Torticollis Research Articles

Development of hardware and algorithms for the wearable monitoring device for the motor activity of the human cervical spine

The article discusses the theoretical prerequisites for the development of a monitoring system for determining the position, movements and tilts of the human head. Purpose of the study: development of hardware and algorithms for the specified system. Results. A three-point model has been developed that takes into account the structural and motor characteristics of the cervical spine. The choice of reference points for installing sensors is justified. Options for moving these sensors for different positions of the human head are shown. The static and dynamic indicators necessary to assess the movements of the cervical spine are described. The developed system is described – a hardware and software complex for monitoring the position, movements and tilts of the human head, a block diagram and the electronic components used are presented. The prospects for further development and application of the developed system are considered. Discussion. The system being developed will become the basis for creating a medical complex that will provide diagnoses related to the violation of the morphological and functional relationship of the blood circulation and the osseous-ligamentous apparatus, support decision-making by the doctor and the possibility of its correction by means of biocontrol.

Mechanisms for Positive Bielschowsky Head Tilt Testing in Horizontal Strabismus

ABSTRACT Purpose To elucidate the induced effects of horizontal strabismus on the Bielschowsky Head Tilt Test (BHTT). Design Prospective clinical study. Methods Prospective analysis of BHTT testing in 85 patients with exotropia and 71 patients with esotropia who were examined in a strabismus clinic. Results Eighty-four of 85 patients with exotropia (98.82%) showed a positive BHTT with an induced hyperdeviation on the side of the tilt (to both sides in 67% and to one side in 32%). Fifty-seven of 71 patients with esotropia (80.2%) showed a positive BHTT with an induced hypodeviation on the side of the tilt (to both sides in 57.7% and to one side in 22.5%). These induced vertical deviations were greater in patients with larger horizontal deviations and in those with constant rather than intermittent deviations; however, they were not influenced by the presence or absence of associated primary oblique muscle overaction. Conclusions Exotropia and esotropia produce hyperdeviations during BHTT testing, with a hyperdeviation on the side of the tilt observed in patients with exotropia, and hypotropia on the side of the tilt observed in patients with esotropia. These diametrical results are not attributable to any preexistent alteration of neurologic output inherent to these two forms of horizontal strabismus or to associated torsion. Rather, they arise directly from the altered anatomical positions of the two eyes, which cause the eyes to approximate their visual axes more closely to the vertical rectus muscles (in exotropia) and the oblique muscles (in esotropia), enabling the vertical actions of specific cyclovertical muscles to predominate in response to altered utricular output generated by the BHTT.

Congenital muscular torticollis

Torticollis is a clinical condition in which there are head tilt on the affected side and chin lift toward the contralateral side. Congenital muscular torticollis is the second most common cause of congenital musculoskeletal deformities. Torticollis is one of the most common causes of postural deformity. Congenital muscular torticollis is the most common cause of torticollis, others being nonmuscular causes. The incidence of congenital muscular torticollis is ranging from 0.2% to 3%. We report a 3-year-old female child with muscular torticollis with facial asymmetry. The child was investigated. Computed tomography was normal. The child was treated with sternocleidomastoid release. In this case, we emphasize the importance of early diagnosis and early intervention.

Torsion and clinical features in patients with acquired fourth cranial nerve palsy

This retrospective study aimed to compare objective/subjective torsion and other clinical characteristics of patients with acquired trochlear nerve palsy. This study included 82 consecutive patients who were diagnosed with acquired fourth cranial nerve palsy between 2014 and 2021 and who were followed up for ≥ 6 months. The etiologies, ocular deviation, objective and subjective torsions were reviewed. The etiologies were classified as ischemic, traumatic, brain lesion, idiopathic, or other. The patients were classified into two groups according to the recovery state: full recovery and partial/no-recovery. We compared the torsion and clinical features based on the etiology and recovery state. The average age was 59.1 ± 11.1 years, and 58 (71.0%) of the patients were male. The most common cause was ischemic (n = 49, 59.7%) and other common causes included traumatic (n = 16, 19.5%), brain lesion (n = 8, 9.8%), idiopathic (n = 5, 6.1%) and others (n = 4, 4.9%). Of the 82 patients, 56 (68.3%) were assigned to the full recovery group, and 26 (31.7%) were assigned to the partial/no-recovery group. The average age and number of patients with ischemic causes of palsy were greater in the full recovery group (p = 0.026 and p < 0.000, respectively). The vertical deviation angle, tilted angle on the Lancaster red-green test (LRGT), proportion of patients who experienced subjective torsion on the LRGT, and head tilt were smaller in the full recovery group (p = 0.037, 0.042, 0.045, and 0.006, respectively). Ischemic trochlear nerve palsy, advanced age, a small deviation angle at the primary position, and few cases of excyclotorsion on LRGT were characteristic of the full recovery group of acquired unilateral trochlear nerve palsy patients.

Conservative treatment of 3- and 4-part proximal humeral fractures: Can poor outcomes be predicted?

3- and 4-part proximal humeral fractures are frequently treated conservatively. This study aims to combine radiographic, and patient reported outcome data to identify factors leading to poor outcomes following conservative treatment. A retrospective local database analysis identified 3- and 4-part fractures. Radiographic and functional outcomes including Oxford Shoulder Score (OSS), QuickDash (QD), Subjective Shoulder Score (SSV) and VAS pain scores were collected. 104 patients were included at mean follow-up of 55months. Analysis highlighted significant OSS differences in 3- versus 4-part (p = 0.027), dominant arm injury (p = 0.046), age > 65 (p = 0.006), varus coronal neck-shaft angle < 115 versus 115-155 degrees (p = 0.008), posterior head tilt > 155 degrees (p = 0.005), greater tuberosity (GT) displacement > 5mm (p = 0.001), GT comminution (p = 0.01), medial calcar hinge displacement > 2mm (p = 0.032). According to QD scores; age > 65 (p = 0.012), varus neck-shaft angle (p = 0.01), GT displacement > 5mm (p = 0.001), GT comminution (p = 0.01), medial calcar hinge displacement > 2mm (p = 0.006). SSV varied significantly with 3- versus 4-part fractures (p = 0.005), age > 65 (p = 0.04), varus neck-shaft angle (p = 0.001), posterior head tilt (p = 0.005), GT displacement > 5mm (p = 0.001), GT comminution (p = 0.003), and medial calcar hinge displacement > 2mm (p = 0.001). We highlight risk factors for unfavourable outcomes following conservative management, aiding surgeons in shared decision-making and patient expectation management.

Effects of core stability and feedback music on upper body mediolateral movements during cycling

BackgroundAsymmetry in involuntary trunk motion during voluntary movements of the lower extremities is a risk factor for musculoskeletal injuries and may be related to core stability. Core stability plays a pivotal role in maintaining postural stability during distal segment movements. Because mediolateral head motion partially represents trunk motion during rhythmic movements, controlling it can help ensure symmetric trunk motion. This study aimed to investigate the relationship between core stability and asymmetric trunk motion during rhythmic movements, and to evaluate the effects of feedback music on mediolateral head motion.MethodsWe developed a system that uses a wireless earbud and a high-resolution inertial measurement unit sensor to measure head angle and provide feedback music. When the head angle exceeds a predefined threshold, the music is muted in the earbud on the side of the head tilt. In our lab-based study, we measured head angles during cycling at 70% of maximum speed using this self-developed system, and compared them between individuals with good (Sahrmann core stability test: 2–5 level) and poor core stability (0–1 level). The amplitude of mediolateral head motion was represented by the difference between the left and right peak angles, and the symmetry in mediolateral head motion was represented by the average of left and right peak angles.ResultsIndividuals with poor core stability demonstrated significantly greater amplitude of, and less symmetry in, mediolateral head motion than those with good core stability. Additionally, feedback music significantly reduced the amplitude of mediolateral head motion in both the good- and poor-core-stability groups.ConclusionOur findings indicate that core stability is crucial for maintaining symmetric head motion during rhythmic movements like cycling. Feedback music could serve as an effective tool for promoting symmetry in head motion and thus preventing musculoskeletal injuries.

Gravity-Dependent Modulation of Downbeat Nystagmus and Subjective Visual Vertical in the Roll Plane

Downbeat nystagmus (DBN) is the most common form of acquired central vestibular nystagmus. Gravity perception in patients with DBN has previously been investigated by means of subjective visual straight ahead (SVA) and subjective visual vertical (SVV) in the pitch and roll planes only during whole-body tilts. To our knowledge, the effect of head tilt in the roll plane on the SVV and on DBN has not yet been systematically studied in patients. In this study, we investigated static and dynamic graviceptive function in the roll-plane in patients with DBN (patients) and healthy-controls (controls) by assessment of the Subjective Visual Vertical (SVV) and the modulation of slow-phase-velocity (SPV) of DBN. SPV of DBN and SVV were tested at different head-on trunk-tilt positions in the roll-plane (0°,30° clockwise (cw) and 30° counterclockwise (ccw)) in 26 patients suffering from DBN and 13 controls. In patients, SPV of DBN did not show significant modulations at different head-tilt angles in the roll-plane. SVV ratings did not differ significantly between DBN patients vs. controls, however patients with DBN exhibited a higher variability in mean SVV estimates than controls. Our results show that the DBN does not exhibit any modulation in the roll-plane, in contrast to the pitch-plane. Furthermore, patients with DBN show a higher uncertainty in the perception of verticality in the roll-plane in form of a higher variability of responses.

Complete ocular tilt reaction with subjective visual vertical tilt in a patient with a medial prefrontal cortex lesion: a case report

A 61-year-old male patient undergoing chemotherapy for esophageal cancer presented with symptoms of rightward tilting while both sitting and walking. A neurological examination revealed a head tilt, skew deviation with hypertrophy of the left eye, and a rightward shift in his gait. No spontaneous nystagmus was observed, and the vestibulo-ocular reflex was normal. Magnetic resonance imaging of the head revealed a suspected metastatic lesion in the right medial prefrontal cortex. Following the initiation of levetiracetam treatment, the patient demonstrated marked improvement, with the resolution of both head tilt and skew deviation within 1 month. Traditionally, the ocular tilt reaction has been attributed to unilateral or asymmetric dysfunction of the graviceptive pathways extending from the utricle to the upper midbrain lesions. However, this case highlights the potential involvement of the prefrontal cortex in the ocular tilt reaction. Further research is warranted on the role of the prefrontal cortex within the vestibular system.

Odds ratio of occurrence of pain, postural changes, and disabilities of violinists

The objective of this study is to evaluate the odds ratio of occurrence of pain, postural changes, and disabilities of violinists. Thirty-eight violinists were assessed. Photographs from anterior, posterior, and lateral views were taken and analyzed using Software of Postural Analysis. Pain was assessed by the Visual Analogue Pain Scale and the musculoskeletal disability of the arm, shoulder, and hand questionnaire (DASH). A logistic regression model was employed and all variables related to posture, age, gender, hours of practice, and duration of practice were considered. The results regarding the VAS and DASH were analyzed using multivariate techniques. The most important variables for the discrimination between the groups regarding the VAS scores were head and shoulder and thoracic kyphosis. For the DASH index, the key variables were the lateral spinal deviation and the head tilt. The odds ratio of occurrence pain was associated with the duration of the practice and the following postural variables: shoulder asymmetries, head postures, and lumbar lordosis. Scapular postures and thoracic kyphosis were associated with hours of practice, and the scapular postures with the duration of practice. This article provides new evidence of occurrence of pain, postural changes and disabilities in violinists. The odds ratio of occurrence pain was associated with the duration of the professional practice.

Safety and efficacy of dynamic catheter-directed cerebral digital subtraction angiography for diagnosis of bowhunter syndrome spectrum disorders: A systematic review of the literature.

Dynamic catheter-directed cerebral digital subtraction angiography (dcDSA) is the gold standard for diagnosing dynamic vascular occlusion syndromes such as bowhunter syndrome (BHS). Nonetheless, concerns about its safety exist and no standardized protocols have been published to date. We describe our methodology and insights regarding the use of dcDSA in patients with BHS. We also perform a systematic literature review to identify cases of typical and atypical presentations of BHS wherein dcDSA was utilized and report on any procedural complications related to dcDSA. Our study included 104 cases wherein dcDSA was used for the diagnosis of BHS. There were 0 reported complications of dcDSA. DcDSA successfully established diagnosis in 102 of these cases. Thirty-eight cases were deemed atypical presentations of BHS. Fourteen patients endorsed symptoms during neck flexion/extension. In eight cases, there was dynamic occlusion of bilateral vertebral arteries during a single maneuver. Three patients had multiple areas of occlusion along a single vertebral artery (VA). An anomalous entry of the VA above the C6 transverse foramen was observed in four patients. One patient had VA occlusion with neutral head position and recanalization upon contralateral lateral head tilt. Our study highlights the safety and diagnostic benefits of dcDSA in characterizing the broad spectrum of BHS pathology encountered in clinical practice. This technique offers a powerful means to evaluate changes in cerebral blood flow and cervical arterial morphology in real time, overcoming the constraints of static imaging methods. Our findings pave the way for further studies on dcDSA to enhance cross-sectional imaging methods for the characterization of BHS and other dynamic vascular occlusion syndromes.

Clinical effect of superior oblique re-tucking for recurrent or residual compensatory head position

Objective: To evaluate the effects of re-tucking the superior oblique muscle on recurrent or residual compensatory head position. Methods: A retrospective case series study was conducted. 12 recurrent or residual compensatory head position patients (12 eyes) with congenital superior oblique palsy who underwent superior oblique re-tucking in Tianjin Eye Hospital from March 2015 to February 2021 were included. All patients had a history of superior oblique tucking procedure and showed signs of superior oblique muscle palsy without inferior oblique muscle overaction. During surgery, the Guyton forced duction test is used to evaluate the relaxation of the superior oblique muscle tendon, which affects the re-tucking length of the muscle.Their head position, vertical deviation, eye movement, fovea-disa angle, and Bielschowsky head tilt test were assessed pre-and post-surgery. Statistical analysis was performed using ttest and paired samples Wilcoxon signed rank test. Results: Out of the 12 patients, 8 were male and 4 were female, aged between 2 and 9 years. The initial surgery was done at age 6, with a superior oblique recession length of (7.17±1.03) mm. Recurrent head tilt occurred in 11 patients after (3.82±0.98) months postoperatively, and 1 patient had residual head tilt, with a followup period of six months or more. Ocular motility examination revealed underaction of the superior oblique muscle, positive Bielschowsky's head tilt test, and Guyton forced duction tese indicating relaxation of the paralyzed superior oblique muscle tendon. Scar adhesion was observed at the stop of the superior oblique muscle, as well as the previous sutures. The scar and the sutures around the stop of the superior oblique muscle were released, the mean re-tucking amount was(7.83±1.59)mm. Follow-up at 12 to 18 months postoperatively showed disappearance of compensatory head position, significant improvement in superior oblique muscle lag, normal ocular motility, and no occurrence of Brown syndrome. The results of Bielschowsky head tilt were negative in 9 cases and still positive in 3 cases after superior oblique re-tucking. The primary vertical deviation was 2.5 (2.0, 5.3) prism diopter pre-operatively and 1 (0, 1) prism diopter post-operatively, respectively. The difference was statistically significant (U=6.00, P<0.001). The total amount of FDA in both eyes was (-22.04±5.47)° and (-15.27±6.08)° pre-and post-operatively, respectively. The difference was statistically significant (t=2.87, P=0.009). All 12 patients have normal eye movement after superior oblique re-tucking procedure. All patients had no compensatory head position at last follow-up. Conclusions: Superior oblique re-tucking is suitable for patients with relaxation of the superior oblique muscle tendon and extrocular rotation as the main sign. It can effectively and safely correct the recurrent or residual compensatory head position after re-tucking the superior oblique muscle.

Effect of smartphone use on cervical spine stability

Using a smartphone often involves a sustained head-forward tilt posture, which may deteriorate the mechanism of muscle reaction efficiency or reduce the stiffness of connective tissues of the cervical spine. These changes in muscular and connective tissues can impair cervical spine stability and contribute to developing neck pain symptoms. In this experiment, change in the cervical spine stability associated with a sustained smartphone use posture was evaluated by quantifying the effective stiffness and the reflexive responses of the head to sudden perturbations. Seventeen young smartphone users maintained their heads tilted forward approximately 30° for 30 min while watching videos on their smartphones in sitting. Data show that the measures of cervical spine stability did not change significantly after the smartphone use task despite developing mild to moderate neck and upper body discomfort symptoms. Study findings imply that keeping the head tilt posture for 30 min for smartphone use did not significantly alter spinal stability, rejecting its association with neck discomfort.

Protective human monoclonal antibodies target conserved sites of vulnerability on the underside of influenza virus neuraminidase

Continuously evolving influenza viruses cause seasonal epidemics and pose global pandemic threats. Although viral neuraminidase (NA) is an effective drug and vaccine target, our understanding of the NA antigenic landscape still remains incomplete. Here, we describe NA-specific human antibodies that target the underside of the NA globular head domain, inhibit viral propagation of a wide range of human H3N2, swine-origin variant H3N2, and H2N2 viruses, and confer both pre- and post-exposure protection against lethalH3N2 infection in mice. Cryo-EM structures of two such antibodies in complex with NA reveal non-overlapping epitopes covering the underside of the NA head. These sites are highly conserved among N2 NAs yet inaccessible unless the NA head tilts or dissociates. Our findings help guide the development of effective countermeasures against ever-changing influenza viruses by identifying hidden conserved sites of vulnerability on the NA underside.

Visual cues influence prosody perception among individuals with cochlear implants

Understanding a talker’s intention conveyed through prosody is essential for successful speech communication. Although visual speech cues are typically characterized by lip movements, there are also visual gestures including head tilts and eyebrow raises that signal prosody. Listeners with cochlear implants (CIs) may rely on these visual cues to solidify their prosody perception and guard against misinterpretations, particularly because of their poor perception of voice pitch. This study used audio-visual recordings of sentences in which a talker sometimes focused one word to signify a change in meaning. After characterizing acoustic and visual prosody cues in this stimulus set, we made prosodically mismatched variants of the stimuli by transplanting prosodically focused audio onto broad focus (i.e., prosodically unfocused) video, and vice versa. Visual influences on prosody perception were measured using acoustic analysis of participant reproductions in a vocal mimicry task. Results show reproduction of F0 contour—a key acoustic marker of prosodic focus—is influenced by perception of visual prosody cues. Specifically, visual cues indicating a focused word led to higher peak F0 in vocal reproductions of that word in the sentence. These results underscore the importance of multisensory information in supporting prosody perception for listeners with hearing loss.

Symptom reduction in mal de débarquement syndrome with attenuation of the velocity storage contribution in the central vestibular pathways.

The velocity storage mechanism of the central vestibular system is closely associated with the vestibulo-ocular reflex (VOR), but also contributes to the sense of orientation in space and the perception of self-motion. We postulate that mal de débarquement syndrome (MdDS) is a consequence of inappropriate sensory adaptation of velocity storage. The premise that a maladapted velocity storage may be corrected by spatial readaptation of the VOR has recently been translated into the development of the first effective treatment for MdDS. However, this treatment's initial impact may be reversed by subsequent re-triggering events. Presently, we hypothesized that MdDS symptoms could alternatively be reduced by attenuating the velocity storage contribution in the central vestibular pathways. Forty-three patients with MdDS (aged 47 ± 14 yo; 36 women) were randomly assigned to two treatment groups and followed for 6 months. The horizontal VOR was tested with chair rotation during laboratory visits, and the strength of velocity storage was quantified with model-based parameters-the time constant (Tc) and the gain of coupling from the vestibular primary afferent signals (g0). To attenuate velocity storage, Group 1 underwent a progressively intensifying series of low-frequency earth-vertical oscillatory rotation coupled to conflicting visual stimuli. Group 2 underwent an established protocol combining head tilts and visual stimulation, designed to correct maladapted spatial orientation but not change the velocity storage strength. The symptom severity was self-rated on an 11-point scale and reported before and up to 6 months after the treatment. In Group 1, velocity storage was modified through reduction of g0 (p < 0.001) but not Tc. The symptom rating was at least halved initially in 43% of Group 1 (p = 0.04), the majority of whom retained a similar level of improvement during the 6-month follow-up period. In Group 2, no systematic change was induced in the parameters of velocity storage strength, as expected. The symptom rating was at least halved initially in 80% of Group 2 (p < 0.001), but paralleling previous findings, symptoms often returned subsequently. Attenuation of velocity storage shows promise as a lasting remedy for MdDS that can complement the VOR readaptation approach.

Anisotropy of the R1/T2* value dependent on white matter fiber orientation with respect to the B0 field

The R1 (1/T1) map divided by the T2* map (R1/T2* map) draws attention as a high-resolution myelin-related map. However, both R1 and R2* (1/T2*) values demonstrate anisotropy dependent on the white matter (WM) fiber orientation with respect to the static magnetic (B0) field. Therefore, this study primarily aimed to investigate the comprehensive impact of these angular-dependent anisotropies on the R1/T2* value.This study enrolled 10 healthy human volunteers (age = 25 ± 1.3) on the 3.0 T MRI system. For R1/T2* map calculation, whole brain R1 and T2* maps were repeatedly obtained in three head tilt positions by magnetization-prepared two rapid gradient echoes and multiple spoiled gradient echo sequences, respectively. Afterward, all maps were spatially normalized and registered to the Johns Hopkins University WM atlas. R1/T2*, R1, and R2* values were binned for fiber orientation related to the B0 field, which was estimated from diffusion-weighted echo-planar imaging data with 3° intervals, to investigate angular-dependent anisotropies in vivo.A larger change in the R1/T2* value in the global WM region as a function of fiber orientation with respect to the B0 field was observed compared to the R1 and R2* values alone. The minimum R1/T2* value at the near magic-angle range was 18.86% lower than the maximum value at the perpendicular angle range. Furthermore, R1/T2* values in the corpus callosum tract and the right and left cingulum cingulate gyrus tracts changed among the three head tilt positions due to fiber orientation changes. In conclusion, the R1/T2* value demonstrates distinctive and complicated angular-dependent anisotropy indicating the trends of both R1 and R2* values and may provide supplemental information for detecting slight changes in the microstructure of myelin and axons.

The Duplicity of Incidents: Cervical Lymphatic Malformation in two Newborns

We report on two neonates born the same day, both with an isolated cervical lymphatic malformation. Cervical masses were detected by ultrasound late in the third trimester. Following interdisciplinary case conferences, a caesarean section in the presence of a neonatal team was the chosen delivery mode in both cases. Delivery and transition of the newborns were uneventful. The suspected diagnosis was confirmed by postnatal MRIs, which demonstrated neither associated malformations nor compression of vital structures. Therefore, an expectant approach was chosen for the newborn with the smaller lesion. The other newborn featured a sizeable lymphatic malformation, and due to consecutive head tilt, sclerotherapy was initiated in its second week of life. Our case report outlines the challenges of a rare connatal malformation. Guidelines are often missing. Individual decisions regarding delivery mode, diagnostics and therapy have to be made on an interdisciplinary basis and patients as well as parents need counseling and support over a long period. All the more significant is good, interdisciplinary collaboration between the involved disciplines.

Comparison of Three Airway Maneuvers of Jaw Thrust, Two-Handed E-C Technique With Head in Neutral Position, and Two-Handed E-C Technique With Head Fully Extended: A Prospective, Randomized, Double-Blind Crossover Study.

Background Bag-mask ventilation is an essential life-saving skill. The E-C technique of mask holding is the most popular. In patients with suspected cervical injury, the jaw thrust maneuver is recommended instead of the E-C technique with head tilt-chin lift. Should jaw thrust fail to produce adequate chest rise, the operator is advised to switch to the E-C technique with the head tilt-chin lift maneuver with head extension as it is vital to move oxygen into the lungs. We hypothesized that the E-C clamp with the head in the neutral position without head tilt might permit adequate ventilation without producing excessive movement of the cervical spine, which in turn might translate as less strain to the cervical spine. Methods In this prospective, randomized, double-blind, crossover study, we evaluated the relative efficacy of three airway maneuvers in opening the airway in anesthetized and paralyzed adults: jaw thrust, two-handed E-C technique with head in the neutral position, and two-handed E-C technique with head fully extended. The tidal volume generated during mechanical ventilation using these three techniques was considered as the primary outcome. Seventy-two subjects were recruited for this trial and all three techniques of mask holding were performed in each of these subjects in a sequence as dictated by a randomization table. Results The jaw thrust technique provided a mean tidal volume significantly higher than the two-handed E-C technique, with the head in the neutral position (p<0.001). Similarly, the two-handed E-C technique with the head fully extended provided a mean tidal volume significantly higher than the two-handed E-C technique with the head in neutral position (p<0.011). The mean tidal volume obtained with jaw thrust and two-handed E-C technique with head fully extended were comparable (p=0.78). Conclusion The two-handed E-C technique with the head fully extended, and the jaw thrust technique both produce good and comparable tidal volumes. The two-handed E-C technique with the head in a neutral position provides adequate though lower tidal volumes as compared to the other two techniques.

Facial and mandibular landmark tracking with habitual head posture estimation using linear and fiducial markers.

This study compared the accuracy of facial landmark measurements using deep learning-based fiducial marker (FM) and arbitrary width reference (AWR) approaches. It quantitatively analysed mandibular hard and soft tissue lateral excursions and head tilting from consumer camera footage of 37 participants. A custom deep learning system recognised facial landmarks for measuring head tilt and mandibular lateral excursions. Circular fiducial markers (FM) and inter-zygion measurements (AWR) were validated against physical measurements using electrognathography and electronic rulers. Results showed notable differences in lower and mid-face estimations for both FM and AWR compared to physical measurements. The study also demonstrated the comparability of both approaches in assessing lateral movement, though fiducial markers exhibited variability in mid-face and lower face parameter assessments. Regardless of the technique applied, hard tissue movement was typically seen to be 30% less than soft tissue among the participants. Additionally, a significant number of participants consistently displayed a 5 to 10° head tilt.

Diagnosis of lymphoma based on magnetic resonance imaging, analysis of cerebrospinal fluid, intraocular fluid and fine‐needle aspirate of a uveal mass lesion in a dog

AbstractA 10.5‐year‐old, male, entire labrador retriever dog was presented for chronic progressive ataxia and recent onset of a left‐sided head tilt and salivation. Neurological examination findings were deemed consistent with a multifocal brain and spinal cord neuroanatomic localisation. Ophthalmological examination of the right eye revealed pupil shape abnormality (dyscoria), a pale uveal mass lesion and white cellular sediment in the anterior chamber. Magnetic resonance imaging of the brain, eyes, thoracolumbar and lumbosacral spinal cord and surrounding structures showed multiple lesions affecting the central nervous system (brain), peripheral nervous system (left trigeminal nerve) and right eye. Cerebrospinal fluid, right eye anterior chamber fluid and fine‐needle aspirate biopsy of the uveal mass lesion yielded a cytological diagnosis of lymphoma (suspected large granular lymphocytic). The dog was discharged with palliative treatment and euthanased at home 4 days later. This case report documents the cytological diagnosis of lymphoma in the cerebrospinal fluid, intraocular fluid and fine‐needle aspirate of a uveal mass in a dog.