Changes in alpha, theta, and gamma oscillations in distinct cortical areas are associated with altered acute pain responses in chronic low back pain patients.

Introduction: Chronic pain negatively impacts a range of sensory and affective behaviors. Previous studies have shown that the presence of chronic pain not only causes hypersensitivity at the site of injury but may also be associated with pain-aversive experiences at anatomically unrelated sites. While animal studies have indicated that the cingulate and prefrontal cortices are involved in this generalized hyperalgesia, the mechanisms distinguishing increased sensitivity at the site of injury from a generalized site-nonspecific enhancement in the aversive response to nociceptive inputs are not well known. Methods: We compared measured pain responses to peripheral mechanical stimuli applied to a site of chronic pain and at a pain-free site in participants suffering from chronic lower back pain (n = 15) versus pain-free control participants (n = 15) by analyzing behavioral and electroencephalographic (EEG) data. Results: As expected, participants with chronic pain endorsed enhanced pain with mechanical stimuli in both back and hand. We further analyzed electroencephalographic (EEG) recordings during these evoked pain episodes. Brain oscillations in theta and alpha bands in the medial orbitofrontal cortex (mOFC) were associated with localized hypersensitivity, while increased gamma oscillations in the anterior cingulate cortex (ACC) and increased theta oscillations in the dorsolateral prefrontal cortex (dlPFC) were associated with generalized hyperalgesia. Discussion: These findings indicate that chronic pain may disrupt multiple cortical circuits to impact nociceptive processing.

Validity of the Hum Test, a Simple and Reliable Alternative to the Weber Test.

OBJECTIVES: To compare the diagnostic performance of the Hum Test against the Weber Test using pure tone audiometry (PTA) as the "gold standard" comparator. METHODS: 29 participants with normal hearing of ages 18 to 35 without any history of hearing abnormalities or otologic conditions were enrolled. Subjects underwent three tests (Hum Test, Weber Test, and PTA) across two conditions: with an ear plug in one ear (side randomized) and without ear plugs. RESULTS: When examining the ability of the Hum Test to detect simulated conductive hearing loss (CHL), the test had a sensitivity of 89.7% and specificity of 100% with high pitched humming and 93.1% and 100%, respectively, with low pitched humming. The Weber Test had a sensitivity and specificity of 96.6% and 100%, respectively. McNemar's test demonstrated agreement between the Hum Test, performed with either high pitched ( P = .32) or low pitched ( P = .56) humming, and the Weber Test. Receiver operating characteristic (ROC) curves for the Hum Test (both high and low pitched) and Weber test were compared and demonstrated no statistically significant difference. CONCLUSION: The Hum Test is comparable to the Weber Test with regards to its sensitivity, specificity, and diagnostic accuracy in assessing new onset unilateral CHL in previously normal hearing subjects.

Anterolateral approach to the lower cervical spine: a step-by-step description.

The anterolateral approach is a popular and safe method of exposing the lower cervical spine (levels C3 to T1) for management of cervical spine disease. We present a description of the technique we use in conducting the procedure, a review of the literature, and a retrospective chart review of 30 consecutive patients who underwent cervical spine exposure via a left anterolateral approach. All patients had an uneventful perioperative course, and the two patients who experienced postprocedure symptoms recovered completely within 1 month without treatment.