[Brain functional network reconstruction based on compressed sensing and fast iterative shrinkage-thresholding algorithm].

The construction of brain functional network based on resting-state functional magnetic resonance imaging (fMRI) is an effective method to reveal the mechanism of human brain operation, but the common brain functional network generally contains a lot of noise, which leads to wrong analysis results. In this paper, the least absolute shrinkage and selection operator (LASSO) model in compressed sensing is used to reconstruct the brain functional network. This model uses the sparsity of L1-norm penalty term to avoid over fitting problem. Then, it is solved by the fast iterative shrinkage-thresholding algorithm (FISTA), which updates the variables through a shrinkage threshold operation in each iteration to converge to the global optimal solution. The experimental results show that compared with other methods, this method can improve the accuracy of noise reduction and reconstruction of brain functional network to more than 98%, effectively suppress the noise, and help to better explore the function of human brain in noisy environment.

A Randomized Comparative Study of Pulsed Radiofrequency Treatment With or Without Selective Nerve Root Block for Chronic Cervical Radicular Pain.

BACKGROUND: We demonstrated a combination of pulsed radiofrequency (PRF) and cervical nerve root block (CNRB) via a posterior approach was superior to a transforaminal epidural steroid injection through the anterolateral approach for cervical radicular pain in a previous study. This randomized trial was conducted to determine the comparative efficacy between CNRB, PRF, and CNRB + PRF for cervical radicular pain. METHODS: A prospective and randomized design was used in this study. Sixty-two patients were randomized into three parallel groups: CNRB, PRF, or CNRB + PRF. Numeric Rating Scale (NRS) was used to measure pain intensity, and global perceived effect (GPE) was scored by the patient on a 7-point scale, ranging from much worse (-3), no change (0), to total improvement (+3). The outcomes were evaluated at 1 week, 1 month, 3 months, and 6 months. Side effects and complications were noted. RESULTS: The NRS was significantly reduced in all three groups 1 week after the treatments (P < 0.001), and the rates of positive GPE (+2 or +3) were not significantly different between the three groups. At 1, 3, and 6 months of follow-ups, the combined therapy achieved significantly lower NRS and higher GPE compared to CNRB or PRF alone group (P < 0.001). There were no significant differences between the CNRB and PRF groups (P > 0.05). No serious complications were observed in any of the patients. CONCLUSIONS: Combining CNRB and PRF appeared to be a safe and efficacious technique for cervical radicular pain. The combination therapy yielded better outcomes than either CNRB or PRF alone.

Combining Botulinum Toxin (A) Injection With Peripheral Nerve Stimulation in a Patient for Intractable Ophthalmic Postherpetic Neuralgia.

BACKGROUND: Postherpetic neuralgia (PHN) is a particularly challenging neuropathic pain condition, especially when it involves the trigeminal nerve. Peripheral nerve stimulation (PNS) can provide 50-70% improvement in pain to many who fail medical management. However, this pain relief can be incomplete, and residual pain may persist for many years. Here we report a case that was successfully managed by a novel technique of combining supraorbital nerve stimulation with botulinum toxin type A (BTA) for intractable ophthalmic PHN. CASE: A 73-year-old man presented with burning, stabbing, constant, severe pain in the ophthalmic branch of left trigeminal nerve dermatome, which had been present for a year. A permanent PNS provided 50% pain relief, but there was residual pain in the left orbital area that has remained, which was refractory to pharmaceutical treatment. Because of the restricted location of the residual pain, this patient was an appropriate candidate for BTA injection. RESULTS: Following the BTA injection, the patient had a significant improvement in pain relief and this continued for six months without any oral medication. CONCLUSIONS: In a patient with trigeminal PHN, local injection of BTA effectively reduced pain remaining after treatment with PNS.

A comprehensive survey on deep learning techniques in CT image quality improvement.

High-quality computed tomography (CT) images are key to clinical diagnosis. However, the current quality of an image is limited by reconstruction algorithms and other factors and still needs to be improved. When using CT, a large quantity of imaging data, including intermediate data and final images, that can reflect important physical processes in a statistical sense are accumulated. However, traditional imaging techniques cannot make full use of them. Recently, deep learning, in which the large quantity of imaging data can be utilized and patterns can be learned by a hierarchical structure, has provided new ideas for CT image quality improvement. Many researchers have proposed a large number of deep learning algorithms to improve CT image quality, especially in the field of image postprocessing. This survey reviews these algorithms and identifies future directions.

EEG Beta-Band Spectral Entropy Can Predict the Effect of Drug Treatment on Pain in Patients With Herpes Zoster.

BACKGROUND: Medication is the main approach for early treatment of herpes zoster, but it could be ineffective in some patients. It is highly desired to predict the medication responses to control the degree of pain for herpes zoster patients. The present study is aimed to elucidate the relationship between medication outcome and neural activity using EEG and to establish a machine learning model for early prediction of the medication responses from EEG. METHODS: The authors acquired and analyzed eye-closed resting-state EEG data 1 to 2 days after medication from 70 herpes zoster patients with different drug treatment outcomes (measured 5-6 days after medication): 45 medication-sensitive pain patients and 25 medication-resistant pain patients. EEG power spectral entropy of each frequency band was compared at each channel between medication-sensitive pain and medication-resistant pain patients, and those features showing significant difference between two groups were used to predict medication outcome with different machine learning methods. RESULTS: Medication-sensitive pain patients showed significantly weaker beta-band power spectral entropy in the central-parietal regions than medication-resistant pain patients. Based on these EEG power spectral entropy features and a k-nearest neighbors classifier, the medication outcome can be predicted with 80% ± 11.7% accuracy, 82.5% ± 14.7% sensitivity, 77.7% ± 27.3% specificity, and an area under the receiver operating characteristic curve of 0.85. CONCLUSIONS: EEG beta-band power spectral entropy in the central-parietal region is predictive of the effectiveness of drug treatment on herpes zoster patients, and it could potentially be used for early pain management and therapeutic prognosis.

Abnormal Intrinsic Brain Activity and Neuroimaging-Based fMRI Classification in Patients With Herpes Zoster and Postherpetic Neuralgia.

Objective: Neuroimaging studies on neuropathic pain have discovered abnormalities in brain structure and function. However, the brain pattern changes from herpes zoster (HZ) to postherpetic neuralgia (PHN) remain unclear. The present study aimed to compare the brain activity between HZ and PHN patients and explore the potential neural mechanisms underlying cognitive impairment in neuropathic pain patients. Methods: Resting-state functional magnetic resonance imaging (MRI) was carried out among 28 right-handed HZ patients, 24 right-handed PHN patients, and 20 healthy controls (HC), using a 3T MRI system. The amplitude of low-frequency fluctuation (ALFF) was analyzed to detect the brain activity of the patients. Correlations between ALFF and clinical pain scales were assessed in two groups of patients. Differences in brain activity between groups were examined and used in a support vector machine (SVM) algorithm for the subjects' classification. Results: Spontaneous brain activity was reduced in both patient groups. Compared with HC, patients from both groups had decreased ALFF in the precuneus, posterior cingulate cortex, and middle temporal gyrus. Meanwhile, the neural activities of angular gyrus and middle frontal gyrus were lowered in HZ and PHN patients, respectively. Reduced ALFF in these regions was associated with clinical pain scales in PHN patients only. Using SVM algorithm, the decreased brain activity in these regions allowed for the classification of neuropathic pain patients (HZ and PHN) and HC. Moreover, HZ and PHN patients are also roughly classified by the same model. Conclusion: Our study indicated that mean ALFF values in these pain-related regions can be used as a functional MRI-based biomarker for the classification of subjects with different pain conditions. Altered brain activity might contribute to PHN-induced pain.

Early Treatment with Temporary Spinal Cord Stimulation Effectively Prevents Development of Postherpetic Neuralgia.

BACKGROUND: Some 7.7% of the Chinese population suffer from herpes zoster each year, with 29.8% proceeding on to develop postherpetic neuralgia (PHN). This amounts to over 32 million people per year. PHN is preceded by 2 phases of pain: acute herpetic neuralgia (AHN), and subacute herpetic neuralgia (SHN). Considering the large individual and economic burden, preventing the transition of AHN/SHN to PHN is crucial. However, to date this has been difficult. OBJECTIVES: To evaluate the efficacy of temporary spinal cord stimulation (tSCS) treatment and prevention of PHN. STUDY DESIGN: A retrospective, observational study. SETTING: Department of Pain Medicine. METHODS: From 2013 to 2017, 99 patients with AHN (n = 42), SHN (n = 34), and PHN (n = 23) underwent tSCS treatment (7-14 days) after failed pharmacologic and interventional therapies. Visual analog scale (VAS), Pittsburgh Sleep Quality Index (PSQI), and analgesic consumption were recorded at baseline, post-tSCS, and 1, 3, 6, and 12 months after tSCS treatment. RESULTS: Pooled results demonstrated statistically significant decreases in VAS scores and PSQI post-tSCS and at 1, 3, 6, and 12 months follow-up (P < 0.001). When compared with the PHN group, both AHN and SHN groups were clinically and statistically improved in VAS scores and PSQI (P < 0.001). Analgesic consumption decreased in all 3 groups after tSCS treatment, and downward linear gradient of medication in the AHN group was more significant than that in the SHN and PHN groups. At 12 months follow-up, 2.5% (1/40) patients in the AHN group, 16.0% (4/25) in the SHN group, and 62.5% (10/16) in the PHN group had ongoing pain >= 3/10 VAS score requiring analgesia. Expressed differently, at 12 months, 97.5% of the AHN group and 84% of the SHN group had pain of 2/10 VAS score or less versus only 37.5% of the PHN group. LIMITATIONS: This was a single-center, retrospective study, which made it difficult to collect complete data for all variables. The therapeutic effect of tSCS could not be studied independently. CONCLUSIONS: This retrospective analyses of 99 patients treated with tSCS (7-14 days) suggests that tSCS may be effective for treating and preventing PHN. Early treatment within 4 to 8 weeks was more likely to result in pain <= 2/10 VAS score, improvement in sleep, and no requirement for analgesia at 12 months. Early tSCS may be a promising prevention strategy against the development of chronic neuropathic pain following herpes zoster infection. Further research is justified. KEY WORDS: Herpes zoster, zoster-related pain, postherpetic neuralgia, temporary spinal cord stimulation.

Changes of gamma-band oscillatory activity to tonic muscle pain.

It is well know that phasic pain could induce suppression of alpha oscillations and enhancement of gamma oscillations. However, the cortical responses to tonic pain, especially tonic pain originating from deep tissue, which was proposed to better resemble the clinical pain, are not well understood. Here we aimed to investigate electroencephalographic (EEG) responses to tonic muscle pain. EEG signals and pain perceptions of three order-counterbalanced conditions: innocuous condition (A, infusion of isotonic saline), noxious conditions with low (B) and medium (C) intensities (infusion of hypertonic saline) were recorded from 43 subjects. We observed the enhancement of gamma oscillations in frontal-central region in condition C, as compared to either condition A or B. Positive relationship between the amplitude of gamma oscillations and pain intensity was also observed in frontal-central region. Therefore, we provide novel evidence for the encoding of frontal-central gamma oscillations in tonic pain processing.

A posterior approach to cervical nerve root block and pulsed radiofrequency treatment for cervical radicular pain: a retrospective study.

BACKGROUND: Catastrophic complications have been reported for selective cervical nerve root block (SCNRB) or pulsed radiofrequency (PRF) via an anterolateral transforaminal approach. A posterior approach to these procedures under computed tomography guidance has been reported. Here, we report the clinical outcomes of 42 patients with chronic cervical radicular pain (CCRP) treated with a combination of SCNRB and PRF through a posterior approach under fluoroscopy guidance. METHODS: We retrospectively reviewed the clinical outcomes of 42 consecutive patients with CCRP who received a combination of SCNRB and PRF through a posterior approach under fluoroscopy guidance. The thresholds of electrical stimulation and imaging of the nerve roots after contrast injection were used to evaluate the accuracy of needle placement. The numeric rating scale was used to measure the pain and numbness levels as primary clinical outcomes, which were evaluate in scheduled follow-up visits of up to 3 months. RESULTS: A total of 53 procedures were performed on 42 patients at the levels of C5-C8. All patients reported concordant paresthesia in response to electrical stimulation. The average sensory and motor thresholds of stimulation were 0.28 ± 0.14 and 0.36 ± 0.14 V, respectively. Injection of nonionic contrast resulted in excellent spread along the target nerve root in large majority of the procedures. The numeric rating scale scores for both pain and numbness improved significantly at 1 day, 1 week, and 1 and 3 months after the treatment. No serious adverse effects were observed in any of the patients. CONCLUSIONS: The posterior approach to combined SCNRB and PRF under fluoroscopy guidance appears to be safe and efficacious in the management of CCRP.