Analysis of magnetic resonance tomographic angiography false negatives in trigeminal neuralgia before microvascular decompression

Different MRI-based methods for the diagnosis of neurovascular compression in trigeminal neuralgia or hemifacial spasm: A network meta-analysis

BACKGROUND

Accurate preoperative diagnosis of neurovascular compression (NVC) is crucial in the treatment of trigeminal neuralgia (TN) or hemifacial spasm (HFS). At present, there are many magnetic resonance imaging (MRI)-based methods for diagnosing NVC in clinical practice. This network meta-analysis (NMA) aimed to evaluate the diagnostic performance of different MRI-based imaging methods for NVC in patients with TN and HFS.

MATERIALS AND METHODS

Related studies based on a search of PubMed, Embase, Web of Science and the Cochrane Library were retrieved. A two-way analysis of variance model was constructed for the Bayesian NMA to compare the performance of different diagnostic imaging methods.

RESULTS

Our search identified 595 articles, of which 26 studies (including 2085 patients) related to 4 diagnostic imaging methods (3D time-of-flight magnetic resonance angiography (3D TOF MRA), high resolution T2-weighted imaging (HR T2WI), 3D TOF MRA combined with HR T2WI, and 3D multimodal image fusion (MIF) based on 3D TOF MRA combined with HR T2WI) were included in this NMA. The results showed that 3D MIF based on 3D TOF MRA combined with HR T2WI had the highest related sensitivity, the highest superiority index and the largest area under the receiver operating characteristic curve among all the methods.

CONCLUSIONS

3D MIF based on 3D TOF MRA combined with HR T2WI had better diagnostic performance for detecting NVC in patients with TN or HSF than other MRI-based imaging methods. This method can be used as an effective tool for preoperative evaluation of MVD.

The leptomeninges as a critical organ for normal CNS development and function: First patient and public involved systematic review of arachnoiditis (chronic meningitis)

BACKGROUND & IMPORTANCE

This patient and public-involved systematic review originally focused on arachnoiditis, a supposedly rare "iatrogenic chronic meningitis" causing permanent neurologic damage and intractable pain. We sought to prove disease existence, causation, symptoms, and inform future directions. After 63 terms for the same pathology were found, the study was renamed Diseases of the Leptomeninges (DLMs). We present results that nullify traditional clinical thinking about DLMs, answer study questions, and create a unified path forward.

METHODS

The prospective PRISMA protocol is published at Arcsology.org. We used four platforms, 10 sources, extraction software, and critical review with ≥2 researchers at each phase. All human sources to 12/6/2020 were eligible for qualitative synthesis utilizing R. Weekly updates since cutoff strengthen conclusions.

RESULTS

Included were 887/14286 sources containing 12721 DLMs patients. Pathology involves the subarachnoid space (SAS) and pia. DLMs occurred in all countries as a contributor to the top 10 causes of disability-adjusted life years lost, with communicable diseases (CDs) predominating. In the USA, the ratio of CDs to iatrogenic causes is 2.4:1, contradicting arachnoiditis literature. Spinal fusion surgery comprised 54.7% of the iatrogenic category, with rhBMP-2 resulting in 2.4x more DLMs than no use (p<0.0001). Spinal injections and neuraxial anesthesia procedures cause 1.1%, and 0.2% permanent DLMs, respectively. Syringomyelia, hydrocephalus, and arachnoid cysts are complications caused by blocked CSF flow. CNS neuron death occurs due to insufficient arterial supply from compromised vasculature and nerves traversing the SAS. Contrast MRI is currently the diagnostic test of choice. Lack of radiologist recognition is problematic.

DISCUSSION & CONCLUSION

DLMs are common. The LM clinically functions as an organ with critical CNS-sustaining roles involving the SAS-pia structure, enclosed cells, lymphatics, and biologic pathways. Cases involve all specialties. Causes are numerous, symptoms predictable, and outcomes dependent on time to treatment and extent of residual SAS damage. An international disease classification and possible treatment trials are proposed.

Radiologic and Neurosurgical Diagnosis of Arterial Neurovascular Conflict on Magnetic Resonance Imaging for Trigeminal Neuralgia in Routine Clinical Practice

OBJECTIVE

The most common cause of trigeminal neuralgia is neurovascular conflict, particularly arterial compression of the trigeminal nerve (ACTN). It is possible to show this condition preoperatively on fine-cut constructive interference in steady state magnetic resonance imaging (MRI), supplemented by time-of-flight magnetic resonance angiography. We have noticed significant variability in the interpretation of these studies between radiologists and the treating neurosurgeon. We have assessed the sensitivity and specificity of these 2 styles of interpretation compared with the intraoperative observations.

METHODS

We studied 68 patients who underwent de novo microvascular decompression from 2011 to 2018 under the care of a single neurosurgeon in Melbourne, Australia. Data was recorded prospectively in the radiology reports, operation reports, hospital admission records and neurosurgeon correspondence from the perioperative clinic reviews. In particular, the surgical interpretation of the MRI was clearly described prospectively and preoperatively in the correspondence. The presence or absence of ACTN was recorded prospectively in the operation report. These data were collated retrospectively by the first author.

RESULTS

Of patients, 83.8% (57/68) had clear ACTN confirmed at surgery. Radiologists detected this abnormality in 50.9% (29/57) of these patients, with a sensitivity of 50.9% and specificity of 81.8%. The operating neurosurgeon detected ACTN in 87.7% (50/57) of the positive cases with a sensitivity of 87.7% and a specificity of 72.7%. Statistical analysis showed a significant disagreement between both styles of interpretation, with a radiologic accuracy of 55.9% compared with 85.3% neurosurgically (P < 0.0001). Follow-up review of the patient's response to surgery further supported the neurosurgical diagnosis of ACTN.

CONCLUSIONS

There was a strong tendency for radiologists to underreport ACTN on the preoperative MRI compared with the intraoperative findings. In this series, the neurosurgeon was able to accurately detect ACTN in 88% of patients preoperatively. However, the diagnosis of absent ACTN was still associated with a false-negative rate of 46.7% when the neurosurgeon performed the interpretation. At the current standard of fine-cut constructive interference in steady state MRI in Melbourne, underdetection of ACTN remains common. Clinicians using this test need to be acutely aware of its limitations in deciding whether to proceed to microvascular decompression.

[Estradiol significantly increases the expression of antioxidant enzymes in osteoporotic rats and osteoblasts in vitro]

OBJECTIVE

To investigate the effect of estradiol on the expression of antioxidant enzymes in osteoblasts and its role in postmenopausal osteoporosis.

METHODS

Rat models of osteoporosis established by ovariectomy were treated with estradiol for 3 months, and the changes in serum levels of reactive oxygen species (H₂O₂) and antioxidant enzymes (γ -GCS, GSH-ST and GSH-px) were detected. The effects of estradiol on the expression of γ -GCS mRNA and protein in osteoblast-like cells MC3T3-E1, MG63 and OB were examined with PCR and Western blotting. Using a mRNA microarray, we analyzed the changes in the expressions of 84 antioxidant enzymes in the osteoblast cell line MC3T3-E1 following estradiol treatment, and the enzymes with significant changes were verified by PCR. CCK-8 kit was used to evaluate the effect of estradiol and antioxidant NAC on the proliferation of MC3T3-E1 cells.

RESULTS

Rat models of osteoporosis were successfully established with ovariectomy. The osteoporotic rats showed significantly increased serum level of reactive oxygen species (H2O2) and decreased levels of antioxidant enzymes. Estrogen treatment of the osteoporotic rats obviously reversed the phenotype of osteoporosis, lowered serum level of reactive oxygen species, and increased the level of γ -GCS. In MC3T3-E1, MG63 and OB cells, estradiol treatment significantly upregulated the expression levels of γ -GCS mRNA and protein. In MC3T3-E1 cells treated with estrogen, the mRNA chip identified 6 upregulated antioxidant enzymes (Gpx6, Gstk1, Nos2, Prdx2, Ngb and Ccs), and the results of PCR verified that estradiol upregulated Ccs and Ngb mRNAs in MC3T3-E1, MG63 and OB cells. Estradiol and antioxidant NAC obviously promoted the proliferation of MC3T3-E1 cells.

CONCLUSION

Estradiol significantly increases the expression of antioxidase γ -Gcs, Ccs and Ngb in osteoblasts in vitro. Postmenopausal osteoporosis is closely related with the increase of reactive oxygen species and the decrease of antioxidant levels. In osteoblasts, estrogen deficiency may increase the level of reactive oxygen species, decrease the level of antioxidant enzymes, activate the oxidative stress cascade, and consequently inhibit the proliferation of osteoblasts to aggravate the condition of osteoporosis.