Prediction of shunt response in idiopathic normal pressure hydrocephalus by combined lumbar infusion test and preoperative imaging scoring.

BACKGROUND AND PURPOSE: Idiopathic normal pressure hydrocephalus (iNPH) is a potentially treatable disorder, but prognostic tests or biomarkers are lacking. The aim was to study the predictive power of clinical, neuroimaging and lumbar infusion test parameters (resistance to outflow Rout , cardiac-related pulse amplitude PA and the PA to intracranial pressure ICP ratio). METHODS: In all, 127 patients diagnosed with iNPH who had a lumbar infusion test, a subsequent ventriculo-peritoneal shunt operation and at least 2 months of postoperative follow-up were retrospectively included. Preoperative magnetic resonance images were visually scored for NPH features using the iNPH Radscale. Preoperative and postoperative assessment was performed using cognitive testing, as well as gait and incontinence scales. RESULTS: At follow-up (7.4 months, range 2-20 months), an overall positive response was seen in 82% of the patients. Gait was more severely impaired at baseline in responders compared to non-responders. The iNPH Radscale score was borderline significantly higher in responders compared with non-responders, whereas no significant differences in infusion test parameters were seen between responders and non-responders. Infusion test parameters performed modestly with high positive (75%-92%) but low negative (17%-23%) predictive values. Although not significant, PA and PA/ICP seemed to perform better than Rout , and the odds ratio for shunt response seemed to increase in patients with higher PA/ICP, especially in patients with lower iNPH Radscale scores. CONCLUSION: Although only indicative, lumbar infusion test results increased the likelihood of a positive shunt outcome. Pulse amplitude measures showed promising results that should be further explored in prospective studies.

Timing of intraventricular infusion test for diagnosing idiopathic normal pressure hydrocephalus.

BACKGROUND: Infusion tests, which measure resistance to outflow (Rout), are used in selecting patients suspected for idiopathic normal pressure hydrocephalus (iNPH) for shunt surgery. Infusion tests can be performed through an external ventricular drain (EVD). A 24-hour time gap from EVD insertion to an infusion test is a routine practice at our department due to concerns that the surgical procedure might influence the test results in the immediate postoperative period. The objective of the study was to investigate if timing of an intraventricular infusion test influences the results of the test in patients suspected for iNPH. METHODS: Ten patients scheduled for an intraventricular infusion test were included. Measurements of baseline intracranial pressure (ICP) and plateau ICP were obtained during constant rate intraventricular infusion test performed at two time points (1 and 24 h after EVD insertion) and Rout was calculated from these measures and compared within patients. RESULTS: Eight patients completed both infusion tests. In one of the 18 infusion tests performed, it was not possible to define an ICP plateau and this infusion test was excluded, leaving 7 paired infusion tests. Median Rout was 12.9 mmHg/ml/min (range 7.0-22.0) 1 h after EVD insertion and 11.3 mmHg/ml/min (range 7.8-18.1) after 24 h. Overall, there were no statistically significant differences in Rout (P = 0.83), baseline ICP (P = 0.70), or plateau ICP (P = 0.81) between the recordings performed 1 h and 24 h after EVD insertion. For two of the seven patients with paired infusion tests, there was poor agreement between Rout values at 1 and 24 h. CONCLUSION: Overall, Rout estimates do not change significantly between 1 and 24 h after EVD insertion. We therefore propose that infusion tests can be performed shortly after surgery to reduce the period of indwelling EVD and duration of hospitalization.

Valved or valveless ventriculoperitoneal shunting in the treatment of post-haemorrhagic hydrocephalus: a population-based consecutive cohort study.

BACKGROUND: Implant infection and obstruction are major complications for ventriculoperitoneal shunts in patients with post-haemorrhagic hydrocephalus. In an effort to (1) reduce the incidence of these complications, (2) reduce the rate of shunt failure and (3) shorten the duration of neurosurgical hospitalisation, we have implemented valveless ventriculoperitoneal shunts at our department for adult patients with post-haemorrhagic hydrocephalus and haemorrhagic cerebrospinal fluid at the time of shunt insertion. METHODS: All adult patients (>18 years old) treated for post-haemorrhagic hydrocephalus with ventriculoperitoneal shunting at our institution from 1 January 2008 to 31 December 2014 were included in this retrospective population-based consecutive cohort study. Data were collected by retrospectively reviewing medical records. We compared two different shunt modalities (valveless vs valve-regulated), analysing frequencies of complications, shunt survival and duration of neurosurgical hospitalisation. RESULTS: A total of 214 patients aged 22-86 (mean age, 60.5 ± 11.5 years) were included, comprising 137 valveless and 77 valve-regulated shunts. We found no difference in the rate of surgical shunt revision (p = 0.65) or differences in time interval from insertion to first surgical revision (p = 0.31) between the two shunt modalities. The duration of neurosurgical hospitalisation was shorter for patients receiving a valveless shunt (p = 0.004). Patients with valveless shunts had a lower rate of shunt infection (5.1 % vs 14.3 %, p = 0.02), but a higher rate of overdrainage (10.3 % vs 2.6 %, p = 0.04). CONCLUSION: The use of a valveless shunting for patients with post-haemorrhagic hydrocephalus results in shorter duration of neurosurgical hospitalisation and lower rate of shunt infection, although these advantages should be held up against the risk of overdrainage. We propose valveless shunting to be used as first-line shunting strategy in this patient category, with careful follow-up ensuring that these are substituted by a valve-bearing system if necessary.

Incidental findings in MRI of the brain.

This review investigates that there has been an increase in incidental brain MRI findings due to better technology and more scans. These unexpected, asymptomatic anomalies range from harmless to serious, requiring careful clinical and ethical handling. The prevalence of incidental findings with brain MRI is 4.2% and even higher when including white matter hyperintensities. There is a significant variation in this number dependent on the age of the person being scanned and the MRI quality.

Intracranial pressure following surgery of an unruptured intracranial aneurysm-a model for normal intracranial pressure in humans.

OBJECTIVE: Optimizing the treatment of several neurosurgical and neurological disorders relies on knowledge of the intracranial pressure (ICP). However, exploration of normal ICP and intracranial pressure pulse wave amplitude (PWA) values in healthy individuals poses ethical challenges, and thus the current documentation remains scarce. This study explores ICP and PWA values for healthy adults without intracranial pathology expected to influence ICP. METHODS: Adult patients (age > 18 years) undergoing surgery for an unruptured intracranial aneurysm without any other neurological co-morbidities were included. Patients had a telemetric ICP sensor inserted, and ICP was measured in four different positions: supine, lateral recumbent, standing upright, and 45-degree sitting, at day 1, 14, 30, and 90 following the surgery. RESULTS: ICP in each position did not change with time after surgery. Median ICP was 6.7 mmHg and median PWA 2.1 mmHg in the supine position, while in the upright standing position median ICP was - 3.4 mmHg and median PWA was 1.9 mmHg. After standardization of the measurements from the transducer site to the external acoustic meatus, the median ICPmidbrain was 8.3 mmHg in the supine position and 1.2 mmHg in the upright standing position. CONCLUSION: Our study provides insights into normal ICP dynamics in healthy adults following a uncomplicated surgery for an unruptured aneurysm. These results suggest a slightly wider normal reference range for invasive intracranial pressure than previously suggested, and present the first normal values for PWA in different positions. Further studies are, however, essential to enhance our understanding of normal ICP. Trial registration The study was preregistered at www. CLINICALTRIALS: gov (NCT03594136) (11 July 2018).

Treatment options for intracranial arachnoid cysts: a retrospective study of 69 patients.

The best surgical treatment of cerebral arachnoid cysts is yet to be established. Treatment options are shunting, endoscopic fenestration or microsurgical fenestration through craniotomy.Data from 69 patients with cerebral arachnoid cysts treated in our institution between 1997 and 2007 were reviewed.Cysts were located infratentorially in 20% (n = 14) and supratentorially in 80% (n = 55); of these 73% (n = 40) were in the middle cranial fossa. Mean cyst size was 61 mm (range 15-100 mm). The most common symptoms were headache (51%), dizziness (26%), cranial nerve dysfunction (23%), seizure (22%), nausea and vomiting (18%), and hemiparesis (13%). Surgery was performed in 83% (n = 57). First-line treatments were microsurgical fenestration (n = 30), endoscopic fenestration (n = 15), and cystoperitoneal/ventriculoperitoneal shunting (n = 11). More than one intervention was needed in 42% (n = 24). A particularly high rate of relapse (73%) was observed after endoscopic fenestration, following which 11 patients were admitted for reoperation. By comparison, only eight patients (28%) managed with microsurgical fenestration and four (36%) in the shunted group needed a second surgical procedure. Mean follow-up was 30 months. In the surgical series 79% (n = 45) had a good outcome.We conclude that the surgical treatment of arachnoid cysts has an overall good outcome. In our institution the best results were obtained with microsurgical decompression through craniotomy.

[Endoscopic treatment of hydrocephalus].

Endoscopic treatment of hydrocephalus provides an opportunity to reach deeply located intraventricular obstacles and, as such, it is currently the primary treatment for obstructive hydrocephalus in Denmark. This review provides an overview of conditions treatable with endoscopic neurosurgery including the surgical principles, success rate and challenges with this neurosurgical procedure.

[Diagnosis and treatment of normal pressure hydrocephalus].

This review summarises the current knowledge of normal pressure hydrocephalus (NPH), which is considered to be a reversible cause of dementia. Early identification is important to select patients for surgical treatment with ventricular shunting. The symptoms of NPH are gait disturbance, cognitive dysfunction and urinary incontinence. NPH is diagnosed by a combination of the clinical presentation and neuroimaging and preferably supported by cerebrospinal fluid tests. The pathophysiology is not well described and a significant overlap with degenerative and small vessel brain diseases exist, making selection of patients for surgery difficult.

Accuracy of tunnelated vs. bolt-connected external ventricular drains.

BACKGROUND: Ventriculostomy is one of the most common neurosurgical procedures and an important tool in the treatment and monitoring of elevated intracranial pressure. Low accuracy has frequently been reported in the literature with risk of drain misplacement over 20% and with a need for reinsertion in up to 40%. As an alternative to the tunnelated EVD technique we often use a bolt-connected EVD. The aim of the present study was to investigate whether the use of bolt-connected EVDs would lead to higher accuracy, fewer passes and reoperations due to poor placement compared to tunnelated EVDs. PATIENTS AND METHODS: We retrospectively identified all patients who received an EVD from January 1st 2008 to December 31st 2010. Postoperative images were evaluated for anatomical placement of the EVD-tip, distance from tip to optimal placement and were categorized as optimal, suboptimal and undesired. Patient files were evaluated for EVD technique, number of passes and postoperative complications and handling. RESULTS: 147 patients with 154 separate EVDs met the inclusion criteria. We found a statistical significant higher accuracy in the bolt-group compared to the tunnelated-group (p=0.023). Eleven patients were reoperated following ventriculostomy and we found a statistical significant 11.9% reduction in reoperations due to poor placement in the bolt-group (p=0.006). CONCLUSIONS: We have showed in this study that by using a bolt-connected EVD and maintaining the freehanded technique we can significantly increase precision and decrease the number of reoperations due to poor placement.

A severe case of tetracycline-induced intracranial hypertension.

Tetracykline is a first-line treatment of the common skin disorder acne vulgaris. A rare side effect of tetracycline treatment is intracranial hypertension also called pseudotumor cerebri (PTC). We report a severe case of PTC with cranial nerve palsy and visual loss in a 16 year old girl following acne vulgaris treatment with tetracycline.