A systematic review of the impact of compression therapy on quality of life and pain among people with a venous leg ulcer.

AIM: To gain a greater understanding of how compression therapy affects quality of life, this systematic review appraised existing published studies measuring the impact of compression therapy on health quality of life (HRQoL), and pain, among people with venous leg ulcers (VLU). METHOD: Five databases were searched, and two authors extracted data and appraised the quality of selected papers using the RevMan risk of bias tool. Due to heterogeneity in the types of compression and instruments used to evaluate HRQoL, meta-analysis was not appropriate; thus, a narrative synthesis of findings was undertaken. RESULTS: Ten studies were included, 9 RCTs and one before-after study. The studies employed nine different HRQoL tools to measure the impact of a variety of compression therapy systems, with or without an additional exercise programme, versus other compression systems or usual care, and the results are mixed. With the use of the Cardiff Cardiff Wound Impact Schedule, the SF-8 and the SF-12, study authors found no differences in QoL scores between the study groups. This is similar to one study using QUALYs (Iglesias et al., 2004). Conversely, for studies using EuroQol-5D, VEINES-QOL, SF-36 and CIVIQ-20 differences in QoL scores between the study groups were noted, in favour of the study intervention groups. Two further studies using QUALYs found results that favoured a two-layer cohesive compression bandage and the TLCCB group, respectively. Results for the five studies that assessed pain are also mixed, with one study finding no difference between study groups, one finding that pain increased over the study period and three studies finding that pain reduced in the intervention groups. All studies were assessed as being at risk of bias in one or more domains. CONCLUSION: Results were varied, reflecting uncertainty in determining the impact of compression therapy on quality of life and pain among people with a venous leg ulcer. The heterogeneity of the compression systems and the measures used to evaluate HRQoL make it a challenge to interpret the overall evidence. Further studies should strive for homogeneity in design, interventions and comparators to enhance both internal and external validity.

Assessing the healthcare costs associated with venous leg ulcer compression bandages - A scoping review.

AIM: To determine the monetary costs identified in economic evaluations of treatment with compression bandages among adults with venous leg ulcers (VLU). METHOD: A scoping review of existing publications was conducted in February 2023. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were used. RESULTS: Ten studies met the inclusion criteria. To place the costs of treatment into context, these are reported in conjunction with the healing rates. Three comparisons were made: 1.4 layer compression versus no compression (3 studies). One study reported that 4 layer compression was more expensive than usual care (£804.03 vs £681.04, respectively), while the 2 other studies reported the converse (£145 vs £162, respectively) and all costs (£116.87 vs £240.28 respectively). Within the three studies, the odds of healing were statistically significantly greater with 4 layer bandaging (OR: 2.20; 95% CI: 1.54-3.15; p = 0.001).; 2.4 layer compression versus other compression (6 studies). For the three studies reporting the mean costs per patient associated with treatment (bandages alone), over the treatment period, analysis identified a mean difference (MD) in costs for 4 layer vs comparator 1 (2 layer compression, short-stretch compression, 2 layer compression hosiery, 2 layer cohesive compression, 2 layer compression) of -41.60 (95% CI: 91.40 to 8.20; p = 0.10). The OR of healing for 4 layer compression vs comparator 1 (2 layer compression, short-stretch compression, 2 layer compression hosiery, 2 layer cohesive compression, 2 layer compression) is: 0.70 (95% CI: 0.57-0.85; p = 0.004). For 4 layer vs comparator 2 (2 layer compression) the MD is: 14.00 (95% CI: 53.66 to -25.66; p < 0.49). The OR of healing for 4 layer compression vs comparator 2 (2 layer compression) is: 3.26 (95% CI: 2.54-4.18; p < 0.00001). For comparator 1 (2 layer compression, short-stretch compression, 2 layer compression hosiery, 2 layer cohesive compression, 2 layer compression) vs comparator 2 (2 layer compression) the MD in costs is: 55.60 (95% CI: 95.26 to -15.94; p = 0.006). The OR of healing with Comparator 1 (2 layer compression, short-stretch compression, 2 layer compression hosiery, 2 layer cohesive compression, 2 layer compression) is: 5.03 (95% CI:4.10-6.17; p < 0.00001). Three studies presented the mean annual costs per patient associated with treatment (all costs). The MD is 172 (150-194; p = 0.401), indicating no statistically significant difference in costs between the groups. All studies showed faster healing rates in the 4 layer study groups. 3. Compression wrap versus inelastic bandage (one study). Compression wrap was less expensive than inelastic bandage (£201 vs £335, respectively) with more wounds healing in the compression wrap group (78.8%, n = 26/33; 69.7%, n = 23/33). CONCLUSION: The results for the analysis of costs varied across the included studies. As with the primary outcome, the results indicated that the costs of compression therapy are inconsistent. Given the methodological heterogeneity among studies, future studies in this area are needed and these should use specific methodological guidelines to generate high-quality health economic studies.

A meta-review of the impact of compression therapy on venous leg ulcer healing.

This meta-review aimed to appraise and synthesise findings from existing systematic reviews that measured the impact of compression therapy on venous leg ulcers healing. We searched five databases to identify potential papers; three authors extracted data, and a fourth author adjudicated the findings. The AMSTAR-2 tool was used for quality appraisal and the certainty of the evidence was appraised using GRADEpro. Data analysis was undertaken using RevMan. We identified 12 systematic reviews published between 1997 and 2021. AMSTAR-2 assessment identified three as high quality, five as moderate quality, and four as low quality. Seven comparisons were reported, with a meta-analysis undertaken for five of these comparisons: compression vs no compression (risk ratio [RR]: 1.55; 95% confidence interval [CI] 1.34-1.78; P < .00001; moderate-certainty evidence); elastic compression vs inelastic compression (RR: 1.02; 95% CI: 0.96-1.08; P < .61 moderate-certainty evidence); four layer vs

Reconstruction Following Talectomy Due to Disseminated Blastomycosis in Immunocompetent Adult Utilizing Total Talus Prosthesis: A Case Report.

Blastomycosis is a rare condition affecting specific endemic areas in North America. Blastomycosis is characterized primarily as a pulmonary disease but can disseminate to affect other organ systems. Osteomyelitis due to disseminated blastomycosis is a rare condition with limited functional reconstructive options in a young adult. We present a rare case with prolonged antifungal therapy and staged reconstruction with a total talus prosthesis.

Efficacy of an Exercise and Nutritional Supplement Program on Physical Performance and Nutritional Status in Older Adults With Mobility Limitations Residing at Senior Living Facilities.

This cluster-randomized trial was designed to determine the efficacy of a 6-month exercise-nutritional supplement program (ENP) on physical function and nutritional status for older adults and the feasibility of implementing this program in a senior living setting. Twenty senior-living facilities were randomized to either a 3 day per week group-based ENP led by a trained facility staff member or a health education program (SAP). Participants (N = 121) completed a short physical performance battery, 400-m walk, handgrip strength test, and mini-nutrition assessment. 25-hydroxyvitamin D [25(OH)D], insulin-like growth-factor 1 (IGF-1), and activity level were also measured. The ENP did not significantly improve physical function or nutritional status compared with the SAP. Compared with baseline, participants in the ENP engaged in 39 min less physical activity per week at 6 months. Several facility characteristics hindered implementation of the ENP. This study highlights the complexity of implementing an evidence-based program in a field setting.

First in vivo evaluation of a flexible self-apposing left atrial appendage closure device in the canine model.

OBJECTIVES: Aimed to evaluate the feasibility of deployment and healing response of a novel transcatheter left atrial appendage (LAA) occlusion device in the canine model BACKGROUND: LAA occlusion is proposed to reduce the risk of stroke in atrial fibrillation patients METHODS: Transseptal puncture and device deployment was guided under fluoroscopy and transesophageal echocardiography (TEE) in five dogs. First, a distal cylindrical bulb occluder was released and secured to the appendage wall with hooks. Subsequently, a proximal sail was unfolded, covering the LAA ostium. Rotational angiography, TEE, and histology outcomes were assessed 30 days following implantation RESULTS: Pre-operative TEE revealed the mean diameter of the LAA ostium to be 17.2 ± 1.6 mm with a depth of 18.5 ± 1.7 mm. The landing zone for the distal bulb was measured to be 12.8 ± 1.3 mm. The mean bulb diameter at implant was 16.8 ± 1.8 mm. Post-operative TEE showed adequate positioning and successful LAA occlusion with all implanted devices. Pericardial effusion requiring pericardiocentesis was seen in one animal following device implantation. At 30 days, TEE revealed full occlusion of all LAA ostia with the exception of a minimal peri-device leak (<3 mm) observed in one animal. No pericardial effusion or device-related thrombus formation was found at termination. Histological analysis confirmed circumferential occlusion of all appendages and complete neointimal coverage on the luminal aspect of the occluder CONCLUSION: The percutaneous delivery of a novel self-positioning LAA occlusion device is feasible and safe in a canine model. At 30 days, all devices displayed complete healing and occlusion of the LAA without any device related adverse events.

Performance, safety, and biocompatibility of a novel PFO closure device in a long-term porcine model.

BACKGROUND: As the catheter-based device closure of the patent foramen ovale (PFO) is expanding, novel devices aim to address the limitations of first-generation occluders (e.g. bulk, erosion, dislodgment). The second-generation device from Encore Medical (Eagan, MN, USA) features an articulating frame structure which allows the device to better conform to atrial anatomies, has lower disc thickness and metal mass/surface area, and is fully retrievable at any point in the procedure. The aim of the study was to evaluate the feasibility and safety of a novel low-profile, fully retrievable, Encore PFO closure device in the animal model. METHODS: Six swine underwent implantation of the novel PFO occluder under fluoroscopic and intra-cardiac echocardiography guidance and survived for 140 days. Interim transthoracic echocardiography (TTE) was conducted on Day 29. Following terminal angiography and TTE at 140 days, the hearts were subjected to gross and histopathologic analysis. RESULTS: All animals were successfully implanted and survived for 140 days. Interim TTE revealed proper device retention with no blood flow across the septum or thrombus in any of the animals. X-ray and pathology results showed preserved implant integrity with no fractures, and complete integration of the devices into the septum with complete re-endothelialization and nearly complete coverage by a mature, relatively thin neoendocardium. No surface fibrin deposition or thrombosis was reported. CONCLUSIONS: In the standard porcine model, device retention and biocompatibility remained favorable following structural and functional device modifications exemplified by the second-generation PFO occluder from Encore Medical, including marked reduction of metal mass.

The cost of cure: Examining objective and subjective financial toxicity in head and neck cancer survivors.

BACKGROUND: Little is documented regarding objective financial metrics and their impact on subjective financial toxicity in head and neck cancer (HNC) survivors. METHODS: In a cross-sectional analysis, 71 survivors with available claims data for HNC-specific out-of-pocket expenses (OOPE) completed a survey including patient-reported, subjective financial toxicity outcome tools: the Comprehensive Score for financial Toxicity (COST) and the Financial Distress Questionnaire (FDQ). RESULTS: Worse COST scores were significantly associated with lower earnings at survey administration (coefficient = 3.79; 95% CI 2.63-4.95; p < 0.001); loss of earnings after diagnosis (coefficient = 6.03; 95% CI 0.53-11.52; p = 0.032); and greater annual OOPE as a proportion of earnings [log10(Annual OOPE:Earnings at survey): coefficient = -5.66; 95% CI -10.28 to -1.04; p = 0.017]. Similar results were found with FDQ. CONCLUSION: Financial toxicity is associated with particular socioeconomic characteristics which, if understood, would assist the development of pre-treatment screening tools to detect at-risk individuals and intervene early in the HNC cancer survivorship trajectory.

Susceptibility of brainstem to kindling and transfer to the forebrain.

PURPOSE: The kindling of seizures with stimulation of brainstem sites has been reported inconsistently in the literature. The characteristics of the kindling observed, involving high intensities of stimulation and immediate onset of generalized tonic-clonic convulsions, raise questions regarding the nature of kindling from these sites. METHODS: We implanted chronic electrodes in either the nucleus reticularis pontis oralis (RPO), mesencephalic reticular formation (MRF), dorsal periaqueductal gray (dPAG), or ventrolateral periaqueductal gray (vlPAG) in male Long-Evans rats, with a recording electrode in the amygdala. Rats received conventional high-frequency kindling stimulation once daily for 30 days. To test for transfer, we kindled the amygdala beginning 7 weeks after the last brainstem kindling trial. RESULTS: Tonic-clonic seizures were evoked by stimulation from all brainstem sites. Seizures were brief and were associated with characteristic low-amplitude high-frequency afterdischarge (AD). Kindling of the dPAG resulted in the development of classic AD and increased AD duration. Prior kindling of the dPAG facilitated subsequent kindling of the amygdala; however, no transfer was observed with prekindling of other brainstem sites. DISCUSSION: The variability in the response to kindling stimulation suggests that certain brainstem sites are resistant to kindling, whereas other sites are more susceptible to kindling but are still relatively resistant in comparison to sites in the forebrain. The development of classic AD in later trials of dPAG stimulation suggests that epileptogenesis can occur even in the initial absence of classic AD when low-amplitude high-frequency AD is present.

Conditioning of interictal behaviours, but not ictal behaviours, seizures or afterdischarge threshold, by kindling of the amygdala in rats.

Rats received 45 pairings of kindling or sham stimulation in distinctive contexts before a conditioned place preference/aversion test, to determine whether the stimulation and seizures were rewarding or punishing. After more pairings, rats received kindling stimulation in each context (switch test). Ictal measures in this test included afterdischarge duration, clonus duration, latency to clonus, class of convulsion and falls. After more pairings, afterdischarge threshold was measured in each context. On every fourth day of pairings, the rats' behaviour in the prestimulation interval was recorded, to measure conditioned anticipatory defensive behaviour. We partially replicated the finding of Barnes et al. (2001, Behav. Neurosci., 115, 1065-1072) that conditioned anticipatory responses and conditioned place aversion are associated with the kindling environment. However, there were no conditioned effects on any ictal measures, including afterdischarge threshold. Our results fail to support the hypothesis that conditioning is a universal mechanism for kindling.

The Use of Battlefield Acupuncture Prior to Botulinum Toxin A Administration: A 2-Patient Case Series.

Background: Botulinum toxin type A injection is a common and safe procedure used for the treatment of overactive muscles through local injection. This toxin inhibits the release of acetylcholine in the neuromuscular junction. The benefits usually last only 3-6 months; thus, repeated injections are often required. The procedure, however, can be difficult if a patient's spasticity and pain prevents access to the muscles for injection or if a patient is anxious. Battlefield Acupuncture (BFA), a technique developed by Richard C. Niemtzow, MD, PhD, MPH, in 2001, is a form of auricular acupuncture using a very specific sequence of gold Aiguille semipermanente needles inserted into the ear. BFA can be very effective for reducing pain quickly, with few potential side-effects. Cases: BFA was performed prior to Botulinum toxin A injections on 2 patients who had either pain limitations or anxiety limitations during prior Botulinum toxin A injections. Case 1 was a 70-year-old male veteran with painful, right upper-extremity spasticity with hand contractures. Case 2 was a 69-year-old male veteran with spasticity who had anxiety related to his fear of needles. Results: Application of BFA prior to Botulinum toxin A injections enabled the 2 patients who either had pain limitations or anxiety limitations to tolerate the toxin injections much better. Conclusions: BFA is a safe and effective treatment option for rapid pain reduction, enabling Botulinum toxin A to be administered more easily to patients who have had pain or anxiety during prior injections.

Individualized hydration plans improve performance outcomes for collegiate athletes engaging in in-season training.

BACKGROUND: Athletes commonly consume insufficient fluid and electrolytes just prior to, or during training and competition. Unlike non-athletes or athletes who do not engage in frequent rigorous and prolonged training sessions, "hard trainers" may require additional sodium and better benefit from a hydration plan tailored to their individual physiology. The purpose of this randomized cross-over study was to determine whether a hydration plan based off of an athlete's sweat rate and sodium loss improves anaerobic and neurocognitive performance during a moderate to hard training session as well as heart rate recovery from this session. METHODS: Collegiate athletes who were injury free and could exercise at ≥ 75% of their maximum heart rate for a minimum of 45 min were recruited for this randomized, cross-over study. After completing a questionnaire assessing hydration habits, participants were randomized either to a prescription hydration plan (PHP), which considered sweat rate and sodium loss or instructed to follow their normal ad libitum hydration habits (NHP) during training. Attention and awareness, as well as lower body anaerobic power (standing long jump) were assessed immediately before and after a moderate to hard training session of ≥ 45 min. Heart rate recovery was also measured. After a washout period of 7 days, the PHP group repeated the training bout with their normal hydration routine, while the NHP group were provided with a PHP plan and were assessed as previously described. RESULTS: Fifteen athletes from three different sports, aged 20 ± 0.85 years, participated in this study. Most participants reported feeling somewhat or very dehydrated after a typical training session. Compared to their NHP, participants following a PHP jumped 4.53 ± 3.80 in. farther, tracked moving objects 0.36 ± 0.60 m/second faster, and exhibited a faster heart rate recovery following a moderate to hard training session of 45-120 min in duration. CONCLUSION: A tailored hydration plan, based on an athlete's fluid and sodium loss has the potential to improve anaerobic power, attention and awareness, and heart rate recovery time.

Evaluating behavioral responses of nesting lesser snow geese to unmanned aircraft surveys.

Unmanned aircraft systems (UAS) are relatively new technologies gaining popularity among wildlife biologists. As with any new tool in wildlife science, operating protocols must be developed through rigorous protocol testing. Few studies have been conducted that quantify the impacts UAS may have on unhabituated individuals in the wild using standard aerial survey protocols. We evaluated impacts of unmanned surveys by measuring UAS-induced behavioral responses during the nesting phase of lesser snow geese (Anser caerulescens caerulescens) in Wapusk National Park, Manitoba, Canada. We conducted surveys with a fixed-wing Trimble UX5 and monitored behavioral changes via discreet surveillance cameras at 25 nests. Days with UAS surveys resulted in decreased resting and increased nest maintenance, low scanning, high scanning, head-cocking and off-nest behaviors when compared to days without UAS surveys. In the group of birds flown over, head-cocking for overhead vigilance was rarely seen prior to launch or after landing (mean estimates 0.03% and 0.02%, respectively) but increased to 0.56% of the time when the aircraft was flying overhead suggesting that birds were able to detect the aircraft during flight. Neither UAS survey altitude nor launch distance alone in this study was strong predictors of nesting behaviors, although our flight altitudes (≥75 m above ground level) were much higher than previously published behavioral studies. Synthesis and applications: The diversity of UAS models makes generalizations on behavioral impacts difficult, and we caution that researchers should design UAS studies with knowledge that some minimal disturbance is likely to occur. We recommend flight designs take potential behavioral impacts into account by increasing survey altitude where data quality requirements permit. Such flight designs should consider a priori knowledge of focal species' behavioral characteristics. Research is needed to determine whether any such disturbance is a result of visual or auditory stimuli.

Skeletal muscle lipid deposition and insulin resistance: effect of dietary fatty acids and exercise.

Mounting evidence indicates that elevated intramyocellular triacylglycerol concentrations are associated with diminished insulin sensitivity in skeletal muscle. This lipid accumulation is most likely due to enhanced fatty acid uptake into the muscle coupled with diminished mitochondrial lipid oxidation. The excess fatty acids are esterified and either stored or metabolized to various molecules that may participate or interfere with normal cellular signaling, particularly insulin-mediated signal transduction, thus altering cellular and, subsequently, whole-body glucose metabolism. Impaired insulin responsiveness, if not managed, can further progress to type 2 diabetes mellitus, an all too common condition. For most of the human population this is avoidable, given that causes of intramyocellular lipid deposition are predominantly lifestyle-mediated. Chronic overconsumption of calories coupled with deleterious intakes of saturated or trans-unsaturated fatty acids inconsistent with the recommendations outlined in the Dietary Guidelines for Americans have been shown to increase the risk of insulin resistance. Furthermore, lack of exercise, which can have a profound effect on skeletal muscle lipid turnover, is implicated in this lipid-induced insulin resistance. This review summarizes the current understanding of the effects of elevated intramyocellular lipids on insulin signaling and how these effects may be altered by varying dietary fat composition and exercise.

Thalamic and hippocampal mechanisms in spatial navigation: a dissociation between brain mechanisms for learning how versus learning where to navigate.

Various studies of hippocampus and medial thalamus (MT) suggest that these brain areas play a crucial, marginal, or no essential role in spatial navigation. These divergent views were examined in experiments using electrolytic Lesions of fimbria-fornix (FF) or radiofrequency or neurotoxic Lesions of MT of rats subsequently trained to find a stable visible (experiment 1) or hidden platform (experiments 2 and 3) in a water maze (WM) pool. Rats with electrolytic Lesions of FF or radiofrequency Lesions of MT were impaired in swimming to a stable visible platform, particularly the MT Lesion Group, suggesting impairment of WM strategies acquisition. Additional Lesioned rats were then tested in a hidden platform version of the WM task. Some rats were given Morris's nonspatial pretraining prior to Lesioning to provide them with training in the required WM behavioral strategies. Nonspatially Pretrained rats with FF Lesions eventually were able to navigate to the hidden platform, but the accuracy of place responding was impaired. This impairment occurred without problems in the motoric control of swimming or the use of WM behavioral strategies, suggesting that these rats had a spatial mapping impairment. Radiofrequency MT Lesions blocked acquisition of WM behavioral strategies by Naive rats throughout 3 days of training, severely impairing performance on all aspects of the hidden platform task. Nonspatially Pretrained rats given the same MT Lesions readily learned the hidden platform location and were indistinguishable from controls throughout spatial training. Rats given neurotoxic Lesions of MT for removal of cells were only mildly impaired and improved considerably during training, suggesting an important role for fibers of passage in WM strategies learning. The results provide a clear dissociation between a role for MT in learning WM behavioral strategies and the hippocampal formation in spatial mapping and memory. This is the first identification of a brain area, MT, that is essential for learning behavioral strategies that by themselves do not constitute the solution to the task but are necessary for the successful use of an innate learning ability: place response learning using spatial mapping.

Recruitment of Mobility Limited Older Adults Into a Facility-Led Exercise-Nutrition Study: The Effect of Social Involvement.

PURPOSE OF THE STUDY: Older adults are among the most challenging population groups to enroll into health-related research. This article describes two methods used by investigators to recruit mobility limited older adults residing at assisted living or senior housing (SH) facilities into a facility-led exercise-nutrition research study. DESIGN AND METHODS: Sedentary older adults were recruited from 42 different assisted living facilities (ALFs) or SH communities. Two different recruitment approaches were used: At 22 sites, investigators conducted heavily advertised informational sessions to recruit participants (Info only). At 20 locations, these sessions were preceded by attendance of a study team member at various activities offered by the facility over the preceding 2 weeks (activity attendance). Population reach, enrollment, personnel cost, and time required to recruit at least five participants at each facility was measured. Reasons for declining participation and withdrawal rate were also measured. RESULTS: Sixty percent more residents elected to be screened for eligibility when study personnel attended an activity offered by the facility. Activity attendance resulted in significantly less time, costs, and participant withdrawals compared with facilities with no activity attendance. IMPLICATIONS: Study team member attendance at activities offered by senior living facilities reduces cost and duration of recruitment and improves study retention. Interventions targeting this demographic are likely to benefit from deliberately building trust and familiarity among the resident population at senior living communities as part of the recruitment process.

Eta Carinae's Thermal X-ray Tail Measured with XMM-Newton and NuSTAR.

The evolved, massive highly eccentric binary system, η Car, underwent a periastron passage in the summer of 2014. We obtained two coordinated X-ray observations with XMM-Newton and NuSTAR during the elevated X-ray flux state and just before the X-ray minimum flux state around this passage. These NuSTAR observations clearly detected X-ray emission associated with η Car extending up to ~50 keV for the first time. The NuSTAR spectrum above 10 keV can be fit with the bremsstrahlung tail from a kT ~6 keV plasma. This temperature is ΔkT ~2 keV higher than those measured from the iron K emission line complex, if the shocked gas is in collisional ionization equilibrium. This result may suggest that the companion star's pre-shock wind velocity is underestimated. The NuSTAR observation near the X-ray minimum state showed a gradual decline in the X-ray emission by 40% at energies above 5 keV in a day, the largest rate of change of the X-ray flux yet observed in individual η Car observations. The column density to the hardest emission component, N H ~1024 H cm-2, marked one of the highest values ever observed for η Car, strongly suggesting the increased obscuration of the wind-wind colliding X-ray emission by the thick primary stellar wind prior to superior conjunction. Neither observation detected the power-law component in the extremely hard band that INTEGRAL and Suzaku observed prior to 2011. The power-law source might have faded before these observations.

Relations between brain pathology and temporal lobe epilepsy.

Temporal lobe epilepsy, the most common type of epilepsy in adult humans, is characterized clinically by the progressive development of spontaneous recurrent seizures of temporal lobe origin and pathologically by hippocampal neuronal loss and mossy fiber sprouting. In this study, we sought to test the prominent hypothesis that neuronal loss and mossy fiber sprouting play a critical role in the genesis and progression of temporal lobe epilepsy. Rats receiving a single kainic acid injection experienced a single sustained episode of epileptic status with massive neuronal loss and mossy fiber sprouting, whereas rats receiving triple kainic acid injections experienced two priming episodes and one sustained episode of epileptic status with no detectable neuronal loss and mossy fiber sprouting. Early in the process of chronic seizure development, primed rats that failed to show detectable neuronal loss and mossy fiber sprouting exhibited a starting date and a frequency of spontaneous recurrent seizures similar to those of nonprimed rats that showed massive neuronal loss and mossy fiber sprouting. However, nonprimed rats displayed significantly prolonged episodes of spontaneous recurrent seizures over the whole process of chronic seizure development and more frequent severe seizures later in the process. Similar results were observed in both Fischer-344 and Wistar rats as well as in the rat pilocarpine preparation of temporal lobe epilepsy. These results fail to reveal a relation between neuronal loss-mossy fiber sprouting and the genesis of temporal lobe epilepsy but suggest that neuronal loss, mossy fiber sprouting, or both contribute to the intensification of chronic seizures.