hyperexcitability via increased backward excitation.

Navigation-guided opening of the internal auditory canal via the retrosigmoid route for acoustic neuroma surgery: cadaveric, radiological, and preliminary clinical study.

OBJECTIVE: We investigated the usefulness of a microscope-based navigational system (Multi Koordinaten Manipulator; Zeiss, Oberkochen, Germany) for removal of the posterior wall of the internal auditory canal (IAC) via the retrosigmoid route. METHODS: A cadaveric study was performed to assess the navigational localization error for the retrosigmoid approach to the IAC. Computed tomographic findings for 47 acoustic neuroma cases were divided into three groups, on the basis of the relationship between the labyrinth and the sigmoid-fundus line (medial, on the line, or lateral). Furthermore, the shortest distances between the most medial labyrinthine extension and the resection line were measured. In 20 acoustic neuroma operations, the different features and the practicality of the microscope-based navigational system for opening of the IAC were evaluated. RESULTS: The mean anatomic localization errors were 0.67 +/- 0.2 mm (95th percentile, 1.32 mm) for navigation to the IAC and 0.71 +/- 0.37 mm (95th percentile, 1.68 mm) for navigation to the posterior semicircular canal. The average distances between the most medial labyrinthine extension and the resection line were 3.65, 3.36, and 2.0 mm for the lateral, on-the-line, and medial groups, respectively. Direct contouring of structures at risk does not take into account the localization error, nor does it provide reliable navigational information. A novel indirect contouring concept that takes into account the localization error (the safety corridor method) was therefore introduced. CONCLUSION: The value of navigational assistance for opening of the IAC is promising but still limited. Further development is required before the clinical effects of this navigational approach can be evaluated.

Bedside microdialysis for early detection of cerebral hypoxia in traumatic brain injury.

OBJECT: The authors evaluated the use of bedside cerebral online microdialysis for the detection of impending and present cerebral hypoxia in patients who had sustained traumatic brain injury. METHODS: Thirty-five severely head injured patients (with Glasgow Coma Scale scores < or = 8) were studied. Patients underwent continuous brain tissue PO2 (PtiO2) monitoring. The PtiO2 catheter was placed into the unaffected frontal white matter within 32.2 hours postinjury (range 7-48 hours). The microdialysis catheter was placed close to the PtiO2 probe via a 2- or 3-way skull screw that was connected to a pump and perfused with Ringer's solution at 0.3 microl/minute. The microdialysis samples were collected hourly and analyzed at the bedside for glucose, lactate, lactate-pyruvate ratio, and glutamate. Data were analyzed for identification of episodes of impending (PtiO2 10-15 mm, Hg > 5-minute duration) and present cerebral hypoxia (PtiO2 10 mm Hg, > 5-minute duration). In 62% of the patients hypoxic episodes occurred and were most frequently associated with hyperventilation (p < 0.001). During impending hypoxia, extracellular glutamate concentrations were increased (p = 0.006) whereas energy metabolites remained stable. During cerebral hypoxia, the extracellular glutamate (p < 0.001) and lactate (p = 0.001) concentrations were significantly higher than during normal oxygenation, whereas the lactate-pyruvate ratio was only slightly increased (p = 0.088, not significant). CONCLUSIONS: The authors conclude that a PtiO2 below 10 mm Hg is critical to induce metabolic changes seen during hypoxia/ischemia. Early markers of cerebral hypoxia are increased levels of glutamate and lactate. Regional hypoxia is not always associated with anaerobic cerebral metabolism. In the future, this technology of bedside monitoring may allow optimization of the treatment of severely head injured patients.

Vertebral arteriovenous fistula associated with neurofibromatosis type I misdiagnosed as a giant aneurysm.

SUMMARY: A 59-year-old man with neurofibromatosis type 1 (NF1) presented with bruits and neck pain due to a space occupying lesion in the right neck tissue. Digital subtraction angiography (DSA) showed an arteriovenous fistula (AVF) of the right extracranial vertebral artery (VA) with a giant venous pouch and an intracranial berry aneurysm of the right middle cerebral artery (MCA). First, the MCA aneurysm was surgically clipped, then the patient was treated by embolisation with coils. The coils were placed transarterially from the left VA resulting in a partial thrombosis of the venous pouch. Complete closure was achieved secondarily by retrograde transvenous catheterization. Etiology and treatment modalities are discussed.