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H Kingma

Publications and source records attributed to H Kingma.

At least 19 recordsLinked to original sources
PubMed2006

Functional outcome of treatment of Ménière's disease with the Meniett pressure generator.

CONCLUSION: Use of the Meniett pressure generator in patients with active Ménière's disease (MD) did not affect labyrinthine function. OBJECTIVE: To investigate whether application of the Meniett pressure generator in patients with active MD significantly affects their labyrinthine function. MATERIAL AND METHODS: We measured hearing and labyrinth sensitivity in patients with established MD according to American Academy of Otolaryngology-Head and Neck Surgery (AAO-HNS) criteria at five different time periods: at baseline; before ventilation tube placement; before Meniett treatment; immediately after Meniett treatment; and 1 month after cessation of Meniett treatment. RESULTS: A total of 32 patients met the inclusion criteria and were included in the study. They were graded as having definite MD (AAO-HNS stages 2 and 3). No statistically significant changes in labyrinthine function were found during Meniett treatment.

Adult↗
PubMed2005

Thresholds for perception of direction of linear acceleration as a possible evaluation of the otolith function.

BACKGROUND: Previous attempts to measure otolith function using ocular counter-rolling have shown poor sensitivity and specificity, thereby hindering a useful clinical application. We have conducted a study to investigate whether thresholds for the perception of the direction of linear acceleration might be an alternative for the clinical evaluation of otolith or statolith function. METHODS: Perception of the direction of motion was evaluated in 28 healthy subjects while all external auditory and visual cues were eliminated. Whole body motion stimulus was generated by a motor driven linear sled at a stimulus frequency of 1 Hz at a linear acceleration ranging from 0 to maximum 40 cm/s2. Subjects were required to correctly indicate the direction of motion (anterior-posterior or lateral) or whether they were stationary. Both velocity and acceleration thresholds were measured. RESULTS: The median acceleration thresholds for the perception of direction of linear movement for anterior-posterior movement was 8.5 cm/s2 and for lateral movement 6.5 cm/s2. According to the literature, acceleration thresholds depend on the stimulus profile whereas velocity thresholds do not. The median velocity thresholds for the perception of direction of linear movement for anterior-posterior movement was 13.5 cm/s and for lateral movement was 10.4 cm/s. The median velocity thresholds for the perception of direction of linear movement for anterior-posterior movement increased linearly with age, whereas the median velocity threshold for lateral movement was not correlated with age. CONCLUSION: The thresholds found in this study are lower than reported in the literature before which may be due to the repetitive predictive sinusoidal stimulus which makes it relatively easy to lower the threshold by learning already within one test profile. The variability is large in line with the previous literature, but our experiments indicate that variability decreases after a training session. We interpret the literature and our current results that linear velocity thresholds after some training might reflect the sensitivity of the otolith system per se.

Journal Article↗
PubMed2002

The influence of eye muscle surgery on shape and relative orientation of displacement planes: Indirect evidence for neural control of 3D eye movements.

Is Listing's law a consequence of 2D control of eye positioning, where eye torsion is determined by the biomechanical properties of the orbit, or is it a reflection of full 3D neuronal control? This was investigated by observing the influence of a change in mechanical properties of the eye socket on 3D eye movements. The shape and relative orientation of displacement planes were measured using scleral search coils before and after operation of five patients with strabismus. The operation influenced the shape of displacement planes in both eyes of all patients. After the operation, most patients obeyed Listing's law more accurately: a monocular, surgically induced, orbital change caused binocular improvements of torsional control. The relative orientation of planes also changed, but no clear relationship was found between the type of operation and the direction of rotation. The results suggest that Listing's law is not just a result of the biomechanical properties of the eye socket, but has a neural basis.

Adult↗
PubMed2001

The internal vertebral venous plexus prevents compression of the dural sac during atlanto-axial rotation.

Deformation of the extradural space and the possibility of impression upon the dural sac during atlanto-axial rotation are investigated. Atlanto-axial rotation leads to a reduction in the cross-sectional area of the bony spinal canal of approximately 40%. Atlanto-axial rotation was recorded by endocanalar views from a video camera fixed inside the skull of six unembalmed cadavers. Axial thin-section T1-weighted MRI slice sets were acquired from three volunteers (mid-position and maximal left and right rotation of the head and cervical spine). The axial cross-sectional areas of the bony spinal canal, dural sac and spinal cord were measured. In two other persons post-gadolinium contrast-enhanced T1-weighted MRI volume scans with fat-suppression prepulse were acquired (mid-position and rotation) to determine venous contents of the extradural space. The 50:50 ratio between left and right extradural halves in mid-position changed to an ipsilateral:contralateral ratio of 20:80 in maximum rotation at the level just above the lateral C1-C2 joints. Directly below these joints the opposite occurred. The post-contrast studies showed an enhancing internal vertebral venous plexus (IVVP), which almost completely occupied the extradural space at the atlanto-axial level. This could not be shown in the cadaver experiments, because of absence of blood and cerebrospinal fluid (CSF) pressure. During atlanto-axial rotation blood displacement in the IVVP allows major deformations of the extradural space. This prevents dural sac impression.

Aged↗
PubMed2001

CT study of craniovertebral rotation in whiplash injury.

The present study investigates the diagnostic value of rotatory computed tomography (CT) examinations in normal subjects and patients with whiplash associated disorders (WAD), with the aim of reproducing earlier findings of rotatory CT studies. Forty-seven WAD patients with persistent complaints after a rear-end collision (non-cranial contact acceleration/deceleration trauma) were enrolled in this study. To guarantee a maximally homogeneous study population, only WAD patients with a marked passive cervical retroflexion restriction were included. Transversal CT slices in left and right rotation were made for all cervical levels (the skull included). CT slices in neutral position were used to reconstruct partially depicted vertebrae. Absolute rotatory values were estimated according the method of Penning and Dvorak. For all levels the relative rotatory (RR) value was calculated by dividing absolute rotation values of a particular cervical level by the corresponding total cervical rotation. The measuring error was estimated by comparing the findings of two separately performed measuring procedures. Two age groups of WAD patients were formed. A younger group was matched for age with 26 normal healthy volunteers (the original data of an earlier study). The use of neutral CT slices for reconstruction of a partially depicted cervical vertebra resulted in a measurement error of 1.9 degrees at the level of C0/C1 (occiput/atlas) and 3.5 degrees at C1/C2. Suspected hypermobility as defined by Dvorak was rare in our WAD patients (6.4% C0/C1 and 10.6% C1/C2). RR values at C0/C1 were significantly larger in 79% of the WAD patients. Discriminant analysis of the RR values showed 80% correctly classified WAD patients. Only 11.5% of the normal subjects were classified as false-positive. Since no hypermobility was found at C1/C2, a traumatic lesion of the alar ligaments is less likely. It was concluded that the use of absolute rotation values in rotatory CT scan procedures has a low diagnostic value in WAD patients. Excessive RR values were only found at C0/C1. A traumatic lesion of the ligaments at C0/C1, which prevent vertical translation of the skull with regard to the atlas, is hypothesised. The results of the discriminant analysis of the RR values make this method applicable for the individual WAD patient in daily practice.

Adult↗
PubMed2000

Effects of spatial and symbolic precues on localization performance.

One of the fundamental properties of spatial vision is the ability to localize objects in space. According to a recent proposal, accurate localization performance involves the operation of two systems: the attention system and the eye movement system. Upon stimulus presentation, attention is shifted to the target area: this provides coarse location information. Subsequently, a saccadic eye movement is executed: this provides fine location information. In this study we tested predictions derived from this model concerning the effects of precue information on localization performance. In a series of five experiments we manipulated duration of precue (71, 400, and 1,000 ms) and type of precue (spatial versus symbolic). Results showed that very short duration (i.e., 71 ms) spatial precues improved localization performance whereas very short duration symbolic precues did not. In contrast, the 1,000 ms duration precue condition showed similar amounts of precuing benefit for the spatial and symbolic precues. This pattern of differential precuing effects corroborated the two-process model of localization performance.

Adult↗
PubMed2000

Control of rapid aimed hand movements: the one-target advantage.

A series of 8 experiments examined the phenomenon that a rapid aimed hand movement is executed faster when it is performed as a single, isolated movement than when it is followed by a second movement (the 1-target advantage). Three new accounts of this effect are proposed and tested: the eye movement hypothesis, the target uncertainty hypothesis, and the movement integration hypothesis. Data are reported that corroborate the 3rd hypothesis, but not the first 2 hypotheses. According to the movement integration hypothesis, the first movement in a series is slowed because control of the second movement may overlap with execution of the first. It is shown that manipulations of target size and movement direction mediate this process and determine the presence and absence of the 1-target advantage. Possible neurophysiological mechanisms and implications for motor control theory are discussed.

Adult↗
PubMed2000

Dizziness in discus throwers is related to motion sickness generated while spinning.

While both discus and hammer throwing involve rotating movements resulting in the throw of an object, discus throwers sometimes report dizziness, a condition never experienced by hammer throwers. We investigated whether this susceptibility was related to the sensitivity of the thrower or to the type of throwing achieved. For the latter, we compared the determining features of gesture, gaze stabilization and projectile trajectory in both sports. A total of 22 high-level sportsmen in these 2 disciplines, half of them practising both sports, were interviewed. Slow motion video recordings of discus and hammer throwing were examined to determine the visual referential, head movements and plantar surface support area involved at each stage of the motions. Discomfort was reported by 59% of the sportsmen while throwing discus, but by none while throwing hammer. Because several individuals practised both sports, these results exclude the hypothesis of individual susceptibility to dizziness. Video analysis evidenced that during hammer throwing, visual bearings can be used more easily than during discus throwing. Moreover, there is a loss of plantar afferents and generation of head movements liable to induce motion sickness, such as Coriolis acceleration. In conclusion, although hammer and discus-throwing present numerous similarities, we demonstrate here that crucial differences in the specific execution of each sport are responsible for the dizziness experienced by discus throwers.

Adult↗
PubMed2000

Vestibular ocular reflexes in Ménière's disease patients evaluated by passive high frequency head rotation (yaw) and sidewards acceleration.

Despite the fact that vertigo is the most apparent complaint at the onset of Ménière's disease, standard vestibular examination seldom shows vestibular function loss in the early phase. In this study, three relatively advanced diagnostic tests (passive high frequency head shaking, passive head impulse test and sidewards linear acceleration) were applied to trace vestibular function loss in the early phase in 25 patients with possible Ménière's disease (American Academy of Otolaryngology-Head and Neck Surgery 1995 criteria); one test (passive high frequency head shaking) was also conducted in 20 chronic definite Ménière's disease patients. Head movements were induced by a head shaker and whole-body linear translation by a motor-driven linear slit. Eye movements were detected by electro-oculography (head shaking) and the scleral coil technique (impulse test and linear translation). Standard vestibular examination showed no vestibular function loss in the early phase patient group. In contrast, 17 out of 25 patients (68%) showed a phase lag upon head shaking that was 1-2 degrees larger than the 95% confidence interval in healthy subjects; the remaining 8 patients showed a normal phase lag. Gain was normal in all 25 patients. In the chronic patient group, standard vestibular examination was abnormal (calorics) in 16 out of 20 patients (60%) and 18 out of 20 (90%) showed an abnormal phase on passive head shaking. In 11 of the 25 early phase patients (44%), an increased latency was observed in the response to a passive head impulse to one side. The side to which the abnormal latency occurred did not correspond to the documented or reported side of the hearing loss in 2 out of the 11 patients. The amplitude of ocular counter rolling induced by sidewards sinusoidal translation was reduced in 17 out of the 25 early phase Ménière's disease patients, of whom 6 showed a normal head impulse and head shaking test. Our findings indicate that vestibular function loss occurs in Ménière's disease patients within 9 months of the first vertigo attack. Also, the results support the hypothesis that, at least in some patients, function loss in the statolith system might precede function loss in the horizontal canals.

Acceleration↗
PubMed2000

Balance control near the limit of stability in various sensory conditions in healthy subjects and patients suffering from vertigo or balance disorders: impact of sensory input on balance control.

The large inter-individual variability within the normal population, the limited reproducibility due to habituation or fatigue, and the impact of instruction and the subject's motivation, all constitute a major problem in posturography. These aspects hinder reliable evaluation of the changes in balance control in the case of disease and complicate objectivation of the impact of therapy and sensory input on balance control. In this study, we examine whether measurement of balance control near individualized limits of stability and under very challenging sensory conditions might reduce inter- and intra-individual variability compared to the well-known Sensory Organization Test (SOT). To do so, subjects balance on a platform on which instability increases automatically until body orientation or body sway velocity surpasses a safety limit. The maximum tolerated platform instability is then used as a measure for balance control under 10 different sensory conditions. Ninety-seven healthy subjects and 107 patients suffering from chronic dizziness (whiplash syndrome (n = 25), Meniere's disease (n = 28), acute (n = 28) or gradual (n = 26) peripheral function loss) were tested. In both healthy subjects and patients this approach resulted in a low intra-individual variability (< 14.5(%). In healthy subjects and patients, balance control was maximally affected by closure of the eyes and by vibration of the Achilles' tendons. The other perturbation techniques applied (sway referenced vision or platform, cooling of the foot soles) were less effective. Combining perturbation techniques reduced balance control even more, but the effect was less than the linear summation of the effect induced by the techniques applied separately. The group averages of healthy subjects show that vision contributed maximum 37%, propriocepsis minimum 26%, and labyrinths maximum 44% to balance control in healthy subjects. However, a large inter-individual variability was observed. Balance control of each patient group was less than in healthy subjects in all sensory conditions. Similar to healthy subjects, patients also show a large inter-individual variability, which results in a low sensitivity of the test. With the exception of some minor differences between Whiplash and Meniere patients, balance control did not differ between the four patient groups. This points to a low specificity of the test. Balance control was not correlated with the outcome of the standard vestibular examination. This study strengthens our notion that the contribution of the sensory inputs to balance control differs considerably per individual and may simply be due to differences in the vestibular function related to the specific pathology, but also to differences in motor learning strategies in relation to daily life requirements. It is difficult to provide clinically relevant normative data. We conclude that, like the SOT, the current test is merely a functional test of balance with limited diagnostic value.

Adolescent↗
PubMed2000

Helmet versus nonhelmet treatment in nonsynostotic positional posterior plagiocephaly.

A total of 105 infants with nonsynostotic posterior plagiocephaly were treated using a helmet or by head positioning. Effect of treatment was scored using a cosmetic outcome score (0-10 points) assigned by the parents. The onset of the observed skull deformity correction was not different for the helmet vs. nonhelmet treatment. Improvement was significantly better and faster in the helmet group compared with nonhelmet treatment (p < 0.01 and p < 0.001, respectively).

Craniosynostoses↗
PubMed2000

Listing's law in strabismus and amblyopia: a preliminary report.

We investigated whether Listing's law applies in patients with diminished or no stereopsis due to strabismus or amblyopia. Eye movements of normal subjects and patients with strabismus and/or amblyopia were recorded during monocular and binocular fixation; from these data the shape and relative orientation of displacement planes were calculated. In normal subjects, monocular or binocular fixation did not influence the thickness and relative orientation of displacement planes. No differences were found between normals and the patient with amblyopia due to anisometropia. In one patient with strabismus but without amblyopia, the orientation of displacement planes depended on the fixation conditions; a coupling between horizontal vergence effort and plane orientation was observed. Patients with amblyopia and strabismus showed abnormally shaped and/or abnormally orientated displacement planes, which depended on the fixation conditions. Differences between both eyes in the shape of the planes were also observed. These results show that normal Listing behavior can be present in subjects with diminished stereopsis. They also show that normal stereopsis does not necessarily mean normal Listing behavior, suggesting that Listing's law is mainly a result of motor strategy.

Adult↗
PubMed1999

The influence of visual input on the vestibulo-ocular reflex.

In order to stabilise a fixation target on the retina, eye movements have to compensate for head movements. During slow head movements visual feedback can control these eye movements. During fast movements of the head, mainly the vestibulo-ocular reflex (VOR) controls eye movements, as visual feedback is too slow. However, visual feedback is an important factor in controlling the VOR; e.g. the gain of the VOR depends on the distance of the target. This study investigates the influence of retinal image position during fast head movements. The experiments were carried out in five human subjects using scleral search coils. The adaptation of each eye individually to a change of retinal position of a target was examined during head shaking. The change in visual input was carried out by placing Fresnel prisms of different strengths in front of both eyes, thus inducing a change in retinal image position without changing the retinal slip. The results show, that both eyes make the appropriate corrections when the visual input changes, even during fast head-movements. These corrections did not influence the gain of the VOR. From these results we conclude, that retinal image position besides retinal slip has a major influence on the monocular eye movements even at high head rotation frequencies.

Adaptation, Ocular↗
PubMed1997

Ocular torsion induced by static and dynamic visual stimulation and static whole body roll.

By means of real-time infra-red video-oculography we studied eye torsion in 12 normal healthy subjects. Ocular torsion was induced by visual stimulation or static whole body roll with and without visual orientation ("head-fixed" or "earth-fixed"). Visual stimulation was achieved by a horizontal grating that oscillated sinusoidally in a frontal plane. The oscillation frequency varied from 0 to 0.6 Hz while amplitude varied from 6 degrees to 33 degrees. Visual orientation during whole body roll was established by mounting a 32 lx illuminated horizontal grating either on a tilting device (head-fixed) or on the wall in the frontal plane (earth-fixed). Maximum visual-induced eye torsion gain was reached at about 0.2 Hz. No eye torsion was observed in static (0 Hz) visual tilts of the grating. Maximum gain was about 0.36 at amplitudes between 6 degrees and 10 degrees. Eye torsion gain decreased with increasing amplitude and increasing frequency (> 0.2 Hz). Static whole body roll in the dark up to 180 degrees clockwise and counterclockwise induced static ocular counter rolling with a maximum amplitude of 12 degrees and a maximum gain of 0.22. Gain decreased with increasing roll down to zero at 180 degrees. Visual orientation with either head or earth fixed did not affect the amplitude or gain of the body roll induced ocular counter-rolling. The results are interpreted in terms of improving the reliability of clinical statolith testing and understanding the processes involved in motion sickness.

Adult↗
PubMed1997

The influence of head position and head position change on spontaneous body posture and motility in full-term AGA and SGA newborn infants.

No consensus exists concerning the influence of head position and head position change on body posture and motility. Especially the existence of an asymmetric tonic neck reflex (ATNR) in full-term newborns is an issue of discussion. Three-hour video recordings were made of 15 full-term appropriate for gestational age (AGA) and 15 full-term small for gestational age (SGA) infants between the third and eight postnatal day. During a playback of the video recording head position, head position change and several movement patterns of the four limbs were fed into a computer using an event-detecting program. Furthermore, spontaneous head turnings were selected and body posture just before, immediately at and 1 min after the head turning were sketched. The data were analyzed concerning: (1) influence of head position on symmetry of movement of the four limbs; (2) the existence of an ATNR and ATNR-related patterns. In both AGA and SGA infants all movement patterns except hand-face and hand-mouth contact showed a symmetrical distribution, independent of head position. Furthermore, the occurrence of an ATNR following a spontaneous head turning in both AGA and SGA infants was rare. From our results it may be concluded that the ATNR is rare in full-term AGA and SGA newborns. Furthermore, this study demonstrates that head position is not a major factor influencing quantitative aspects of spontaneous motor behaviour. The results are of clinical importance as they imply that in the examination of the neurological condition of the full-term newborn infant by means of observation of spontaneous posture and motility, head position is not of major importance.

Functional Laterality↗
PubMed1997

Dose-dependent effect of betahistine on the vestibulo-ocular reflex: a double-blind, placebo controlled study in patients with paroxysmal vertigo.

The effect of betahistine on the vestibulo-ocular reflex (VOR) was assessed in 12 patients suffering from paroxysmal vertigo. Only patients who responded to betahistine treatment were admitted to the study in order to increase the probability of quantifying the effect of the drug on vestibular function. Patients received placebo or 16, 32 or 64 mg betahistine orally under double-blind conditions. Vestibular function was tested a few minutes before intake, and 1, 2, 3, 4, 6 and 8 h after intake, by torsion swing stimulus in the dark, visuo-vestibular interaction upon simultaneous visual and vestibular stimulation and high frequency passive head shaking. Betahistine significantly affected the velocity gain of low and high frequency VOR. The reduction in gain was maximal about 4 h after administration of the 16 mg dose in the torsion swing experiment and the 32 mg dose in the head shaking experiment. Above these doses, the effect on velocity gain was less marked. Betahistine had no effect on visuo-vestibular interaction or nystagmus duration during low frequency torsion. These results suggest that betahistine has a complex action on H3 receptors and that the site of action may be in the vestibular nuclei.

Adolescent↗
PubMed1997

Clinical testing of the statolith system in patients with Menière's disease.

The statolith ocular reflex induced by whole body roll was assessed in 10 patients with Meniere's disease who had undergone a standard vestibular test battery. Normal eye torsion was noted in 4 patients despite the presence of severe symptoms, and a caloric hyporeflexia in one patient. Eye torsion was diminished in one direction of body roll in 4 patients and in both directions of body roll in 2 patients. An abnormal asymmetry of eye torsion (> 16%) was found in the case of body roll towards the normal ear irrespective of whether a caloric asymmetry was found. An abnormal asymmetry of the statolith ocular reflex seems to indicate the side with the functional hearing loss. The results suggest that Meniere's disease might involve pathology of the statolith system. However, the absence of abnormal eye torsion does not imply normal vestibular function.

Adult↗