Software compatibility analysis for quantitative measures of [18F]flutemetamol amyloid PET burden in mild cognitive impairment.

RATIONALE: Amyloid-ß (Aß) pathology is one of the earliest detectable brain changes in Alzheimer's disease pathogenesis. In clinical practice, trained readers will visually categorise positron emission tomography (PET) scans as either Aß positive or negative. However, adjunct quantitative analysis is becoming more widely available, where regulatory approved software can currently generate metrics such as standardised uptake value ratios (SUVr) and individual Z-scores. Therefore, it is of direct value to the imaging community to assess the compatibility of commercially available software packages. In this collaborative project, the compatibility of amyloid PET quantification was investigated across four regulatory approved software packages. In doing so, the intention is to increase visibility and understanding of clinically relevant quantitative methods. METHODS: Composite SUVr using the pons as the reference region was generated from [18F]flutemetamol (GE Healthcare) PET in a retrospective cohort of 80 amnestic mild cognitive impairment (aMCI) patients (40 each male/female; mean age = 73 years, SD = 8.52). Based on previous autopsy validation work, an Aß positivity threshold of ≥ 0.6 SUVrpons was applied. Quantitative results from MIM Software's MIMneuro, Syntermed's NeuroQ, Hermes Medical Solutions' BRASS and GE Healthcare's CortexID were analysed using intraclass correlation coefficient (ICC), percentage agreement around the Aß positivity threshold and kappa scores. RESULTS: Using an Aß positivity threshold of ≥ 0.6 SUVrpons, 95% agreement was achieved across the four software packages. Two patients were narrowly classed as Aß negative by one software package but positive by the others, and two patients vice versa. All kappa scores around the same Aß positivity threshold, both combined (Fleiss') and individual software pairings (Cohen's), were ≥ 0.9 signifying "almost perfect" inter-rater reliability. Excellent reliability was found between composite SUVr measurements for all four software packages, with an average measure ICC of 0.97 and 95% confidence interval of 0.957-0.979. Correlation coefficient analysis between the two software packages reporting composite z-scores was strong (r2 = 0.98). CONCLUSION: Using an optimised cortical mask, regulatory approved software packages provided highly correlated and reliable quantification of [18F]flutemetamol amyloid PET with a ≥ 0.6 SUVrpons positivity threshold. In particular, this work could be of interest to physicians performing routine clinical imaging rather than researchers performing more bespoke image analysis. Similar analysis is encouraged using other reference regions as well as the Centiloid scale, when it has been implemented by more software packages.

Perineurioma: A Rare Entity of Peripheral Nerve Sheath Tumors.

OBJECTIVE: Intraneural perineurioma is a rare tumor entity. It is a benign, very slow growing peripheral nerve sheath tumor that typically occurs in children and young adults. Motor deficits and muscle atrophy are classic presenting symptoms, while sensory deficits are rare at the onset of the disease. Recommended treatment strategies are lacking. We have evaluated the clinical follow-up and our experience with treatment of this rare entity. METHODS: A total of 30 patients with intraneural perineuriomas were assessed retrospectively. Demographic data, clinical symptoms, diagnostic examinations, therapy strategies, and clinical outcome were analyzed. Descriptive statistical methods were used for evaluation. RESULTS: The mean age was 22 years. Eleven women and 19 men were affected. The lesion occurred in the area of the upper extremity in 16 patients and in the area of the lower extremity in 14 patients. The most frequently affected nerve was the sciatic nerve, followed by the radial nerve. All patients showed a motor deficit to some extent. Seventy percent (n = 21) revealed atrophy, 43.3% (n = 13) had sensitive deficits, and 17% (n = 5) suffered of pain. Fascicle biopsies were performed in 26 patients (87%). In four patients (13%), the tumor was completely resected and then reconstructed via nerve grafts. Seventy percent of the patients (n = 21) received a magnetic resonance imaging (MRI) within 5 years postoperatively, in which no progress was shown. CONCLUSIONS: To diagnose perineurioma, it is essential to take a biopsy of an enlarged, nonfunctional fascicle. Furthermore, a long-distance epineuriotomy to decompress the hypertrophic fascicle is reasonable. To preserve the nerves' residual function, a complete resection is not recommended. Results after grafting are poor. One reason for this might be residual tumor cells along the nerve that cannot be visualized. Malignant transformation is not yet reported and tumor growth is stable for years.

Practical Application of DaTQUANT with Optimal Threshold for Diagnostic Accuracy of Dopamine Transporter SPECT.

Evaluation of Parkinsonian Syndromes (PS) with Ioflupane iodine-123 dopamine transporter single photon emission computed tomography (DaT-SPECT), in conjunction with history and clinical examination, aids in diagnosis. FDA-approved, semi-quantitative software, DaTQUANTTM (GE Healthcare, Chicago, IL, USA) is available to assist in interpretation. This study aims to evaluate the optimal variables and thresholds of DaTQUANT to yield the optimal diagnostic accuracy. It is a retrospective review with three different patient populations. DaT-SPECT images from all three study groups were evaluated using DaTQUANTTM software, and both single and multi-variable logistic regression were used to model PS status. The optimal models were chosen via accuracy, sensitivity, and specificity, then evaluated on the other study groups. Among single variable models, the posterior putamen yielded the highest accuracy (84% to 95%), while balancing sensitivity and specificity. Multi-variable models did not substantially improve the accuracy. When the optimal single variable models for each group were used to evaluate the remaining two groups, comparable results were achieved. In typical utilization of DaT-SPECT for differentiation between nigrostriatal degenerative disease (NSDD) and non-NSDD, the posterior putamen was the single variable that yielded the highest accuracy across three different patient populations. The posterior putamen's recommended thresholds for DaTQUANT are SBR ≤ 1.0, z-score of ≤-1.8 and percent deviation ≤ -0.34.

Clinical utility of DaTscan in patients with suspected Parkinsonian syndrome: a systematic review and meta-analysis.

Images of DaTscan (ioflupane [123I] SPECT) have been used as an adjunct to clinical diagnosis to facilitate the differential diagnosis of neurodegenerative (ND) Parkinsonian Syndrome (PS) vs. non-dopamine deficiency aetiologies of Parkinsonism. Despite several systematic reviews having summarised the evidence on diagnostic accuracy, the impact of imaging results on clinical utility has not been systematically assessed. Our objective was to examine the available evidence on the clinical utility of DaTscan imaging in changing diagnosis and subsequent management of patients with suspected PS. We performed a systematic review of published studies of clinical utility from 2000 to 2019 without language restrictions. A meta-analysis of change in diagnosis and management rates reported from each study was performed using a random-effects model and logit transformation. Sub-group analysis, meta-regression and sensitivity analysis was performed to explore heterogeneity. Twenty studies met the inclusion criteria. Thirteen of these contributed to the meta-analyses including 950 and 779 patients with a reported change in management and change in diagnosis, respectively. The use of DaTscan imaging resulted in a change in management in 54% (95% CI: 47-61%) of patients. Change in diagnosis occurred in 31% (95% CI: 22-42%) of patients. The two pooled analyses were characterised by high levels of heterogeneity. Our systematic review and meta-analysis show that imaging with DaTscan was associated with a change in management in approximately half the patients tested and the diagnosis was modified in one third. Regardless of time from symptom onset to scan results, these changes were consistent. Further research focusing on specific patient subgroups could provide additional evidence on the impact on clinical outcomes.

Lipid metabolism adaptations are reduced in human compared to murine Schwann cells following injury.

Mammals differ in their regeneration potential after traumatic injury, which might be caused by species-specific regeneration programs. Here, we compared murine and human Schwann cell (SC) response to injury and developed an ex vivo injury model employing surgery-derived human sural nerves. Transcriptomic and lipid metabolism analysis of murine SCs following injury of sural nerves revealed down-regulation of lipogenic genes and regulator of lipid metabolism, including Pparg (peroxisome proliferator-activated receptor gamma) and S1P (sphingosine-1-phosphate). Human SCs failed to induce similar adaptations following ex vivo nerve injury. Pharmacological PPARg and S1P stimulation in mice resulted in up-regulation of lipid gene expression, suggesting a role in SCs switching towards a myelinating state. Altogether, our results suggest that murine SC switching towards a repair state is accompanied by transcriptome and lipidome adaptations, which are reduced in humans.

Do Complication Rates of Ventricular Drain Placement Differ between Twist Drill and Burr Hole in Acute Hydrocephalus?

OBJECTIVE: The aim of the study was to compare two techniques for external ventricular drainage (EVD) placement with respect to their complication rates. METHODS: A retrospective descriptive study was performed to analyze all patients who had undergone EVD implantation for acute hydrocephalus between January 2010 and December 2013 with a focus on surgical technique and rate of complications. The burr hole technique (BHT) was used in one group and the twist-drill technique (TDT) in the other. Particular attention was paid to malposition, hemorrhage, and catheter-associated infection. RESULTS: A total of 350 consecutive patients underwent EVD implantation for acute hydrocephalus: BHT was performed in 201 and TDT in 147 of the patients, whereas in two patients the technique used was unknown. The overall infection rate was 6.3% (n = 22). Fourteen patients (4%) in the BHT group developed an infection compared with eight patients (9.5%) in the TDT group (p = 0.154). In 16 (4.5%) of all cases, postoperative computed tomography revealed catheter-induced hemorrhage.In one case (0.3%), surgery was necessary due to acute subdural hematoma. The difference between both techniques was not statistically significant (p = 0.343). In 44 (12.6%) of all cases, the position of the EVD tip was contralateral; in 36 (10.3%) of all cases, the EVD tip was in the brain parenchyma. The rate of malposition was 11.6% (n = 17) in the TDT group and 9.5% (n = 19) in the BHT group (p = 0.078). CONCLUSION: Neither technique showed significantly different numbers in terms of infection, malposition, and hemorrhagic complications. EVD implantation using the TDT is an adequate method compared with BHT. The advantages of TDT are clear: the duration of surgery is shorter, the size of the wound is smaller, and the surgeon is not confined to the operating room.

The evolution of invasive cerebral vasospasm treatment in patients with spontaneous subarachnoid hemorrhage and delayed cerebral ischemia-continuous selective intracarotid nimodipine therapy in awake patients without sedation.

Cerebral vasospasm (CV) and delayed cerebral ischemia (DCI) are major factors that limit good outcome in patients with spontaneous subarachnoid hemorrhage (SAH). Continuous therapy with intra-arterial calcium channel blockers has been introduced as a new step in the invasive treatment cascade of CV and DCI. Sedation is routinely necessary for this procedure. We report about the feasibility to apply this therapy in awake compliant patients without intubation and sedation. Out of 67 patients with invasive endovascular treatment of cerebral vasospasm due to spontaneous SAH, 5 patients underwent continuous superselective intracarotid nimodipine therapy without intubation and sedation. Complications, neurological improvement, and outcome at discharge were summarized. Very good outcome was achieved in all 5 patients. The Barthel scale was 100 and the modified Rankin scale 0-1 in all cases at discharge. We found no severe complications and excellent neurological monitoring was possible in all cases due to patients' alert status. Symptoms of DCI resolved within 24 h in all 5 cases. We could demonstrate the feasibility and safety of selective intracarotid arterial nimodipine treatment in awake, compliant patients with spontaneous SAH and symptomatic CV and DCI. Using this method, an excellent monitoring of neurological function as well as early detection of other complications is possible. It might be an important step in the risk reduction of invasive CV therapy to improve the outcome with CV and DCI after SAH in selected patients.

Quality of Life After Treatment of Unruptured Intracranial Aneurysms.

OBJECTIVE: Quality of life is an important factor in the decision making for the treatment of unruptured intracranial aneurysms (UIA). The data dealing with QoL in patients after the treatment are spare. We have evaluated QoL of patients after endovascular or surgical treatment of incidental intracranial aneurysm. METHODS: We performed a prospective analysis of retrospectively collected data. All patients received 36-Item Short Form Health Survey (SF-36), Hospital Anxiety and Depression Scale (HADS), German questionnaire for self-perceived deficits in attention (FEDA) and not standardized questionnaire analyzing personal job-related situation, family circumstances and chronic illnesses. RESULTS: 177 patients were treated during the evaluated period. 79 (44.6%) patients responded. In this cohort, 62.03% of patients underwent coiling. Complications were noted in 13.9% of patients. Stroke was the most common complication (7.6%). All SF-36 related data except for pain showed significant lower mean, if compared to the standard German population (p < 0.01). For both genders, anxiety (males, P = 0.003 and females, P = 0.002) but not depression was more common than in the standard population. According to the FEDA test, treated patients showed significant difference only for fatigue in comparison to healthy population (P < 0.001). 54.4% of patients suffered from chronic illnesses, and among them only 1 patient (1.3%) had aneurysm associated chronic disease. No significant differences were found between treatment modalities. CONCLUSIONS: The risk for depression and pain is not significantly increased after elective treatment of UIA. According to our results, decreased QoL is common in this cohort of patients but often related to factors not associated with aneurysm treatment.

The Value of Intraoperative Magnetic Resonance Imaging in Endoscopic and Microsurgical Transsphenoidal Pituitary Adenoma Resection.

BACKGROUND: The routine use of intraoperative magnetic resonance imaging (iMRI) helps to achieve gross total resection in transsphenoidal pituitary surgery. We compared the added value of iMRI for extent of resection in endoscopic versus microsurgical transsphenoidal adenomectomy. METHODS: A total of 96 patients with pituitary adenoma were included. Twenty-eight consecutive patients underwent endoscopic transsphenoidal tumor resection. For comparison, we used a historic cohort of 68 consecutive patients treated microsurgically. We evaluated the additional resection after conducting iMRI using intraoperative and late postoperative volumetric tumor analysis 3 months after surgery. Demographic data, clinical symptoms, and complications as well as pituitary function were evaluated. RESULTS: We found significantly fewer additional resections after conducting iMRI in the endoscopic group (P = 0.042). The difference was even more profound in Knosp grade 0-2 adenomas (P = 0.029). There was no significant difference in Knosp grade 3-4 adenomas (P = 0.520). The endoscopic approach was associated with smaller intraoperative tumor volume (P = 0.023). No significant difference was found between both techniques in postoperative tumor volume (P = 0.228). Satisfactory results of pituitary function were significantly more often associated with an endoscopic approach in the multiple regression analysis (P = 0.007; odds ratio, 17.614; confidence interval 95%, 2.164-143.396). CONCLUSIONS: With the endoscopic approach, significantly more tumor volume reduction was achieved before conducting iMRI, decreasing the need for further resection. This finding was even more pronounced in adenomas graded Knosp 0-2. In the case of extensive and invasive adenomas with infiltration of cavernous sinus and suprasellar or parasellar extension, additional tumor resection and increase in the extent of resection was achieved with iMRI in both groups. The endoscopic approach seems to result in better endocrine outcomes, especially in Knosp grade 0-2 pituitary adenomas.

The Value of Intraoperative and Early Postoperative Magnetic Resonance Imaging in Low-Grade Glioma Surgery: A Retrospective Study.

BACKGROUND: The presence of residual tumor is crucial in decision-making for low-grade gliomas (LGGs), because patients older than 40 years of age with residual tumor are considered for adjuvant treatment. There are hints that early postoperative fluid-attenuated inversion recovery (FLAIR) and T2 (within 48 hours) may overestimate residual tumor volume in LGG. Intraoperative magnetic resonance imaging (MRI) without subsequent resection or ultra-early postoperative MRI may assess the amount of residual tumor more adequately. To evaluate the utility of postoperative imaging in LGG, we volumetrically analyzed intraoperative, early, and late (3-4 months after surgery) postoperative MRIs of LGGs. PATIENTS AND METHODS: A total of 33 patients with LGG were assessed retrospectively. Residual tumor was defined as signal-enhanced tissue in T2 and FLAIR. Volumetric assessment was performed with intraoperative, early, and late postoperative T2/FLAIR via Brainlab-iPlan 3.0. Wilcoxon and χ(2) tests were used for statistical analysis. RESULTS: A significant difference of FLAIR/T2 abnormalities was found in intraoperative and early postoperative MRIs (FLAIR mean volume = 5.433 cm(3), T2 mean volume = 3.374 cm(3) vs. FLAIR mean volume = 14.090 cm(3), P = 0.002, T2 mean volume = 7.597 cm(3), P = 0.006). There was no significant difference between intraoperative and late postoperative FLAIR/T2 abnormalities (late postoperative FLAIR/T2 mean volume = 5.560 cm(3) and 2.370 cm(3), P = 0.520, P = 0.398), whereas a significant difference was detected between early and late postoperative images (FLAIR, P < 0.0001; T2, P < 0.00001). CONCLUSION: Intraoperative MRI without further resection or ultra-early postoperative MRI seems to reflect the actual volume of residual tumor in LGG more precisely compared with early postoperative MRI and therefore seems to be more useful regarding decisions for adjuvant therapy.

Outcome After Decompressive Craniectomy in Different Pathologies.

BACKGROUND: We compare the outcome after decompressive craniectomy for various neurologic diseases with the final common pathway of coma, compression of the basal cisterns, a midline shift, or refractory intracranial hypertension. METHODS: Between January 2005 and June 2009, 134 patients underwent decompressive craniectomy for traumatic brain injury (n = 74), intracerebral hemorrhage (n = 21), spontaneous subarachnoid hemorrhage (n = 11), malignant cerebral infarction (n = 27), or encephalitis (n = 1). The outcome was classified at discharge and up to 12 months after treatment in accordance with the Glasgow Outcome Scale (GOS), as well as the Glasgow Coma Scale, Marshall classification, or National Institutes of Health Stroke Scale. Significance was established as P ≤ 0.05. RESULTS: Median and mean scores on the Glasgow Coma Scale at time of neurosurgical assessment in all patients were ≤7. Midline shift was reduced in each subset as a result of surgery (mean, 0.26-0.46 cm; P ≤ 0.049). Overall outcome based on the median GOS score at discharge ranged from death to severe disability. After 12 months, the median range narrowed to a range of death to persistent vegetative state. At various time points, mean GOS score was not found to differ significantly between the subsets. Unfavorable outcome after 3 months was found in a smaller group of patients after traumatic brain injury than was found in patients with other diseases (P = 0.016). CONCLUSIONS: The outcome after decompressive craniectomy does not differ significantly in different diseases once the final pathophysiologic pathway of refractory intracranial hypertension, coma, compression of the basal cisterns, or midline shift has been reached.

Cognitive performance following spontaneous subarachnoid haemorrhage versus other forms of intracranial haemorrhage.

OBJECTIVE: The exact cause of cognitive deficits following intracranial haemorrhage is unclear. This prospective study examines the abilities after spontaneous subarachnoid haemorrhage (SAH), intracerebral haemorrhage (ICH) and chronic subdural haematoma (SDH) to elucidate the cognitive outcome. PATIENTS AND METHODS: Ninety-nine patients with SAH (N = 60), ICH (N = 25), and SDH (N = 14) were followed up for an average of 6 and 12 months post-haemorrhage. Cognitive tests were used to examine attention, memory, concentration, and executive function. Following were used for analysis: 1. the percentage of patients falling below the 25th percentile per test, 2. the general development from the first to second test point and 3. the incidence of significant changes between the test points. Significance was established as p ≤ 0.05. RESULTS: All three types of haemorrhage resulted in deficits as concerns abstract language (53%-75%). The processing speed was below the normal levels in more than 70% of the patients tested. The cognitive performance of SAH patients was similar to that of patients with SDH and ICH patients after 6 months. The number of patients with outcomes falling below the 25th percentile (to some extent more than 75% in patients post-SAH) is high in all patient groups and mostly decreases over the course. Nevertheless, patients with SAH reveal improvements in many more areas than with ICH and SDH (p ≤ 0.006). CONCLUSIONS: The cognitive impairments following SAH, ICH and SDH deficits appear to develop in a similar way regardless of the type of haemorrhage. Cognitive improvement is most pronounced in patients with SAH.

A microarray analysis of retinal transcripts that are controlled by image contrast in mice.

PURPOSE: The development of myopia is controlled by still largely unknown retinal signals. The aim of this study was to investigate the changes in retinal mRNA expression after different periods of visual deprivation in mice, while controlling for retinal illuminance. METHODS: Each group consisted of three male C57BL/6 mice. Treatment periods were 30 min, 4 h, and 6+6 h. High spatial frequencies were filtered from the retinal image by frosted diffusers over one eye while the fellow eyes were covered by clear neutral density (ND) filters that exhibited similar light attenuating properties (0.1 log units) as the diffusers. For the final 30 min of the respective treatment period mice were individually placed in a clear Perspex cylinder that was positioned in the center of a rotating (60 degrees) large drum. The inside of the drum was covered with a 0.1 cyc/degree vertical square wave grating. This visual environment was chosen to standardize illuminances and contrasts seen by the mice. Labeled cRNA was prepared and hybridized to Affymetrix GeneChip Mouse Genome 430 2.0 arrays. Alterations in mRNA expression levels of candidate genes with potential biological relevance were confirmed by semi-quantitative real-time reverse transcription polymerase chain reaction (RT-PCR). RESULTS: In all groups, Egr-1 mRNA expression was reduced in diffuser-treated eyes. Furthermore, the degradation of the spatial frequency spectrum also changed the cFos mRNA level, with reduced expression after 4 h of diffuser treatment. Other interesting candidates were Akt2, which was up-regulated after 30 min of deprivation and Mapk8ip3, a neuron specific JNK binding and scaffolding protein that was temporally regulated in the diffuser-treated eyes only. CONCLUSIONS: The microarray analysis demonstrated a pattern of differential transcriptional changes, even though differences in the retinal images were restricted to spatial features. The candidate genes may provide further insight into the biochemical short-term changes following retinal image degradation in mice. Because deprivation of spatial vision leads to increased eye growth and myopia in both animals and humans, it is believed some of the identified genes play a role in myopia development.

Changes in scleral MMP-2, TIMP-2 and TGFbeta-2 mRNA expression after imposed myopic and hyperopic defocus in chickens.

Induction of myopia leads to a decreased glycosaminoglycan synthesis and smaller collagen fibrillar diameters, increased levels of gelatinase-A (MMP-2) and decreased amounts of tissue inhibitor of matrix metalloproteinase-2 (TIMP-2) in the fibrous sclera of both chicks and tree shrews. Another factor found to be involved in altered eye growth is the transforming growth factor beta-2 (TGFbeta-2). The aim of the current study was to measure MMP-2, TIMP-2 and TGFbeta-2 mRNA expression changes separately in the two scleral layers of chicks, following myopic and hyperopic defocus. Chicks were treated unilaterally with positive and negative lenses for different time periods. All contralateral eyes wore plano lenses and additional controls, treated binocularly with plano lenses, were included. Real-time PCR was used to measure MMP-2, TIMP-2 and TGFbeta-2 mRNA levels. Few changes in MMP-2 and TIMP-2 mRNA levels were measured following treatment with plus and minus lenses for up to 3 days. The mRNA levels of MMP-2 and TIMP-2 were either unchanged or co-regulated in both eyes, even though only the eye with the powered lens actually displayed changes in growth. In contrast, TGFbeta-2 mRNA was significantly up-regulated in the cartilaginous layer following treatment with plus lenses after 24 hr, compared to all other groups. These changes were confined to the eyes that also displayed reduced growth, suggesting a role of TGFbeta-2 in the final steps of visual eye growth regulation.

Regulation of Egr-1, VIP, and Shh mRNA and Egr-1 protein in the mouse retina by light and image quality.

PURPOSE: To analyze mRNA expression changes of Egr-1, VIP, and Shh under different light and treatment conditions in mice. The mRNA expression levels of the three genes and additionally the Egr-1 protein expression were compared in form deprived eyes and eyes with normal vision. Moreover, the influence of dark to light and light to dark transitions and of changes in retinal illumination on mRNA levels was investigated. METHODS: Form deprivation of mice was induced by fitting frosted diffusers over one eye and an attentuation matched neutral density (ND) filter over the other eye. To measure the effects of retinal illumination changes on mRNA expression, animals were bilaterally fitted with different ND filters. Semiquantitative real-time RT-PCR was used to measure the mRNA levels and immunohistochemistry was applied to localize and detect Egr-1 protein. RESULTS: The expression levels of both Egr-1 mRNA and protein were reduced in form deprived eyes compared to their fellow eyes after 30 min and 1 h, respectively. Egr-1 mRNA was strikingly upregulated both after dark to light and light to dark transitions, whereas minor changes in retinal illumination by covering the eyes with neutral density filters did not alter Egr-1 mRNA expression. In mice, the mRNA levels of VIP and Shh were not affected by form deprivation, but they were found to be regulated depending on the time of day. CONCLUSIONS: Both Egr-1 mRNA and protein expression levels were strongly regulated by light, especially by transitions between light and darkness. Image contrast may exert an additional influence on mRNA and protein expression of Egr-1, particularly in the cells in the ganglion cell layer and in bipolar cells.