Association between days for concussion recovery and initial specialty clinic evaluation within 48 hours.

BACKGROUND: Researchers have highlighted the importance of early access to concussion care within one week of injury in reducing recovery times. However, a persisting question for concussion researchers is "just how early is important?" The purpose of this study was to examine differences in recovery time as predicted by the number of days elapsed since injury (DSI) to initial evaluation among patients who had access to a specialty concussion clinic within seven days. We hypothesized that DSI group membership, even within seven days, would significantly predict risk of protracted recovery (i.e., beyond 21 days). METHODS: In this archival study, retrospective data were gathered from electronic medical records between September 2020 to March 2022. Records of participants between ages 12-18, those diagnosed with a sports-related concussion based on initial clinic visit diagnosis by a medical provider and those who established care within seven days of injury at a large pediatric specialty concussion clinic were examined. Participants were divided into three DSI groups (patients seen in < 48 h: "acute", patients seen between 49 h < and < 96 h: "sub-acute", and patients seen between 97 < and < 168 h: "post-acute"). A general linear model was constructed to examine relationships between relevant concussion factors (e.g., Post Concussion Scale Score, neurodevelopmental history, psychiatric history, concussion history, migraine history, overall VOMS change score, cognitive testing, sex, age, race, and ethnicity) that were either significant in the preliminary analysis or in clinical judgement and recovery time. Adjusted odds ratios (OR) were derived from a binary logistic regression model, in which recovery time was normal (≤ 21 recovery days) or protracted (> 21 recovery days). RESULTS: A total of 856 participants were eligible. Adolescents in the acute group (M = 15.12, SD = 8.04) had shorter recovery times in days compared to those in the sub-acute (M = 17.98, SD = 10.18) and post-acute (M = 21.12, SD = 10.12; F = 26.00, p < .001) groups. Further, participants in the acute (OR = 4.16) and sub-acute (OR = 1.37) groups who accessed specialty concussion clinics within 48 h were 4 times more likely to have a normal recovery and recovered approximately 6 days faster than the post-acute care group. CONCLUSIONS: Earlier concussion care access predicted recovery times and was associated with lower risk for protracted recovery.

Prospective evaluation of 24-hour movement behaviors among adolescents recovering from a sport-related concussion.

This study aimed to describe the 24-hour composition of movement behaviors, including sleep, sedentary behavior, and physical activity (PA), among pediatric sports-related concussion (SRC) patients over their recovery period, assess the association between movement compositions and recovery time, and understand feasibility of 24-hour accelerometry in the study population. A cohort of 50 pediatric SRC patients were asked to wear a wrist-worn accelerometer continuously for the duration of their recovery. Among all enrolled participants, the sample was primarily 14 or 15 years of age (65%), female (55%), and recovered in under 28 days (88%). Accelerometer compliance was moderate; 35 participants (70%) were compliant with the protocol. Compositional analysis was used to address time-use objectives in 33 participants who provided adequate data for inclusion. Overall, participants spent an average of 50% of their 24-hour day sedentary, 33% sleeping, 11% in light intensity PA, and 6% in moderate or vigorous intensity PA. The 24-hour composition of movement behaviors was not associated with recovery time (p = .09-.99). However, the limited sample size may have contributed to null findings. Given recent evidence supporting the effects of sedentary behavior and PA on concussion recovery, future studies should aim to further validate these findings in a larger sample.

Comparison of Prescribed Physical Therapy to a Home Exercise Program for Pediatric Sports-Related Concussion Patients.

The purpose of this retrospective chart review was to compare sports-related concussion (SRC) recovery time in protracted recovery (≥28 days) patients who were prescribed physical therapy (PPT) with those who were only provided a home exercise program (HEP). We hypothesized PPT would be associated with shorter recovery times relative to HEP. Associations were evaluated with multivariable zero-truncated negative binomial regressions. Among the 48 (30.2%) PPT and 111 (69.8%) HEP patients, the majority were female (57.9%), the mean age was 15.3 ± 1.4 (PPT) and 14.2 ± 2.8 (HEP), and time to clinic was a median 6.0 (IQR = 3.0-27.0; PPT) and 7.0 (IQR = 3.0-23.0; HEP) days. After adjusting for demographic (age, sex) and clinical measures (concussion history, convergence, VOMS, PCSS score, and days to clinic), PPT unexpectedly was associated with 1.21 (95% CI: 1.05, 1.41) additional recovery days compared with HEP. One reason for this could be related to patients adhering to the number of a priori prescribed PT sessions which may or may not have aligned with the patient's symptom resolution. Future research should explore this hypothesis while aiming to evaluate the effect of PPT versus HEP using a randomized design. If confirmed, these findings are encouraging for patients who could not otherwise access or afford specialty rehabilitation.

Distinguishing Between Genuine and Feigned Dementia Using Event-related Potentials.

BACKGROUND: Individuals with probable Alzheimer disease (AD) may perform below cutoffs on traditional, memory-based performance validity tests. Previous studies have found success using event-related potentials (ERPs) to detect feigned neurocognitive impairment in younger populations. OBJECTIVE: To evaluate the utility of an auditory oddball task in conjunction with the P3b peak amplitude to distinguish probable AD from simulated dementia. METHOD: Twenty individuals with probable AD and 20 older healthy controls (HC) underwent an ERP auditory oddball protocol and the Test of Memory Malingering (TOMM). The HC were asked to perform honestly for one condition and to simulate dementia for the other. The individuals with probable AD were asked to perform honestly. The P3b peak amplitude and button press accuracy were collected from each participant and were analyzed to determine their effectiveness in detecting performance validity. RESULTS: The P3b peak amplitude remained stable regardless of behavioral condition in the HC group. When combined with the TOMM Trial 2 score, the P3b peak amplitude further improved the ability to correctly differentiate individuals with probable AD from HC simulating dementia with 100% sensitivity and 90% specificity. CONCLUSION: The P3b peak amplitude was found to be an effective physiologic measure of cognitive impairment in individuals with probable AD compared with HC simulating dementia. When combined with the TOMM Trial 2 score, the P3b peak amplitude served as a promising performance validity measure for differentiating individuals with probable AD from HC simulating dementia.

Exploring Vestibular/Ocular and Cognitive Dysfunction as Prognostic Factors for Protracted Recovery in Sports-Related Concussion Patients Aged 8 to 12 Years.

OBJECTIVE: To explore the prognostic ability of the vestibular/ocular motor screening (VOMS), King-Devick (K-D) Test, and C3 Logix Trails A and B to identify protracted recovery from sports-related concussion (SRC) in patients aged 8 to 12 years. DESIGN: Retrospective cohort analysis. SETTING: Specialty pediatric sports concussion clinic. PARTICIPANTS: A total of 114 youth athletes aged 8 to 12 years who were diagnosed with an SRC within 7 days of injury. INDEPENDENT VARIABLES: A positive screen on the VOMS, K-D, and C3 Logix Trails A and Trails B. Combined positive screens on multiple tests (ie, 2, 3, or all 4 positive screens of 4 possible). MAIN OUTCOME MEASURES: Recovery time in days and protracted recovery (recovery time ≥30-days) were the primary outcomes of interest. RESULTS: A positive VOMS screen was associated with 1.31 greater days to SRC recovery ( P = 0.02) than a negative VOMS screen. The K-D and C3 Logix tests were not significantly associated with recovery time, nor were any combinations of tests ( P > 0.05). The VOMS demonstrated moderate prognostic ability to predict normal recovery (negative predictive value = 80.78% [95% CI = 63.73-90.95]). Overall predictive accuracy of normal versus protracted recovery was strongest when a participant screened positive on all 4 tests (Accuracy = 76.32% [95% CI = 67.45-83.78]). CONCLUSIONS: The VOMS was associated with overall recovery time and proved to be a useful test to identify those who would experience a normal recovery time. Combining the 4 tests improved the prognostic accuracy of the protocol in predicting protracted versus normal recovery. These findings suggest that combining multiple, varied assessments of cognition and vestibular/ocular functions may better explain factors contributing to protracted recovery.

Effects of Sex and Load Carried per Kilogram of Body Mass on Landing Technique.

Sex differences and heavy load carriage may contribute to the high rate of musculoskeletal injury in military recruits, particularly within the female population. Thus, the purposes of this study were to determine if load influenced landing quality differently in females compared to males and if load carried per kg body mass was associated to quality of landing. Twenty-eight participants were recruited for this study (males: n = 14; females: n = 14). Participants were grouped by sex. All twenty-eight participants performed three drop-jumps (DJ) under unloaded and loaded conditions. The loaded condition included a combat helmet, tactical vest, and rucksack (22 kg). Two cameras recorded in the frontal and sagittal directions during the three DJ trials. DJ trials were scored using the LESS. There was no significant difference in LESS difference scores between males and females, t(26) = -1.014, p = 0.320, 95% CI = -2.01 to 0.68. Load carried per kg body mass (r s = 0.401, p = 0.034) was significantly correlated to LESS rank order. The results suggest load does not significantly alter landing quality as measured by the LESS. However, participant body mass and load per kg of body may play a role in a person's ability to adapt to heavy loads.

Systematic Review of Recent Pediatric Down Syndrome Neuropsychology Literature: Considerations for Regression Assessment and Monitoring.

OBJECTIVES: To conduct a systematic review of recent pediatric Down syndrome (DS) neuropsychology research that may be useful to clinicians and researchers examining regression in this population. METHODS: We reviewed original peer-reviewed articles published between 2013 and 2018 studying neuropsychological profiles in DS. RESULTS: Thirty-one articles (of 1231 included in the original search) passed all inclusion criteria, were evaluated for bias, and were included in the analysis. CONCLUSION: Findings argued against a single "DS profile" and revealed multiple within-group differences as well as expected and unexpected differences relative to typically developing children and children with other intellectual and developmental disabilities. Areas identified as most germane to regression monitoring included working memory, inhibition, letter and word identification, navigational route learning, motor skills (when strong at baseline), single word receptive/expressive vocabulary, and adaptive function.

Independent risk factors for long-term skeletal relapse after mandibular advancement with bilateral sagittal split osteotomy.

The purpose of this retrospective cohort study was to identify the independent risk factors for long-term skeletal relapse following mandibular advancement with bilateral sagittal split osteotomy. Univariate and multivariate linear regression analyses were performed including nine common risk factors for relapse as independent variables and horizontal/vertical long-term (≥2 years) skeletal relapse as dependent variables. Ninety-six patients were analyzed; 66 were female (68.8%) and the average age of the patients was 29.7±10.5 years. Over an average follow-up of 3.8±1.8 years after an initial mandibular advancement of 8.8±2.4 mm, long-term skeletal relapse of 1.6±1.0 mm horizontal and 0.9±0.7 mm vertical was found. Multivariate analysis identified age, preoperative mandibular plane angle (MPA), bimaxillary surgery, counterclockwise mandibular rotation, and the magnitude of mandibular advancement to be significantly associated with horizontal long-term skeletal relapse. Preoperative MPA, counterclockwise mandibular rotation, and the magnitude of mandibular advancement were significantly associated with vertical long-term skeletal relapse. Thus preoperative MPA, the magnitude of mandibular advancement, and counterclockwise mandibular rotation of the mandible were found to be independent risk factors for both horizontal and vertical long-term skeletal relapse. Although long-term skeletal relapse cannot be avoided entirely, understanding the independent risk factors and their contributions will optimize treatment planning and long-term stability.

Clear cell odontogenic carcinoma: a rare jaw tumor. A summary of 107 reported cases.

The purpose of this study was to summarize the currently published cases of clear cell odontogenic carcinoma (CCOC). The PubMed and Springer databases were used to collect available reports, searching for 'clear cell odontogenic carcinoma', 'CCOC', or 'clear cell ameloblastoma'. The search resulted in 75 reports detailing 107 cases between 1985 and 2018. Clinically the tumor manifests as a swelling in the posterior mandible (n=46), anterior mandible (n=33), and maxilla (n=28). Radiological analysis of 85 cases typically showed a poorly defined expansive radiolucency (n=83). Of the 70 patients with symptoms reported, 44 specified a swelling, 11 tooth mobility, seven gingival/periodontal issues, five numbness, and three decreased jaw opening. One patient presented with a neck mass. The duration of symptoms prior to seeking care was specified for 52 patients: 2 months to 1 year for 34 patients, 1-2 years for seven, 2-4 years for two, 4-7 years for six, and 7-12 years for three. The incidence of recurrence appeared to be 38 of the 88 cases where recurrence was reported. CCOC can be distinguished from other oral cancers by its distinctive histology and immunohistochemical characteristics and less aggressive behavior. Currently, treatment should be early and aggressive resection with clear surgical margins and long-term follow-up. The overall goal is to collect a cohort of patients.

Genetic predisposition for medication-related osteonecrosis of the jaws: a systematic review.

The purpose of this study was to assess whether genetic variation is a predictor for the development of medication-related osteonecrosis of the jaws (MRONJ) in patients receiving bisphosphonate therapy for various conditions. A systematic review based on the PRISMA guidelines was performed. A search strategy was developed. Comprehensive searches of major databases were conducted for studies published January 2003 through July 2018. The PICOS strategy was used to develop the inclusion criteria. The analysis in each study was performed primarily using single nucleotide polymorphism (SNP) frequency mean values and odds ratios between cases and controls. A total of 3301 patients were enrolled in the 15 included studies (two genome-wide association studies, n = 1877; 10 candidate gene studies, n = 1195; three whole genome/whole exome studies, n = 229). Multiple myeloma was the most prevalent primary disease (54.8%). Zoledronate was prescribed in 68.8% of patients. No one SNP was definitively identified as a risk factor for the development of MRONJ. To date, studies have failed to show a single gene as a risk factor for MRONJ. Heterogeneity of case and control populations may be contributory. Next generation sequencing studies may help elucidate the role and interplay of genetic events in the development of MRONJ.

Identifying dental panoramic radiograph features for the screening of low bone mass in postmenopausal women.

A retrospective cohort study was performed to evaluate the use of panoramic radiographs as a screening tool for low bone mass in postmenopausal women. Female subjects aged ≥50 years were included. The predictor variables were gonial angle, antegonial angle, mandibular cortical bone integrity, periodontal disease status, and number of remaining teeth. The primary outcome variable was bone mineral density status. Descriptive and logistic regression statistics were computed; P<0.05 was considered significant. The sample was composed of 273 subjects, aged 50-89 years. Visual assessment of mandibular cortical bone integrity demonstrated a statistically significant correlation with low bone mass diagnosis on univariate logistic regression (P=0.019), but lost significance on multivariate analysis with age, body mass index, and number of remaining teeth (P=0.6). A visual estimation of the mandibular cortical bone integrity from panoramic radiographs may be useful for identifying postmenopausal women at high risk for osteoporosis.

cGMP inhibition of type 3 phosphodiesterase is the major mechanism by which C-type natriuretic peptide activates CFTR in the shark rectal gland.

The in vitro perfused rectal gland of the dogfish shark (Squalus acanthias) and filter-grown monolayers of primary cultures of shark rectal gland (SRG) epithelial cells were used to analyze the signal transduction pathway by which C-type natriuretic peptide (CNP) stimulates chloride secretion. CNP binds to natriuretic receptors in the basolateral membrane, elevates cellular cGMP, and opens cystic fibrosis transmembrane conductance regulator (CFTR) chloride channels in the apical membrane. CNP-provoked chloride secretion was completely inhibitable by the nonspecific protein kinase inhibitor staurosporine and the PKA inhibitor H89 but insensitive to H8, an inhibitor of type I and II isoforms of cGMP-dependent protein kinase (cGKI and cGKII). CNP-induced secretion could not be mimicked by nonhydrolyzable cGMP analogs added alone or in combination with the protein kinase C activator phorbolester, arguing against a role for cGK or for cGMP-induced PKC signaling. We failed to detect a dogfish ortholog of cGKII by molecular cloning and affinity chromatography. However, inhibitors of the cGMP-inhibitable isoform of phosphodiesterase (PDE3) including milrinone, amrinone, and cilostamide but not inhibitors of other PDE isoenzymes mimicked the effect of CNP on chloride secretion in perfused glands and monolayers. CNP raised cGMP and cAMP levels in the SRG epithelial cells. This rise in cAMP as well as the CNP and amrinone-provoked chloride secretion, but not the rise in cGMP, was almost completely blocked by the Gαi-coupled adenylyl cyclase inhibitor somatostatin, arguing against a role for cGMP cross-activation of PKA in CNP action. These data provide molecular, functional, and pharmacological evidence for a CNP/cGMP/PDE3/cAMP/PKA signaling cascade coupled to CFTR in the SRG.

Randomized phase III placebo-controlled trial of letrozole plus oral temsirolimus as first-line endocrine therapy in postmenopausal women with locally advanced or metastatic breast cancer.

PURPOSE: Recent data showed improvement in progression-free survival (PFS) when adding everolimus to exemestane in patients with advanced breast cancer experiencing recurrence/progression after nonsteroidal aromatase inhibitor (AI) therapy. Here, we report clinical outcomes of combining the mammalian target of rapamycin (mTOR) inhibitor temsirolimus with letrozole in AI-naive patients. PATIENTS AND METHODS: This phase III randomized placebo-controlled study tested efficacy/safety of first-line oral letrozole 2.5 mg daily/temsirolimus 30 mg daily (5 days every 2 weeks) versus letrozole/placebo in 1,112 patients with AI-naive, hormone receptor-positive advanced disease. An independent data monitoring committee recommended study termination for futility at the second preplanned interim analysis (382 PFS events). RESULTS: Patients were balanced (median age, 63 years; 10% stage III, 40% had received adjuvant endocrine therapy). Those on letrozole/temsirolimus experienced more grade 3 to 4 events (37% v 24%). There was no overall improvement in primary end point PFS (median, 9 months; hazard ratio [HR], 0.90; 95% CI, 0.76 to 1.07; P = .25) nor in the 40% patient subset with prior adjuvant endocrine therapy. An exploratory analysis showed improved PFS favoring letrozole/temsirolimus in patients ≤ age 65 years (9.0 v 5.6 months; HR, 0.75; 95% CI, 0.60 to 0.93; P = .009), which was separately examined by an exploratory analysis of 5-month PFS using subpopulation treatment effect pattern plot methodology (P = .003). CONCLUSION: Adding temsirolimus to letrozole did not improve PFS as first-line therapy in patients with AI-naive advanced breast cancer. Exploratory analyses of benefit in younger postmenopausal patients require external confirmation.

Residual urine as a risk factor for lower urinary tract infection: a 1-year follow-up study in nursing homes.

OBJECTIVES: To determine whether postvoid urine is a risk factor for the development of lower urinary tract infections (UTIs) in nursing home residents. DESIGN: Prospective surveillance with a follow-up period of 1 year. SETTING: Six Norwegian nursing homes. PARTICIPANTS: One hundred fifty nursing home residents. METHODS: Postvoid residual (PVR) urine volumes were measured using a portable ultrasound. UTIs were registered prospectively for 1 year. RESULTS: Ninety-eight residents (65.3%) had a PVR less than 100 mL, and 52 (34.7%) had a PVR of 100 mL or greater. During the follow-up period, 51 residents (34.0%) developed one or more UTIs. The prevalence of UTI in women was higher than in men (40.4% vs 19.6%; P=.02). There was no significant difference in mean PVR between residents who did and did not develop a UTI (79 vs 97 mL, P=.26). PVR of 100 mL or greater was not associated with greater risk of developing a UTI (P=.59). CONCLUSION: High PVR is common in nursing home residents. No association between PVR and UTI was found.

Renal cell carcinoma: a clinicopathological follow-up study after radical nephrectomy.

OBJECTIVE: To examine the prognostic significance of performance status, tumour stage, histological subtype, nuclear grade and histological tumour necrosis (HTN) in a population of consecutive patients subjected to radical nephrectomy for renal cell carcinoma (RCC). MATERIAL AND METHODS: The cohort consisted of 110 males and 86 females with a mean age of 66 years (range 39-88 years). The Eastern Cooperative Oncology Group performance status (ECOG PS) was determined in all cases. The tumours were staged according to the 2002 TNM classification of the American Joint Committee on Cancer. Histological subtype was diagnosed using the Heidelberg classification. Nuclear grading was performed by means of Fuhrman's method. The median follow-up period was 65 months (mean 83 months; range 1-232 months). RESULTS: Median overall survival (OS) was 65 months and median cancer-specific survival (CSS) was 171 months. CSS was correlated with TNM classification, with the longest survival occurring for stage I and II tumours, shorter survival for stage III tumours and shortest survival for stage IV tumours (p<0.001). A significant difference in CSS was found between T1N0M0 and T2N0M0 tumours (p<0.01). A 15-year CSS of 100% was revealed in patients with tumours

Factors involved in the long-term prognosis of psychogenic nonepileptic seizures.

INTRODUCTION: Information on the long-term effects of psychogenic nonepileptic seizures (PNES) is limited. We therefore reassessed 22 patients 4-6 years after the initial diagnosis of PNES in a tertiary referral epilepsy center. The diagnosis was confirmed using clinical description and additional electroencephalogram investigations in 1998, 1999, and 2000. Patients with epilepsy and PNES as comorbid symptoms were not included. Reassessments were aimed at seizure reduction and possible psychogenic factors. METHODS: Three psychological tests were used at baseline at the time of diagnosis and repeated at end point. These three tests assessed different "levels" of psychological function [i.e., complaints (The Symptoms Check List Revised), coping strategy (The Dissociation Questionnaire), and personality factors/psychopathology Nederlandse Verkorte MMPI]. RESULTS: Twenty-two patients were included. Seizure frequency showed statistically significant reduction. At the time of diagnosis, none of the patients was seizure-free or had only yearly seizures, whereas at end point, 7 of 22 patients were completely in remission and 3 patients had only occasional seizures. The number of patients with daily seizures dropped from nine to two. It has not been fully clarified which factors caused this improvement, but the common denominators are that a definitive expert diagnosis in a tertiary center was made and all possible efforts were made to inform the patient in a respectful manner about the diagnosis. In addition to seizure reduction, there was improvement on different levels of psychological function, showing reduction in psychological distress, reduction in dissociative features such as amnesia, increase in self-control, reduction in feelings of dissatisfaction and passive avoidant behavior, and a more active attitude towards social contact. CONCLUSION: In the long term, the patients with PNES who were included in our study have more self-control and approach social contact with a more self-confident attitude. This does not necessary reflect a causal relationship with the observed seizure reduction. Nonetheless, it is noteworthy that, post aut propter, the eradication of a symptom (i.e., seizures) with social consequences is followed by or is associated with a more confident social attitude. This opens possibilities for treatment strategies.

Bladder Adelta afferent nerve activity in normal cats and cats with feline interstitial cystitis.

PURPOSE: Symptoms associated with interstitial cystitis (IC) (urinary frequency, urgency and pain) resemble those in cats diagnosed with feline IC (FIC). Patients with IC also show enhanced sensitivity to intravesical application of KCl solution. In the current study we compared the effect of bladder distention and intravesical infusion of KCl solution on Adelta bladder afferent nerve activity in normal and FIC cats. MATERIALS AND METHODS: Cats were anesthetized with alpha-chloralose (60 to 70 mg/kg intravenously). Single and multiunit afferent nerve activity was recorded with platinum electrodes from fibers dissected from the transected pelvic nerve. Bladder Adelta afferents were activated by bladder distention at constant pressures (5 to 80 cm H2O) by infusing saline or KCl solution (80 to 300 mM). RESULTS: Increasing bladder pressure by saline infusion over a range of constant pressures (5 to 80 cm H2O) increased afferent firing in normal and FIC cats. However, the slope of the pressure-firing curve was significantly steeper in cats with FIC. In normal cats KCl infusion (80 to 300 mM) into the bladder produced a pressure-firing curve similar to that induced by saline infusion. However, in FIC cats KCl at concentrations of 150 to 300 mM produced almost complete inhibition of afferent firing at pressures between 30 and 80 cm H2O. CONCLUSIONS: These data suggest that 1) bladder Adelta afferents in FIC cats are more sensitive to pressure changes than are afferents in normal cats and 2) the inhibition of afferent firing by high concentrations of KCl in FIC cats is likely the result of afferent nerve depolarization and it is consistent with the idea of increased permeability of bladder epithelium in FIC.

Bladder and urethral sphincter responses evoked by microstimulation of S2 sacral spinal cord in spinal cord intact and chronic spinal cord injured cats.

Urinary bladder and urethral sphincter responses evoked by bladder distention, ventral root stimulation, or microstimulation of S2 segment of the sacral spinal cord were investigated under alpha-chloralose anesthesia in cats with an intact spinal cord and in chronic spinal cord injured (SCI) cats 6-8 weeks after spinal cord transection at T9-T10 spinal segment. Both SCI and normal cats exhibited large amplitude reflex bladder contractions when the bladder was fully distended. SCI cats also exhibited hyperreflexic bladder contractions during filling and detrusor-sphincter dyssynergia during voiding, neither was observed in normal cats. Electrical stimulation of the ventral roots revealed that the S2 sacral spinal cord was the most effective segment for evoking large amplitude bladder contractions or voiding in both types of cats. Microstimulation with a stimulus intensity of 100 microA and duration of 30-60 s via a single microelectrode in the S2 lateral ventral horn or ventral funiculus evoked large amplitude bladder contractions with small urethral contractions in both normal and SCI cats. However, this stimulation evoked incomplete voiding due to either co-activation of the urethral sphincter or detrusor-sphincter dyssynergia. Stimulation in the S2 dorsal horn evoked large amplitude sphincter responses. The effectiveness of spinal cord microstimulation with a single electrode to induce prominent bladder and urethral sphincter responses in SCI animals demonstrates the potential for using microstimulation techniques to modulate lower urinary tract function in patients with neurogenic voiding dysfunctions.

Multi-joint movement of the cat hindlimb evoked by microstimulation of the lumbosacral spinal cord.

Microstimulation of the lumbosacral spinal cord may be an effective tool for the restoration of locomotion after spinal cord injury. To examine this possibility, complex coordinated multi-joint hindlimb movements were evoked by electrical stimulation with sine waveform modulation using a single microelectrode positioned in the L5-S1 spinal cord. Four types of hindlimb movement (flexion, extension, abduction, and adduction) were identified, and their stimulation locations were mapped onto cross-sectional drawings of L5-S1 spinal cord following histological examination of electrode tracks in the cord. Hindlimb flexion was evoked without abduction/adduction at many locations in the dorsal part of the L5-S1 spinal cord, whereas extension was evoked with abduction/adduction in the ventral part of the cord. Bilateral reciprocal lifting of the hindlimb was evoked by implanting two microelectrodes (one on each side) in the spinal cord. This study indicates that functional hindlimb movements can be elicited by activating a small number of sites in lumbosacral spinal cord.