Unilateral Resection Research Articles

Olfactory dysfunction management following unilateral cranial resection for olfactory neuroblastoma.

Despite advances in techniques for olfactory neuroblastoma (ONB), such as unilateral cranial resection, preserving the patient’s sense of smell remains a challenge. This study aimed to examine the effectiveness of post-operative olfactory training in patients who underwent unilateral resection of ONB. This retrospective cohort study assessed the effect of post-operative olfactory training on olfactory preservation in patients with ONB undergoing unilateral cranial resection. Patients were divided into training intervention (n = 5) and non-intervention (n = 6) groups. Olfactory tests were conducted pre-operatively and at multiple post-operative intervals. Partial olfactory function was preserved in all cases in the training intervention group, whereas only 17% of cases in the non-intervention group maintained partial olfactory function. Significant improvements in olfactory test scores were observed in the training intervention group compared with the non-intervention group. Our findings suggest that post-operative olfactory training could aid in olfactory preservation for patients with ONB after unilateral cranial resection. However, these results should be interpreted with caution, and further research with larger cohorts and extended follow-up periods is needed to confirm these observations.

Postoperative hungry bone syndrome in primary hyperparathyroidism: A case report.

Hungry bone syndrome (HBS) is a forgotten and underdiagnosed cause. Postoperative HBS refers to patients with high bone turnover before surgery, but after surgery, the inhibition of osteoclast resorption by intact parathyroid hormone suddenly decreases, resulting in a sudden increase in the amount of calcium resorbed by the bone, and a rapid, severe and persistent hypocalcemia, which may be accompanied by hypophosphatemia and hypomagnesemia. We present a case with information about HBS and related complications after parathyroidectomy (PTX). The patient was a 57-year-old woman who presented to the hospital with "pain in both ankles for more than 3 years and in both knees for more than 2 years." A parathyroid mass was found preoperative. Unilateral resection of the lesion was performed under general anesthesia. On gross examination, the mass was reddish brown in color, about 2.9 × 2.5 × 2.3 cm, with abundant blood supply. Postoperative pathology diagnosed parathyroid adenoma. The patient was diagnosed with HBS on day 3 post-PTX, which lasted for 9 days. After active calcium supplementation and other pharmacological interventions, her test parameters gradually returned to normal and she was discharged on the 13th day after surgery. Using the case of a patient with primary hyperparathyroidism with HBS lasting 9 days after PTX for diagnosis and management, we aimed to summarize possible predictors and perioperative management strategies to reduce the incidence, severity, and duration of postoperative HBS.

Olfaction Preservation and Long-Term Outcomes in Patients with Unilateral Endoscopic Resection of Olfactory Neuroblastoma: A Systematic Review and Institutional Experience

BackgroundEndoscopic endonasal surgical resection is an effective therapeutic approach for olfactory neuroblastoma (ONB). Unilateral excision of ONBs with limited extension has been reported with the purpose of preserving olfactory function. We aimed to review implications of surgical management, olfactory preservation feasibility, and survival outcomes in patients who underwent endoscopic unilateral resection of olfactory neuroblastoma. MethodsA systematic literature review was conducted using the search terms [(“Olfactory neuroblastoma”) OR (“Esthesioneuroblastoma”)] AND [(“Unilateral resection”) OR (“Olfaction preservation”)]. Studies reporting cases of unilateral olfactory neuroblastoma endoscopic resection with postoperative olfaction assessment were included. Concurrently, records of patients who met inclusion criteria at our institution were reviewed retrospectively. The survival and olfactory outcomes were analyzed in both cohorts. ResultsThirty-three patients were identified in the published literature. Twenty-three (69.7%) reported postoperative olfaction preservation. Olfactory function after surgery did not show an association with Kadish stage (p=0.128). No evidence of disease was observed at the latest follow-up in this group of patients. Nine patients who met inclusion criteria were identified at our institution. The extent of resection influenced the level of olfaction preservation when cribriform plate and nasal septum resection coexisted (p=0.05). A single patient at our institution developed recurrence after being lost to follow-up for 22 months. ConclusionsOlfaction preservation can be achieved in patients who undergo endoscopic unilateral resection and adjuvant radiotherapy. The extent of resection should aim for negative margins, particularly in the midline. Larger studies are required to assess the risk of contralateral microscopic disease, and, hence, close follow-up is advised.

The impact of bilateral versus unilateral anterior temporal lobe damage on face recognition, person knowledge and semantic memory.

The functional importance of the anterior temporal lobes (ATLs) has come to prominence in two active, albeit unconnected literatures-(i) face recognition and (ii) semantic memory. To generate a unified account of the ATLs, we tested the predictions from each literature and examined the effects of bilateral versus unilateral ATL damage on face recognition, person knowledge, and semantic memory. Sixteen people with bilateral ATL atrophy from semantic dementia (SD), 17 people with unilateral ATL resection for temporal lobe epilepsy (TLE; left = 10, right = 7), and 14 controls completed tasks assessing perceptual face matching, person knowledge and general semantic memory. People with SD were impaired across all semantic tasks, including person knowledge. Despite commensurate total ATL damage, unilateral resection generated mild impairments, with minimal differences between left- and right-ATL resection. Face matching performance was largely preserved but slightly reduced in SD and right TLE. All groups displayed the familiarity effect in face matching; however, it was reduced in SD and right TLE and was aligned with the level of item-specific semantic knowledge in all participants. We propose a neurocognitive framework whereby the ATLs underpin a resilient bilateral representation system that supports semantic memory, person knowledge and face recognition.

Distinctive clinical and molecular aberrations of colorectal cancer patients with ovarian metastases.

e15595 Background: Ovarian metastases (OM) from colorectal cancer (CRC) are a rare phenomenon. There are limited data detailing outcomes from surgical interventions on OM. However, there is a lack of studies integrating genetic aberrations identified in these patients with clinical characteristics. Methods: We conducted a retrospective review of CRC patients with OM. Demographic variables of interest included age and stage at diagnosis, time from diagnosis to discovery of OM, laterality of OM, primary tumor sidedness, and choice of chemotherapy. Next Generation Sequencing was utilized to collect solid tumor DNA sequencing, in addition to cell-free DNA (cfDNA). Results: A cohort of 12 MSI-S patients was identified between December 2023 and January 2024. Median age of diagnosis was 42.5 y/o. Demographics noted: Primary tumor sidedness included descending colon [58%; 86% of these sigmoid] and ascending colon (42%). AJCC T4 (50%) with OM at presentation (83%); unilateral (58%); 57% in the left ovary. 67% of patients underwent bilateral salpingo-oophorectomy (BSO), 25% unilateral resection, and 8.3% had no resection. 9 patients continue to receive treatment; 3 patients are deceased. Tissue NGS data was available for 75% of patients. The most common mutations were p53 (100%), APC (88%), KRAS (G12A, G12C and G12D; 38%), and PIK3CA (25%). cfDNA data was available for 58% of patients; common mutations were APC (86%), p53 (71%), KRAS [G12C (2); G12D; 43%), PMS2 (29%), BRAF V600E (14%) and BRAF amplification (14%). Conclusions: In our cohort, CRC patients with OM were of early age onset with sigmoid > ascending colon cancer with similar molecular alterations by tissue and cfDNA noting increased KRAS aberrations. Hence, NGS should be completed in all CRC as an opportunity to further characterize potentially actionable mutations in patients with OM, expanding precision oncology availability to this select patient population.

Treatment of unilateral olfactory neuroblastoma: Appropriate extent of surgical resection and potential for olfactory preservation.

Historically, comprehensive surgical resection for olfactory neuroblastoma has included the bilateral olfactory epithelium, cribriform plate, overlying dura, olfactory bulbs and tracts. This results in postoperative anosmia that may significantly impact a patient's quality of life without definitive added benefit in survival. The prevalence of occult intracranial disease is low, especially for Hyams grade I and II tumors. A unilateral approach sparing the contralateral cribriform plate and olfactory system can be considered for select cases of early stage, low-grade tumors when the disease does not cross midline to involve the contralateral olfactory cleft or septal mucosa and when midline dural margins can be cleared with frozen pathology. Approximately half of patients who undergo unilateral resection may have residual olfaction even with adjuvant unilateral radiation. Early data suggest favorable disease-free survival and overall survival for patients who underwent the unilateral approach; however, larger sample studies are needed to confirm comparability to bilateral resections regarding oncologic outcomes.

Impairment of unconscious emotional processing after unilateral medial temporal structure resection

The role of the amygdala in unconscious emotional processing remains a topic of debate. Past lesion studies have indicated that amygdala damage leads to impaired electrodermal activity in response to subliminally presented emotional stimuli. However, electrodermal activity can reflect both emotional and nonemotional processes. To provide behavioral evidence highlighting the critical role of the amygdala in unconscious emotional processing, we examined patients (n = 16) who had undergone unilateral resection of medial temporal lobe structures, including the amygdala. We utilized the subliminal affective priming paradigm in conjunction with unilateral visual presentation. Fearful or happy dynamic facial expressions were presented in unilateral visual fields for 30 ms, serving as negative or positive primes. Subsequently, neutral target faces were displayed, and participants were tasked with rating the valence of these targets. Positive primes, compared to negative ones, enhanced valence ratings of the target to a greater extent when they stimulated the intact hemisphere (i.e., were presented in the contralateral visual field of the intact hemisphere) than when they stimulated the resected hemisphere (i.e., were presented in the contralateral visual field of the resected hemisphere). These results suggest that the amygdala is causally involved in unconscious emotional processing.

Delineating abnormal individual structural covariance brain network organization in pediatric epilepsy with unilateral resection of visual cortex

Although several previous studies have used resting-state functional magnetic resonance imaging and diffusion tensor imaging to report topological changes in the brain in epilepsy, it remains unclear whether the individual structural covariance network (SCN) changes in epilepsy, especially in pediatric epilepsy with visual cortex resection but with normal functions. Herein, individual SCNs were mapped and analyzed for seven pediatric patients with epilepsy after surgery and 15 age-matched healthy controls. A whole-brain individual SCN was constructed based on an automated anatomical labeling template, and global and nodal network metrics were calculated for statistical analyses. Small-world properties were exhibited by pediatric patients after brain surgery and by healthy controls. After brain surgery, pediatric patients with epilepsy exhibited a higher shortest path length, lower global efficiency, and higher nodal efficiency in the cuneus than those in healthy controls. These results revealed that pediatric epilepsy after brain surgery, even with normal functions, showed altered topological organization of the individual SCNs, which revealed residual network topological abnormalities and may provide initial evidence for the underlying functional impairments in the brain of pediatric patients with epilepsy after surgery that can occur in the future.

Unilateral Fixation of the Bony Pyramid in Deviated Nose Correction.

Deviated nose correction is one of the most challenging procedures in rhinoplasty. Recent studies proposed effectiveness of preservation techniques even for patients with crooked nose deformity, although the long-term results are still controversial. Obviously, only addressing the blocking points is not enough to achieve stable midline position in crooked nose. To ensure consistent long-term results, we proposed a unilateral suturing of the bony pyramid along with unilateral resection of the excessive bone along the lateral osteotomy line. The first results of described surgical technique have proven its simplicity, reliability, and high efficiency both in primary and in revision surgeries. LEVEL OF EVIDENCE V: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

THORAX AND IDIOPATHIC SCOLIOSIS

This review is related to the role of thorax in scoliogenesis. The embryology, the prenatal and the postnatal growth of the rib cage of (RC) and the lungs are briefly described. The development of normal RC, the frontal and sagittal diameters of it, the values of mid-thoracic diameters, the thoracic index, the biomechanical contribution of the RC to thoracic stability, the increase in frontal and sagittal thoracic diameter during breathing are defined. The infancy, childhood, puberty (ICP) model of growth is used in both the segmental thoracic ratios (TR) and the Segmental Rib-vertebra angles (RVA) in order to assess the normal and deformed RC in Early Onset (EOS) and Late Onset Scoliosis (LOS). The neuromuscular mechanisms as possible factors causing age-related RVAs changes are discussed. Then the posterior truncal/thoracic asymmetries are reviewed related to school scoliosis screening (SSS) referrals. Next, the development of RC is analyzed in resolving and progressive infantile idiopathic scoliosis (IIS), and in adolescent idiopathic scoliosis (AIS). The menarche and laterality of thoracic scoliotic curves, congenitally fused ribs and pulmonary function in children with idiopathic scoliosis (IS) is also discussed. The pathogenesis of IS according to the Nottingham concept and RC, the thorax and pelvis complex during gait and rotational inertia, the Double Rib Contour Sign (DRCS) and Rib Index (RI), the effect of growth on the relationship of spinal and thoracic deformity are explained. The postoperative fate of IS hump deformity in relation to the RI and the aetiological implications for IS are then stated. The role of the rib-sternum complex is mentioned. John Sevastiks thoracospinal concept of aetiopathogenesis of AIS and his research about IS are described, namely experiments on ribs, correction of experimentally produced scoliosis, suggested surgical intervention on the ribs, experiments on nerves, vascular changes in the chest wall after unilateral resection of the intercostal nerves, and breast asymmetries in female suffering AIS. A biomechanical model using different Cobb angle and rib hump (RH) correction is mentioned. The issue of thoracic kyphosis and hypokyphosis and the impact of the lateral spinal profile (LSP), that is the sagittal plane, is discussed. Finally, IS and evolution of thoracic shape as a scar of evolution are pointed out.

Risk Factors and Complications in Reduction Mammaplasty: A Systematic Review and Meta-analysis.

Reduction mammaplasty (RM) has become established as the standard effective method for treating macromastia, but reports on the risk factors that predispose to postoperative complications have been conflicting. This meta-analysis aimed to pool the available data to identify predictors of complications following RM. The PubMed, Web of Science, Embase, and Cochrane databases were screened from inception to 1 Jan 2022, and studies were included based on predefined criteria. The perioperative risk factors BMI, smoking, age, diabetes, radiation therapy, and tissue resection weight were extracted and their correlation with complications assessed. A total of 40 studies comprising of 5908 patients were included. BMI ≥ 30kg/m2 (OR = 1.65, 95% CI 1.35-2.02; p < 0.01) and ≥ 40kg/m2 (OR = 1.97, 95% CI 1.26-3.08; p < 0.01), smoking (OR = 2.57, 95% CI 2.01-3.28; p < 0.01), diabetes (OR = 2.21, 95% CI 1.19-4.07; p < 0.05), a unilateral resection weight ≥ 1000g (OR = 1.76, 95% CI 1.02-3.05; p < 0.05), and radiation therapy (OR = 11.11, 95% CI 2.01-3.28; p < 0.01) were associated with higher rates of postoperative complications. Obese patients (BMI ≥ 30kg/m2) were more likely to experience fat necrosis (OR = 3.00, 95% CI 1.37-6.57; p < 0.01) and infection (OR = 1.66, 95% CI 1.15-2.40; p < 0.05). Smokers had a 2.03 times higher risk of infection (95% CI 1.24-3.31; p < 0.01) and 2.34 times higher risk of dehiscence (95% CI 1.38-3.98; p < 0.01). No association between complication occurrence and age 40 or 50 years or total tissue resection weight ≥ 1000g was identified. This meta-analysis provides evidence that obesity, smoking, diabetes, unilateral resection weight ≥ 1000g, and preoperative radiation therapy predispose to complication occurrence in RM. This information can optimize the ability of surgeons to provide preoperative patient education, perioperative assessment, and postoperative care planning. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Primary bilateral macronodular adrenal hyperplasia: A series of 32 cases and literature review

Primary bilateral macronodular adrenal hyperplasia (PBMAH) accounts for <2% of cases of Cushing's syndrome. The majority of patients present with no obvious steroid excess it means with autonomous cortisol secretion (ACS). The classic treatment for patients with overt Cushing's syndrome is bilateral adrenalectomy, but unilateral resection of the larger adrenal gland can result in clinical and/or biochemical remission in >90% of cases, especially in cases of ACS. In this article, a series of 32 cases with PBMAH is described. Most of the cases of PBMAH had ACS, except for one case with overt Cushing's syndrome. A study of aberrant receptors was performed in six patients, being negative in three cases, positive in the metoclopramide test in two cases and positive in the metoclopramide test and in the mixed meal test in another patient. The patient with overt Cushing's syndrome was treated with adrenostatic therapy achieving biochemical control, while two patients with ACS underwent unilateral adrenalectomy with resection of the largest adrenal gland, demonstrating hypercortisolism remission and improvement of cardiovascular risk factors after surgery. This article describes a series of 32 cases of PBMAH and offers a comprehensive review of PBMAH.

Primary bilateral macronodular adrenal hyperplasia: A series of 32 cases and literature review

Primary bilateral macronodular adrenal hyperplasia (PBMAH) accounts for <2% of cases of Cushing's syndrome. The majority of patients present with no obvious steroid excess it means with autonomous cortisol secretion (ACS). The classic treatment for patients with overt Cushing's syndrome is bilateral adrenalectomy, but unilateral resection of the larger adrenal gland can result in clinical and/or biochemical remission in >90% of cases, especially in cases of ACS. In this article, a series of 32 cases with PBMAH is described. Most of the cases of PBMAH had ACS, except for one case with overt Cushing's syndrome. A study of aberrant receptors was performed in six patients, being negative in three cases, positive in the metoclopramide test in two cases and positive in the metoclopramide test and in the mixed meal test in another patient. The patient with overt Cushing's syndrome was treated with adrenostatic therapy achieving biochemical control, while two patients with ACS underwent unilateral adrenalectomy with resection of the largest adrenal gland, demonstrating hypercortisolism remission and improvement of cardiovascular risk factors after surgery. This article describes a series of 32 cases of PBMAH and offers a comprehensive review of PBMAH.

Vertebral artery is an anatomical landmark in the posterior unilateral resection of cervical benign nerve sheath tumors with dumbbell extension of Eden type 2 or 3.

In the cervical nerve sheath tumor (NST) surgery with dumbbell extension of Eden type 2 or 3, selection of anterior, posterior, or combined approach remains controversial. This technical note aimed to propose possible advantages of the posterior unilateral approach (PUA). Methods: Six patients who underwent the surgical treatment of cervical NSTs with dumbbell extension of Eden type 2 or 3 were included. The critical surgical steps included (1) complete separation of extradural and intradural procedures, (2) careful peeling of the neural membranes (epineurium and perineurium) from the tumor surface in the extradural procedure, (3) complete removal of the extradural tumor within the neural membranes, (4) intradural disconnection of tumor origin, and (5) intentional tumor removal up to the vertebral artery (VA), i.e., the VA line. The tumor location of dumbbell extension was Eden types 2 and 3 in two and four patients. Gross total resection was achieved in two patients and intentional posterior removal of the tumor to the VA line was achieved in the remaining four patients. No vascular or neural injuries associated with surgical procedures occurred. Postoperative neurological assessment revealed no symptomatic aggravation in all patients. No secondary surgery was performed during the study period. PUA was safe and less invasive for functional recovery and tumor resection, if the anatomical relationship between the tumor and VA is clearly understood. The VA line is an important anatomical landmark to limit the extent of tumor resection.

Effect of ACDF combined with different degrees of partial resection of uncovertebral joints on cervical stability and degeneration: a three-dimensional finite element analysis

BackgroundTo evaluate the influence of the resection of different amounts of the uncovertebral joints on the stability of the cervical spine by comparing and analyzing the stress distribution and peak displacement characteristics of the internal fixation structures and endplates.MethodsAfter obtaining the CT data of a 34-year-old male healthy cervical spine, a three-dimensional finite element model was established and verified. The three-dimensional finite element method was used to establish the models of anterior cervical compression fusion and internal fixation surgical implants and anterior cervical compression fusion and internal fixation combined with the partial resection of different amounts of the unilateral or bilateral uncovertebral joints. The models were tested under six working conditions: flexion, extension, left bending, right bending, left rotation, and right rotation. The surgical models were compared regarding the stress distribution of the titanium mesh, titanium plate and screw, and endplate, and the peak displacement of the vertebral body.ResultsThere were no significant differences in the stress distribution and peak displacement of the vertebral body of ACDF combined with different amounts of uncovertebral joint resection in the states of flexion and extension. However, there were significant increases in the stress distribution and peak displacement of the vertebral body in the states of left and right bending and rotation. In the states of left and right bending and rotation, the stress distribution and peak displacement of the vertebral body were significantly greater in the models with bilateral partial resection of the uncovertebral joints than in the models with unilateral partial resection of the uncovertebral joints. Bilateral resection of the uncovertebral joints by 30–40% and unilateral resection of the uncovertebral joints by 40–50% resulted in the greatest increases in the maximum stress distribution of the titanium plate and screw and the peak displacement of the vertebral body.ConclusionFinite element analysis of the biomechanical changes in the cervical spine showed that anterior cervical compression fusion and internal fixation combined with bilateral resection of less than 30% of the uncovertebral joints or unilateral resection of less than 40% of the uncovertebral joints had little effect on the stability of the cervical spine.

Sacrospinous and sacrotuberous ligaments influence in pelvis kinematics.

The alteration in mechanical properties of posterior pelvis ligaments may cause a biased pelvis deformation which, in turn, may contribute to hip and spine instability and malfunction. Here, the effect of different mechanical properties of ligaments on lumbopelvic deformation is analyzed via the finite element method. First, the improved finite element model was validated using experimental data from previous studies and then used to calculate the sensitivity of lumbopelvic deformation to changes in ligament mechanical properties, load magnitude, and unilateral ligament resection. The deformation of the lumbopelvic complex relative to a given load was predominant in the medial plane. The effect of unilateral resection on deformation appeared to be counterintuitive, suggesting that ligaments have the ability to redistribute load and that they play an important role in the mechanics of the lumbopelvic complex.

A novel and feasible mouse model of modified inoculation method by subcutaneous EMT6 cells injection for subclinical breast cancer

To create a subclinical breast cancer mouse model. Using a modified inoculation method, we injected EMT6 cells subcutaneously into the bilateral 4th mammary fat pads of six BALB/c mice. The mice were then bilaterally inoculated with various cell numbers. Each group underwent unilateral resection of the 4th nipple and mammary fat pad at a 24-h interval. The modified subcutaneous inoculation method was simple, safe, and demonstrated good consistency in bilateral tumor growth rates during the early stages of tumor formation. The physical differences in the physical characteristics of the bilateral tumors ranged from 75% to 120% for each mouse. Additionally, by varying the number of injected cells, the times for forming solid tumors of approximately 5 mm in maximum length were 5–6 days (0.5 × 106 EMT6 cells) and 6–8 days (1 × 106 EMT6 cells) after injection, and the difference was statistical significant (P = 0.008); for these models, the ideal time points representing subclinical stages were 24 h and 72 h after inoculation, respectively. Our findings show that the optimal time point for isolating the subclinical stage of breast cancer differs depending on the number of EMT6 cells injected into the 4th mammary fat pad of BALB/c mice.

Inferior alveolar nerve preservation during resection and reconstruction of the mandible for benign tumors as a factor improving patient's quality of life

This prospective study aimed to evaluate neurosensory disturbance and quality of life in patients who underwent mandibular resection for benign tumors and whose inferior alveolar nerve (IAN) was either preserved or sacrificed. Mandibular resection was indicated owing to the presence of osteoradionecrosis in 25 patients and ameloblastoma in 15 patients. Resection was unilateral in 24 patients and bilateral in 16 patients.The authors assessed the inferior alveolar nerve's sensory dysfunction by measuring the electroexcitability of skin receptors using an electro-odontometer. Study participants' quality of life was estimated with the oral health impact profile (OHIP)-14 and short-form (SF)-36 questionnaire. All the patients in whom the inferior alveolar nerve was sacrificed experienced persistent numbness in the area of innervation with mental nerve on the affected side. The average pain threshold reached preoperative levels (point 1–22.7 ± 2.5, p-value = .025; point 2–25.8 ± 2.7, p-value = .023) 6 months after the operation in patients in whom the IAN was preserved (point 1–23.7 ± 2.3, p-value = .022; point 2–25.4 ± 2.8, p-value = .025). The results of the OHIP-14 and SF-36 showed that patients with preserved IANs had a significantly better quality of life than the patients in whom the IAN was sacrificed. The results of OHIP-14 twelve months after the operation in unilateral resection: control group - 16.0 ± 1.6, p-value = .029; study group - 8.0 ± 0.8, p-value = .029, and in bilateral resection: control group - 26.0 ± 3.2, p-value = .044; study group - 9.0 ± 0.7, p-value = .027. The possibility of sparing the inferior alveolar nerve should not be ignored when planning mandibular resection and reconstruction.

Unilateral resection of both cortical visual pathways in a pediatric patient alters action but not perception

The human cortical visual system consists of two major pathways, a ventral pathway which subserves perception and a dorsal pathway which primarily subserves visuomotor control. Previous studies have found that children with cortical resections of the ventral visual pathway retain largely normal visuoperceptual abilities. Whether visually guided actions, supported by computations carried out by the dorsal pathway, follow a similar pattern of preservation remains unknown. To address this question, we examined visuoperceptual and visuomotor behaviors in a pediatric patient, TC, who underwent a cortical resection that included portions of the left ventral and dorsal pathways. We collected kinematic data when TC used her right and left hands to perceptually estimate the width of blocks that varied in width and length, and, separately, to grasp the same blocks. TC's perceptual estimation performance was comparable to that of controls, independent of the hand used. In contrast, relative to controls, she showed reduced visuomotor sensitivity to object shape and this was more evident when she grasped the objects with her contralesional right hand. These results provide novel evidence for a striking difference in the competence of the two visual pathways to cortical injuries acquired in childhood.

The sympathetic nervous system exacerbates carotid body sensitivity in hypertension.

The carotid bodies (CBs) of spontaneously hypertensive (SH) rats exhibit hypertonicity and hyperreflexia contributing to heightened peripheral sympathetic outflow. We hypothesized that CB hyperexcitability is driven by its own sympathetic innervation. To test this, the chemoreflex was activated (NaCN 50-100 µL, 0.4 µg/µL) in SH and Wistar rats in situ before and after: (i) electrical stimulation (ES; 30 Hz, 2 ms, 10 V) of the superior cervical ganglion (SCG), which innervates the CB; (ii) unilateral resection of the SCG (SCGx); (iii) CB injections of an α1-adrenergic receptor agonist (phenylephrine, 50 µL, 1 mmol/L), and (iv) α1-adrenergic receptor antagonist prazosin (40 µL, 1 mmol/L) or tamsulosin (50 µL, 1 mmol/L). ES of the SCG enhanced CB-evoked sympathoexcitation by 40-50% (P < 0.05) with no difference between rat strains. Unilateral SCGx attenuated the CB-evoked sympathoexcitation in SH (62%; P < 0.01) but was without effect in Wistar rats; it also abolished the ongoing firing of chemoreceptive petrosal neurones of SH rats, which became hyperpolarized. In Wistar rats, CB injections of phenylephrine enhanced CB-evoked sympathoexcitation (33%; P < 0.05), which was prevented by prazosin (26%; P < 0.05) in SH rats. Tamsulosin alone reproduced the effects of prazosin in SH rats and prevented the sensitizing effect of the SCG following ES. Within the CB, α1A- and α1B-adrenoreceptors were co-localized on both glomus cells and blood vessels. In conscious SH rats instrumented for recording blood pressure (BP), the CB-evoked pressor response was attenuated after SCGx, and systolic BP fell by 16 ± 4.85 mmHg. The sympathetic innervation of the CB is tonically activated and sensitizes the CB of SH but not Wistar rats. Furthermore, sensitization of CB-evoked reflex sympathoexcitation appears to be mediated by α1-adrenoceptors located either on the vasculature and/or glomus cells. The SCG is novel target for controlling CB pathophysiology in hypertension.