Is it really on your hand? Spontaneous sensations are not peripheral sensations - Evidence from able-bodied individuals and a phantom limb syndrome patient

Among other bodily signals, the perception of sensations arising spontaneously on the skin with no external triggers contributes to body awareness. The topic of spontaneous sensations (SPS) being quite recent in the literature, there is still a debate whether this phenomenon is elicited by peripheral cutaneous units' activity underlying tactile perception or originates directly from central mechanisms. In a first experiment, we figured that, if SPS depended on peripheral afferents, their perception on the glabrous hand should relate to the hand tactile sensitivity. On the contrary, we found no relationship at all, which led us to envisage the scenario of SPS in the absence of cutaneous units. In a second experiment, we present the case of Julie, a right-hand amputee that could perceive and report SPS arising on her phantom limb syndrome. We found that SPS distribution on the phantom limb followed the same gradient as that observed in control participants, unlike SPS perceived on the intact left hand. Those findings are crucial to the understanding of neural factors determining body awareness through SPS perception and provide insights into the existence of a precise neural gradient underlying somesthesis.

Phantom limb syndrome: Assessment of psychiatric and medical comorbidities associated with Phantom pain in 44,028 below knee amputees

INTRODUCTION

Phantom limb syndrome is a debilitating complication after extremity amputation that poses significant challenges to recovery. This study aims to examine the relationship between phantom limb syndrome and mental and physical comorbidities, including a comparison between phantom limb pain and phantom limb syndrome without pain in below knee amputees.

METHODS

This is a retrospective cohort study of patients who underwent below knee amputation of the lower extremity in the PearlDiver database, as identified using CPT codes. Analysis was carried out to evaluate the absence or presence of phantom limb syndrome. Matched bivariate analysis accounting for age, sex, Charlson Comorbidity Index score, and region was used to assess whether the presence of pain in phantom limb syndrome patients was associated with increased comorbidity.

RESULTS

In total, 44,028 patients with below knee amputation were examined: 95% (42,493 patients) did not develop phantom limb syndrome while 4.8% (1,535 patients) of patients did develop phantom limb syndrome. Phantom limb syndrome was significantly associated with increased odds of coexistent major depressive disorder (OR = 1.86, p <0.0001), generalized anxiety disorder (OR = 2.14, p = 0.04), posttraumatic stress disorder (OR = 1.7, p <0.0001), suicidal ideation (OR = 1.62, p <0.0001), obesity (OR = 1.28, p = 0.0007), osteoarthritis (OR = 1.53, p <0.0001), osteoporosis (OR = 1.64, p <0.0001), and low back pain (OR = 2.31, p <0.0001). Analysis of patient cohorts of phantom limb syndrome with pain and those without pain did not reveal a statistically significant relationship between the presence of pain and any dependent variable.

CONCLUSIONS

This investigation of over 44,000 patients with below knee amputation revealed that patients with phantom limb syndrome exhibit significantly higher rate of psychiatric comorbidities compared to those without documented phantom limb pain. Suicidal ideation, major depressive disorder, generalized anxiety disorder, and post-traumatic stress disorder were especially common, and consequently a multi-disciplinary approach to management is essential.

Comparison of Ultrasound-Guided Caudal Epidural Blocks and Spinal Anesthesia for Anorectal Surgery: A Randomized Controlled Trial

INTRODUCTION

The aim of this study is to observe the effect of spinal anesthesia (SA) and ultrasound-guided caudal epidural blocks (CEB) on perioperative satisfaction in patients undergoing anorectal surgery.

METHODS

A group of 106 patients were randomly allocated to receive either SA (the SA group) or CEB (the CEB group), and 11 patients were excluded. Finally, 95 patients were left, with 48 in the SA group and 47 in the CEB group for data analysis. The primary endpoint was patient satisfaction with the quality of their anesthetic technique. The secondary outcome measures included postoperative pain at 2, 4, 8, 16, 24, and 48 h after surgery at rest, time to first analgesic request, analgesia requirements, incidence of phantom limb syndrome (PLS), time until return of bowel function, time to ambulation, incidence of postoperative nausea and vomiting (PONV), intraoperative mean arterial pressure (MAP) reduction > 20% from baseline, and surgeon satisfaction.

RESULTS

A significantly lower proportion of patients in the SA group was highly satisfied with the quality of their anesthetic technique compared with the CEB group (20.8% versus 68.1%). NRS scores at rest were significantly lower at 4, 8, 16, and 24 h after surgery in the CEB group compared with the SA group. The time to first analgesic request was significantly earlier for patients in the SA group compared with patients in the CEB group. Analgesia requirements, the incidence of PLS, the incidence of PONV, and intraoperative MAP reduction > 20% from baseline were significantly decreased in the CEB group. There were no significant differences between the groups in time until return of bowel function, surgeon satisfaction, or time to ambulation.

CONCLUSIONS

Ultrasound-guided caudal epidural blocks have higher patient satisfaction compared with spinal anesthesia.

TRIAL REGISTRATION

This study was registered in the Chinese Clinical Trial Registry (ChiCTR 2000041026) on 06/12/2020.