| 1. |
- Abu Hamdeh, Sami, et al.
(författare)
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Brain tissue Aβ42 levels are linked to shunt response in idiopathic normal pressure hydrocephalus
- 2019
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Ingår i: Journal of Neurosurgery. - : Journal of Neurosurgery Publishing Group (JNSPG). - 0022-3085 .- 1933-0693. ; 130:1, s. 121-129
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Tidskriftsartikel (refereegranskat)abstract
- Objective The authors conducted a study to test if the cortical brain tissue levels of soluble amyloid beta (Aβ) reflect the propensity of cortical Aβ aggregate formation and may be an additional factor predicting surgical outcome following idiopathic normal pressure hydrocephalus (iNPH) treatment.Methods Highly selective ELISAs (enzyme-linked immunosorbent assays) were used to quantify soluble Aβ40, Aβ42, and neurotoxic Aβ oligomers/protofibrils, associated with Aβ aggregation, in cortical biopsy samples obtained in patients with iNPH (n = 20), sampled during ventriculoperitoneal (VP) shunt surgery. Patients underwent pre- and postoperative (3-month) clinical assessment with a modified iNPH scale. The preoperative CSF biomarkers and the levels of soluble and insoluble Aβ species in cortical biopsy samples were analyzed for their association with a favorable outcome following the VP shunt procedure, defined as a ≥ 5-point increase in the iNPH scale.Rrsults The brain tissue levels of Aβ42 were negatively correlated with CSF Aβ42 (Spearman's r = -0.53, p < 0.05). The Aβ40, Aβ42, and Aβ oligomer/protofibril levels in cortical biopsy samples were higher in patients with insoluble cortical Aβ aggregates (p < 0.05). The preoperative CSF Aβ42 levels were similar in patients responding (n = 11) and not responding (n = 9) to VP shunt treatment at 3 months postsurgery. In contrast, the presence of cortical Aβ aggregates and high brain tissue Aβ42 levels were associated with a poor outcome following VP shunt treatment (p < 0.05).Conclusions Brain tissue measurements of soluble Aβ species are feasible. Since high Aβ42 levels in cortical biopsy samples obtained in patients with iNPH indicated a poor surgical outcome, tissue levels of Aβ species may be associated with the clinical response to shunt treatment.
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| 2. |
- Abu Hamdeh, Sami, et al.
(författare)
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Intracranial pressure elevations in diffuse axonal injury : association with nonhemorrhagic MR lesions in central mesencephalic structures
- 2019
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Ingår i: Journal of Neurosurgery. - 0022-3085 .- 1933-0693. ; 131:2, s. 604-611
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Tidskriftsartikel (refereegranskat)abstract
- Objective: Increased intracranial pressure (ICP) in patients with severe traumatic brain injury (TBI) with diffuse axonal injury (DAI) is not well defined. This study investigated the occurrence of increased ICP and whether clinical factors and lesion localization on MRI were associated with increased ICP in patients with DAI.Methods: Fifty-two patients with severe TBI (median age 24 years, range 9–61 years), who had undergone ICP monitoring and had DAI on MRI, as determined using T2*-weighted gradient echo, susceptibility-weighted imaging, and diffusion-weighted imaging (DWI) sequences, were enrolled. The proportion of good monitoring time (GMT) with ICP > 20 mm Hg during the first 120 hours postinjury was calculated and associations with clinical and MRI-related factors were evaluated using linear regression.Results: All patients had episodes of ICP > 20 mm Hg. The mean proportion of GMT with ICP > 20 mm Hg was 5%, and 27% of the patients (14/52) spent more than 5% of GMT with ICP > 20 mm Hg. The Glasgow Coma Scale motor score at admission (p = 0.04) and lesions on DWI sequences in the substantia nigra and mesencephalic tegmentum (SN-T, p = 0.001) were associated with the proportion of GMT with ICP > 20 mm Hg. In multivariable linear regression, lesions on DWI sequences in SN-T (8% of GMT with ICP > 20 mm Hg, 95% CI 3%–13%, p = 0.004) and young age (−0.2% of GMT with ICP > 20 mm Hg, 95% CI −0.07% to −0.3%, p = 0.002) were associated with increased ICP.Conclusions: Increased ICP occurs in approximately one-third of patients with severe TBI who have DAI. Age and lesions on DWI sequences in the central mesencephalon (i.e., SN-T) are associated with elevated ICP. These findings suggest that MR lesion localization may aid prediction of increased ICP in patients with DAI.Abbreviations: ADC = apparent diffusion coefficient; CPP = cerebral perfusion pressure; DAI = diffuse axonal injury; DWI = diffusion-weighted imaging; EVD = external ventricular drain; GCS = Glasgow Coma Scale; GMT = good monitoring time; GOSE = Glasgow Outcome Scale–Extended; ICC = intraclass correlation coefficient; ICP = intracranial pressure; MAP = mean arterial blood pressure; NICU = neurointensive care unit; SN-T = substantia nigra and mesencephalic tegmentum; SWI = susceptibility-weighted imaging; TBI = traumatic brain injury; T2*GRE = T2*-weighted gradient echo.
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| 3. |
- Andersson, Nina, et al.
(författare)
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Dependency of cerebrospinal fluid outflow resistance on intracranial pressure
- 2008
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Ingår i: Journal of Neurosurgery. - 0022-3085 .- 1933-0693. ; 109:5, s. 918-922
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Tidskriftsartikel (refereegranskat)abstract
- OBJECT: The outflow resistance (Rout) of the cerebrospinal fluid (CSF) system has generally been accepted by most investigators as independent of intracranial pressure (ICP), but there are also those claiming that it is not. The general belief is that this question has been investigated numerous times in the past, but few studies have actually been specifically aimed at looking at this relationship, and no study has been able to provide scientific evidence to elucidate fully this fundamental and important issue. The objective of this study was to investigate the relationship between ICP and CSF outflow in 30 patients investigated for idiopathic normal-pressure hydrocephalus. METHODS: Lumbar infusion tests with constant pressure levels were performed, and ICP and corresponding flow were measured on 6 pressure levels for each patient. All data were standardized for comparison. RESULTS: In the range of moderate increases from baseline pressure (approximately 5-12 mm Hg, mean baseline pressure 11.7 mm Hg), the assumption of a pressure-independent Rout was confirmed (p = 0.5). However, when the pressure increment from baseline pressure was larger (approximately 15-22 mm Hg), the relationship had a nonlinear tendency (p < 0.05). CONCLUSIONS: The results of this study support the classic textbook theory of a pressure-independent Rout in the normal ICP range, where the CSF system is commonly operating. However, the theory might have to be questioned in regions where ICP exceeds baseline pressure by too much.
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| 4. |
- Andisheh, Bahram, 1967-, et al.
(författare)
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Clinical and radiobiological advantages of single-dose stereotactic light-ion radiation therapy for large intracranial arteriovenous malformations. Technical note
- 2009
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Ingår i: Journal of Neurosurgery. - : Journal of Neurosurgery Publishing Group (JNSPG). - 0022-3085 .- 1933-0693. ; 111:5, s. 919-926
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Tidskriftsartikel (refereegranskat)abstract
- OBJECT:Radiation treatment of large arteriovenous malformations (AVMs) remains difficult and not very effective, even though seemingly promising methods such as staged volume treatments have been proposed by some radiation treatment centers. In symptomatic patients harboring large intracranial AVMs not amenable to embolization or resection, single-session high-dose stereotactic radiation therapy is a viable option, and the special characteristics of high-ionization-density light-ion beams offer several treatment advantages over photon and proton beams. These advantages include a more favorable depth-dose distribution in tissue, an almost negligible lateral scatter of the beam, a sharper penumbra, a steep dose falloff beyond the Bragg peak, and a higher probability of vascular response due to high ionization density and associated induction of endothelial cell proliferation and/or apoptosis. Carbon ions were recently shown to be an effective treatment for skull-base tumors. Bearing that in mind, the authors postulate that the unique physical and biological characteristics of light-ion beams should convey considerable clinical advantages in the treatment of large AVMs. In the present meta-analysis the authors present a comparison between light-ion beam therapy and more conventional modalities of radiation treatment with respect to these lesions.METHODS:Dose-volume histograms and data on peripheral radiation doses for treatment of large AVMs were collected from various radiation treatment centers. Dose-response parameters were then derived by applying a maximum likelihood fitting of a binomial model to these data. The present binomial model was needed because the effective number of crucial blood vessels in AVMs (the number of vessels that must be obliterated to effect a cure, such as large fistulous nidus vessels) is low, making the Poisson model less suitable. In this study the authors also focused on radiobiological differences between various radiation treatments.RESULTS:Light-ion Bragg-peak dose delivery has the precision required for treating very large AVMs as well as for delivering extremely sharp, focused beams to irregular lesions. Stereotactic light-ion radiosurgery resulted in better angiographically defined obliteration rates, less white-matter necrosis, lower complication rates, and more favorable clinical outcomes. In addition, in patients treated by He ion beams, a sharper dose-response gradient was observed, probably due to a more homogeneous radiosensitivity of the AVM nidus to light-ion beam radiation than that seen when low-ionization-density radiation modalities, such as photons and protons, are used.CONCLUSIONS:Bragg-peak radiosurgery can be recommended for most large and irregular AVMs and for the treatment of lesions located in front of or adjacent to sensitive and functionally important brain structures. The unique physical and biological characteristics of light-ion beams are of considerable advantage for the treatment of AVMs: the densely ionizing beams of light ions create a better dose and biological effect distribution than conventional radiation modalities such as photons and protons. Using light ions, greater flexibility can be achieved while avoiding healthy critical structures such as diencephalic and brainstem nuclei and tracts. Treatment with the light ion He or Li is more suitable for AVMs
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| 5. |
- Ansar, Saema, et al.
(författare)
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Equal contribution of increased intracranial pressure and subarachnoid blood to cerebral blood flow reduction and receptor upregulation after subarachnoid hemorrhage.
- 2009
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Ingår i: Journal of Neurosurgery. - : Journal of Neurosurgery Publishing Group (JNSPG). - 0022-3085 .- 1933-0693. ; 111, s. 978-987
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Tidskriftsartikel (refereegranskat)abstract
- Object Cerebral ischemia remains the key cause of disability and death in the late phase after subarachnoid hemorrhage (SAH), and its pathogenesis is still poorly understood. The purpose of this study was to examine whether the change in intracranial pressure or the extravasated blood causes the late cerebral ischemia and the upregulation of receptors or the cerebral vasoconstriction observed following SAH. Methods Rats were allocated to 1 of 3 experimental conditions: 1) cisternal injection of 250 mul blood (SAH Group), 2) cisternal injection of 250 mul NaCl (Saline Group), or 3) the same procedure but without fluid injection (Sham Group). Two days after the procedure, the basilar and middle cerebral arteries were harvested, and contractile responses to endothelin (ET)-1 and 5-carboxamidotryptamine (5-CT) were investigated by means of myography. In addition, real-time polymerase chain reaction was used to determine the mRNA levels for ET(A), ET(B), and 5-HT(1) receptors. Regional and global cerebral blood flow (CBF) were quantified by means of an autoradiographic technique. Results Compared with the sham condition, both SAH and saline injection resulted in significantly enhanced contraction of cerebral arteries in response to ET-1 and 5-CT. Regional and global CBF were reduced both in the Saline and SAH groups compared with the Sham Group. The mRNA levels for ET(B) and 5-HT(1B) receptors were upregulated after SAH and saline injection compared with the sham procedure. The effects in all parameters were more pronounced for SAH than for saline injection. Conclusions This study revealed that both the elevation of intracranial pressure and subarachnoid blood per se contribute approximately equally to the late CBF reductions and receptor upregulation following SAH.
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| 6. |
- Arnell, Kai, et al.
(författare)
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Treatment of cerebrospinal fluid shunt infections in children using systemic and intraventricular antibiotic therapy in combination with externalization of the ventricular catheter : efficacy in 34 consecutively treated infections
- 2007
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Ingår i: Journal of Neurosurgery. - 0022-3085 .- 1933-0693. ; 107:3, s. 213-219
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Tidskriftsartikel (refereegranskat)abstract
- OBJECT: There are no randomized studies comparing the efficacy of different antibiotic regimens for the treatment of cerebrospinal fluid (CSF) shunt infections, and in the studies that have been reported, efficacy data are limited. The aim of this study was therefore to report the authors' experience using a specific protocol for the management of shunt infections in children. Standard treatment included a two-stage procedure involving externalization of the ventricular catheter in combination with intraventricular and systemic administration of antibiotic medication followed by shunt replacement. Intraventricular treatment consisted of daily instillations of vancomycin or gentamicin with trough concentrations held at high levels of 7 to 17 mg/L for both antibiotic agents. METHODS: During a 13-year study period, the authors treated 34 consecutive intraventricular shunt infections in 30 children. Infections with coagulase-negative staphylococci predominated, and Gram-negative bacterial infection occurred in five children. Ten of the children were initially treated with intravenous antibiotic therapy for at least 3 days, but this treatment did not sterilize the CSF. After externalization of the ventricular catheter, high-dose intraventricular treatment was given for a median of 8 days (range 3-17 days) before shunt replacement. RESULTS: The CSF was found to be sterile (cultures were negative for bacteria) in one of three, seven of eight, 20 of 20, and six of six cases after 1, 2, 3, and more than 3 days' treatment, respectively. In no case was any subsequent culture positive after a negative result had been obtained. Clinical symptoms resolved in parallel with the sterilization of the CSF. There were no relapses or deaths during the 6-month follow-up period, and there have been none as of April 2007. CONCLUSIONS: Despite the ventricular catheter being left in place and the short duration of therapy, the treatment regimen described by the authors resulted in quick sterilization of the CSF, a low relapse rate, and survival of all patients in this series.
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| 7. |
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| 8. |
- Backlund, EO
(författare)
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Letter: Gamma hypophysectomy
- 2004
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Ingår i: Journal of Neurosurgery. - 0022-3085 .- 1933-0693. ; 100:6, s. 1133-1134
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
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| 9. |
- Barany, P
(författare)
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Bárány and traumatic brain injury
- 2013
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Ingår i: Journal of neurosurgery. - 1933-0693. ; 118:4, s. 908-908
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)
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| 10. |
- Behrens, Anders, et al.
(författare)
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The Computerized General Neuropsychological INPH Test revealed improvement in idiopathic normal pressure hydrocephalus after shunt surgery
- 2020
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Ingår i: Journal of Neurosurgery. - : AMER ASSOC NEUROLOGICAL SURGEONS. - 0022-3085 .- 1933-0693. ; 132:3, s. 733-740
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE The Computerized General Neuropsychological INPH Test (CoGNIT) provides the clinician and the researcher with standardized and accessible cognitive assessments in patients with idiopathic normal pressure hydrocephalus (INPH). CoGNIT includes tests of memory, executive functions, attention, manual dexterity, and psychomotor speed. Investigations of the validity and reliability of CoGNIT have been published previously. The aim of this study was to evaluate CoGNIT's sensitivity to cognitive change after shunt surgery in patients with INPH.METHODS Forty-one patients with INPH (median Mini-Mental State Examination score 26) were given CoGNIT preoperatively and at a postoperative follow-up 4 months after shunt surgery. Scores were compared to those of 44 healthy elderly control volunteers. CoGNIT was administered by either a nurse or an occupational therapist.RESULTS Improvement after shunt surgery was seen in all cognitive domains: memory (10-word list test, p < 0.01); executive functions (Stroop incongruent color and word test, p < 0.01); attention (2-choice reaction test, p < 0.01); psychomotor speed (Stroop congruent color and word test, p < 0.01); and manual dexterity (4-finger tapping, p < 0.01). No improvement was seen in the Mini-Mental State Examination score. Preoperative INPH test scores were significantly impaired compared to healthy control subjects (p < 0.001 for all tests).CONCLUSIONS In this study the feasibility for CoGNIT to detect a preoperative impairment and postoperative improvement in INPH was demonstrated. CoGNIT has the potential to become a valuable tool in clinical and research work.
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