Dysfunctional Movement Research Articles

Relationship Between Functional Movement Patterns And Performance Between Division Iii Women’S Soccer And Volleyball

The functional movement screen (FMS) has been shown to be a valid and reliable tool for assessing fundamental movement patterns. While dysfunctional movement patterns have been shown to increase an athlete’s risk for injury, it is unclear what influence they have on athletic performance. PURPOSE: To examine the relationship between FMS testing and sport specific performance tests for Division III (D3) women’s soccer (SOC) and volleyball (VB), as well as compare performance differences between sports. METHODS: 17 SOC (19+0.3 yo) and 13 VB (19.2+ 0.4 yo) players consented to the study and performed pre-season FMS, a 3-site % body fat (%BF) skinfold analysis, and performance testing. Performance testing included 1-min push-up test, Vertical Jump (VJ) test, Illinois Agility (IA) test, and 12x 20 m repeated sprint test (RST) with 20 sec recovery each sprint. 1-way ANOVA was run to compare differences between sports. Pearson correlations were run to examine the relationships between the FMS and performance measures. All data were expressed as mean + se, and all significance levels were set at α=0.05. RESULTS: Players were of similar height but VB players weighed (76.5 + 2.1 kg) significantly (p<0.0001) more than SOC (63.0 + 1.9 kg). %BF was significantly higher (p=0.0022) for VB (28.6 + 1.4% vs 22.2 + 1.3%), which resulted 5.8 kg greater fat free mass (FFM) for VB (p=0.0001). There were no significant differences in any of the performance measures, including VJ. However, the estimated power output for the VJ was significantly higher (p<0.0001) for VB (3888.1 + 105.8 W) than SOC (3094.6 + 92.6 W). The FMS lunge score was moderately related to both mean (r= -0.46, p= 0.0140) and best (r= -0.41, p= 0.0295) RST time (sec). The total FMS score showed a similar relationship for mean (r= -0.42, p= 0.00251) and best (r= -0.50, p= 0.0066) RST. %BF appears to negatively impact FMS scores (r= -0.36, p=0.0447). CONCLUSIONS: In a cohort of D3 women athletes, there appears to be no differences between athletes in common skill-related performance measures, despite significant differences in %BF and FFM. The inverse relationship between %BF and lower FMS scores suggests that reducing body fat could improve performance measures. The FMS may be useful in identifying potential skill-related performance decrements in similar athletes.

Changes In Functional Movement Patterns And Injuries For In-season Division III Women.

Athletes achieve high-level performances utilizing dysfunctional movement patterns that can increase an athlete’s injury risk. Little is known about how movement patterns change during the competitive season with or without corrective intervention. PURPOSE: To compare the functional movement patterns of Division III (D3) women’s (S) and volleyball (V), and how those movement patterns are affected during a single competitive season. METHODS: 17 S (19+0.3 yo) and 14 V (19.2+ 0.4 yo) D3 players volunteered for the study. Injury history was obtained before the season and then after. FMS testing and 3-site % body fat (%BF) skinfold analysis were performed 1-wk prior to in-season, twice in-season, and 1-wk post season. After pre-season FMS, teams were split into matched pairs and allocated to either a corrective exercise (CE) or sham (SH) exercise group. CE groups were prescribed exercises to improve specific FMS issues after the first in-season re-test. Repeated measures ANOVA with post-hoc Tukey were run comparing differences within and between sports at each time period. Pearson correlations were run to examine the relationships between the FMS and %BF. All data were expressed as mean + se, and all significance levels were set at α=0.05. RESULTS: Pre-season FMS showed that S players scored significantly higher (Tukey p < 0.05) in Squat (Sq) 1.7 + 0.2 vs 1.2 + 0.2, Hurdle (Hd) 1.8 + 0.2 vs 1.1 + 0.18, and leg raise (ASLR) 2.59 + 0.14 vs 1.8 + 0.16 scores, but lower in Lunge (Ln) 1.4 + 0.2 vs 2.1 + 0.2 and Push-up (PU) 1.3 + 0.1 vs 1.9 + 0.2. Total scores (S 12.9 + 0.6 vs V 12.3 + 0.6) did not differ. After 4-wk, S improved (p < 0.05) Ln 2.4 + 0.2, PU 2.2 + 0.1, and Total scores 15.5 + 0.5, while V scores failed to improve. %BF appears to negatively impact FMS scores (r= -0.36, p=0.0447). Injury rates were not available, but S reported engaging in a structured strength training program. CONCLUSION: There appears to be significant disparities in FMS scores among D3 women. Initial in-season 4-wk improvement was only seen in S players with all scores trending higher. A plausible conclusion is that the structured strength training program by S, compared to no training for V, accounted for these differences. The negative relationship between %BF and lower FMS scores supports prior research that increased BF limits movement quality and increases risk for injury.

Western Faculty Profile: Dr. Jessica Grahn

Dr. Jessica Grahn is an Associate Professor in the Brain and Mind Institute and the Department of Psychology at Western University. Her research focuses on how movement and rhythm may be connected in the brain with a practical focus on how music influences the dysfunctional movements of Parkinson patients. She currently supervises music neuroscience MSc and PhD students in the Behavioural and Cognitive Neuroscience program and the Neuroscience program at Western University. Emerald Liang, a member of the academic affairs committee for WURJHNS, had the pleasure of interviewing Dr Jessica Grahn to find out a bit about her unique career choice and to acquire some insightful advice for current undergraduate students.

High prevalence of dysfunctional, asymmetrical, and painful movement in elite junior Australian Football players assessed using the Functional Movement Screen.

The purpose of this study was to describe the prevalence of dysfunctional, asymmetrical, and painful movement in junior Australian Football players using the Functional Movement Screen (FMS). Cross-sectional study. Elite junior male Australian Football players (n=301) aged 15-18 years completed pre-season FMS testing. The FMS consists of 7 sub-tests: deep squat, hurdle step, in-line lunge, shoulder mobility, active straight leg raise, trunk stability push-up (TSPU) and rotary stability. The shoulder mobility, TSPU, and rotary stability tests were combined with an accompanying clearing test to assess pain. Each sub-test was scored on an ordinal scale from 0 to 3 and summed to give a composite score out of 21. Composite scores ≤14 were operationally defined as indicating dysfunctional movement. Players scoring differently on left and right sides were considered asymmetrical. Players reported whether they missed any games due to injury in the preceding 22 game season. Sixty percent of players (n=182) had composite scores ≤14, 65% of players (n=196) had at least one asymmetrical sub-test, and 38% of players (n=113) had at least one painful sub-test. Forty-two percent of players (n=126) missed at least one game in the previous season due to injury. Previous injury did not influence composite score (p=0.951) or asymmetry (p=0.629). Players reporting an injury during the previous season were more likely to experience pain during FMS testing (odds ratio 1.97, 95% confidence interval 1.23-3.18; p=0.005). Junior Australian Football players demonstrate a high prevalence of dysfunctional, asymmetrical, and painful movement during FMS testing.

Transcriptional Responses and Mechanisms of Copper-Induced Dysfunctional Locomotor Behavior in Zebrafish Embryos.

Copper-induced delayed hatching and dysfunctional movement had been reported previously, and unbalanced free copper was found in the body of humans with Alzheimer's disease and other neural diseases, but details of the underlying mechanisms are still unknown. In this study, zebrafish (Danio rerio) embryos exposed to over 3.9 μM of copper-exhibited delayed hatching and significantly dysfunctional movement. Using high-throughput in situ hybridization screening and by conducting an in-depth analysis of gene characterization in embryos exposed to copper, we found that copper caused neural crest defects from the initiation stage of neurogenesis, and embryos younger than the 70% epiboly stage were sensitive to copper toxicity. The myelination of Schwann cells, other than melanophores, cartilage, and neurons, was inhibited by copper during neurogenesis. In addition, axon guidance was blocked by copper. Downregulated cdx4-hox might have contributed to the neurogenesis-related defects. Moreover, copper inhibited the differentiation of muscle fibers and myotomes but not the specification of muscle progenitors. In summary, our data reveal a novel molecular mechanism for copper-inhibited locomotor behavior in embryos, in which copper blocks functional muscle fiber specification during myogenesis and inhibits the specification of axons and Schwann cell myelination during neurogenesis. A combination of these processes results in dysfunctional locomotor behavior in zebrafish embryos exposed to copper.

Comparing lumbo-pelvic kinematics in people with and without back pain: a systematic review and meta-analysis.

BackgroundClinicians commonly examine posture and movement in people with the belief that correcting dysfunctional movement may reduce pain. If dysfunctional movement is to be accurately identified, clinicians should know what constitutes normal movement and how this differs in people with low back pain (LBP). This systematic review examined studies that compared biomechanical aspects of lumbo-pelvic movement in people with and without LBP.MethodsMEDLINE, Cochrane Central, EMBASE, AMI, CINAHL, Scopus, AMED, ISI Web of Science were searched from inception until January 2014 for relevant studies. Studies had to compare adults with and without LBP using skin surface measurement techniques to measure lumbo-pelvic posture or movement. Two reviewers independently applied inclusion and exclusion criteria, and identified and extracted data. Standardised mean differences and 95% confidence intervals were estimated for group differences between people with and without LBP, and where possible, meta-analyses were performed. Within-group variability in all measurements was also compared.ResultsThe search identified 43 eligible studies. Compared to people without LBP, on average, people with LBP display: (i) no difference in lordosis angle (8 studies), (ii) reduced lumbar ROM (19 studies), (iii) no difference in lumbar relative to hip contribution to end-range flexion (4 studies), (iv) no difference in standing pelvic tilt angle (3 studies), (v) slower movement (8 studies), and (vi) reduced proprioception (17 studies). Movement variability appeared greater for people with LBP for flexion, lateral flexion and rotation ROM, and movement speed, but not for other movement characteristics. Considerable heterogeneity exists between studies, including a lack of detail or standardization between studies on the criteria used to define participants as people with LBP (cases) or without LBP (controls).ConclusionsOn average, people with LBP have reduced lumbar ROM and proprioception, and move more slowly compared to people without LBP. Whether these deficits exist prior to LBP onset is unknown.

Three-Dimensional Motion Analysis: Relevant Concepts in Physiotherapy Movement Dysfunction Management

The explorations of typical and dysfunctional movements are recognized physiotherapy assessment and management strategies. With the development of state-of-the-art three-dimensional (3-D) motion capture systems, traditional two-dimensional and observational movement quantification are being used less frequently in research initiatives. This technology is slowly infiltrating physiotherapy practice as systems become more accessible. Knowledge of 3-D acquisition methodology will provide insight into advancing movement dysfunction theories in physiotherapy. The objective of this commentary is to introduce the clinician to 3-D motion capture while providing a basic theoretical framework for understanding this methodology. The current use of 3-D systems and the limitations of this study methodology are reviewed. Familiarization with the use of this technology and understanding the methods in capturing 3-D motion will provide the physiotherapist with the latest knowledge in movement dysfunction. These concepts are an exceptional addition to the clinical reasoning strategies currently employed in the profession of physiotherapy.

Neuromolecular Imaging Shows Temporal Synchrony Patterns between Serotonin and Movement within Neuronal Motor Circuits in the Brain.

The present discourse links the electrical and chemical properties of the brain with neurotransmitters and movement behaviors to further elucidate strategies to diagnose and treat brain disease. Neuromolecular imaging (NMI), based on electrochemical principles, is used to detect serotonin in nerve terminals (dorsal and ventral striata) and somatodendrites (ventral tegmentum) of reward/motor mesocorticolimbic and nigrostriatal brain circuits. Neuronal release of serotonin is detected at the same time and in the same animal, freely moving and unrestrained, while open-field behaviors are monitored via infrared photobeams. The purpose is to emphasize the unique ability of NMI and the BRODERICK PROBE® biosensors to empirically image a pattern of temporal synchrony, previously reported, for example, in Aplysia using central pattern generators (CPGs), serotonin and cerebral peptide-2. Temporal synchrony is reviewed within the context of the literature on central pattern generators, neurotransmitters and movement disorders. Specifically, temporal synchrony data are derived from studies on psychostimulant behavior with and without cocaine while at the same time and continuously, serotonin release in motor neurons within basal ganglia, is detected. The results show that temporal synchrony between the neurotransmitter, serotonin and natural movement occurs when the brain is NOT injured via, e.g., trauma, addictive drugs or psychiatric illness. In striking contrast, in the case of serotonin and cocaine-induced psychostimulant behavior, a different form of synchrony and also asynchrony can occur. Thus, the known dysfunctional movement behavior produced by cocaine may well be related to the loss of temporal synchrony, the loss of the ability to match serotonin in brain with motor activity. The empirical study of temporal synchrony patterns in humans and animals may be more relevant to the dynamics of motor circuits and movement behaviors than are studies of static parameters currently relied upon within the realms of science and medicine. There are myriad applications for the use of NMI to discover clinically relevant diagnoses and treatments for brain disease involving the motor system.

Middle Ear Myoclonus: Two Informative Cases and a Systematic Discussion of Myogenic Tinnitus

<strong>Background:</strong> The term middle ear myoclonus (MEM) has been invoked to explain symptoms of tinnitus presumably caused by the dysfunctional movement of either of the two muscles that insert in the middle ear: tensor tympani and stapedius. MEM has been characterized through heterogeneous case reports in the otolaryngology literature, where clinical presentation is variable, phenomenology is scarcely described, the pathogenic muscle is usually not specified, natural history is unknown, and the presumptive definitive treatment, tensor tympani or stapedius tendon lysis, is inconsistently effective. It is not surprising that no unique acoustogenic mechanism or pathophysiologic process has been identified to explain MEM, one of several descriptive diagnoses associated with the complicated disorders of myogenic tinnitus. <strong>Methods:</strong> Here, we explore MEM from the neurologist’s perspective. Following the detailed descriptions of two informative cases from our clinic, we systematically evaluate the different mechanisms and movement disorder phenomena that could lead to a diagnosis of MEM. <strong>Results:</strong> From a functional neuroanatomic perspective, we explain how tensor tympani MEM is best explained as a form of peritubal myogenic tinnitus, similar to the related disorder of essential palatal tremor. From a pathogenic perspective, we discuss how MEM symptomatology may reflect different mechanical and neurologic processes. We emphasize the diagnostic imperative to recognize when myogenic tinnitus is consistent with a psychogenic origin. <strong>Discussion:</strong> Both individual patient care and further elucidation of MEM will rely on more detailed clinical characterization as well as multidisciplinary input from neurology, otolaryngology, and dentistry.

Middle ear myoclonus: two informative cases and a systematic discussion of myogenic tinnitus.

The term middle ear myoclonus (mem) has been invoked to explain symptoms of tinnitus presumably caused by the dysfunctional movement of either of the two muscles that insert in the middle ear: tensor tympani and stapedius. MEM has been characterized through heterogeneous case reports in the otolaryngology literature, where clinical presentation is variable, phenomenology is scarcely described, the pathogenic muscle is usually not specified, natural history is unknown, and the presumptive definitive treatment, tensor tympani or stapedius tendon lysis, is inconsistently effective. It is not surprising that no unique acoustogenic mechanism or pathophysiologic process has been identified to explain MEM, one of several descriptive diagnoses associated with the complicated disorders of myogenic tinnitus. Here, we explore MEM from the neurologist's perspective. Following the detailed descriptions of two informative cases from our clinic, we systematically evaluate the different mechanisms and movement disorder phenomena that could lead to a diagnosis of MEM. From a functional neuroanatomic perspective, we explain how tensor tympani MEM is best explained as a form of peritubal myogenic tinnitus, similar to the related disorder of essential palatal tremor. From a pathogenic perspective, we discuss how MEM symptomatology may reflect different mechanical and neurologic processes. We emphasize the diagnostic imperative to recognize when myogenic tinnitus is consistent with a psychogenic origin. Both individual patient care and further elucidation of MEM will rely on more detailed clinical characterization as well as multidisciplinary input from neurology, otolaryngology, and dentistry.

A null effect of target's velocity in the visual representation of motion with schizophrenic patients.

When people are shown a moving object that suddenly disappears and are instructed to locate its vanishing position, systematic errors in the direction of motion and in the direction of gravity are usually observed. Entitled, respectively, Representational Momentum (RepMo) and Representational Gravity, these phenomena seem to be influenced by low-level perceptual mechanisms and high-level cognitive aspects alike. Although being widely acknowledged that schizophrenic patients reveal several deficits in the perception and processing of motion, no study to date has explored these behavioral spatial mislocalizations of smoothly moving targets. The present study reports two experiments intending to fill this gap. The outcomes systematically disclosed a null effect of target's velocity for schizophrenic patients, a well established determinant of RepMo's magnitude with nonpsychiatric populations. No other variables (implied mass and motion direction) revealed this dissociation between the groups. The results are discussed within the distinction of kinematic and dynamic variables, with schizophrenic patients revealing a deficit in the processing of the former, and a link with dysfunctional smooth pursuit eye movements is suggested.

The force-length operating range of the human soleus muscle during walking and running

Introduction: Knowledge of where skeletal muscles operate on their force–length relationship is important for understanding the mechanics and control of both normal and dysfunctional movement. However, relating the force–length relationship of muscles to human movement, and gait in particular, has been hampered by a lack of reliable experimental data. The purpose of this study was to determine the force–length operating range of the soleus muscle during both walking (preferred speed) and running (3m/s) based on (a) subject-specific muscle force-length data; (b) direct muscle fascicle imaging, and (c) electromyography (emg) data.

Robotic thoracoscopic plication for symptomatic diaphragm paralysis.

Diaphragmatic paralysis is an uncommon condition characterized by significant elevation of a hemidiaphragm, and can cause dyspnea. The goal of diaphragm plication is to improve dyspnea by correcting the dysfunctional movement of a diaphragm during inspiration. Minimally invasive thoracoscopic diaphragm plication has been widely used and has been reported to lead to significant improvements in dyspnea and postoperative pulmonary function. Advantages of thoracoscopic plication compared to open thoracotomy are less postoperative pain and shorter hospitalization, yet technical difficulties due to limited workspace afforded by the ribcage and the elevated hemidiaphragm have been a major drawback in using the thoracoscopic approach for this disorder. We describe our experience with robotic thoracoscopic plication for the treatment of diaphragmatic paralysis. This is, to our knowledge, the first report of this kind.

Scapular muscle imbalance: implications for shoulder pain and pathology

Background: The scapula is important for normal shoulder function. The correct length, strength, and sequence of recruitment of the scapulothoracic muscles are important in controlling the movement of the scapula which must maintain an optimal position in relation to the elevating humerus. Changes in the action of scapulothoracic muscles may potentially affect alignment and forces and may contribute to glenohumeral joint pathology.Objective: The purpose of this paper is to review the literature that associates abnormal scapulothoracic muscle function with shoulder joint pain and pathology.Major findings: Shoulder impingement syndrome, superior labrum anterior to posterior (SLAP) lesions and multidirectional instability have all been associated with dysfunctional movement patterns of the scapula. It is not clear if the observed changes in scapular movements and muscular control are the result of or are the cause of these various pathologies at the shoulder joint. Alterations in the force production of the scapulothoracic musculature including all parts of the trapezius and serratus anterior muscles have been reported. Tightness in the pectoralis minor and/or in the posterior glenohumeral joint capsule may also affect movement due to a general anterior tilting of the scapula which impairs its ability to attain a normally upwardly rotated position.Conclusions: The results of the investigations reviewed imply that appropriate assessment of the length, strength, and activation of all parts of the upper trapezius, serratus anterior, and pectoralis minor are important in the rehabilitation of patients with glenohumeral joint pathology.

Designing a spinal stability program to break the recurrent pain cycle

Dynamic motor control of the lumbo/pelvic /hip region involves complex movement patterns and interrelated kinematics of many joints. Not only must key muscles have endurance and contraction specific strength, but the central nervous system must consider input form the periphery and adjust its pre-programmed responses accordingly. An explosion of research into muscle and proprioceptive requirements in the region and changes that occur with pain, give us insight into the many aspects of rehabilitation that must be considered to maximise dynamic function. Such changes include-local muscle changes, function specific recruitment patterns, degradation of proprioceptive, balance and motor planning systems, all combined with faulty virtual body engrams within the motor cortex itself. The aim of this workshop is to present an exercise based strategy to break the recurrent pain cycle. This strategy involves specific, graded and functional exercises to optimise not only stabiliser muscle endurance but optimise dynamic function. The graded and progressed exercise principles can be used both within the clinic and incorporated into rehabilitation and maintenance training programs for athletes. If motor control retraining is too unidimentional and does not address retraining the complex proprioceptive and motor planning components of dynamics movement, than dysfunctional movement patterns can continue well after initial pain has settled predisposing the individual to recurrent pain and suboptimal performance.

Pursuit eye movements: A review

No abstract available

Eye movement and visual motion perception in schizophrenia I: Apparent motion evoked smooth pursuit eye movement reveals a hidden dysfunction in smooth pursuit eye movement in schizophrenia

To date, smooth pursuit eye movement in schizophrenia has only been investigated using a target stimulus in continuous motion. However, smooth pursuit can also be evoked by an oscillating jumping dot that appears to be in apparent motion and although there is no continuous motion on the retinal surface this apparently moving stimulus can effortlessly elicit smooth-pursuit eye movement. In the first of two experiments smooth pursuit eye movement was evoked by target stimuli in continuous (real) motion at seven target velocities from 5.0 to 35.0 deg/s, and in a second experiment it was measured in response to an oscillating jumping dot in apparent motion at eight target velocities from 5.0 to 25.0 deg/s in a group with mixed-symptoms in schizophrenia and in a control group. The results of Experiment 1 provided no evidence for a dysfunction in continuous motion evoked smooth pursuit eye movement in the group with schizophrenia. However, following the removal of saccadic eye movements in smooth pursuit, the group with schizophrenia showed significantly lower smooth pursuit eye velocity at target velocities from 20.0 to 35.0 deg/s. The results of Experiment 2 revealed that apparent motion evoked smooth pursuit eye velocity in the group with schizophrenia was significantly lower in comparison with normal observers at all target velocities up to 25.0 deg/s with the inclusion or exclusion of saccadic eye movements. The findings demonstrate that overall smooth pursuit eye movement evoked in response to a continuous (real) motion target in the group with schizophrenia may nevertheless contain a hidden temporal resolution and integration dysfunction that is revealed when smooth pursuit eye movement is evoked in response to an oscillating jumping dot in apparent motion. The findings also demonstrate that normal smooth pursuit eye movement in normal observers can be made to resemble the dysfunctional smooth pursuit eye movement that is naturally found in some people with schizophrenia by using a target stimulus in apparent motion.

Dynamical stability in the acquisition and performance of rhythmic ball manipulation: theoretical insights with a clinical slant.

Three experiments illustrate how a task-based approach and dynamical modeling of a perceptual-motor task can provide a useful framework for understanding functional and dysfunctional behavior. In the chosen task, subjects held a racket and bounced a ball rhythmically in the air with invariant ball amplitude. As such, the task could be cast into a mechanical model that encompassed the movements of the actor (racket) and the manipulandum (ball). In this form, the movement task is a dynamical system that displays dynamical stability, i.e., performance where perturbations die out by themselves. The hypothesis is that skilled actors seek to perform with this "passive" stability as it alleviates the control demands because perturbations do not require explicit corrections. In the experimental data, this strategy could be characterized by a single parameter, the acceleration of the racket at impact, which provided quantitative predictions. Experiment 1 established that subjects with normal sensorimotor functions indeed performed with racket acceleration values that were predicted to provide passive stability. Experiment 2 showed that subjects improved their skill over a course of 40 practice trials, as evidenced in decreased variability and accompanied by a change in racket acceleration toward values that provided optimal stability. In experiment 3, perturbations were applied and the subjects' adaptability was tested. When perturbations were large enough, subjects altered their racket timing to resume contact that provided stability. The results are discussed with their relevance to clinical contexts: How can such a task-based approach provide insights into the control of functional and dysfunctional movements? Can such behavioral results serve as a diagnostic tool? How can this approach to sensorimotor behavior stimulate physicians and therapists to progress therapeutic measures?

A dysfunctional movement protein of tobacco mosaic virus interferes with targeting of wild-type movement protein to microtubules.

The Tobacco mosaic virus (TMV) movement protein (MPTMV) mediates cell-to-cell viral trafficking by altering properties of the plasmodesmata (Pd) in infected cells. During the infection cycle, MPTMV becomes transiently associated with endomembranes, microfilaments, and microtubules (MT). It has been shown that the cell-to-cell spread of TMV is reduced in plants expressing the dysfunctional MP mutant MPNT-1. To expand our understanding of the MP function, we analyzed events occurring during the intracellular and intercellular targeting of MPTMV and MPNT-1 when expressed as a fusion protein to green fluorescent protein (GFP), either by biolistic bombardment in a viral-free system or from a recombinant virus. The accumulation of MPTMV:GFP, when expressed in a viral-free system, is similar to MPTMV:GFP in TMV-infected tissues. Pd localization and cell-to-cell spread are late events, occurring only after accumulation of MP:GFP in aggregate bodies and on MT in the target cell. MPNT-1:GFP localizes to MT but does not target to Pd nor does it move cell to cell. The spread of transiently expressed MPTMV:GFP in leaves of transgenic plants that produce MPNT-1 is reduced, and targeting of the MPTMV:GFP to the cytoskeleton is inhibited. Although MPTMV:GFP targets to the Pd in these plants, it is partially impaired for movement. It has been suggested that MPNT-1 interferes with host-dependent processes that occur during the intracellular targeting program that makes MP movement competent.

Evaluation of chronic neurological sequelae after acute pesticide exposure using spect brain scans

A case in which SPECT brain imaging was used in the diagnosis and treatment of chronic effects from acute acetylcholinesterase inhibitor poisoning is presented. The patient was exposed to an insecticide mixture containing phosphorothiate, pyrethrin, piperonyl butoxide, and petroleum distillates, which produced symptoms consistent with acute acetylcholinesterase inhibitor poisoning as well as an upper respiratory tract irritant. Delayed sequelae of gross neurologic symptoms followed, that is, coarse tremor, intermittent hemiballistic movements of the right arm and leg, flaccid muscular tone, fasciculations of muscle groups, muscle cramps, and sensory disturbances. A brain single-photon emission computerized tomography (SPECT) scan was performed 34 mo postexposure, revealing significantly decreased blood flow to the left temporal lobe and to the right and left basal ganglia. The patient's paresthesias were treated with phenytoin, which resulted in worsening of her movement disorder. A trial of amantadine and selegiline (Deprenyl) resulted in a dramatic reduction in dysfunctional movements and ataxia. Post amantadine and selegiline therapy, brain SPECT images revealed significantly improved blood flow with minimally decreased blood flow to the right and left basal ganglia. The use of SPECT scan techniques helped to elucidate objective chronic central nervous system effects subsequent to an acute insecticide exposure and also assisted in the evaluation of the effectiveness of therapeutic intervention.