Functional Bandaging in Children with Idiopathic Toe-Walking.

BACKGROUND: Idiopathic toe-walking (ITW) is a persistent gait pattern with no known etiology characterized as premature heel rise or no heel contact. We investigated the effects of functional bandaging in children with ITW on heel contact during stance phase and on gait quality. METHODS: Nineteen children aged 4 to 16 years with ITW and ten age-matched healthy children were included in the study. Elastic adhesive bandages were applied to children with ITW to assist with dorsiflexion. Before bandaging (T0) and immediately (T1) and 1 week (T2) after initial bandaging, the initial contact, loading response, and midstance subphases of gait were analyzed using light pressure sensors and the Edinburgh Visual Gait Score (EVGS). Ten age-matched children with typical gait participated for comparison in T0. The data were analyzed with Friedman and Wilcoxon signed rank tests for within-group comparisons and Mann-Whitney U tests for between-group comparisons. RESULTS: In T0, for the ITW group, no heel contact was observed during stance. In T1, all of the participants achieved heel contact at initial contact and loading response and 56.8% at midstance. In T2, all of the heels continued contact at initial contact and loading response and 54.3% at midstance. The EVGS significantly improved. The Friedman test showed that there were noteworthy improvements between T0-T1 and T0-T2 in video-based observational gait analysis and EVGSs (P < .001), although no difference was found between T1-T2 in video-based observational gait analysis (P = .913) and EVGSs (P = .450). CONCLUSIONS: In children with ITW, dorsiflexion assistive functional bandaging was an effective tool to help achieve heel contact on the ground and improve walking quality for a short period after application. Further studies with longer follow-up and larger sample sizes are required to confirm the long-term therapeutic effects of this promising functional bandaging.

Intraoperative testing of passive and active state mechanics of spastic semitendinosus in conditions involving intermuscular mechanical interactions and gait relevant joint positions.

In cerebral palsy (CP) patients suffering pathological knee joint motion, spastic muscle's passive state forces have not been quantified intraoperatively. Besides, assessment of spastic muscle's active state forces in conditions involving intermuscular mechanical interactions and gait relevant joint positions is lacking. Therefore, the source of flexor forces limiting joint motion remains unclear. The aim was to test the following hypotheses: (i) in both passive and active states, spastic semitendinosus (ST) per se shows its highest forces within gait relevant knee angle (KA) range and (ii) due to intermuscular mechanical interactions, the active state forces elevate. Isometric forces (seven children with CP, GMFCS-II) were measured during surgery over a range of KA from flexion to full extension, at hip angle (HA) = 45° and 20°, in four conditions: (I) passive state, (II) individual stimulation of the ST, simultaneous stimulation of the ST (III) with its synergists, and (IV) also with an antagonist. Gait analyses: intraoperative data for KA = 17-61° (HA = 45°) and KA = 0-33° (HA = 20°) represent the loading response and terminal swing, and mid/terminal stance phases of gait, respectively. Intraoperative tests: Passive forces maximally approximated half of peak force in condition II (HA = 45°). Added muscle activations did increase muscle forces significantly (HA = 45°: on average by 42.0% and 72.5%; HA = 20°: maximally by 131.8% and 123.7%, respectively in conditions III and IV, p < 0.01). In conclusion, intermuscular mechanical interactions yield elevated active state forces, which are well above passive state forces. This indicates that intermuscular mechanical interactions may be a source of high flexor forces in CP.

Intraoperative experiments combined with gait analyses indicate that active state rather than passive dominates the spastic gracilis muscle's joint movement limiting effect in cerebral palsy.

BACKGROUND: In cerebral palsy, spastic muscle's passive forces are considered to be high but have not been assessed directly. Although activated spastic muscle's force-joint angle relations were studied, this was independent of gait relevant joint positions. The aim was to test the following hypotheses intraoperatively: (i) spastic gracilis passive forces are high even in flexed knee positions, (ii) its active state forces attain high amplitudes within the gait relevant knee angle range, and (iii) increase with added activations of other muscles. METHODS: Isometric forces (seven children with cerebral palsy, gross motor function classification score = II) were measured during surgery from knee flexion to full extension, at hip angles of 45° and 20° and in four conditions: (I) passive state, after gracilis was stimulated (II) alone, (III) simultaneously with its synergists, and (IV) also with an antagonist. FINDINGS: Directly measured peak passive force of spastic gracilis was only a certain fraction of the peak active state forces (maximally 26%) measured in condition II. Conditions III and IV caused gracilis forces to increase (for hip angle = 45°, by 32.8% and 71.9%, and for hip angle = 20°, by 24.5% and 45.1%, respectively). Gait analyses indicated that intraoperative data for knee angles 61-17° and 33-0° (for hip angles 45° and 20°, respectively) are particularly relevant, where active state force approximates its peak values. INTERPRETATION: Active state muscular mechanics, rather than passive, of spastic gracilis present a capacity to limit joint movement. The findings can be highly relevant for diagnosis and orthopaedic surgery in individuals with cerebral palsy.

Does clinically measured ankle plantar flexor muscle strength or weakness correlate with walking performance in healthy individuals?

OBJECTIVE: Muscle strength is usually measured using isometric hand-held dynamometers (HHDs) in the clinic. However, during functional activities, the muscle acts more dynamically. The aim of this study was to investigate the relation between clinically measured plantar flexor (PF) muscle strength (PFMS) and laboratory measurements of peak ankle plantar flexion power generation (APFPG), peak ankle moment (PAM), peak plantar flexion velocity (PFV) and mean gait velocity in healthy participants. METHODS: The maximum PFMS on non-dominant sides in 18 able-bodied persons 23.88 (SD 3.55 years) was measured before (Pre-S) and after a stretching (Post-S) procedure (135 sec. × 13 rep. with 5 sec. rest) by using a HHD. The stretching procedure was used to generate temporary PF muscle weakness. Gait analysis was carried out for Pre-S and Post-S conditions. Normalized (by weight and height) and non-normalized HHD scores and differences for both conditions were correlated by Pearson correlation coefficient calculations (p< 0.05). RESULTS: Reduced PFMS (%23, p< 0.001) in Post-S, according to the HHD scores, has only a weak correlation with APFPG (r> 0.3, p< 0.5). Gait velocity was found to be strongly correlated with APFPG only in the Post-S condition (r= 0.68, p< 0.002). HHD scores and PAM were moderately correlated with the non-normalized Post-S condition (r= 0.44, p= 0.70) and strongly correlated with the non-normalized Pre-S condition (r= 0.62, p< 0.01). DISCUSSION: HHD scores of plantar flexor muscles give very limited information about the PF performance during walking in healthy individuals. Simple normalization did not improve the relations. Clinically measured isometric muscle strength and muscle weakness have only moderate strengths for establishing a treatment protocol and for predicting performance during walking in neurologically intact individuals.

Weakening iliopsoas muscle in healthy adults may induce stiff knee pattern.

OBJECTIVE: The goal of the present study was to investigate the relationship between iliopsoas muscle group weakness and related hip joint velocity reduction and stiff-knee gait (SKG) during walking in healthy individuals. METHODS: A load of 5% of each individual's body weight was placed on non-dominant thigh of 15 neurologically intact, able-bodied participants (average age: 22.4 ± 0.81 years). For 33 min (135 s × 13 repetitions × 5 s rest), a passive stretch (PS) was applied with the load in place until hip flexor muscle strength dropped from 5/5 to 3+/5 according to manual muscle test. All participants underwent gait analysis before and after PS to compare sagittal plane hip, knee, and ankle kinematics and kinetics and temporo-spatial parameters. Paired t-test was used to compare pre- and post-stretch findings and Pearson correlation coefficient (r) was calculated to determine strength of correlation between SKG parameters and gait parameters of interest (p < 0.05). RESULTS: Reduced hip flexion velocity (mean: 21.5%; p = 0.005) was a contributor to SKG, decreasing peak knee flexion (PKF) (-20%; p = 0.0008), total knee range (-18.9%; p = 0.003), and range of knee flexion between toe-off and PKF (-26.7%; p = 0.001), and shortening duration between toe-off to PKF (-16.3%; p = 0.0005). CONCLUSION: These findings verify that any treatment protocol that slows hip flexion during gait by weakening iliopsoas muscle may have great potential to produce SKG pattern combined with reduced gait velocity.

Plantar flexor muscle weakness may cause stiff-knee gait.

AIM: The iterative simulation studies proclaim that plantar flexor (PF) muscle weakness is one of the contributors of stiff knee gait (SKG), although, whether isolated PF weakness generates SKG has not been validated in able-bodied people or individuals with neuromuscular disorders. The aim of the study was to investigate the effects of isolated PF muscle weakness on knee flexion velocity and SKG in healthy individuals. METHOD: Twenty able-bodied young adults (23±3 years) participated in this study. Passive stretch (PS) protocol was applied until the PF muscle strength dropped 33.1% according to the hand-held dynamometric measurement. Seven additional age-matched able-bodies were compared with participants' to discriminate the influence of slow-walking. All participants underwent 3D gait analysis before and after the PS. Peak knee flexion angle, range of knee flexion between toe-off and peak knee flexion, total range of knee-flexion, and time of peak knee flexion in swing were selected to describe SKG pattern. RESULTS: After PS, the reduction of plantar flexor muscle strength (33.14%) caused knee flexion velocity drop at toe-off (p=0.008) and developed SKG pattern by decreasing peak knee flexion (p=0.0001), range of knee flexion in early swing (p=0.006), and total knee flexion range (p=0.002). These parameters were significantly correlated with decreased PF velocity at toe-off (p=0.015, p=0.0001, p=0.005, respectively). The time of peak knee flexion was not significantly different between before and after stretch conditions (p=0.130). CONCLUSIONS: These findings verified that plantar flexor weakness cause SKG pattern by completing three of SKG parameters. Any treatment protocol that weakens the plantar flexor muscle might impact the SKG pattern.

Femoral derotation osteotomy with multi-level soft tissue procedures in children with cerebral palsy: Does it improve gait quality?

PURPOSE: Poor motor control and delayed thumb function and a delay in walking are the main factors which retard the natural decrease of the femoral anteversion (FA) with age. In addition, cerebral palsy (CP) patients usually have muscular imbalance around the hip as well as muscle contractures, both of which are main factors accounting for the increased FA which is commonly present in CP patients. The purpose of this retrospective study was to analyze the mid-term results of femoral derotational osteotomy (FDO) on the clinical findings, temporospatial and kinematic parameters of gait in children with CP. METHODS: We performed a retrospective review of all patients diagnosed with CP and increased FA who were treated with FDO with multi-level soft tissue surgeries at a single institution between 1992 and 2011. FA assessment was done in the prone position, and internal (IR) and external rotation (ER) of the hip was measured in the absence of pelvis rotation. Surgical procedures were performed on the basis of both clinical findings and video analysis. Clinical findings, Edinburgh Visual Gait Scores (EVGS) and results from three-dimensional gait analysis were analyzed preoperatively and last follow-up. RESULTS: A total of 93 patients with 175 affected extremities were included in this review. Mean age was 6.2 ± 3.1 (standard deviation) at initial surgery. The average length of the follow-up period was 6.3 ± 3.7 years. At the last follow-up, the postoperative hip IR had significantly decreased (73.9° vs. 46.2°; p < 0.0001), the hip ER had significantly improved (23.8° vs. 37°; p < 0.0001) and the popliteal angle had significantly decreased (64.2° vs. 55.8°; p < 0.0001). The total EVGS showed significant improvement after FDO (35.2 ± 6.4 vs. 22.5 ± 6.1; p < 0.001). Computed gait analysis showed significant improvement in the foot progression angle (FPA; 8.1° vs. -16.9°; p = 0.005) and hip rotation (-13.9° vs. 5.7°; p = 0.01) at the last follow-up. Stance time was improved (60.2 vs. 65.1 %; p = 0.02) and swing time was decreased (39.9 vs. 35.2 %; p = 0.03). Double support time and cadence were both decreased (p = 0.032 and p = 0.01). CONCLUSIONS: Our data suggest that the FDO is an appropriate treatment strategy for the correction of FA and associated in-toeing gait in children with CP. Improvements in clinical and kinematic parameters were observed in both groups after FDO with multi-level soft tissue release. The most prominent effects of FDO were on transverse plane hip rotation and FPA.

Contributors of stiff knee gait pattern for able bodies: Hip and knee velocity reduction and tiptoe gait.

UNLABELLED: Stiff-knee gait (SKG) is commonly encountered in clinic; many other gait abnormalities are seen together with this pathology. Simulation studies revealed that diminished knee flexion (KF) velocity and increased knee extension moments are strongly related with SKG. This study aimed to determine whether tiptoe walking and hip-knee flexion velocity reduction causes SKG pattern in healthy participants. METHODS: Fourteen able-bodied adults' (Av. age: 23.0±2.4) heel-toe (N), tiptoe (T), and walking with 5% body weight on both shanks (W) were analyzed using 3D gait analysis by controlling cadence (90step/min). Repeated measures analysis of variance was used followed by Bonferroni correction (p<0.05). RESULTS: Walking velocity and cadence were similar for all conditions (p>0.1). Maximum hip flexion velocity was reduced (15%) significantly as well as the KF velocity (10%) in the W condition. The peak knee flexion (PKF) (8.3% for T, 8.6% for W) and total knee range (10.9% for T, 13% for W) were reduced for both conditions (p<0.05). The knee range in early swing and the duration between toe-off and PKF were reduced only in the weighted-leg condition (p<0.05). CONCLUSIONS: Slow hip and knee flexion diminished all SKG parameters except timing of PKF. Tiptoe gait itself generated a borderline SKG pattern by reducing the PKF and total knee range. By considering that tiptoe gait and SKG commonly seen together, some of the SKG contributors can be treated by normalizing the ankle motion in the stance and increasing the hip-knee flexion velocity by rigorously planned muscle lengthening procedures and effective strengthening exercises.

Cell death and survival mechanisms are concomitantly active in the hippocampus of patients with mesial temporal sclerosis.

Mesial temporal lobe epilepsy (MTLE) is often characterized pathologically by severe neuronal loss in the hippocampus. In this study we investigated concomitant appearance of the pro-apoptotic and anti-apoptotic mechanisms in injured neurons in epileptic human hippocampi. Postsurgical hippocampal specimens of randomly selected 25 patients with MTLE were studied with standard immunohistochemical techniques to detect the below markers of cell death pathways: truncated Bid - tBid, mitochondrial translocation of Bax (markers of pro-apoptotic Bcl-2 protein activation) and nuclear translocation of AIF (caspase-independent pro-apoptotic pathway). For cell survival pathways, we investigated the expression of c-IAP1, c-IAP2 and Hsp70 (heat shock protein). Immunopositive cells were counted in different regions of the hippocampus. We also verified IAP (inhibitor of apoptosis) expression with Western blotting. The results were statistically compared with hippocampi from non-epileptic autopsy controls. In patient hippocampi, Bax and tBid immunoreactivity were significantly increased and Bax staining was consistent with mitochondrial translocation. AIF was not translocated to the nucleus. c-IAP1 and c-IAP2 were barely detectable in control hippocampi, whereas their expression was dramatically increased in the patients in all hippocampal subfields. Interestingly, these neurons were also positively co-labeled for tBid and translocated Bax. Hsp70 immunreactivity was significantly increased in all surviving neurons in patient hippocampi whereas degenerating neurons failed to express Hsp70. Our findings are consistent with both pro-apoptotic and anti-apoptotic mechanisms being active within the same hippocampal neurons of patients with MTLE, illustrating an ongoing struggle between cell death and survival mechanisms in neurons under stress.

Effects of unilateral backpack carriage on biomechanics of gait in adolescents: a kinematic analysis.

OBJECTIVE: The aim of this study was to analyze the biomechanical alterations during unilateral backpack carriage in adolescents and to compare the kinematic parameters of the loaded and unloaded sides. METHODS: Twenty adolescents (mean age: 13 ± 1.2 years) were assessed during walking with no backpack and with a backpack on one shoulder. The kinematic parameters of a gait at a self-selected speed were analyzed using motion analysis. Specific kinematic peak points were compared between asymmetric walking; unloaded, loaded side and mean of unloaded walking. RESULTS: Peak ankle dorsal flexion, mean knee varum angle, peak value of hip extension and range of pelvic rotation decreased; and knee flexion at initial contact, hip adduction angle, mean pelvic anterior tilt and mean pelvic obliquity increased on the loaded side relative to the unloaded side and unloaded walking. Decreased maximum hip extension during late stance, increased hip adduction, elevated pelvis and increased anterior pelvic tilt were seen on the loaded side and the pelvis was lowered, ankle dorsal flexion increased and the hip was abducted on the unloaded side as a counter effect. CONCLUSION: Both the unloaded and loaded sides were affected by asymmetrical backpack carriage. The biomechanical alterations seen in asymmetrical backpack carriage may put some extra load on the lumbar vertebral joints and altered frontal knee biomechanics contribute to low back pain and pathologies in the knee joint.

Primitive neuroectodermal tumors of the central nervous system associated with genetic and metabolic defects.

AIM: To evaluate the genetic, congenital and metabolic disorders which were detected concurrently with primitive neuroectodermal tumors (PNET) of the central nervous system in children. METHODS: Medical records of 1030 children who were admitted to our department with diagnosis of brain tumor between 1975 and 2005 were reviewed retrospectively. Medulloblastoma and supratentorial PNETs were detected in 289 patients. They were reviewed for associated metabolic conditions, genetic and congenital defects. RESULTS: One of the following conditions were detected in 10 patients with medulloblastoma and supratentorial PNETs: Neurofibromatosis type 1, Gorlin syndrome, juvenile polyposis coli, cancer prone syndrome of total premature chromatid separation and Fanconi anemia, bilateral retinoblastoma, L-2-hydroxyglutaric aciduria, Gilbert syndrome, gray platelet syndrome, cleft lip-palate and left renal agenesis. In the patients with multiple malignant diseases, cancer prone syndrome of total premature chromatid separation and Fanconi anemia, Gorlin syndrome and juvenile polyposis coli were diagnosed after diagnosis of the malignant tumors. Medulloblastoma was the first manifestation in the case with Gorlin syndrome. In case with retinoblastoma, pineal PNET was detected 2 months after diagnosis of retinoblastoma. Cleft lip-palate and L-2-Hydroxyglutaric aciduria were detected previously in the patients before their brain tumors whereas Gray platelet, Gilbert syndrome and left renal agenesis were diagnosed during treatment of medulloblastoma. CONCLUSION: Associated genetic, metabolic and congenital conditions were detected in 3.5% of the cases. Thus the patients with PNET should be followed for these defects.

Myelomeningocele (open spina bifida) - surgical management.

Myelomeningocele has been recognized since ancient times although written descriptions began not before the 17th century. Among all serious congenital malformations, myelomeningocele is unique that is has a steady and considerable prevalence while being compatible with life. It has a dismal prognosis when left untreated where virtually all die within the first year while aggressive treatment have a profound effect on survival and quality of life. Effective surgical treatment became possible parallel to the treatment of hydrocephalus in the late 1950s. Advent of the shunt systems undoubtedly changed the morbidity and mortality rates due to associated hydrocephalus. Aggressive and effective treatment improved survival rates but also those suffering physical and mental disabilities have increased as well. Ethical and socioeconomic concerns have led to proposal for selective treatment criteria which have raised arguments on medical and ethico-legal rounds. After the swing of the pendulum between early treatment in all affected children and selective treatment of those who fulfilled the criteria for good prognosis, early myelomeningocele repair is practiced widely unless the infant is critically ill.Incidence of myelomeningocele has been decreasing especially in the Western world, partly due to prenatal diagnosis and elective terminations, dietary folate supplementation. Still, it is the most common central nervous system malformation and one of the leading causes of paraplegia, worldwide. Unfortunately, gains in the management of myelomeningocele have been mainly on antenatal diagnosis and prevention while efforts on understanding its cause, mechanisms involved are still tentative. Concerning the surgical management, no revolutionary modification improving outcome has been introduced unlike other fields of neurosurgery.Medical management of a child with myelomeningocele requires a lifelong effort of several disciplines including urology, orthopedics physical and social therapy besides neurosurgery. The initial and probably the most crucial step begin with proper repair of the lesion. The aim of surgery, with its simplest definition should be towards maintaining the medical condition of the newborn. In other words, consequences of an open spinal cord segment with associated malformations have to be avoided with appropriate measures. Comparable to the surgical treatment of any congenital malformation, myelomeningocele repair consist of reversing the failed steps of normal neural tube closure. This requires a thorough understanding of the normal and abnormal embryological sequence of events in formation of the spinal cord. Although the purpose of this chapter is to describe the basic concepts and technique of myelomeningocele repair, contemporary information and progress on epidemiology, and etiology and embryology is presented with discussion of controversial issues regarding the selection process, optimal time for surgery and technical modifications.

[Treatment approaches to flexion contractures of the knee]. / Diz fleksiyon kontraktüründe tedavi yaklasimlari.

The knee is the most affected joint in children with cerebral palsy. Flexion contracture of the knee is the cause of crouch gait pattern, instability in stance phase of gait, and difficulties during standing and sitting, and for daily living activities. It may also cause patella alta, degeneration of the patellofemoral joint, and stress fractures of the patella and tibial tubercle in young adults. Children with cerebral palsy may even give up walking due to its high energy demand in the adult period. The purpose of this article is to review the causes of the knee flexion contractures, clinical and radiological evaluations, and treatment principles in children with cerebral palsy. The biomechanical reasons of knee flexion deformity are discussed in detail in the light of previous studies and gait analysis data.

L-2-hydroxyglutaric aciduria and brain tumors in children with mutations in the L2HGDH gene: neuroimaging findings.

L-2-Hydroxyglutaric aciduria (L-2-HGA, MIM 236792) is a rare autosomal recessive neurodegenerative disorder characterized by psychomotor delay, cerebellar and extrapyramidal signs and subcortical leukoencephalopathy with basal ganglia and dentate nuclei involvement. Mutations in the gene L2HGDH ( C14ORF160/DURANIN/) have been identified as causative for L-2-HGA. A feature disproportionally associated with L-2-HGA is the development of malignant brain tumors. In our cohort of 40 patients with L-2-HGA, two developed medulloblastoma and glioblastoma multiforme during the course of the disease. Two missense mutations in two patients were identified in the L2HGDH gene in exon 3 (c.292C-->T) and in exon 7 (c.887T-->A). Both mutations were present in the homozygous state. Serial MR imaging findings as well as MR spectroscopy imaging is reported in a patient who developed glioblastoma multiforme.

Three-dimensional knee model: constrained by isometric ligament bundles and experimentally obtained tibio-femoral contacts.

The purpose of this study is to investigate the effect of anterior portion of anterior cruciate ligament, posterior cruciate ligament, anterior and deep portions of medial collateral ligament and the tibio-femoral articular contacts on passive knee motion. A well-accepted reference model for a normal tibio-femoral joint is reconstructed from the literature. The proposed three-dimensional dynamic tibio-femoral model includes the isometric fascicles, ligament bundles and irregularly shaped medial-lateral contact surfaces. With the approach we aim to analyze bone shape and ligament related abnormalities of knee kinematics. The rotations, translations and the contact forces during passive knee flexion were compared against a reference model and the results were found in close accordance. This study demonstrated that isometric ligament bundles play an important role in understanding the femur shape from contact points on tibia. Femoral condyles are not necessarily spherical. The surgical treatments should consider both ligament bundle lengths and contact surface geometries to achieve a problem free knee kinematics after a knee surgery.

Effects of back loading on the biomechanics of sit-to-stand motion in healthy children.

The goal of the present study was to determine the thus far unstudied effects of back loading on the kinematics and kinetics of sit-to-stand (STS) motion in healthy children. Fifteen children (8 boys, 7 girls, mean age 9.6 years, SD 1.2 years) were tested with no back load and with a back load of 10% and 20% of body weight, respectively. A motion analysis system was used with six infrared cameras and two force plates. Total STS duration did not change; however, differential effects were shown for the durations of its phases. Back loading increased ankle dorsiflexion yielding a greater maximal dorsiflexion angle. Effects on the knee angle were limited except for a significant decrease in final knee flexion. Initial and maximal hip flexion increased but final hip angle did not change. Initial backward pelvic tilt decreased and a shift to forward pelvic tilt occurred at an earlier stage of STS motion. Back loading affected trunk motion: maximal and final forward shoulder tilt increased. Maximal ankle and knee moments and powers increased; however, hip joint kinetics was not affected significantly. Therefore, while maintaining the general pattern of STS motion, participants showed selectively significant adjustments to back loading during its different phases. The main kinematic adjustments were increased trunk flexion and greater ankle dorsiflexion, while the major kinetic adjustment was increased knee extension moment. Increased back loading yielded more pronounced effects, primarily in the ankle. In sum, back loading substantially affected the biomechanics of STS motion even for the lower load level studied. This finding may be of clinical relevance for musculoskeletal disorders, but this needs to be examined.

Interaction of ligament bundles and articular contacts for the simulation of passive knee flexion.

The purpose of this study is to investigate the effects of anterior bundle of ACL (aACL), anterior portion of PCL (aPCL), anterior and deep portions of MCL (aMCL, dMCL) and the tibio-femoral articular contacts on to passive knee motion. A three-dimensional simplistic anatomical dynamic model, based on the literature was used as a reference. This reference model attaches the bundles of the ligaments on medial and the lateral spherical condyles of the femur and tibial plateau giving us a representation close enough to a normal natural tibio-femoral joint, but does not allow to study abnormalities of the knee kinematics due to the assumptions of the femur shape. The proposed three-dimensional dynamic tibio-femoral model, however includes the isometric fascicles, aACL, aPCL, aMCL, dMCL, and irregularly shaped medial-lateral contact surfaces. The approach taken in this model is capable of ligament and bone surface modifications that will enable us to analyze bone shape and ligament related abnormalities of knee kinematics.

Serial analysis of gene expression in the hippocampus of patients with mesial temporal lobe epilepsy.

Hippocampal sclerosis constitutes the most frequent neuropathological finding in patients with medically intractable mesial temporal lobe epilepsy. Serial analysis of gene expression was used to get a global view of the gene profile in human hippocampus in control condition and in epileptic condition associated with hippocampal sclerosis. Libraries were generated from control hippocampus, obtained by rapid autopsy, and from hippocampal surgical specimens of patients with mesial temporal lobe epilepsy and the classical pattern of hippocampal sclerosis. More than 50,000 tags were analyzed (28,282, control hippocampus; 25,953, hippocampal sclerosis) resulting in 9206 (control hippocampus) and 9599 (hippocampal sclerosis) unique tags (genes), each representing a specific mRNA transcript. Comparison of the two libraries resulted in the identification of 143 transcripts that were differentially expressed. These genes belong to a variety of functional classes, including basic metabolism, transcription regulation, protein synthesis and degradation, signal transduction, structural proteins, regeneration and synaptic plasticity and genes of unknown identity of function. The database generated by this study provides an extensive inventory of genes expressed in human control hippocampus, identifies new high-abundant genes associated with altered hippocampal morphology in patients with mesial temporal lobe epilepsy and serves as a reference for future studies aimed at detecting hippocampal transcriptional responses under various pathological conditions.

Psychiatric morbidity, quality of life, and disability in mesial temporal lobe epilepsy patients before and after anterior temporal lobectomy.

Considerable interest has been focused on the psychiatric complications of medically refractory temporal lobe epilepsy (TLE) before and after epilepsy surgery. The aim of the present study was to evaluate the psychiatric status, quality of life, and level of disability in medically refractory mesial temporal lobe epilepsy (MTLE) patients, a homogenous subgroup of patients with TLE, before and after anterior temporal lobectomy (ATL). The study population consisted of 22 patients with medically refractory MTLE who were candidates for ATL. Patients were examined before surgery as well as in the third and sixth months of the postoperative period. Psychiatric diagnosis was determined by using SCID-I. To rate the severity of psychiatric disorders, BPRS, HDRS, and HARS were employed on each visit. WHO-DAS-II and WHOQOL-BREF were used to determine the level of disability and quality of life. Preoperatively, six patients had a psychiatric diagnosis. Three months after surgery, six of the patients had psychiatric diagnoses. Five of these six patients had not been previously diagnosed. There was no significant difference between preoperative and postoperative follow-up evaluations in terms of HDRS, HARS, and BPRS ratings. With respect to the total scores and domains of WHO-DAS-II, the change in pre- and postoperative evaluations was statistically significant only for the social life attendance domain. There was no significant difference in the mean scores on the WHOQOL-BREF domains or on the first question about general evaluation of quality of life. For the second question on the level of satisfaction with health, the difference between the three ratings was statistically significant. Preoperative and postoperative rates of psychiatric disorders in our sample were low. While social phobia was frequently seen preoperatively, the postoperative period was spearheaded by major depressive disorder. The decrease in disability in attendance to social life and improvement in the quality of health were in concordance with the literature, indicating the positive results of surgical treatment of epilepsy on quality of life. This study suggests that surgical intervention might be one of the causes of postoperative psychiatric disorders in patients with MTLE.

Effect of hydrophilic coating on microorganism colonization in silicone tubing.

BACKGROUND: Shunt infections are one of the major causes of mortality and morbidity of patients with hydrocephalus. The aim of this research is to compare the bacterial colonization characteristics of a regular silicone elastomer shunt material coated with polyvinylpyrrolidone and dimethylpolysiloxane (silicone). METHOD: Regular coated shunt materials were compared by in-vivo and in-vitro methods. In the in-vitro experiment, silicone and coated material immersed and not immersed in vancomycin solution was treated with a certain concentration of Staphylococcus epidermidis. In the in-vivo study, silicone and coated material specimens were treated with Staphylococcus epidermidis and they were stereotactically placed in the lateral ventricles of the rats. One week after the inoculation, shunt pieces were removed and the colonies were counted by using a scanning electron microscope. FINDINGS: There was a statistically significant difference of colonization in the in-vitro groups in coated material vs. silicone, coated material vs. vancomycin treated silicone, vancomycin treated coated material vs. silicone, vancomycin treated coated material vs. vancomycin treated silicone. There was no statistically significant difference for colonization in in-vitro groups of coated material and vancomycin treated coated material. With in-vivo experiments we can say that, coated material catheters are superior than the silicone catheters in respect to colonization but after the bacterial colonization has occurred, the amount of colonization did not differ. INTERPRETATION: Coated material catheters are superior to silicone catheters and they prevent bacterial colonization in some respect.