The N13 component of somatosensory evoked potential (N13 SEP) represents the segmental response of dorsal horn neurons. In this neurophysiological study, we aimed to verify whether N13 SEP might ...reflect excitability changes of dorsal horn neurons during central sensitization. In 22 healthy participants, we investigated how central sensitization induced by application of topical capsaicin to the ulnar nerve territory of the hand dorsum modulated N13 SEP elicited by ulnar nerve stimulation. Using a double-blind placebo-controlled crossover design, we also tested whether pregabalin, an analgesic drug with proven efficacy on the dorsal horn, influenced capsaicin-induced N13 SEP modulation. Topical application of capsaicin produced an area of secondary mechanical hyperalgesia, a sign of central sensitization, and increased the N13 SEP amplitude but not the peripheral N9 nor the cortical N20-P25 amplitude. This increase in N13 SEP amplitude paralleled the mechanical hyperalgesia and persisted for 120 min. Pregabalin prevented the N13 SEP modulation associated with capsaicin-induced central sensitization, whereas capsaicin application still increased N13 SEP amplitude in the placebo treatment session. Our neurophysiological study showed that capsaicin application specifically modulates N13 SEP and that this modulation is prevented by pregabalin, thus suggesting that N13 SEP may reflect changes in dorsal horn excitability and represent a useful biomarker of central sensitization in human studies.
•Our study compares the clinical usefulness of nerve ultrasound and nerve conduction study in patients with Bell’s palsy.•Nerve Ultrasound may show abnormally increased facial nerve diameter in the ...acute phase of Bell’s palsy.•The predictive value of facial nerve ultrasound for incomplete recovery is lower than that of the nerve conduction study.
This longitudinal study aims at assessing the predictive value of facial nerve high-resolution ultrasound (HRUS) for incomplete clinical recovery in patients with Bell’s palsy, the most common facial nerve disease.
We prospectively enrolled 34 consecutive patients with Bell’s palsy. All patients underwent neurophysiological testing (including facial nerve conduction study) and HRUS evaluations 10–15 days (T1), one month (T2), and three months (T3) after the onset of Bell’s palsy. Patients who did not experience complete recovery within three months were also evaluated after six months (T4). We have then compared the accuracy of HRUS with that of the facial nerve conduction study in predicting incomplete clinical recovery at three and six months.
At T1, the facial nerve diameter, as assessed with HRUS, was larger on the affected side than on the normal side, particularly in patients with incomplete recovery at T2, T3 and T4. ROC curve analysis, however, showed that the facial nerve diameter at T1 had a lower predictive value than the facial nerve conduction study for an incomplete clinical recovery at three (T3) and six (T4) months. Still, the facial nerve diameter asymmetry, as assessed with HRUS, had a relatively high negative predictive value (thus indicating a strong association between normal HRUS examination and a good prognosis).
Although HRUS shows abnormally increased facial nerve diameter in patients in the acute phase of Bell’s palsy, the predictive value of this technique for incomplete clinical recovery at three and six months is lower than that of the nerve conduction study.
Nerve ultrasound has a low predictive value for incomplete clinical recovery in patients with Bell’s Palsy.
The indications for microsurgical breast reconstruction remain debated, particularly concerning the safety of deep inferior epigastric perforator (DIEP) flaps in elderly women. Free tissue transfer ...still carries a risk of perioperative morbidity and mortality in elderly patients. We conducted this comparative study to clarify this issue.
This retrospective cohort study included all unilateral DIEP breast reconstructions performed at a single institution. Patients were divided into two groups based on age: an elderly (60 years or older) and a non-elderly cohort (younger than 60 years). Demographic and comorbidity data were secondary predictor variables. The primary outcomes were complete flap loss, partial flap loss, and the need for flap re-exploration. The secondary outcomes included surgical site occurrences, such as wound healing-related complications, seroma, and others.
We included 214 flaps, 177 in the non-elderly and 37 in the elderly cohort. Elderly women had slightly higher comorbidity rates than those of non-elderly women, although these differences were not statistically significant. BMI was significantly lower in elderly women than in non-elderly women. The incidence of total or partial flap loss did not differ significantly between the two cohorts (2.7% vs 1.1%, p = 0.459% and 0.0% vs 5.1%, p = 0.161), nor did the flap re-exploration (8.1% vs 10.1%, p = 0.937). Similarly, postoperative complication rates did not differ significantly between the two groups (45.9% vs 61.8%, p = 0.074). On logistic regression, being elderly was not a risk factor for complete flap loss, nor for any complications. The overall success rate for the non-elderly cohort was 98.7%, whereas that for the elderly cohort was 97.3%.
Microsurgical breast reconstruction using DIEP is safe in elderly patients, as it achieves outcomes and complications rates comparable to those observed in a younger population. Patients should not be denied DIEP flaps because of their age alone.
•Nerve Ultrasound reveals enlarged nerves in Friedreich’s Ataxia.•Nerve abnormalities correlate with clinical disability scales.•Nerve ultrasound can provide useful information where nerve conduction ...study is no longer informative.
In Friedreich's ataxia research, the focus is on discovering treatments and biomarkers to assess disease severity and treatment effects. Our study examines high-resolution nerve ultrasound in these patients, seeking correlations with established clinical markers of disease severity.
Ten patients with Friedreich’s Ataxia underwent a comprehensive clinical assessment with established scales (SARA, FARS, mFARS, INCAT, ADL 0-36, IADL). Additionally, they underwent nerve conduction studies and high-resolution nerve ultrasound. Quantitative evaluation of nerve cross-sectional area, conducted at 24 nerve sites using high-resolution nerve ultrasound, was compared with data obtained from 20 healthy volunteers.
All the patients had a severe sensory axonal neuropathy. High-resolution nerve ultrasound showed significant increase, in cross sectional area, of median and ulnar nerves at the axilla and arm. The cumulative count of affected nerve sites was directly associated with clinical disability, as determined by SARA, FARS, mFARS, ADL 0-36, and INCAT score, while displaying an inverse correlation with IADL.
Our study shows that high-resolution ultrasound reveals notable nerve abnormalities, primarily in the upper limbs of patients diagnosed with Friedreich’s Ataxia. The observed correlation between these nerve abnormalities and clinical disability scales indicates the potential use of this technique as a biomarker for evaluating disease severity and treatment effects.
Nerve Ultrasound is a potential biomarker of disease severity in Friedreich’s Ataxia.
Objective:
There is striking paucity in consensus on the terminology, definition, and diagnostic criteria of mycotic aortic aneurysms. This literature study aims to elucidate this scientific ...omission, discuss its consequences, and present a proposition for reporting items on this disease.
Methods:
A systematic literature review on PubMed and Medline using mycotic and infected aortic aneurysms between 1850 and 2017 was performed. Articles were assessed according to a protocol regarding terminology, definition, and diagnostic criteria. Case series with less than 5 patients were excluded.
Results:
A total of 49 articles were included. The most prevalent term was mycotic aortic aneurysm but there was no widely accepted definition. Most modern publications used a diagnostic workup based on a combination on clinical presentation, laboratory results, imaging findings, and intraoperative findings. How these protean variables should be balanced was unclear. A proposition of reporting items was framed and consisted of definition of disease used, basis of diagnostic workup, exclusion criteria, patient characteristics, laboratory and imaging findings, aneurysm anatomy, details on treatment, pre/postoperative antibiotic treatment, and details on follow-up.
Conclusions:
This article emphasizes the need to standardize definition, terminology, and diagnostic criteria for mycotic aortic aneurysms and proposes reporting items enhancing comparability between studies.
•Central sensitization manifesting with secondary hyperalgesia is similarly induced by high-frequency stimulation and topical capsaicin.•High frequency stimulation and topical capsaicin do not ...significantly activate the endogenous pain modulatory system.•RIII reflex variables reflecting central sensitization are similarly modulated by high frequency stimulation and topical capsaicin.
In this neurophysiological study in healthy humans, we assessed how central sensitization induced by either high-frequency stimulation (HFS) or topical capsaicin application modulates features of the RIII reflex response. The ability of these stimuli to engage the endogenous pain modulatory system was also tested.
In 26 healthy participants we elicited an RIII reflex using suprathreshold stimulation of the sural nerve. Subsequently HFS or capsaicin were applied to the foot and the RIII reflex repeated after 15 minutes. Contact heating of the volar forearm served as the heterotopic test stimulus to probe activation of the endogenous pain modulatory system.
HFS significantly reduced the pain threshold by 29% and the RIII reflex threshold by 20%. Capsaicin significantly reduced the pain threshold by 17% and the RIII reflex threshold by 18%. Both HFS and capsaicin left RIII reflex size unaffected. Numerical Rating Scale (NRS) pain scores elicited by the heterotopic noxious heat stimulus were unaffected by capsaicin and slightly increased by HFS.
HFS and capsaicin similarly modulated the pain threshold and RIII reflex threshold, without a concomitant inhibitory effect of the endogenous pain modulatory system.
Our neurophysiological study supports the use of the RIII reflex in investigating central sensitization in humans.
•High and low frequency stimulation have a different effect on the N13 SEP component.•Dorsal horn excitability changes induced by low frequency stimulation can modulate the N13.•Different ...experimental models of central sensitization may induce dorsal horn excitability changes through different mechanisms.
The N13 component of somatosensory evoked potential (N13 SEP) represents the segmental response of cervical dorsal horn neurons. Neurophysiological studies in healthy participants showed that capsaicin-induced central sensitization causes an increase of the N13 SEP amplitude. Consequently, in human research, this spinal component may serve as a valuable readout of central sensitization.
In this study, we wanted to verify if the sensitivity of the N13 SEP for detecting central sensitization is consistent across different experimental pain models inducing central sensitization and secondary hyperalgesia, namely high and low-frequency electrical stimulation (HFS and LFS).
In 18 healthy participants, we recorded SEP after bilateral ulnar nerve stimulation before and after secondary hyperalgesia was induced through HFS and LFS applied on the ulnar nerve territory of the hand of one side. The area of secondary hyperalgesia was mapped with a calibrated 128-mN pinprick probe, and the mechanical pain sensitivity with three calibrated 16–64-256-mN pinprick probes.
Although both HFS and LFS successfully induced secondary hyperalgesia only LFS increased the amplitude of the N13 SEP.
These findings suggest that the sensitivity of the N13 SEP for detecting dorsal horn excitability changes may critically depend on the different experimental pain models.
Our results indicate that LFS and HFS could trigger central sensitization at the dorsal horn level through distinct mechanisms, however this still needs confirmation by replication studies.
: Open fracture of the lower limb can lead to substantial bone and soft tissue damage, resulting in a challenging reconstructive scenarios, especially in presence of bone or periosteal loss, with a ...relevant risk of non-union. This work analyzes outcomes of using a double approach for orthoplastic reconstruction, adopting the free medial condyle flap to solve the bone defects, associated to a second free flap for specific soft tissue coverage. Indications, outcomes and reconstructive rationales are discussed.
: A retrospective investigation was performed on patients who underwent complex two-flap microsurgical reconstruction from January 2018 to January 2022. Inclusion criteria in this study were the use of a free femoral condyle periostal/bone flap together with a second skin-only flap. Only distal third lower limb reconstructions were included in order to help equalize our findings. Out of the total number of patients, only patients with complete pre- and post-operative follow-up (minimum 6 months) data were included in the study.
: Seven patients were included in the study, with a total of 14 free flaps. The average age was 49. Among comorbidities, four patients were smokers and none suffered from diabetes. Etiology of the defect was acute trauma in four cases and septic non-union in three cases. No major complications occurred, and all flaps healed uneventfully with complete bone union.
: Combining a bone periosteal FMC to a second skin free flap for tailored defect coverage allowed achievement of bone union in all patients, despite the lack of initial bone vascularization or chronic infection. FMC is confirmed to be a versatile flap for small-to-medium bone defects, especially considering its use as a periosteal-only flap, with minimal donor site morbidity. Choosing a second flap for coverage allows for a higher inset freedom and tailored reconstruction, finally enhancing orthoplastic success.
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