Repetitive Head Movements Research Articles

Study on risk prediction model of neck work-related musculoskeletal disorders among automobile manufacturing enterprise workers

Objective: To explore the risk factors of neck work-related musculoskeletal disorders (WMSDs) among automobile manufacturing enterprise workers, and construct the risk prediction model. Methods: In May 2022, a cluster convenience sampling method was used to selet all front-line workers from an automobile manufacturing factory in Xiangyang City as the research objects. And a questionnaire survey was conducted using the modified Musculoskeletal Disorders Questionnaire to analyze the occurrence and exposure to risk factors of neck WMSDs. Logistic regression was used to analyze the influencing factors of workers' neck WMSDs symptoms, and Nomogram column charts was used to construct the risk prediction model. The accuracy of the model was evaluated by the receiver operating characteristic (ROC) curve, the Bootstrap resampling method was used to verify the model, Hosmer-Lemeshow goodness of fit test was used to evaluate the model, and the Calibration curve was drawn. Results: A total of 1783 workers were surveyed, and the incidence of neck WMSDs symptoms was 24.8% (442/1783). Univariate logistic regression showed that age, female, smoking, working in uncomfortable postures, repetitive head movement, feeling constantly stressed at work, and completing conflicting tasks in work could increase the risk of neck WMSDs symptoms in automobile manufacturing enterprise workers (OR=1.37, 95%CI: 1.16-1.62; OR=2.85, 95%CI: 1.56-5.20; OR=1.50, 95%CI: 1.18-1.91; OR=1.18, 95%CI: 1.02-1.37; OR=1.34, 95%CI: 1.04-1.72; OR=1.62, 95%CI: 1.21-2.17; OR=1.48, 95%CI: 1.13-1.92; P<0.05). While adequate rest time could reduce the risk of neck WMSDs symptoms (OR=0.56, 95%CI: 0.52-0.86, P<0.05). The risk prediction model of neck WMSDs of workers in automobile manutacturing factory had good prediction efficiency, and the area under the ROC curve was 0.72 (95%CI: 0.70-0.75, P<0.001) . Conclusion: The occurrence of neck WMSDs symptoms of workers in automobile manufacturing factory is relatively high. The risk prediction model constructed in this study can play a certain auxiliary role in predicting neck WMSDs symptoms of workers in automobile manufacturing enterprise workers.

Neck Health Metrics and Quality of Life: A Comparative Study in Bike Drivers with and without Neck Pain.

Neck pain is a prevalent musculoskeletal issue among bike drivers, often resulting from extended static postures, repetitive head movements, and exposure to vibrations. This study aims to assess the connection between cervical ROM, neck proprioception, CVA, and QOL in bike drivers with neck pain compared to those without neck pain so that the targeted interventions can be developed to enhance their well-being. A cross-sectional study involving 100 bike drivers aged 20-50 years was conducted, split into two groups: those with neck pain (n=50) and those without neck pain (n=50). Cervical ROM was measured using a smartphone, neck proprioception was assessed through a head repositioning test, and CVA was determined using lateral-view photographs with a plumb line. The Short Form-36 (SF-36) questionnaire was employed to evaluate QOL. Data analysis was conducted using independent t-tests and Pearson's correlation coefficient. Bike drivers with neck pain exhibited significantly reduced cervical ROM (p-value=<0.001), impaired neck proprioception (p-value=<0.001), and decreased CVA (p-value=<0.001) compared to their counterparts without neck pain. A strong negative correlation was found between neck pain and QOL, with lower scores in all eight domains of the SF-36. Cervical ROM, neck proprioception, and CVA showed moderate correlations with various QOL domains (p-value=<0.05). Neck pain in bike drivers is linked to decrease cervical ROM, compromised neck proprioception, and reduced CVA. These factors correlate with a lower quality of life, both physical and mental domains. Interventions addressing these aspects may enhance the quality of life for bike drivers experiencing neck pain.

Automated anomalous child repetitive head movement identification through transformer networks.

The increasing prevalence of behavioral disorders in children is of growing concern within the medical community. Recognising the significance of early identification and intervention for atypical behaviors, there is a consensus on their pivotal role in improving outcomes. Due to inadequate facilities and a shortage of medical professionals with specialized expertise, traditional diagnostic methods have been unable to effectively address the rising incidence of behavioral disorders. Hence, there is a need to develop automated approaches for the diagnosis of behavioral disorders in children, to overcome the challenges with traditional methods. The purpose of this study is to develop an automated model capable of analyzing videos to differentiate between typical and atypical repetitive head movements in. To address problems resulting from the limited availability of child datasets, various learning methods are employed to mitigate these issues. In this work, we present a fusion of transformer networks, and Non-deterministic Finite Automata (NFA) techniques, which classify repetitive head movements of a child as typical or atypical based on an analysis of gender, age, and type of repetitive head movement, along with count, duration, and frequency of each repetitive head movement. Experimentation was carried out with different transfer learning methods to enhance the performance of the model. The experimental results on five datasets: NIR face dataset, Bosphorus 3D face dataset, ASD dataset, SSBD dataset, and the Head Movements in the Wild dataset, indicate that our proposed model has outperformed many state-of-the-art frameworks when distinguishing typical and atypical repetitive head movements in children.

Neck musculoskeletal disorders and their influence factors among welders in an automobile factory

Objective: To explore the prevalence and risk factors of neck musculoskeletal diseases (MSDs) of welders among an automobile factory. Methods: In June 2019, a cluster random sampling method was used to select 677 electric welders from an automobile manufacturing plant in Shiyan City as the survey objects, and a questionnaire survey was conducted using the "Musculoskeletal Disorders Questionnaire" to analyze the prevalence and influencing factors of neck MSDs, and used logistic regression to analyze the relationship between the influencing factors and the prevalence of cervical MSDs. Results: The prevalence rate of MSDs in neck of welders was 54.8% (371/677) . The exposure rate of occupational factors, from high to low, were neckin a bent formord porsure was 71.6% (486/677) , repetitive head movements was 55.1% (373/677) , working in uncomfortable postures was 48.7% (330/677) and neck twisted was 46.8% (317/677) respectively. Sex, age, educational level, length of service, smoking, neck tilt, neck twist, working in uncomfortable posture and head repetitive movements were the risk factors of neck MSDs (P<0.05) . Multiple logistic regression analysis showed that, the main influencing factors of neck MSDs were sex, education level, age, length of service, smoking, neck tilt, working in uncomfortable posture (OR = 2.11, 2.03, 1.83, 1.21, 1.78, 1.90, 1.58, 95%CI: 1.28~3.48、1.47~2.81、1.33~2.52、1.03~1.41、1.22~2.60、1.28~2.83、1.11~2.27, P<0.05) , rest had protective effect on neck MSDs (OR= 0.38, 95%CI: 0.17~0.88, P<0.05) . Conclusion: Welders in automobile factory was highly exposed to occupational risk factors for neck MSDs. Occupational risk factors such as neck in a bent forward posture, working in an uncomfortable posture, prolonged siting, repetitive head movement should be the focus of intervention.

Horses’ physiological and behavioural responses during undergraduate veterinary practical teaching classes

Horses are used in many equine and veterinary science degree programmes during practical teaching classes for students to develop and refine their handling and clinical skills. There are few studies investigating the stress responses of these horses within the teaching environment. The aim of this study was to evaluate the physiological and behavioural responses of teaching horses during three types of practical teaching classes: equine handling (EH), medical rectal examination (MR) and mare reproductive rectal examination (RR). The study population included 20 teaching horses from three herds (mean time in herd of 7 ± 3 years). The horses’ heart rate (HR) was assessed before (horses in holding yard and entering the stocks/teaching yard), during (horses in stocks/teaching yard, with or without interaction with students or lecturer) and after (horses in holding yard and leaving the stocks/teaching yard) a practical class. In addition, behaviour (pawing, eating hay, vocalisation, head surveying, tail swishing, repetitive head movement, shifting weight backwards and ears orientation) of the horses used during rectal examination classes was recorded. Median class duration was 99.50 min (IQR: 95.75−112.25 min) for EH, 37.50 min (IQR: 32.25−40 min) for MR, and 47 min (IQR: 47−48 min) for RR classes. Horses interacted with students for 26 % (RR) to 40 % (EH and MR) of the classes’ duration. There was no change in median HR (35 bpm, interquartile range [IQR]: 33–39 bpm) between activities during EH classes. Median HR was greater when horses entered the stocks compared to the holding yard before the class in MR (entering stocks: 52.5 bpm, IQR: 43–58 bpm; yard-before: 39 bpm, IQR: 36–40 bpm; p = 0.047) and RR (entering stocks: 46 bpm, IQR = 41–49 bpm; yard-before: 37 bpm, IQR: 33−41 bpm; p = 0.031) classes. For both rectal examination classes, horses spent most of their time eating hay (MR: 94 %, IQR: 73–100 %; RR: 61 %, IQR: 46–79 %). In RR classes, horses spent less time eating hay (36 %) and had their ears pointed backwards more frequently (1.39 occurrences/min) during an interaction with a student compared to no interaction. Limited physiological and behavioural stress responses were observed in response to the three types of practical classes, suggesting this population of teaching horses may be habituated to both their use and environment for teaching.

Hashimoto encephalopathy induced by coronavirus

Background: Multiple factors can induce thyroid disease. The mechanism is not precise; a possible mimicry effect in the thyroid tissue could be the cause. Encephalopathy could be one manifestation of this thyroid disorder, but its mechanism is not well understood. There is a lack of data showing coronavirus as a possible cause of Hashimoto encephalopathy. Case Report: A 34-year-old obese Hispanic female was brought to our emergency department due to acute “Behavioral changes”. Her family noted her anxiety with repetitive head movement.; the patient presented with psychotic behavior, reporting family members were killed (The same that brought her), having auditory hallucinations; the family could not precisely predict the duration of this behavior. Her history includes asthma (never intubated, not on steroids), morbid obesity, galactorrhea, and extensive HTN and DM. She denied chest pain, palpitations, nausea, vomit, fever, malaise, recent flu-like symptoms. No abnormality in the physical examination was noted except for repetitive head movement; due to her acute mental status changes and lactic acidosis, she was admitted under critical care service. During her admission, the TSH/T3/ T4: 47.10/34/0.15, Antimicrosomal Ab and Coronavirus PCR were positive (Table1); CXR: No acute pathology, CT Head: Unremarkable, ultrasound neck showed Enlarged heterogeneous thyroid gland, which limits evaluation of underlying parenchyma; no measurable demonstrated solid, cystic or complex nodule (Figure 1). MRI head showed no pituitary adenoma. The patient was started on levothyroxine initially IV then transitioned to 200 mcg PO, and received ceftriaxone, dexamethasone, enoxaparin (As prophylaxis) for C19; after thyroid replacement was initiated; the patient started improving mental status drastically, she was transferred to the medical floor, later improved to baseline, and then was discharged. As an outpatient, the repeated thyroid panel showed normal values, and mental status was status as her baseline previous to her admission. Conclusion: Our case report describes a case of Hashimoto encephalopathy induced by SARS-CoV2 virus. Besides reports relating this thyroiditis with viral other viral entities, there is no data about this thyroid disorder in the 2020 pandemic.

A Short Review of Biochemical Mechanisms in Iminodipropionitrile-Induced Movement Disorder

Iminodipropionitrile (IDPN) is a synthetic nitrile that produces permanent behavioral syndrome characterized by repetitive head movements, circling and back walking in rodents. Other synthetic nitriles of industrial importance such as crotonitrile and allylnitrile are also able to produce similar motor deficits in experimental animals. Among these nitriles, IDPN has been recognized as a prototype nitrile to be used as a positive control for behavioral testing battery. Due to the well-defined behavioral deficits and their easy quantification, IDPN-induced behavioral syndrome is a preferential animal model to test the interaction of various agents with synthetic nitriles. The mechanism of IDPN-induced dyskinesia is multifactorial. This short review focuses on the roles of neurotransmitters, oxidative stress and inflammation in the pathogenesis of IDPN-induced neurotoxicity and behavioral deficits.

Neuropathology in Consecutive Forensic Consultation Cases with a History of Remote Traumatic Brain Injury

Traumatic brain injury (TBI) is widely assumed to be causal in neurodegenerative disease, based on epidemiological surveys demonstrating an increased risk of Alzheimer disease (AD) following TBI, and on recent theories surrounding repetitive head movement. We tested this assumption by evaluating 30 consecutive forensic examinations in which neuropathology consultation was sought, and in which a history of remote TBI was uncovered during the course of the investigation. In this series, there was a high frequency of psychiatric co-morbidities (100%), remote contusion (90%), and seizures (63%). Extent of proteinopathy showed no differences with age-matched controls. A subset of the cases showed focal geographic tauopathy that correlated with older age at autopsy, but had no correlation with clinical signs, and was minimal in comparison with the encephalomalacia secondary to trauma. The results suggest that cerebral contusion and post-traumatic epilepsy may be over-represented in civilian TBI, while structural brain damage from trauma is the predominant cause of morbidity following TBI. We found no evidence that TBI initiates a progressive proteinopathy.

Soft Material-Enabled, Active Wireless, Thin-Film Bioelectronics for Quantitative Diagnostics of Cervical Dystonia.

Recent advances in flexible materials, nanomanufacturing, and system integration have provided a great opportunity to develop wearable flexible hybrid electronics for human healthcare, diagnostics, and therapeutics. However, existing medical devices still rely on rigid electronics with many wires and separate components, which hinders wireless, comfortable, continuous monitoring of health-related human motions. Here, we introduce advanced materials and system integration technologies that enable a soft, active wireless, thin-film bioelectronics. The low-modulus, highly flexible wearable electronic system incorporates a nanomembrane wireless circuit and functional chip components, enclosed by a soft elastomeric membrane. The bioelectronic system offers a gentle, seamless mounting on the skin, while offering a comfortable, highly sensitive and accurate detection of head movements. We utilize the wireless wearable hybrid system for quantitative diagnostics of cervical dystonia (CD) that is characterized by involuntary abnormal head postures and repetitive head movements, sometimes with neck muscle pain. A set of analytical and experimental studies shows a soft system packaging, hard-soft materials integration, and quantitative assessment of physiological signals detected by the SKINTRONICS. In vivo demonstration, involving ten human subjects, captures the device feasibility for use in CD measurement.

Language-Model Assisted And Icon-based Communication Through a Brain Computer Interface With Different Presentation Paradigms.

Augmentative and alternative communication (AAC) is typically used by people with severe speech and physical disabilities (SSPI) and is one of the main application areas for brain computer interface (BCI) technology. The target population includes people with cerebral palsy (CP), amyotrophic lateral sclerosis (ALS) and locked-in-syndrome (LIS). Word-based AAC systems are mainly faster than letter-based counterparts and are usually supplemented by icons to aid the users. Those iconbased AAC systems that use binary signaling methods such as single click can convert into a single input BCI systems such as ERP detection. Matrix speller paradigm are typically used to help users identify their target icon on the screen, however it ties screen space to vocabulary size and navigation complexity, which may require users to make repetitive head, neck, or eye movements to visually locate their intended targets on the screen. Rapid serial visual presentation (RSVP) is an alternative interface that minimizes required movement by displaying all icons at a fix location, one at a time. IconMessenger is an icon-based BCI-AAC system that combines ERP signal detection with a unified framework for different presentation paradigms including RSVP, matrix speller row&column presentation (RCP) and matrix speller single character presentation (SCP). Icon- Messenger also take advantage of a unique sem-gram language model, incorporated tightly in the inference engine. In this study, we assess the ERP shape, classification accuracy and typing performance of different presentation paradigms on 10 healthy participants.

Postoperative lead migration in deep brain stimulation surgery: Incidence, risk factors, and clinical impact.

IntroductionDeep brain stimulation (DBS) is an effective treatment for multiple movement disorders and shows substantial promise for the treatment of some neuropsychiatric and other disorders of brain neurocircuitry. Optimal neuroanatomical lead position is a critical determinant of clinical outcomes in DBS surgery. Lead migration, defined as an unintended post-operative displacement of the DBS lead, has been previously reported. Despite several reports, however, there have been no systematic investigations of this issue. This study aimed to: 1) quantify the incidence of lead migration in a large series of DBS patients, 2) identify potential risk factors contributing to DBS lead migration, and 3) investigate the practical importance of this complication by correlating its occurrence with clinical outcomes.MethodsA database of all DBS procedures performed at UF was queried for patients who had undergone multiple post-operative DBS lead localization imaging studies separated by at least two months. Bilateral DBS implantation has commonly been performed as a staged procedure at UF, with an interval of six or more months between sides. To localize the position of each DBS lead, a head CT is acquired ~4 weeks after lead implantation and fused to the pre-operative targeting MRI. The fused targeting images (MR + stereotactic CT) acquired in preparation for the delayed second side lead implantation provide an opportunity to repeat the localization of the first implanted lead. This paradigm offers an ideal patient population for the study of delayed DBS lead migration because it provides a large cohort of patients with localization of the same implanted DBS lead at two time points. The position of the tip of each implanted DBS lead was measured on both the initial post-operative lead localization CT and the delayed CT. Lead tip displacement, intracranial lead length, and ventricular indices were collected and analyzed. Clinical outcomes were characterized with validated rating scales for all cases, and a comparison was made between outcomes of cases with lead migration versus those where migration of the lead did not occur.ResultsData from 138 leads in 132 patients with initial and delayed lead localization CT scans were analyzed. The mean distance between initial and delayed DBS lead tip position was 2.2 mm and the mean change in intracranial lead length was 0.45 mm. Significant delayed migration (>3 mm) was observed in 17 leads in 16 patients (12.3% of leads, 12.1% of patients). Factors associated with lead migration were: technical error, repetitive dystonic head movement, and twiddler’s syndrome. Outcomes were worse in dystonia patients with lead migration (p = 0.035). In the PD group, worse clinical outcomes trended in cases with lead migration.ConclusionsOver 10% of DBS leads in this large single center cohort were displaced by greater than 3 mm on delayed measurement, adversely affecting outcomes. Multiple risk factors emerged, including technical error during implantation of the DBS pulse generator and failure of lead fixation at the burr hole site. We hypothesize that a change in surgical technique and a more effective lead fixation device might mitigate this problem.

A Channel Rejection Method for Attenuating Motion-Related Artifacts in EEG Recordings during Walking.

Recording scalp electroencephalography (EEG) during human motion can introduce motion artifacts. Repetitive head movements can generate artifact patterns across scalp EEG sensors. There are many methods for identifying and rejecting bad channels and independent components from EEG datasets, but there is a lack of methods dedicated to evaluate specific intra-channel amplitude patterns for identifying motion-related artifacts. In this study, we proposed a template correlation rejection (TCR) as a novel method for identifying and rejecting EEG channels and independent components carrying motion-related artifacts. We recorded EEG data from 10 subjects during treadmill walking. The template correlation rejection method consists of creating templates of amplitude patterns and determining the fraction of total epochs presenting relevant correlation to the template. For EEG channels, the template correlation rejection removed channels presenting the majority of epochs (>75%) correlated to the template, and presenting pronounced amplitude in comparison to all recorded channels. For independent components, the template correlation rejection removed components presenting the majority of epochs correlated to the template. Evaluation of scalp maps and power spectra confirmed low neural content for the rejected components. We found that channels identified for rejection contained ~60% higher delta power, and had spectral properties locked to the gait phases. After rejecting the identified channels and running independent component analysis on the EEG datasets, the proposed method identified 4.3 ± 1.8 independent components (out of 198 ± 12) with substantive motion-related artifacts. These results indicate that template correlation rejection is an effective method for rejecting EEG channels contaminated with motion-related artifact during human locomotion.

Case study: Treatment of oral and locomotory stereotypic behaviors in a mature sow

A 32-month-old female 225-kg nonpregnant cross-bred Newsham sow presented a 6-week history of stereotypic behaviors when housed in a laboratory research facility. A behavioral examination over 12 daylight hours revealed 3 main stereotypic motor patterns, namely (1) oral-nasal gate manipulation defined as placement of the snout between the bars of the pen gate with repetitive, forceful up and down movement; (2) head weaving defined as repetitive lateral head and snout movement toward the pen gates while rocking back and forth on her forequarters with hooves remaining on ground at all times; and (3) body weaving defined as repetitive shifting of body weight from one side to the other with front hooves lifting alternately off the ground. The sow performed the oral-nasal gate manipulation and head and body weaving 4.0%, 12.4%, and 6.8% of her total baseline time budget, respectively. The presumptive diagnosis was oral-nasal and locomotory stereotypies. Three treatments were used to mitigate the duration and frequency of these stereotypic behaviors. Treatment 1—Social treatment (change social stimuli by providing visual and nose-to-nose contact with different neighboring sows); Treatment 2—Forage treatment (change foraging substrates by providing peat moss as a rooting substrate); and Treatment 3—Space treatment (change pen configuration by increasing space). The sow performed the oral-nasal gate manipulation and head and body weaving 0%, 0.4%, and 0.1% of her total time budget, respectively; social treatment: the sow performed the oral-nasal gate manipulation and head and body weaving 0.9%, 15.3%, and 11.3% of her total time budget, respectively; and forage treatment: the sow performed the oral-nasal gate manipulation and head and body weaving 0.5%, 28.0%, and 15.5% of her total time budget, respectively. This study is one of the first reports to evaluate the treatment of established stereotypies in a mature sow. Results suggest the promise of environmental enrichment as an effective treatment strategy. Further research is needed to evaluate the persistence of these behavioral changes and relative importance of different environmental manipulations provided.

Bobble-head doll syndrome: therapeutic outcome and long-term follow-up in four children

Bobble-head doll syndrome (BHDS) is a complex syndrome with the dominant symptom of repetitive anteroposterior head movement. Only 57 patients are quoted in the literature. The etiology of this syndrome remains unknown and no standard treatment has yet been established. We hereby report four cases treated at our department. All the patients presented a psychomotor retardation due to an obstructive hydrocephalus. All the patients were treated using neuroendoscopic techniques: two with ventriculocystostomy, and two with ventriculocystocisternostomy. Cyst decompression was achieved in all four cases and clinical recovery was evident in three of the four patients observed. After surgery, BHDS persisted longer the more the subsequent treatment was delayed. In this article, we provide a concise overview of the theories of pathogenesis, presentation, and management of this syndrome. Based on our own experience, we state that the method of choice should be the neuroendoscopy and this must be performed promptly after diagnosis is made.

Variant of Rett Syndrome and CDKL5 Gene: Clinical and Autonomic Description of 10 Cases

Rett syndrome (RTT) is a severe neurodevelopmental disorder affecting almost exclusively females. The Hanefeld variant, or early-onset seizure variant, has been associated with mutations in CDKL5 gene. In recent years more than 60 patients with mutations in the CDKL5 gene have been described in the literature, but the cardiorespiratory phenotype has not been reported. Our aim is to describe clinical and autonomic features of these girls. 10 girls with CDKL5 mutations and a diagnosis of Hanefeld variant have been evaluated on axiological and clinical aspects. In all subjects an evaluation of the autonomic system was performed using the Neuroscope. Common features were gaze avoidance, repetitive head movements and hand stereotypies. The autonomic evaluation disclosed eight cases with the Forceful breather cardiorespiratory phenotype and two cases with the Apneustic breather phenotype. The clinical picture remains within the RTT spectrum but some symptoms are more pronounced in addition to the very early onset of seizures. The cardiorespiratory phenotype was dominated by Forceful breathers, while Feeble breathers were not found, differently from the general Rett population, suggesting a specific behavioral and cardiorespiratory phenotype of the RTT the Hanefeld variant.

Persistent Psychosis After a Single Ingestion of “Ecstasy” (MDMA)

Persistent Psychosis After a Single Ingestion of “Ecstasy” (MDMA)

The effects of display delay on simulator sickness

The experience of simulator sickness (SS) during head-mounted display (HMD) exposure continues to be a problem. The aim of these two experiments was to examine the effect of delay on SS while viewing a real, live video scene via an HMD. An object search task was performed in both experiments. Experiment 1 examined 0 and 200 ms of delay and Experiment 2 examined 0, 145, and 300 ms of delay. SS did not differ as a function of delay. However, SS increased as duration exposure increased in both experiments. In Experiment 1, SS was greater during the first experimental session than the second. SS did not differ between those who donned an HMD and a No HMD control condition in Experiment 2. It is possible that this is due to adaptation to repeated exposure to the sickening stimulus. This adaptation could have confounded the delay effects from Experiment 1. For this reason, a second experiment with an increased intersession interval was conducted. Intersession intervals for Experiment 2 were increased to 11–14 days from 7 days in Experiment 1. However, no effect of delay or session was found in Experiment 2. These results suggested that SS does not increase as a function of delay, but exposure duration increases SS. Also, performing repetitive head movements alone may have elicited symptoms of SS. As reported by other researchers, it appears that adaptation can occur to motion sickness stimuli with intersession intervals of up to 7 days, but not with 11–14 days. Other characteristics of HMD VEs need to be examined because SS occurs and delay does not appear to be as strong of a causal factor as once thought.

N-nitro-l-arginine, a nitric oxide synthase inhibitor, aggravates iminodipropionitrile-induced neurobehavioral and vestibular toxicities in rats

Exposure of iminodipropionitrile (IDPN) to rodents produces permanent behavioral syndrome characterized by repetitive head movements, circling and back walking. Other synthetic nitriles of industrial importance such as crotonitrile and allylnitrile are also able to produce similar motor deficits in experimental animals. However, due to the well-defined behavioral deficits and their easy quantification, IDPN-induced behavioral syndrome is a preferential animal model to test the interaction of various agents with synthetic nitriles. This study reports the effect of non-specific nitric oxide synthase inhibitor, N-nitro-L-arginine (NARG) on IDPN-induced neurobehavioral toxicity in adult male Wistar rats. Four groups of animals were given i.p. injections of IDPN (100 mg/kg) for 6 days. These rats were treated with oral administration of NARG in the doses of 0 (IDPN alone group), 50, 150 and 300 mg/kg, 60 min before IDPN, respectively. Control rats received vehicle only, whereas another group was treated with 300 mg/kg of NARG alone (without IDPN). The results showed that NARG significantly exacerbated the incidence and intensity of IDPN-induced dyskinetic head movements, circling and back walking. The histology of inner ear showed massive degeneration of the sensory hair cells in the crista ampullaris of rats receiving the combined treatment with IDPN and NARG, suggesting a possible role of nitric oxide in IDPN-induced neurobehavioral syndrome in rats.

An uncommon cause of headache after headbanging at a party

Subdural haematomas can result from bridging vein rupture. Rotational acceleration in the sagittal plane and in a forward direction, as in falls, is very likely the 'mechanical' cause of subdural haematoma, as shown in cadaveric studies. Some recreational activities, for example roller-coaster rides and bungee jumping, have been associated with subdural haematoma, owing to acceleration/deceleration or repetitive head movements. We report a case of chronic subdural haemorrhage in a male teenager without precipitating factors and no history of head trauma. This case shows the value of good history-taking in medical diagnosis and that one should be aware of the risks of violent sports or dancing and the minimal clinical signs encountered.

How barn owls ( Tyto alba) visually follow moving voles ( Microtus socialis) before attacking them

The present study focused on the movements that owls perform before they swoop down on their prey. The working hypothesis was that owl head movements reflect the capacity to efficiently follow visually and auditory a moving prey. To test this hypothesis, five tame barn owls ( Tyto alba) were each exposed 10 times to a live vole in a laboratory setting that enabled us to simultaneously record the behavior of both owl and vole. Bi-dimensional analysis of the horizontal and vertical projections of movements revealed that owl head movements increased in amplitude parallel to the vole's direction of movement (sideways or away from/toward the owl). However, the owls also performed relatively large repetitive horizontal head movements when the voles were progressing in any direction, suggesting that these movements were critical for the owl to accurately locate the prey, independent of prey behavior. From the pattern of head movements we conclude that owls orient toward the prospective clash point, and then return to the target itself (the vole) — a pattern that fits an interception rather than a tracking mode of following a moving target. The large horizontal component of head movement in following live prey may indicate that barn owls either have a horizontally narrow fovea or that these movements serve in forming a motion parallax along with preserving image acuity on a horizontally wide fovea.