Properties and localization of the anterior semicircular canal-activated vestibulocollic neurons in the cat

Summary Unit activites of secondary vestibular neurons that selectively responded to stimulation of the anterior semicircular canal nerve (ACN) were recorded extracellularly in the anesthetized cat. Axonal pathways and projections in the spinal cord of the ACN-activated neurons were examined by recording their antidromic responses to stimulation of the lateral and medial vestibulospinal tracts (LVST and MVST), and the bilateral neck extensor motoneuron pools in the C₁segment (C₁dorsal rami [DR] motoneuron pools). In order to determine whether the neurons had ascending axon collaterals to the extraocular motoneurons, the contralateral (c-) inferior oblique (IO) motoneuron pool was also stimulated. Twenty-seven neurons sent their axons to the ipsilateral (i-) C₁DR motoneuron pool via the LVST without any projection to the extraocular motoneuron pool. All the cells except one were located in the ventral part of the lateral vestibular nucleus. This pathway produced monosynaptic EPSPs with short time-to-peak and short half-width in C₁DR motoneurons (16/16 motoneurons). Eight neurons sent axons to the i-C₁DR motoneuron pool via the MVST without any to the extraocular motoneuron pool. Cell somata were located in the descending nucleus or in the ventral part of the lateral nucleus. These neurons did not produce postsynaptic potentials (PSPs) in any C₁DR motoneurons. All thirty-five neurons sending axons to the c-C₁DR motoneuron pool have ascending axon collaterals to the c-IO motoneuron pool.     

Transcutaneous electrical stimulation and vibration of neck muscles in neglect

Four neglect patients without visual field defects, one with a lesion of the right basal ganglia and three with a right, predominantly parietal lesion, were examined with a cancellation and a copying task before, during and after neck muscle vibration, during transcutaneous electrical stimulation of neck muscles and during vibration of hand muscles on the left side. In all patients, neck muscle vibration improved task performance, while transcutaneous electrical stimulation and hand vibration had little or no effect. The present results demonstrate that the effect of neck muscle vibration cannot be explained as arousal and activation due to unspecific sensory stimulation on the contralesional side of the body. They rather argue for the assumption that the compensatory effect of neck muscle vibration on neglect is an effect induced by the predominant activation of afferent Ia nerve fibres and their specific contribution to the central representation of egocentric space.     

Neuronal responses to horizontal neck deflection in the group X region of the cat's medullary brainstem

Summary Neuronal responses to natural stimulation of neck proprioceptors were studied in the region of the small cell group x in the dorsolateral medullary brainstem of slightly anesthetized and paralyzed cats. Stimulation consisted of horizontal trunk rotations about C₁ with the head fixed in space. Out of 74 neurons recorded, 92% showed an increase in discharge rate with ipsilateral neck stretch and a decrease with contralateral stretch (Type N I responses); 8% showed the reverse response pattern (Type N II responses). In the primary head-to-trunk position, almost all neurons had tonic activity that probably stemmed from prestretched neck proprioceptors. Responses to sinusoidal stimulation and position trapezoids showed a static (position-sensitive) as well as a dynamic (essentially velocitysensitive) component. The relative weight of the two components varied considerably among the neurons. It was not possible to distinguish discrete neuronal populations on the basis of the dynamic characteristics. There was no evidence of a convergent input from other receptor systems, such as the horizontal canal system. Several neurons responded to muscle tapping and showed an increase of the velocity component following systemic injection of succinylcholine. We take this as evidence that they may receive input from muscle spindle receptors.Supported by the Deutsche Forschungsgemeinschaft, SFB 70/U4     

Participation of Ia reciprocal inhibitory neurons in the spinal circuitry of the tonic neck reflex

Summary As part of our studies of the spinal circuitry of the tonic neck reflex, we have recorded extracellularly from Ia reciprocal inhibitory neurons of the decerebrate, labyrinthectomized cat. The activity of a majority of neurons driven by stimulation of the quadriceps nerve was modulated by sinusoidal rotation of the neck; such modulation was much less frequent in the case of neurons driven by stimulation of nerves to more distal muscles. The results suggest that some of the inhibition which is part of the tonic neck reflex is mediated by Ia reciprocal inhibitory neurons, but that other pathways must also play an important role.     

颈部囊肿与瘘管的诊断和治疗

目的：总结颈部囊肿与瘘管的诊治经验。方法：93例行手术治疗,其中鳃裂囊肿15例,鳃裂瘘管10例,皮样囊肿1例,囊状淋巴管瘤4例,甲状舌骨囊肿37例,甲状舌管瘘管25例,癌性淋巴液囊肿1例,随访1－10年。结果：93例中,囊性淋巴管瘤1例复发后失访,另1例行2次手术,癌性淋巴液囊肿1例半年后死于肺转移,鳃裂瘘管2例3次手术,甲状舌管瘘管1例复发,鳃裂瘘管术后1例迟发性面瘫,一次手术治愈,无术后并发症。结论：颈部囊肿与瘘管的诊断除依据术前检查外,主要是依据术中的发现和术后病理检查。B超、CT等是有效的辅助检查.手段治疗上应彻底切除囊壁与瘘管,避免复发。术中应避免损伤颈部的大血管和神经。甲状舌管瘘管须切除舌骨中段2cm,这是防止术后复发的关键。     

铜绿假单胞菌注射液治疗甲状腺乳头状癌颈侧区淋巴结清扫术后淋巴漏的临床观察

背景与目的 淋巴漏为颈部淋巴结清扫术后常见并发症,传统治疗方法作用相对有限,而铜绿假单胞菌注射液处理创面可较好促进局部炎症反应以闭合漏点,因此本研究分析铜绿假单胞菌注射液对甲状腺乳头状癌（PTC）颈侧区淋巴结清扫术后淋巴漏患者引流量的影响及安全性,以明确铜绿假单胞菌注射液的应用价值。方法 回顾性分析2019年1月—2020年1月郑州大学第一附属医院甲状腺外科行颈侧区淋巴结清扫术后出现淋巴漏的69例PTC患者资料,依据淋巴漏治疗方式不同将其分为对照组（37例,术中常规双侧留置负压引流）、观察组（32例,在对照组治疗的基础上,术后第4、6天,通过引流管注入2支铜绿假单胞菌注射液）,比较两组术后引流量、体温变化,记录其引流时间及不良反应发生率。结果 两组术后第1、2、3天引流量比较差异无统计学意义（均P>0.05）,观察组术后第4、5、6天引流量低于对照组［（310.79±32.16）mL vs.（338.64±34.55）mL、（157.82±16.43）mL vs.（325.43±33.96）mL、（87.34±8.59）mL vs.（333.68±34.59）mL,均P<0.05］;观察组术后第6、7 天体温高于对照组［（37.78±3.77）℃ vs.（35.96±3.60）℃、（37.65±3.72）℃ vs.（35.79±3.68）℃,均P<0.05］,其他时点两组体温差异均无统计学意义（均P>0.05）;观察组引流时间明显短于对照组［（6.17±0.63）d vs.（7.28±0.75）d,P<0.01］;观察组部分患者术后2周内出现局部发热、寒战不良反应,予以物理降温后均恢复正常,观察组术后不良反应发生率高与对照组（12.50% vs. 8.11%）,但差异无统计学意义（P>0.05）。结论 铜绿假单胞菌注射液治疗PTC患者颈侧区淋巴结清扫术后淋巴漏患者临床效果较好,可降低引流量,缩短引流时间,部分患者可能有体温升高、发热等现象,经对症处理后均可缓解,不影响治疗。     

Atlantoaxial instability in a patient with neck pain and rheumatoid arthritis

Context: The purpose of this report is to describe the clinical decision-making process for a patient with rheumatoid arthritis with neck pain with underlying atlantoaxial instability.Findings: The patient was evaluated for worsening upper neck pain that began insidiously 1 year prior. The patient denied numbness or tingling in her upper or lower extremities, dizziness or lightheadedness, difficulty maintaining balance with walking, or muscle weakness. Cervical spine range of motion was limited in all planes due to pain and apprehension. The patient’s neurological examination was unremarkable. Prior flexion and extension radiographs of the cervical spine were interpreted as unremarkable with alignment preserved in flexion and extension. However, upon further inspection, the cervical spine flexion radiograph was concerning for inadequate cervical motion, which may have limited the diagnostic utility of these radiographs. Additionally, a Sharp-Purser test was performed, which was positive for excessive motion. Flexion and extension radiographs of the cervical spine were then repeated ensuring the patient adequately flexed and extended during the imaging. Severe anterior subluxation of C1 relative to C2 with cervical flexion was noted, as C1 moved as much as 8–9 mm anterior to C2 with cervical flexion. Given the degree of atlantoaxial instability, the patient subsequently underwent successful posterior fusion from the occiput to C2.Conclusion/Clinical Relevance: This case report demonstrates the importance of properly screening for upper cervical spine instability in patients with rheumatoid arthritis and neck pain and understanding the importance of obtaining adequate and appropriate diagnostic imaging.     

Effects of myofascial release applied to neck muscles and craniocervical flexor training in patients with chronic myofascial TMD: A single arm study

ObjectiveTo evaluate the effects of myofascial trigger point release applied to superficial neck muscles and strengthening of the deep flexor muscles in subjects with myofascial temporomandibular disorders (mTMD).MethodsFourteen women (23.4 ± 3.32 years old) presenting with mTMD and trigger points (TrPs) in the sternocleidomastoid, suboccipital, and upper trapezius muscles were included in this study. They were evaluated on two occasions during a baseline period (3 weeks apart) with no intervention and a third time after a 5-weeks intervention protocol. Outcome measures included pressure pain threshold (PPT) over the masticatory muscles, mandibular function, orofacial pain intensity, maximum mouth opening, and the craniocervical flexion test. All women received 10 treatment sessions that included strain-counterstrain technique applied to TrPs found in the prior listed superficial neck muscles and stabilization exercise using a pressure biofeedback for the deep neck flexor muscles. One-way ANOVA or correspondent non-parametric tests as well as effects sizes were used to compare the outcomes at baseline and after the treatment.ResultsStatistically significant improvements were found in the PPT over left masseter and temporalis (p < 0.05) (mean difference (MD) of 0.50 and 0.42 kg/cm²), orofacial pain intensity (MD = −3.39 points), mandibular function (MD = −7.22 points) and performance of the deep cervical muscles (MD = 130.42 points) compared to baseline period. Effect sizes were moderate or large.ConclusionThe protocol intervention may have positive effects in patients with mTMD. However, studies with better methodological quality need to be performed to confirm those effects.Registrationensaiosclinicos.gov.br (RBR-7x828q);     

Functional coupling of the stabilizing eye and head reflexes during horizontal and vertical linear motion in the cat

Summary The otolith contribution and otolith-visual interaction in eye and head stabilization were investigated in alert cats submitted to sinusoidal linear accelerations in three defined directions of space: up-down (Z motion), left-right (Y motion), and forward-back (X motion). Otolith stimulation alone was performed in total darkness with stimulus frequency varying from 0.05 to 1.39 Hz at a constant half peak-to-peak amplitude of 0.145 m (corresponding acceleration range 0.0014–1.13 g) Optokinetic stimuli were provided by sinusoidally moving a pseudorandom visual pattern in the Z and Y directions, using a similar half peak-to-peak amplitude (0.145 m, i.e., 16.1°) in the 0.025–1.39 Hz frequency domain (corresponding velocity range 2.5°–141°/s). Congruent otolith-visual interaction (costimulation, CS) was produced by moving the cat in front of the earth-stationary visual pattern, while conflicting interaction was obtained by suppressing all visual motion cues during linear motion (visual stabilization method, VS, with cat and visual pattern moving together, in phase). Electromyographic (EMG) activity of antagonist neck extensor (splenius capitis) and flexor (longus capitis) muscles as well as horizontal and vertical eye movements (electrooculography, EOG) were recorded in these different experimental conditions. Results showed that otolith-neck (ONR) and otolith-ocular (OOR) responses were produced during pure otolith stimulation with relatively weak stimuli (0.036 g) in all directions tested. Both EMG and EOG response gain slightly increased, while response phase lead decreased (with respect to stimulus velocity) as stimulus frequency increased in the range 0.25–1.39 Hz. Otolith contribution to compensatory eye and neck responses increased with stimulus frequency, leading to EMG and EOG responses, which oppose the imposed displacement more and more. But the otolith system alone remained unable to produce perfect compensatory responses, even at the highest frequency tested. In contrast, optokinetic stimuli in the Z and Y directions evoked consistent and compensatory eye movement responses (OKR) in a lower frequency range (0.025–0.25 Hz). Increasing stimulus frequency induced strong gain reduction and phase lag. Oculo-neck coupling or eye-head synergy was found during optokinetic stimulation in the Z and Y directions. It was characterized by bilateral activation of neck extensors and flexors during upward and downward eye movements, respectively, and by ipsilateral activation of neck muscles during horizontal eye movements. These visually-induced neck responses seemed related to eye velocity signals. Dynamic properties of neck and eye responses were significantly improved when both inputs were combined (CS). Near perfect compensatory eye movement and neck muscle responses closely related to stimulus velocity were observed over all frequencies tested, in the three directions defined. The present study indicates that eye-head coordination processes during linear motion are mainly dependent on the visual system at low frequencies (below 0.25 Hz), with close functional coupling of OKR and eye-head synergy. The otolith system basically works at higher stimulus frequencies and triggers Synergist OOR and ONR. However, both sensorimotor subsystems combine their dynamic properties to provide better eyehead coordination in an extended frequency range and, as evidenced under VS condition, visual and otolith inputs also contribute to eye and neck responses at high and low frequency, respectively. These general laws on functional coupling of the eye and head stabilizing reflexes during linear motion are valid in the three directions tested, even though the relative weight of visual and otolith inputs may vary according to motion direction and/or kinematics.