Human Studies

Schwannomatosis and neurofibromatosis type 2 (NF2) are two distinct neuro-genetic tumor predisposition disorders which however share some clinical and genetic features. While germline mutations in the NF2 gene are only found in NF2, a majority of schwannomatosis patients have germline mutations in the SMARCB1 or LZTR1 genes. The overlapping clinical phenotypes pose a serious challenge in differential diagnosis and in risk stratification of these two entities which is further complicated by frequent mosaicism in both disorders. Chronic neuropathic pain which is a typical consequence of small fiber neuropathy, is characteristic for schwannomatosis. By contrast, NF2 patients do not have chronic pain but may have moderate to severe sensory deficits and paresis which are not characteristic for schwannomatosis. In the present study, we determined intra-epidermal nerve fiber density (IEND) in skin biopsies of 34 clinically ascertained schwannomatosis and 25 NF2 patients. In the NF2 group, 11/25 (44%) presented with IEND below the age- and gender-matched bottom 5% normative reference IEND. In contrast, nearly all (33/34=97%) schwannomatosis patients showed IEND below or on the bottom 5% normative reference. The reduction of IEND in schwannomatosis patients was age-independent. Paired t-test revealed no difference between the NF2-IEND and the corresponding bottom 5% normative reference (P=0.98). By contrast, IEND in the schwannomatosis patients were highly significantly lower than the corresponding 5% normative reference IEND (P<0.0001). In addition, the difference between the IEND of our patients and the 5% lowest normative reference IEND was highly significantly larger in schwannomatosis patients than in NF2 patients (P<0.0001). IEND of our patients did not correlate with neither the presence nor types of germline mutations in neither the NF2 nor the LZTR1 gene. In conclusion, schwannomatosis patients have marked low IEND which provides a major parameter for diagnosis and differential diagnosis. This article is protected by copyright. All rights reserved.

Persistent pain extending beyond 6 months after breast cancer surgery when adjuvant therapies have ended is a recognised phenomenon. The evolution of postsurgery pain is therefore of interest for future patient management in terms of possible prognoses for distinct groups of patients to enable better patient information.

Mirror image sensory dysfunction (MISD) after breast surgery has not yet been studied. This prospective observational study aimed to determine the incidence of MISD, persistent postoperative pain (PPP) and mirror image pain (MIP) during 6 months after total unilateral mastectomy.Visual analogue scale (VAS), Neuropathic Pain Symptom Inventory (NPSI), Pain Catastrophizing Scale (PCS), Hospital Anxiety and Depression Scale (HADS), Life orientation test (LOT) and Quantitative Sensory Testing (QST) (in ipsi and contralateral breast, axilla and thigh) were recorded. VAS > 3 at 1, 3, and 6 postoperative months was considered PPP. Contralateral changes of QST at any time was considered indicative of MISD and spontaneous contralateral VAS ≥ 1 as MIP.Sixty-four patients were included. PPP at 1, 3 and 6 months was 18.8%, 56.2%, and 21.3%, respectively Ten patients presented MIP. MISD was detected in 79.7% patients in contralateral breast and 62.5% in contralateral axilla. Furthermore, changes in QST were present in 39.1% of patients in thigh. Electronic Von Frey (EVF) changes in both contralateral breast and axilla, and in thigh significantly diminished at all postoperative times. Changes of postoperative EVF ≥ 20% in contralateral breast were associated to higher VAS values. NPSI scores were significantly higher at all postoperative times. At 1 month, PCS, depression HADS subscale and LOT scores were significantly worse than all the other periods.MISD incidence was almost 80%, and 15.6% of patients showed spontaneous contralateral VAS ≥ 1. At 6 months 21.3% of patients manifested PPP. The worst alteration of factors related to PPP occurred at 1 postoperative month. Most consistent QST was EVF.

Research indicates that increased cumulative exposure (duration of administration and strength of dose) is associated with long-term opioid use. Because dentists represent some of the highest opioid prescribing medical professionals in the US, dental practices offer a critical site for intervention. The current study used a randomized clinical trial design to examine the efficacy of an opioid misuse prevention program (OMPP), presented as a brief intervention immediately prior to dental extraction surgery. The OMPP provided educational counseling about risks and appropriate use of opioid medication, as well as 28 tablets of ibuprofen (200 mg) and 28 tablets of acetaminophen (500 mg) for weaning off opioid medication. This was compared with a Treatment as Usual (TAU) control condition. Participants were individuals presenting for surgery who were eligible for opioid medication (N = 76). Follow up assessment was conducted at 1 week following surgery, with 4 individuals refusing follow up or not prescribed opioid. Intent to treat analysis indicated a non-significant treatment group effect (N = 72, Beta = 0.16, p = .0835), such that the OMPP group self-reported less opioid use (in morphine milligram equivalents, MMEs) than the TAU group (37.94 vs. 47.79, effect size d = 0.42). Sensitivity analysis, excluding individuals with complications following surgery (n = 6) indicated a significant treatment group effect (N = 66, Beta = 0.24, p = .0259), such that the OMPP group self-reported significantly less MMEs than the TAU group (29.74 vs. 43.59, effect size d = 0.56). Results indicate that a 10-minute intervention and provision of non-narcotic pain medications may reduce the amount of self-administered opioid medication following dental surgery.