The objective of this prospective study was to find outcome predictors for better selection for treatment of normal-pressure hydrocephalus (NPH) patients. A total of 125 patients were evaluated and ...provided with a gravitational shunt.
Cerebrospinal fluid hydrodynamics provided better predictive values if an algorithm to shunt all patients with a pressure/volume index of <30 mL or resistance to outflow > 13 mmHg/mL × min was used. In general, outcome became worse with increasing anamnesis duration, worse preoperative clinical state, and increasing comorbidity. If one of these parameters was lower than a critical value, the shunt-responder rate was about 90% and the normally negative influence of older age was not seen. The well-known paradigm of a worse prognosis with NPH is not the result of the hydrocephalus etiology itself, but the consequence of a typical accumulation of negative outcome predictors as a consequence of the misinterpretation of normal aging and delayed adequate treatment.
Gravitational shunts for management of chronic hydrocephalus are supposed to avoid or at least to reduce the risk of overdrainage. In order to find out if this hypothesis is correct, we did a ...prospective study and analysed the results of a series of 185 hydrocephalic adults, treated by using gravitational shunts. For the few cases in whom overdrainage occurred, we wanted to establish the reason for it. Especially it should be proven or excluded that overdrainage was caused by shortcomings of the principle of gravitational shunts. Another goal was to compare post-shunting changes of the ventricular size with clinical outcome. A comparably large study has not yet been published.
185 adult patients who suffered from chronic hydrocephalus were shunted between 1996-2000, either using the combination of an adjustable Codmann Hakim Valve & Miethke Shunt Assistant (35 patients) or a Miethke Dual Switch Valve (150 patients). The clinical course of each patient has been followed until the end of 2000. Average follow-up time was 26 months (range 6-60 months).
88% of our patients were shunt responders, 70% had a good or excellent outcome. Overdrainage occurred in only 4%. It turned out that this complication was not a failure of the concept of gravitational shunts, but the result of a wrongly estimated intraperitoneal pressure. After shunting the ventricular size was reduced only marginally. In 92% of the patients the Evans-Index decreased less than 20% after the shunt insertion, but 69% of these patients had a good or excellent outcome. The most obvious difference comparing pre- and postoperative imaging was a better visibility of the high apical sulci after shunting.
In our series gravitational shunts proved to be effective in preventing overdrainage. The 4% negative exceptions are mainly avoidable. There was no correlation between outcome and ventricular size reduction, and as a rule ventricular size was only marginally reduced.
The infection rate of hydrocephalus shunts in children amounts figures of up to 25% and the according mortality rate is alarming high nowadays yet. An antibiotic impregnated shunt-catheter (AIS) was ...designed to reduce the incidence of shunt infections.
In a non randomized trial 56 children were examined between January 2002 inclusive December 2007. The minimal follow-up was six months. Only children were included, who were shunted for the first time. In the study group (n=34) AIS (Bactiseal ) Codman, Johnson & Johnson, MA, Boston, USA) were used, while the control group (n=22) was provided with conventional, not-antibiotic impregnated catheters. To compare the risk profile for shunt infections, we defined, - according to the literature -, some risk factors.
Despite the incidence of shunt infections has been supposed to be higher according to the higher risk profile of the AIS group compared with controls, the shunt infection rate of the AIS group was lower than the shunt infection rate in the control group.
Apparently, AIS can reduce the incidence of shunt infections in children. Further prospective trials with a larger cohort are necessary for a statistically significant prove.
Objects
Puncture of the ventricular system as one of the most frequently performed operative procedures in neurosurgery is usually done in a freehand way without guiding devices. The objective of ...this study is to examine whether ultrasonic guidance is able to heighten the accuracy of ventricular tapping.
Methods
Real-time imaging via a single burr hole approach is achieved by aid of a bajonet-like shaped transducer with a footprint of 8x8 mm only (EUP-NS32, Hitachi Medical Systems). The needle is advanced towards the frontal horn along a displayed guideline. 51 punctures in 48 patients were performed with ultrasonic guidance and compared to 85 punctures in 67 patients without a guiding device.
Conclusion
The presented ultrasound method was not able to heighten the access rate of ventricular tapping, but it improved correct positioning of the catheter tip inside the frontal horn of the ventricular system significantly.
Overdrainage is a common complication observed after shunting patients with idiopathic normal-pressure hydrocephalus (iNPH), with an estimated incidence up to 25%. Gravitational units that ...counterbalance intracranial pressure changes were developed to overcome this problem. We will set out to investigate whether the combination of a programmable valve and a gravitational unit (proGAV, Aesculap/Miethke, Germany) is capable of reducing the incidence of overdrainage and improving patient-centered outcomes compared to a conventional programmable valve (Medos-Codman, Johnson & Johnson, Germany).
SVASONA is a pragmatic randomized controlled trial conducted at seven centers in Germany. Patients with a high probability of iNPH (based on clinical signs and symptoms, lumbar infusion and/or tap test, cranial computed tomography CCT) and no contraindications for surgical drainage will randomly be assigned to receive (1) a shunt assistant valve (proGAV) or (2) a conventional, programmable shunt valve (programmable Medos-Codman).
We will test the primary hypothesis that the experimental device reduces the rate of overdrainage from 25% to 10%. As secondary analyses, we will measure iNPH-specific outcomes (i.e., the Black grading scale and the NPH Recovery Rate), generic quality of life (Short Form 36), and complications and serious adverse events (SAE). One planned interim analysis for safety and efficacy will be performed halfway through the study. To detect the hypothesized difference in the incidence of overdrainage with a type I error of 5% and a type II error of 20%, correcting for multiple testing and an anticipated dropout rate of 10%, 200 patients will be enrolled.
The presented trial is currently recruiting patients, with the first results predicted to be available in late 2008.
Recently a new subtype of chronic hydrocephalus was described: long-standing overt ventriculomegaly in adults (LOVA). Experience to date has indicated that shunt therapy was contraindicated, due to ...over-drainage. Therefore we investigated whether this problem could be overcome using gravitational shunts.
Thirty macrocephalic adults (17–72 years of age), suffering from progressive hydrocephalus were managed with two different gravitational shunts. The post-operative observation period was 5–87 months.
Only two patients developed hygromas, and only one of these required surgical shunt revision. Eighty-seven percent of patients had a long-lasting clinical improvement. Ventricular size was only slightly reduced in 29 patients. There was no correlation between reduction in ventricular size and clinical improvement.
Contrary to clinical guidelines issued to date, we demonstrate that LOVA can be treated reliably with gravitational shunts, making them a genuine alternative to endoscopic third ventriculostomy (ETV).
A correct interpretation of radiological data in cases of suspected hydrocephalus is not possible when ignoring patient age and clinical symptoms.
An in-depth knowledge of clinical findings is ...accordingly essential.
New pathophysiological findings and a detailed assignment of previously unrecognized or ignored clinical symptoms to various entities of the spectrum of hydrocephalus disorders allow a coherent diagnosis drawn from clinical and radiological data. For this purpose it is necessary to know the specific symptoms of hydrocephalus in relation to age. Especially in chronic hydrocephalus, this is of utmost importance to avoid misdiagnosis.
The radiological method of choice depends on the age and the specific issue to be addressed.
The typical clinical symptoms of different hydrocephalus entities presented here must be considered as confirmed knowledge.
Only the synopsis of clinical and radiological findings currently allows correct interpretation of imaging. There is a threat of misdiagnosis if interpretation is restricted purely to radiological findings as the sole predictive value of modern imaging is still too limited despite all innovations.
Intracranial arachnoidal cysts (AC) are relevant due to their space-demanding character. The pathophysiological sequelae are dependent on the size and location of the cyst and the patient's age. ...Direct pressure on surrounding tissue causes headaches (meninges) or rarely seizures (brain tissue). Cerebrospinal fluid (CSF) circulation disturbances resulting from brain mass displacement with occlusion of, for example, the foramen monroi or the aqueduct cause occlusive hydrocephalus, which can lead to an increase in intracranial pressure. Depending on age, the typical primary clinical symptoms or findings differ. In adults and older children, headaches are usually the first clinical symptom. Children, in whom skull growth is not yet complete, present with a head circumference above the 97th percentile. An abnormal one-sided deflection of the calotte in the region of the underlying AC may also be present. Cranial magnetic resonance imaging (cMRI), the first-line diagnostic tool of choice to demonstrate size and location of the cysts and the surrounding intracranial structures, is of utmost importance for therapy planning. In addition, further malformations can be detected. Moreover, cMRI may also be useful for a rough assessment of increased intracranial pressure (ICP). In most symptomatic AC, surgical treatment is unavoidable. The primarily goal is to establish communication between the CSF and the cysts' content in order to effect pressure equalization. If the CSF reabsorption capacity is insufficient, it may also be necessary to implant a CSF shunt. Asymptomatic arachnoidal cysts should be strictly followed clinically and by cMRI over time. The reasonable frequency for follow-up depends on the size and location of the cyst.
Zusammenfassung
Die Relevanz intrakranieller Arachnoidalzysten (AC) ergibt sich aus ihrem raumfordernden Charakter. Die pathopysiologischen Folgen ergeben sich aus der Größe und Lage der Zyste sowie ...dem Alter des Patienten. Durch den direkten Druck auf das Umgebungsgewebe kommt es zu Kopfschmerzen (Meningen) oder seltener Krampfanfällen (Hirngewebe). Durch Okklusion, z. B. des Foramen Monroi oder des Aquädukts, entsteht durch Verlagerung des Hirngewebes ein Okklusivhydrozephalus aufgrund von Liquorzirkulationsstörungen, was zu einer Steigerung des intrakraniellen Drucks führen kann. Bei Erwachsenen und älteren Kindern sind Kopfschmerzen meist das erste klinische Symptom. Bei Säuglingen und Kleinkindern fällt dagegen ein abnorm vergrößerter Kopfumfang über der 97. Perzentile auf. Auffällig kann auch eine unilaterale Kalottendeformation über der Arachnoidalzyste sein. Das diagnostische Instrument der Wahl ist die kranielle Magnetresonanztomographie (MRT). Damit können die Zysten in 3 Ebenen sowie für die Therapieplanung wichtige benachbarte Strukturen dargestellt werden. Darüber hinaus werden eventuelle weitere Fehlbildungen detektiert. Die Darstellung der Optikusscheiden erlaubt eine Beurteilung bezüglich eines erhöhten intrakraniellen Drucks. Bei den meisten symptomatischen Arachnoidalzysten ist eine operative Behandlung unerlässlich. Primäres Ziel ist es, eine Kommunikation zwischen Zysteninhalt und Liquorraum herzustellen, um einen Druckausgleich zu erwirken. Lediglich bei ungenügender Reabsorptionskapazität des Liquors kann es erforderlich sein, zusätzlich einen Liquorshunt zu implantieren. Symptomfreie Arachnoidalzysten müssen klinisch und bildgebend weiter in der Längsbeobachtung verfolgt werden. Größe und Lokalisation der Zyste bestimmen, welche Zeitabstände hier sinnvoll sind.
