Deep Brain Stimulation of the Subgenual Cingulate Cortex for the Treatment of Chronic Low Back Pain

Functional Stimulation and Imaging to Predict Neuromodulation of Chronic Low Back Pain

Back pain is one of the most common aversive sensations in human experience. Pain is not limited to the sensory transduction of tissue damage; rather, it encompasses a range of nervous system activities including lateral modulation, long-distance transmission, encoding, and decoding. Although spine surgery may address peripheral pain generators directly, aberrant signals along canonical aversive pathways and maladaptive influence of affective and cognitive states can result in persistent subjective pain refractory to classical surgical intervention. The clinical identification of who will benefit from surgery-and who will not-is increasingly grounded in neurophysiology.

Current Neurostimulation Therapies for Chronic Pain Conditions

PURPOSE OF REVIEW

Neurostimulation treatment options have become more commonly used for chronic pain conditions refractory to these options. In this review, we characterize current neurostimulation therapies for chronic pain conditions and provide an analysis of their effectiveness and clinical adoption. This manuscript will inform clinicians of treatment options for chronic pain.

RECENT FINDINGS

Non-invasive neurostimulation includes transcranial direct current stimulation and repetitive transcranial magnetic stimulation, while more invasive options include spinal cord stimulation (SCS), peripheral nerve stimulation (PNS), dorsal root ganglion stimulation, motor cortex stimulation, and deep brain stimulation. Developments in transcranial direct current stimulation, repetitive transcranial magnetic stimulation, spinal cord stimulation, and peripheral nerve stimulation render these modalities most promising for the alleviating chronic pain. Neurostimulation for chronic pain involves non-invasive and invasive modalities with varying efficacy. Well-designed randomized controlled trials are required to delineate the outcomes of neurostimulatory modalities more precisely.

70 Years of Human Cingulate Cortex Stimulation. Functions and Dysfunctions Through the Lens of Electrical Stimulation

SUMMARY

In this review, we retrace the results of 70 years of human cingulate cortex (CC) intracerebral electrical stimulation and discuss its contribution to our understanding of the anatomofunctional and clinical aspects of this wide cortical region. The review is divided into three main sections. In the first section, we report the results obtained by the stimulation of the anterior, middle, and posterior CC, in 30 studies conducted on approximately 1,000 patients from the 1950s to the present day. These studies show that specific manifestations can be reliably associated with specific cingulate subfields, with autonomic, interoceptive, and emotional manifestations clustered in the anterior cingulate, goal-oriented motor behaviors elicited from the anterior midcingulate and a variety of sensory symptoms characterizing the posterior cingulate regions. In the second section, we compare the effect of CC intracerebral electrical stimulation with signs and manifestations characterizing cingulate epilepsy, showing that the stimulation mapping of CC subfields provides precious information for understanding cingulate epileptic manifestations. The last section tackles the issue of the discrepancy emerging when comparing the results of clinical (electrical stimulation, epilepsy) studies-revealing the quintessential affective and motor nature of the CC-with that reported by neuroimaging studies-which focus on high-level cognitive functions. Particular attention will be paid to the hypothesis that CC hosts a "Pain Matrix" specifically involved in pain perception, which we will discuss in the light of the fact that the stimulation of CC (as well as cingulate epileptic seizures) does not induce nociceptive effects.

The role of the insula in chronic pain following spinal cord injury: A resting-state fMRI study

BACKGROUND AND PURPOSE

Spinal cord injury (SCI) results in the loss of motor and sensory function from disconnections between efferent and afferent pathways. Most SCI patients are affected with chronic neuropathic pain, but there is a paucity of data concerning neuroplastic changes following SCI. Chronic pain disrupts default networks and is associated with abnormal insular connectivity. The posterior insula (PI) is associated with the degree of pain and intensity of pain. The anterior insula (AI) is related to signal changes. Comprehension of SCI pain mechanisms is essential to elucidate effective treatment options.

METHODS

This study examines the insular gyri functional connectivity (FC) of seven (five male, two female) SCI participants with moderate-severe chronic pain compared to 10 (five male, five female) healthy controls (HC). All subjects had 3-Tesla MRI performed and resting-state functional MRI (fMRI) was acquired. FC metrics were obtained from the comparisons of resting-state fMRI among our various groups. A seed-to-voxel analysis was pursued, encompassing six gyri of the insula. For multiple comparisons, a correction was applied with a significance level of p < .05.

RESULTS

There were significant differences in FC of the insula between SCI participants with chronic pain compared with HC. In the SCI participants, there was hyperconnectivity of the AI and PI to the frontal pole. In addition, there was increased FC noted between the PI and the anterior cingulate cortex. Hyperconnectivity was also observed between the AI and the occipital cortex.

CONCLUSIONS

These findings illustrate that there is a complex hyperconnectivity and modulation of pain pathways after traumatic SCI.

Nomogram for stratifying patients with lifelong premature ejaculation before using the PHQ-9: An observational study

OBJECTIVE

A PHQ-9 score ≥ 15, represented as PHQ-9⁺ , indicates major depressive disorder (MDD). On using PHQ-9, the psychological burden of several patients with lifelong premature ejaculation (LPE) gets aggravated, which may lead to LPE development. We aim to construct a nomogram for predicting the individual risk of PHQ-9⁺ in patients with LPE and discerning those with low risks, who should avoid the PHQ-9.

METHODS

The nomogram was constructed by analysing data of 802 patients from Xijing Hospital and Northwest Women's & Children's Hospital. The LASSO and multivariable logistic regressions were used to identify independent predictors of PHQ-9⁺ , used for developing the nomogram. The discrimination, calibration and clinical usefulness of the nomogram were assessed in the derivation cohort and an independent validation cohort, which was composed of 505 prospectively enrolled patients from Daxing Hospital and Xijing Hospital.

RESULTS

The duration of PE, IELT, a history of PE exacerbation, IIEF-5 score, urinary frequency and physical pain score were identified as independent predictors. The nomogram showed excellent calibration, discrimination and clinical usefulness in the derivation and validation cohorts, with a predictive accuracy of 0.781 and 0.763, respectively. Based on this nomogram, patients were divided into not recommended, recommended and strongly recommended PHQ-9 filling groups, with PHQ-9⁺ rates of 3.5%, 9.3% and 30.7%, respectively.

CONCLUSION

A nomogram to discern LPE patients with low risks of PHQ-9⁺ was established. This tool can increase the positivity of MDD screening and may improve the therapeutic outcomes of those in the low-risk group.

A Prospectively Validated Nomogram for Predicting the Risk of PHQ-9 Score ≥15 in Patients With Erectile Dysfunction: A Multi-Center Study

Background

Although erectile dysfunction (ED) often occurs simultaneously with depression, not all patients with ED suffer major depression (MD), with a PHQ-9 score ≥15 indicating MD. Because the PHQ-9 questionnaire includes phrases such as “I think I am a loser” and “I want to commit suicide,” the psychological burdens of ED patients are likely to increase inevitably after using the PHQ-9, which, in turn, may affect ED therapeutic effects. Accordingly, we endeavored to develop a nomogram to predict individual risk of PHQ-9 score ≥15 in these patients.

Methods

The data of 1,142 patients with ED diagnosed in Xijing Hospital and Northwest Women and Children's Hospital from January 2017 to May 2020 were analyzed. While the Least Absolute Shrinkage and Selection Operator regression was employed to screen PHQ-9 score ≥15 related risk factors, multivariate logistic regression analysis was performed to verify these factors and construct the nomogram. The training cohort and an independent cohort that comprised 877 prospectively enrolled patients were used to demonstrate the efficacy of the nomogram.

Results

The IIEF-5 score, PEDT score, physical pain score, frequent urination, and feeling of endless urination were found to be independent factors of PHQ-9 score ≥15 in patients with ED. The nomogram developed by these five factors showed good calibration and discrimination in internal and external validation, with a predictive accuracy of 0.757 and 0.722, respectively. The sensitivity and specificity of the nomogram in the training cohort were 0.86 and 0.52, respectively. Besides, the sensitivity and specificity of the nomogram in the validation cohort were 0.73 and 0.62, respectively. Moreover, based on the nomogram, the sample was divided into low-risk and high-risk groups.

Conclusion

This study established a nomogram to predict individual risk of PHQ-9 score ≥15 in patients with ED. It is deemed that the nomogram may be employed initially to avoid those with a low risk of MD completing questionnaires unnecessarily.