Surgical management of pelvic organ prolapse.

Despite pelvic organ prolapse being a universal problem experienced in nearly 50% of parous women, the surgical management of vaginal prolapse remains an enigma to many, with wide variation in the rates and types of intervention performed. As part of the 6th International Consultation on Incontinence (ICI) our committee, charged with producing an evidence-based report on the surgical management of prolapse, produced a pathway for the surgical management of prolapse. The 2017 ICI surgical management of prolapse evidence-based pathway will be presented and summarized. Weaknesses of the data and pathway will be discussed and avenues for future research proposed.

Strengthening routine immunization systems to improve global vaccination coverage.

BACKGROUND: Global coverage with the third dose of diphtheria-tetanus-pertussis vaccine among children under 1 year of age stagnated at ∼ 83-84% during 2008-13. SOURCES OF DATA: Annual World Health Organization and UNICEF-derived national vaccination coverage estimates. AREAS OF AGREEMENT: Incomplete vaccination is associated with poor socioeconomic status, lower education, non-use of maternal-child health services, living in conflict-affected areas, missed immunization opportunities and cancelled vaccination sessions. AREAS OF CONTROVERSY: Vaccination platforms must expand to include older ages including the second year of life. Immunization programmes, including eradication and elimination initiatives such as those for polio and measles, must integrate within the broader health system. GROWING POINTS: The Global Vaccine Action Plan (GVAP) 2011-20 is a framework for strengthening immunization systems, emphasizing country ownership, shared responsibility, equity, integration, sustainability and innovation. AREAS TIMELY FOR DEVELOPING RESEARCH: Immunization programmes should identify, monitor and evaluate gaps and interventions within the GVAP framework.

[Clinical treatment of spasticity--spastic movement disorders]. / Klinik der Spastik--spastische Bewegungsstörung.

Spasticity develops as a consequence of damage to the central nervous system (CNS). Clinically, spasticity is characterized by muscle hypertension and exaggerated reflexes and is associated with varying degrees of paresis. Together this results in the syndrome of spastic paresis. Patients suffer from impeded and retarded movement ability. Electrophysiological investigations of functional arm and leg movements (e.g. in walking) show a reduced activation of arm and leg muscles which can be explained by the loss of activating signals from motor brain centers and functional reflex systems. This effect predominates over the increased tendon-reflex activity. The reduced muscle activation caused by paresis is partially compensated by structural alterations of the muscle fibers (e.g. loss of sarcomeres). For this reason a functional improvement mostly cannot be achieved by antispastic medication which targets the deactivation of tendon-reflexes. However, they are useful in immobilized patients. In mobile patients functional improvement can be achieved by functional training which is accompanied by an adapted, i.e. reduced, spastic muscle tone.

Electrosurgical bipolar vessel sealing versus conventional clamping and suturing for vaginal hysterectomy: a randomised controlled trial.

OBJECTIVE: To compare the effects of electrical bipolar vessel sealing and conventional suturing on postoperative pain, recovery, costs and micturition symptoms in women undergoing vaginal hysterectomy. DESIGN: Randomised controlled trial. SETTING: Eight teaching hospitals in the Netherlands. POPULATION: One hundred women scheduled to undergo vaginal hysterectomy for benign conditions excluding pelvic organ prolapse. METHODS: Women were randomised to vessel sealing or conventional surgery. The quality of life related to pelvic floor function was assessed using validated questionnaires before surgery and 6 months after surgery. Pain scores and recovery were assessed using a diary, including daily visual analogue scale scores, starting from the day before surgery until 6 weeks after surgery. MAIN OUTCOME MEASURES: Visual analogue scale pain scores, surgery time, blood loss, complications, quality of life related to pelvic floor function and costs. RESULTS: The evening after surgery, women in the vessel-sealing group reported significantly less pain (5.7 versus 4.5 on a scale of 0-10, P = 0.03), but after that pain scores were similar. Operation duration was shorter for vessel sealing (60 versus 71 minutes, P = 0.05). Blood loss and hospital stay did not differ. We observed no major difference in costs between the two interventions (2903 versus 3102 €, P = 0.26). Changes in micturition and defecation symptoms were not affected by the surgical technique used. CONCLUSION: Using vessel sealing during vaginal hysterectomy resulted in less pain on the first postoperative day, shorter operating time, similar morbidity and similar pelvic floor function. No major differences in costs were found between the two interventions.

Can preoperative urodynamic investigation be omitted in women with stress urinary incontinence? A non-inferiority randomized controlled trial.

AIMS: To assess in women with stress urinary incontinence (SUI) the value of urodynamics prior to treatment. METHODS: We performed a multicenter non-inferiority randomized controlled trial. Women with SUI were randomly allocated to management based on a workup with or without urodynamics. The primary outcome was clinical reduction of complaints as measured with the Urogenital Distress Inventory urinary incontinence subscale (UDI-UI) at 12 months after the onset of treatment. A mean difference in improvement of less than 8 was considered non-inferior. The study was analyzed according to intention-to-treat. RESULTS: The trial was stopped prematurely because of slow recruitment. We randomly allocated 59 women to a strategy with (N = 31) or without (N = 28) urodynamics. The mean difference in improvement on the UDI-UI was 14 in favor of the group without urodynamics (48 SD ± 22 vs. 34 SD ± 22, 95% CI: -28 to -0.26), confirming non-inferiority. Addition of urodynamics did not result in a lower occurrence of de novo overactive bladder complaints compared to a workup without urodynamics (6/31 vs. 1/28; RR 5.4, 95% CI: 0.70-42). In the group allocated to urodynamics, initial surgical management was more often abandoned compared to the group not allocated to urodynamics (5/31 vs. 1/28; RR 4.5, 95% CI: 0.56-36). CONCLUSIONS: In this relatively small study, the omission of urodynamics was not inferior to the use of urodynamics in the preoperative workup of women with SUI. Women with SUI undergoing urodynamics had the risk of a choice for more prudent treatment, which seemed to result in a delay until effective treatment.

Neuronal dysfunction in chronic spinal cord injury.

This review describes the changes of spinal neuronal function that occur after a motor complete spinal cord injury (cSCI) in humans. In healthy subjects, polysynaptic spinal reflex (SR) evoked by non-noxious tibial nerve stimulation consists of an early SR component and rarely a late SR component. Soon after a cSCI, SR and locomotor activity are absent. After spinal shock; however, an early SR component re-appears associated with the recovery of locomotor activity in response to appropriate peripheral afferent input. Clinical signs of spasticity take place in the following months, largely as a result of non-neuronal changes. After around 1 year, the locomotor and SR activity undergo fundamental changes, that is, the electromyographic amplitude in the leg muscles during assisted locomotion exhaust rapidly, accompanied by a shift from early to dominant late SR components. The exhaustion of locomotor activity is also observed in non-ambulatory patients with an incomplete spinal cord injury (SCI). At about 1 year after injury, in most cSCI subjects the neuronal dysfunction is fully established and remains more or less stable in the following years. It is assumed that in chronic SCI, the patient's immobility resulting in a reduced input from supraspinal and peripheral sources leads to a predominance of inhibitory drive within spinal neuronal circuitries underlying locomotor pattern and SR generation. Training of spinal interneuronal circuits including the enhancement of an appropriate afferent input might serve as an intervention to prevent neuronal dysfunction after an SCI.

Recommendations for translation and reliability testing of International Spinal Cord Injury Data Sets.

OBJECTIVE: To provide recommendations regarding translation and reliability testing of International Spinal Cord Injury (SCI) Data Sets. SETTING: The Executive Committee for the International SCI Standards and Data Sets. RECOMMENDATIONS: Translations of any specific International SCI Data Set can be accomplished by translation from the English version into the target language, and be followed by a back-translation into English, to confirm that the original meaning has been preserved. Another approach is to have the initial translation performed by translators who have knowledge of SCI, and afterwards controlled by other person(s) with the same kind of knowledge. The translation process includes both language translation and cultural adaptation, and therefore shall not be made word for word, but will strive to include conceptual equivalence. At a minimum, the inter-rater reliability should be tested by no less than two independent observers, and preferably in multiple countries. Translations must include information on the name, role and background of everyone involved in the translation process, and shall be dated and noted with a version number. CONCLUSION: By following the proposed guidelines, translated data sets should assure comparability of data acquisition across countries and cultures. If the translation process identifies irregularities or misrepresentation in either the original English version or the target language, the working group for the particular International SCI Data Set shall revise the data set accordingly, which may include re-wording of the original English version in order to accomplish a compromise in the content of the data set.

Changes in spinal reflex and locomotor activity after a complete spinal cord injury: a common mechanism?

Locomotor activity and spinal reflexes (SRs) show common features in different mammals, including humans. Here we report the time-course of the development of locomotor activity and SRs after a complete spinal cord injury in humans. SRs evoked by tibial nerve stimulation were studied, as was the leg muscle electromyography activity evoked by mechanically assisted locomotion (Lokomat) in biceps femoris, rectus femoris, tibialis anterior and gastrocenmius medialis. Around 8 weeks after the injury, an early SR component (latency 60-120 ms) appeared, as in healthy subjects, and a well-organized leg muscle activity was present during assisted locomotion. At around 6 months after injury an additional, late reflex component (latency 120-450 ms) appeared, which remained even 15 years after the spinal cord injury. In contrast, the early component had markedly decreased at 18 months after injury. These changes in SR were associated with a loss of electromyography activity and a successively stronger electromyography exhaustion (i.e. decline of electromyography amplitude), when comparing the level of electromyography activity at 2 and 10 min, respectively, during assisted locomotion. These changes in electromyography activity affected mainly the biceps femoris, gastrocenmius medialis and tibialis anterior but less so the rectus femoris. When the amplitude relationship of the early to late SR component was calculated, there was a temporal relationship between the decrease of the early component and an increase of the late component and the degree of exhaustion of locomotor activity. In chronic, severely affected but sensori-motor incomplete spinal cord injury subjects a late SR component, associated with an electromyography exhaustion, was present in subjects who did not regularly perform stepping movements. Our data are consistent with the proposal of a common mechanism underlying the changes in SR activity and locomotor activity after spinal cord injury. These findings should be taken into consideration in the development of novel rehabilitation schemes and programs to facilitate regeneration-inducing therapies in spinal cord injury subjects.

Outcome after incomplete spinal cord injury: central cord versus Brown-Sequard syndrome.

STUDY DESIGN: A retrospective analysis of prospectively collected data. OBJECTIVE: A hemisection of the spinal cord is a frequently used animal model for spinal cord injury (SCI), the corresponding human condition, that is, the Brown-Sequard syndrome (BS), is relatively rare as compared with the central cord syndrome (CC). The time course of neurological deficit, functional recovery, impulse conductivity and rehabilitation length of stay in BS and CC subjects were compared. SETTING: Nine European Spinal Cord Injury Rehabilitation Centers. METHODS: Motor score, walking function, daily life activities, somatosensory evoked potentials and length of stay were evaluated 1 and 6 months after SCI, and were compared between age-matched groups of tetraparetic BS and CC subjects. RESULTS: For all analyzed measures no difference in the time course of improvement was found in 15 matched pairs. CONCLUSION: In contrast to the assumption of a better outcome of subjects with BS, no difference was found between the two incomplete SCI groups. This is of interest with respect to the different potential mechanisms leading to a recovery of functions in these two SCI subgroups.

Coordination of bilateral synchronous and asynchronous hand movements.

This study deals with the coordination of bilateral synchronous and asynchronous hand movements. Cooperative hand movements (e.g. opening a bottle) were shown to be coordinated by a neural coupling, reflected in the appearance of reflex responses in forearm muscles of both sides to unilateral arm nerve stimulation. The mechanical effect of this neural coupling was investigated during bilateral synchronous and asynchronous sinusoidal tracking tasks. During the synchronous tracking task, right handed corrective movements were mirrored by the left hand, suggesting a neural coupling. During the asynchronous tracking task, large non-coupled bilateral corrective hand movements dominated. The findings indicate that during synchronous hand movements an automatic coordination of bilateral hand movements occurs. In contrast, asynchronous tasks require independent hand movements. These appear to be visually guided and voluntarily controlled, leading to larger movement errors and corrections.

Integration of immunization services with other health interventions in the developing world: what works and why? Systematic literature review.

OBJECTIVE: To assess benefits, challenges and characteristics of integrating child and maternal health services with immunization programmes. METHODS: Literature review using journal databases and grey literature. Papers meeting the inclusion criteria were rated for the quality of methodology and relevant information was systematically abstracted. RESULTS: Integrated services were vitamin A supplementation, bednet distribution, deworming tablet distribution, Intermittent Preventive Therapy for infants and referrals for family planning services. Two key characteristics of success were compatibility between interventions and presence of a strong immunization service prior to integration. Overburdened staff, unequal resource allocation and logistical difficulties were mentioned as risks of integration, whereas rapid uptake of the linked intervention and less competition for resources were listed as two key benefits of integration. CONCLUSION: The theoretical strengths of integrating other health services with immunization services remain to be rigorously proved in practice. When additional interventions are carefully selected for compatibility and when they receive adequate support, coverage of these interventions may improve, provided immunization coverage is already high. Evidence for the effectiveness of integration in increasing efficiency of resource use was insufficient and most benefits and challenges were not statistically quantified. More substantive information about the costs of integrated vs. vertical programmes and full documentation of the impacts of integration on immunization services should be published.

Locomotion in Parkinson's disease: neuronal coupling of upper and lower limbs.

Quadrupedal limb coordination during human walking was recently shown to be upregulated during obstacle stepping. An anticipatory activity of coupled cervico-thoraco-lumbar interneuronal circuits is followed by an appropriate executory activation of leg and arm muscles during task performance. This mechanism was studied in subjects with Parkinson's disease and age-matched controls walking on a treadmill with a randomly approaching obstacle. Spinal reflex (SR) responses, evoked by tibial nerve stimulation during mid-stance, were present in all arm and leg muscles investigated. They were larger before execution of obstacle avoidance compared with normal steps in both subject groups. The performance of obstacle stepping was slightly worse in Parkinson's disease than in control subjects. The anticipatory SR in the arm muscles prior to normal and obstacle steps was larger in Parkinson's disease compared with age-matched subjects, but smaller in the tibialis anterior. The arm and leg muscle activation was stronger during obstacle compared with normal swing but did not differ between Parkinson's disease and age-matched subjects. These observations indicate that quadrupedal limb coordination is basically preserved in Parkinson's disease subjects. Our data are consistent with the proposal that in Parkinson's disease subjects the enhanced anticipatory spinal neuronal activity (reflected in the SR) in the arm muscles is required to achieve an appropriate muscle activation for the automatic control of body equilibrium during the performance of the task. In the tibialis anterior the SR is attenuated presumably because of a stronger voluntary (i.e. cortical) control of leg movements.

Obstacle stepping involves spinal anticipatory activity associated with quadrupedal limb coordination.

Obstacle avoidance steps are associated with a facilitation of spinal reflexes in leg muscles. Here we have examined the involvement of both leg and arm muscles. Subjects walking with reduced vision on a treadmill were acoustically informed about an approaching obstacle and received feedback about task performance. Reflex responses evoked by tibial nerve stimulation were observed in all arm and leg muscles examined in this study. They were enhanced before the execution of obstacle avoidance compared with normal steps and showed an exponential adaptation in contralateral arm flexor muscles corresponding to the improvement of task performance. This enhancement was absent when the body was partially supported during the task. During the execution of obstacle steps, electromyographic activity in the arm muscles mimicked the preceding reflex behaviour with respect to enhancement and adaptation. Our results demonstrate an anticipatory quadrupedal limb coordination with an involvement of proximal arm muscles in the acquisition and performance of this precision locomotor task. This is presumably achieved by an up-regulated activity of coupled cervico-thoracal interneuronal circuits.

Vertical perturbations of human gait: organisation and adaptation of leg muscle responses.

During the last several years, evidence has arisen that the neuronal control of human locomotion depends on feedback from load receptors. The aim of the present study was to determine the effects and the course of sudden and unexpected changes in body load (vertical perturbations) on leg muscle activity patterns during walking on a treadmill. Twenty-two healthy subjects walking with 25% body weight support (BWS) were repetitively and randomly loaded to 5% or unloaded to 45% BWS during left mid-stance. At the new level of BWS, the subjects performed 3-11 steps before returning to 25% BWS (base level). EMG activity of upper and lower leg muscles was recorded from both sides. The bilateral leg muscle activity pattern changed following perturbations in the lower leg muscles and the net effect of the vertical perturbations showed onset latencies with a range of 90-105 ms. Body loading enhanced while unloading diminished the magnitude of ipsilateral extensor EMG amplitude, compared to walking at base level. Contralateral leg flexor burst activity was shortened following loading and prolonged following unloading perturbation while flexor EMG amplitude was unchanged. A general decrease in EMG amplitudes occurred during the course of the experiment. This is assumed to be due to adaptation. Only the muscles directly activated by the perturbations did not significantly change EMG amplitude. This is assumed to be due to the required compensation of the perturbations by polysynaptic spinal reflexes released following the perturbations. The findings underline the importance of load receptor input for the control of locomotion.

Standardized assessment of walking capacity after spinal cord injury: the European network approach.

OBJECTIVES: After a spinal cord injury (SCI), walking function is an important outcome measure for rehabilitation and new treatment interventions. The current status of four walking capacity tests that are applied to SCI subjects is presented: the revised walking index for spinal cord injury (WISCI II), the 6 minute walk test (6MinWT), 10 meter walk test (10MWT) and the timed up and go (TUG) test. Then, we investigated which categories of the WISCI II apply to SCI subjects who participated in the European Multicenter Study of Human Spinal Cord Injury (EM-SCI), and the relationship between the 10MWT and the TUG. METHODS: In the EM-SCI, the walking tests were applied 2 weeks and 1, 3, 6 and 12 months after SCI. We identified the WISCI II categories that applied to the EM-SCI subjects at each time point and quantified the relationship between the 10MWT and the TUG using Spearman's correlation coefficients (rho) and linear regression. RESULTS: Five WISCI II categories applied to 71% of the EM-SCI subjects with walking ability, while 11 items applied to 11% of the subjects. The 10MWT correlated excellently with the TUG at each time point (rho>0.80). However, this relationship changed over time. One year after SCI, the time needed to accomplish the TUG was 1.25 times greater than the 10MWT time. DISCUSSION: Some categories of the WISCI II appear to be redundant, while some discriminate to an insufficient degree. In addition, there appear to be ceiling effects, which limit its usefulness. The relationship between the 10MWT and TUG is high, but changes over time. We suggest that, at present, the 10MWT appears to be the best tool to assess walking capacity in SCI subjects. Additional valuable information is provided by assessing the needs for walking aids or personal assistance. To ensure comparability of study results, proposals for standardized instructions are presented.

Cooperative hand movements in tetraplegic spinal cord injury patients: Preserved neural coupling.

OBJECTIVES: To evaluate whether the task-specific neural coupling mechanism during the performance of cooperative hand movements is preserved in tetraplegic subjects. METHODS: Recordings of ipsilateral and contralateral electromyographic reflex responses in activated forearm muscles and bilateral somatosensory potentials (SSEP) to unilateral ulnar nerve stimulations during rest, cooperative and non-cooperative hand movements. RESULTS: Contralateral reflex responses were present in almost all patients during cooperative hand movements but small in amplitude when hand function was severely impaired. Ipsilateral SSEP potentials were enhanced during both cooperative and, in contrast to healthy subjects, also non-cooperative bimanual movements. CONCLUSIONS: Both results indicate a strong involvement of ipsilateral non-damaged cervical tracts and hemispheres in the control of bimanual hand movements in tetraplegic subjects. SIGNIFICANCE: This study on the neural control of bimanual movements in patients suffering a cervical injury allows designing therapeutic approaches for the improvement of hand function that are based on physiological insights.

Automatic gain control of neural coupling during cooperative hand movements.

Cooperative hand movements (e.g. opening a bottle) are controlled by a task-specific neural coupling, reflected in EMG reflex responses contralateral to the stimulation site. In this study the contralateral reflex responses in forearm extensor muscles to ipsilateral ulnar nerve stimulation was analyzed at various resistance and velocities of cooperative hand movements. The size of contralateral reflex responses was closely related to the level of forearm muscle activation required to accomplish the various cooperative hand movement tasks. This indicates an automatic gain control of neural coupling that allows a rapid matching of corrective forces exerted at both sides of an object with the goal 'two hands one action'.

Lumbar spinal stenosis: assessment of cauda equina involvement by electrophysiological recordings.

UNLABELLED: The objective of this study was to investigate the relationship between electrophysiological recordings and clinical as well as radiological findings in patients suggestive to suffer from a lumbar spinal stenosis (LSS). We hypothesise that the electrophysiological recordings, especially SSEP, indicate a lumbar nerve involvement that is complementary to the neurological examination and can provide confirmatory information in less obvious clinical cases. In a prospective cohort study, 54 patients scheduled for surgery due to LSS were enrolled in an unmasked, uncontrolled trial. All patients were assessed by neurological examination, electrophysiological recordings, and magnetic resonance imaging (MRI) of the lumbar spine. The electrophysiological recordings focused on spinal lumbar nerve involvement. RESULTS: About 88% suffered from a multisegmental LSS and 91% of patients respectively complained of chronic lower back pain and/or leg pain for more than 3 months, combined with a restriction in walking distance. The neurological examination revealed only a few patients with sensory and/or motor deficits while 87% of patients showed pathological electrophysiological recordings (abnormal tibial SSEP in 78% of patients, abnormal H-reflex in 52% of patients). CONCLUSIONS: Whereas the clinical examination, even in severe LSS, showed no specific sensory-motor deficit, the electrophysiological recordings indicated that the majority of patients had a neurogenic disorder within the lumbar spine. By the pattern of bilateral pathological tibial SSEP and pathological reflexes associated with normal peripheral nerve conduction, LSS can be separated from a demyelinating polyneuropathy and mono-radiculopathy. The applied electrophysiological recordings, especially SSEP, can confirm a neurogenic claudication due to cauda equina involvement and help to differentiate neurogenic from vascular claudication or musculo-skeletal disorders of the lower limbs. Therefore, electro-physiological recordings provide additional information to the neurological examination when the clinical relevance of a radiologically-suspected LSS needs to be confirmed.

Influence of vestibular and visual stimulation on split-belt walking.

We investigated the influence of vestibular (caloric ear irrigation) and visual (optokinetic) stimulation on slow and fast split-belt walking. The velocity of one belt was fixed (1.5 or 5.0-6.0 km/h) and subjects (N = 8 for vestibular and N = 6 for visual experiments) were asked to adjust the velocity of the other belt to a level at which they perceived the velocity of both the belts as equal. Throughout all experiments, subjects bimanually held on to the space-fixed handles along the treadmill, which provided haptic information on body orientation. While the optokinetic stimulus (displayed on face-mounted virtual reality goggles) had no effect on belt velocity adjustments compared to control trials, cold-water ear irrigation during slow (but not fast) walking effectively influenced belt velocity adjustments in seven of eight subjects. Only two of these subjects decreased the velocity of the ipsilateral belt, consistent with the ipsilateral turning toward the irrigated ear in the Fukuda stepping test. The other five subjects, however, increased the velocity of the ipsilateral belt. A straight-ahead sense mechanism can explain both decreased and increased velocity adjustments. Subjects decrease or increase ipsilateral belt velocity depending on whether the vestibular stimulus is interpreted as an indicator of the straight-ahead direction (decreased velocity) or as an error signal relative to the straight-ahead direction provided by the haptic input from the space-fixed handles along the treadmill (increased velocity). The missing effect during fast walking corroborates the findings by others that the influence of vestibular tone asymmetry on locomotion decreases at higher gait velocities.

In humans Ib facilitation depends on locomotion while suppression of Ib inhibition requires loading.

The role of force feedback during gait is still a matter of debate. From work on cats, it is known that input from Golgi tendon organs from triceps surae does produce Ib facilitation during locomotion instead of autogenic inhibition. In humans, Stephens and Yang (Stephens, M.J., Yang, J.F., 1996. Short latency, non-reciprocal group I inhibition is reduced during the stance phase of walking in humans. Brain Res. 743, 24-31) found that voluntary contraction results in a reduction of Ib inhibition. During gait, they even observed Ib facilitation in a subset of subjects. This raises the question whether the crucial elements involved in these changes are either loading of the leg or locomotion. To examine this question, Ib reflexes were investigated during sitting, lying supine, lying supine with 300 N pressure applied to the foot sole, standing, and a rhythmic loading and unloading task called "reduced" gait. Ib inhibition was obtained during sitting and lying supine. This inhibition was significantly reduced or disappeared during standing and when lying supine but loaded. During the stance phase of "reduced" gait, the inhibition disappeared in eight subjects, and even a facilitation was observed in six subjects. It is concluded that the decrease in Ib inhibition from gastrocnemius to soleus occurs during a load-bearing condition and does not require locomotion. In contrast, Ib facilitation requires locomotion at least in a rudimentary form.