Biomedical subjects

T Ledin

Publications and source records attributed to T Ledin.

At least 19 recordsLinked to original sources

PubMed2004

A virtual reality trauma simulator.

The authors have evaluated a trauma simulator based on virtual reality techniques. Ten surgeons and 15 medical students performed distal locking of a femoral nail (A). Furthermore, 10 medical students performed simulated osteosynthesis of a femoral neck fracture (B). Total surgery time (A) (mean value) was shorter for surgeons (108 s) compared with students (157 s) at the first (p = 0.033), second (102 respectively 138 s, p = 0.13) and third (96 respectively 160 s, p = 0.15) operation. Total fluoroscopy time (A) (mean value) was shorter for surgeons compared with students at the first (45 respectively 89 s, p = 0.001), second (48 respectively 83 s, p = 0.02) and third (50 respectively 107 s, p = 0.10) operation. The positioning of the hip nails (B) improved between the first and last trial. Total surgery and fluoroscopy time were reduced. All participants thought that this and similar simulators should be part of the programme and that this simulator would be helpful if they were about to learn the procedures.

Analysis of Variance↗

PubMed2003

Influence of neck proprioception on vibration-induced postural sway.

OBJECTIVE: Several reports have shown that the direction of the postural responses induced by vestibular stimulation is affected by the positions of the neck and torso. The aim of this study was to investigate whether the postural responses to vibratory proprioceptive stimulation of the calf muscles are affected by the position of the head and thus by proprioceptive and vestibular information from the neck and head. MATERIAL AND METHODS: Ten normal subjects were exposed to vibratory proprioceptive stimulation of the calf muscles when the head was maintained in five different positions: in a neutral position facing forwards, with the head turned to the right or left sides or with the head tilted backwards or forwards. Body movements were evaluated by analyzing the anteroposterior and lateral torques induced towards the supporting surface. RESULTS: The analysis showed that only the anteroposterior body sway was significantly affected by the position of the head. The anteroposterior postural responses were primarily increased during the tests with the head tilted backwards or forwards, whereas the postural responses were unaffected by head torsion towards the sides. The lateral responses were primarily affected by vision and not by the position of the head. CONCLUSIONS: The findings suggest that the responses evoked by vibratory proprioceptive stimulation of the calf muscles may be affected by different mechanisms, either by purely proprioceptive information or by an interaction between proprioceptive and vestibular information. Moreover, the increasing difference between the test conditions over time suggests that fatigue of the neck muscles may be one of the factors affecting the responses induced by the perturbations.

Adult↗

PubMed2002

Cortical blood flow autoregulation revisited using laser Doppler perfusion imaging.

Methods of laser Doppler perfusion monitoring (LDPM) and imaging (LDPI) have been validated and found useful for measurements of brain blood flow in several studies. The present work was undertaken to examine the cortical blood flow autoregulatory phenomenon as it has lately been questioned and claimed to be method-dependent and related to sample volume. Spatial variations in cerebral cortical blood flow (CBF(cortex)) in the pressure range 20-140 mmHg (static cerebral autoregulation; caval block/angiotensin infusion) were studied in six mechanically ventilated (hypocapnic, normocapnic and hypercapnic) pigs anaesthetized with propofol and fentanyl. Although the cortical blood flow values sampled were highly heterogeneously distributed, they were strongly pressure-dependent as well as CO2-dependent (P < 0.001). A cumulative cerebral blood flow (CBF)-pressure (MAP) plot comprising all values obtained indicated a pressure range between 70 and 120 mmHg where CBF remained almost constant. However, at the local level in the cortex (mm2) the same type of 'classic' autoregulatory flow : pressure graphs (FPG) were found in only a few of the cases of the cortical areas examined (n = 96). Alterations in blood P(a)CO2 saturation did not affect the pressure : flow relationship at low perfusion pressures, whereas at normal or above normal values, and as anticipated, hypercapnia considerably increased CBF (P < 0.001). 'Classic' autoregulatory FPGs were found only when all values sampled were clustered together, whereas, as a new finding, data are presented indicating that autoregulatory capacity is lacking at the local level at some cortical surface areas.

Animals↗

PubMed2001

High incidence of pruritus after large doses of hydroxyethyl starch (HES) infusions.

BACKGROUND: There are several studies indicating a correlation between treatment with hydroxyethyl starch (HES) and pruritus. In order to see whether there is a possible dose-response relationship between HES and pruritus, we retrospectively studied 50 patients who had received HES in varying doses (cumulative dose 500-19500 ml) as hemodilution therapy after subarachnoid hemorrhage. METHODS: Of 50 consecutive patients, 6 were excluded due to severe neurological sequelae. A questionnaire was sent to the remaining 44 patients at 6 months (5-12 months) median (range) after the end of HES treatment. RESULTS: We received answers from 37 patients, of whom 54% reported pruritus. On average pruritus lasted for 15 weeks. There was significantly more pruritus in patients who received more than 5000 ml of HES versus those who received less than 5000 ml (P=0.023). Pruritus had a delayed onset and appeared as pruritic crises lasting for 2-30 min. It had a patchy distribution in most patients and no predilected locations. In 4 patients (20%) the pruritus lasted longer than 21 weeks. CONCLUSION: Our study indicates that there is a dose-dependency for the incidence of HES-induced pruritus, and that in some cases the pruritus may be severe and long-lasting.

Blood Volume↗

PubMed2000

Adenoid cystic carcinoma: use of cell proliferation, BCL-2 expression, histologic grade, and clinical stage as predictors of clinical outcome.

BACKGROUND: Although the three basic histologic growth patterns of adenoid cystic carcinomas (tubular, cribriform, and solid) provide some indication of clinical outcome, additional, perhaps superior, predictors of biologic activity are needed for patient management. METHODS: This series is composed of 31 adenoid cystic carcinomas that presented in Linköping between 1982 and 1997. The tumors were clinically staged and histologically graded. For each case, after immunohistochemical identification, the proportion of tumor cells expressing the cell cycle markers MIB-1 and bcl-2 (as an indicator of proliferation and apoptosis, respectively) were quantified. Statistical correlation was sought between tumor stage and grade and the two cell cycle markers. RESULTS: The proportions of cycling tumor cells in adenoid cystic carcinomas ranged from 0.3% to 55%. For patients with no evidence of disease and a follow-up of at least 5 years, the mean percent MIB-1 value was significantly lower than for those patients who were alive with local recurrence and/or metastasis or who had died from their adenoid cystic carcinoma (p =. 024). MIB-1 tumor cell positivity also correlated strongly with tumor grade (p =.053), but not with stage (p =.22). Neither clinical stage nor histologic grade correlated with the degree of bcl-2 tumor cell positivity (p =.97 and p =.49, respectively). CONCLUSIONS: Staging and grading continue to play a vital role in the management of patients with adenoid cystic carcinoma. Furthermore, in this series of patients with adenoid cystic carcinoma, a cycling tumor cell population as measured by the MIB-1 antibody greater than 10% indicates this group as biologically more aggressive and at an increased risk for a fatal course.

Adult↗

PubMed2000

Estrogen effects on postural balance in postmenopausal women without vasomotor symptoms: a randomized masked trial.

OBJECTIVE: To assess whether estrogen treatment given to postmenopausal women without vasomotor symptoms improves balance more than placebo. METHODS: Forty healthy postmenopausal women without vasomotor symptoms were randomized to transdermal 17beta-estradiol (E2) 50 microg/day for 14 weeks or identical transdermal placebo patches. Postural balance was measured with dynamic posturography before and after 4, 12, and 14 weeks of therapy. In this test, the visual, vestibular, and somatosensory systems were provoked with increasing difficulty and body sway was measured with a dual forceplate. A low score showed large sway and a score of 100 showed no sway at all. RESULTS: Thirty-eight women completed the study. Both groups had normal balance for their ages and near maximum scores in the three easier balance tests at baseline. In the most difficult test, both groups improved their postural balance significantly (from 13 to 32 and from 22 to 39, respectively) after 4 weeks. Thereafter, no change was seen. One problem was low statistical power, but the relative change in balance did not differ between groups. The comparison did not show even a minute advantage of E2 over placebo, so a study with higher power would probably not have shown a more pronounced effect of estrogen than placebo. The change over time did not differ between groups, which indicates a significant learning effect. CONCLUSION: In women without vasomotor symptoms, estrogen therapy did not seem to increase postural balance significantly more than placebo. However, we could not rule out that estrogens affect postural balance in women with vasomotor symptoms.

Administration, Cutaneous↗

PubMed2000

Postural stability using different neck positions in normal subjects and patients with neck trauma.

Subjects with neck problems, such as whiplash injuries, often complain of disturbed equilibrium and, in some instances, provocation of the neck position can elicit such problems. The importance of neck proprioceptors for maintaining balance is gaining increased interest, moreover the function or malfunction of the otoliths may disturb equilibrium in certain head positions. The aim of the study was to create a reference material for postural control and its dependence on head position in healthy subjects and to compare this with a set of patients with known neck problems and associated vertiginous problems. A total of 32 healthy subjects (16 men, 16 women, age range 21-58 years) as well as 10 patients age range 27-62 years (mean 44 years) with neck problems and associated balance problems since a whiplash injury were tested for postural control using the EquiTest dynamic posturographic model. The normal subjects were initially split into four age groups in order to estimate the effects of age on performance. The postural stability was evaluated for dependence of support surface conditions (stable or sway-referenced), visual input (eyes open or closed) and head position (neutral, left rotated, right rotated, extended backwards or flexed forward) using analysis of variance (ANOVA) with Tukey's post hoc test in case of a significant factor effect. As expected, visual cues as well as stable support surface improve postural stability (p < 0.001). Postural stability is statistically different in the head extended backwards condition compared with the other four head positions (p < 0.001 in all cases) in both patients and controls. Eliminating this test condition from the analysis, only a slight (p < 0.05) difference between head forwards and head turned left remained. This pattern of results remained if the normal subjects were only split into two age groups instead of four. Finally, the patient group exhibited significantly lower postural performance than all the groups of normal subjects (p <0.01), but none of the normal groups differed significantly from each other. It is concluded that the postural control system is significantly challenged in the head extended backwards condition in both normal subjects and patients with previous whiplash injury and persistent neck problems. The patient group differed statistically from all groups of normal subjects. This suggests that neck problems impair postural control, and that the head extended position is a more challenging task for the postural system to adapt to. Whether this is due to utricular malpositioning, central integrative functions or cervical proprioceptive afferents is not within the scope of this study to answer.

Adult↗

PubMed2000

Disturbances in postural balance are common in postmenopausal women with vasomotor symptoms.

OBJECTIVES: To establish the prevalence of unsteadiness and rotatory vertigo in peri- and postmenopausal women, and whether balance disturbances are more common in women with vasomotor symptoms and without hormone replacement therapy (HRT). METHOD: A validated questionnaire was sent to all 1523 women aged 54 or 55 years in Linköping, Sweden. RESULTS: Daily or weekly unsteadiness was reported by 5%, and daily or weekly rotatory vertigo by 4% of all women. The frequency of vasomotor symptoms correlated with reported unsteadiness (rs = 0.23, p < 0.001). Fourteen per cent of women with daily vasomotor symptoms reported weekly or daily unsteadiness, compared with 3% of those without vasomotor symptoms (odds ratio (OR) 7.58, 95% confidence interval (CI) 3.72-15.45). The frequency of vasomotor symptoms correlated with rotatory vertigo (rs = 0.19, p < 0.001). Ten per cent of women with daily vasomotor symptoms reported weekly or daily rotatory vertigo, compared with 2% of women without vasomotor symptoms (OR 5.21, 95% CI 1.07-25.52). No correlation was seen between vasomotor symptoms and falls. Users of HRT had the same prevalence of balance disturbances as non-users. CONCLUSIONS: Women with frequent vasomotor symptoms seem to run a greater risk of unsteadiness and rotatory vertigo than do women without symptoms. This association may not be explained by means of a cross-sectional study, but there might exist a causal connection between vasomotor symptoms and balance disturbances.

Dizziness↗

PubMed2000

MRI screening of the cerebellopontine angle and inner ear with fast spin-echo T2 technique.

In patients with unilateral hearing loss and dizziness it is important to rule out a cerebellopontine angle process. This is often done by audiological and otoneurological investigations. However, in many cases we must rely on the imaging of the temporal bone and the cerebello-brainstem area. The paper has presented the three dimensional (3D) Fast Spin-Echo (FSE) T2 weighted, 0.7 mm thick MR images, which in addition to being quick, does not require the use of expensive contrast material. Between September 1996 and November 1997, 152 patients with unilateral hearing loss and/or balance disorders were investigated. In normal cases the 7th and 8th nerves could be followed accurately from the brainstem to the internal auditory meatus. The found tumors were hypointense compared to the cerebrospinal fluid and could be outlined with reasonable accuracy even without gadolinium contrast. The inner ear had high signal, like cerebrospinal fluid. The patency of the cochlea could be estimated accurately. Thus, 3D FSE T2 weighted images can reliably differentiate between patients with and without pathologies of the cerebellopontine angle. The use of gadolinium contrast could be avoided in most of the cases, but contrast is necessary for differential diagnostic purposes in patients with alterations in the cerebellopontine angle or in doubtful cases.

Artifacts↗

PubMed1999

Recovery of vestibulo-ocular reflex-function in subjects with an acute unilateral peripheral vestibular deficit.

The centrally controlled compensation for a reduced horizontal vestibulo-ocular reflex (VOR) gain caused by a unilateral afferent deficit is usually studied following a selective surgical procedure which completely lesions the vestibular nerve or blocks the horizontal semicircular canal. The more common, unilateral, vestibular deficit encountered clinically, is a partial loss of peripheral vestibular function, following which peripheral recovery and/or central compensation may occur. We investigated changes of the VOR gain in response to a sudden, idiopathic, unilateral vestibular deficit in 64 subjects by examining the responses to low-frequency, whole-body, rotations about an earth vertical axis with different accelerations (5, 20 and 40 deg/sec2) during in- and out-patient visits separated by 4 months in an attempt to identify changes brought about by peripheral recovery and by central compensation processes. Peripheral function was assumed to be measured by the response to caloric irrigation. It improved some 30% on average between the two visits. VOR responses for rotations towards the deficit side also improved between the two visits. Most improvement occurred for 20 deg/sec2 accelerations. However, the correlation coefficient between rotation and caloric responses was always less than 0.6. Unlike caloric responses which improved over time, responses for rotations to the intact side did not change between the visits. For this reason, the majority of observed VOR rotation responses were nearly symmetrical at the time of the second visit, despite being below normal levels. These findings suggest that both peripheral recovery and central compensation processes help restore symmetrical VOR function for head rotations after a partial unilateral vestibular deficit. However the improvement of VOR response symmetry, particularly to slow (< 40 deg/sec2) accelerations, is largely independent of the recovery of peripheral sensitivity.

Adult↗

PubMed1998

Influence of different conditions for tilt compensation on symptoms of motion sickness in tilting trains.

Increased speeds of trains can be achieved by using tilting trains that decrease the lateral acceleration experienced by passengers on curves, thereby allowing trains to run typically 25-30% faster on existing curved track and maintaining good ride comfort. Unfortunately, motion sickness in tilting trains is a major problem for some passengers. To investigate the incidence of motion sickness and the extent to which different tilt compensation strategies influence its occurrence, tests were conducted with a tilting train on a track with a large number of curves. Eighty healthy volunteers were studied, selected partly for their susceptibility. Three different cars were evaluated during 3 test days, with each test ride lasting about 3 h. On four occasions per test ride, the subjects answered a questionnaire concerning activities during the ride, ride comfort, ability to work and read, vegetative symptoms, fatigue, sleepiness, nausea and well-being. Subjects estimation of average ride comfort and ability to work and read was good in all conditions. However, 10% of the test subjects reported various symptoms of motion sickness (SMS). A 55% degree of tilt compensation of the lateral acceleration instead of the normal 70% reduced the symptoms of motion sickness incidence (SMSI) by 25-40%. SMSI correlated poorly with motion doses, which integrates vertical or lateral acceleration but correlated well with roll acceleration motion dose (r2 = 0.43, p < 0.001). For women, riding backward (p < 0.001) minimized SMSI, but men were insensitive to direction. Future railway design will have to optimize tilt systems by both minimizing motion sickness and avoiding excessive lateral acceleration or jerk.

Adult↗

PubMed1998

Audiological disturbances caused by long-term exposure to industrial solvents. Relation to the diagnosis of toxic encephalopathy.

Sixty workers, consecutively admitted due to suspicion of solvent-induced chronic toxic encephalopathy (CTE), were investigated with pure-tone audiometry, determination of speech recognition of monosyllabic words and distorted speech and cortical response audiometry (CRA). Eighteen workers not exposed to occupational solvents and noise were also investigated. The scores in the distorted speech test were significantly lower and the CRA latencies were significantly longer in the solvent group than in the control group. There was no difference between the groups in the pure-tone and monosyllabic speech recognition tests. In the solvent group, 19 subjects had one or several pathological audiological test results (values exceeding the mean result of the control group by 2 SD). Independently of the audiological examination all the workers in the solvent group underwent the traditional clinical assessment of CTE, which is based on symptoms, history of exposure, clinical neurological examination and a neuropsychological investigation. They were classified in three groups--CTE, incipient CTE and non-CTE. There was no correlation between these groups and the audiological test results. A previous report on vestibular pathology in the same group of subjects and the present investigation on hearing deficits suggest that long-term exposure to solvents causes disturbances of the central pathways in the otovestibular system. Hitherto, no attention has been paid to these disturbances in the definition of the CTE syndrome.

Adult↗

PubMed1998

Postural control--a comparison between patients with chronic anterior cruciate ligament insufficiency and healthy individuals.

Postural control in the sagittal plane was evaluated in 22 patients with chronic anterior cruciate ligament (ACL) deficiency and the result was compared to that of a control group of 20 uninjured subjects. Measurement of the body sway was done on a fixed and sway-referenced force plate in both single-limb and two-limb stance, with the eyes open and closed, respectively. Further, an analysis of the postural reactions to perturbations backwards and forwards, respectively, was made in single-limb stance. The results demonstrated statistically significant deficits of the postural control in the patient group compared to the control group, but also within the patient group. There was a significantly higher body sway within the patient group when standing on a stable support surface on the injured limb than standing on the uninjured limb with the eyes open, but no difference with the eyes closed. When standing on a stable support surface, there was a significantly higher body sway in the patient group standing on the injured leg than in the control group, both with eyes open and closed. The patient group also showed a significantly impaired postural control compared to the control group when standing on the uninjured leg with the eyes closed. There was no difference between the groups in the two-limb stance. When standing on the sway-referenced support surface, the patient group had a significantly larger body sway than the control group when the eyes were open, but there was no significant difference between the groups with the eyes closed. The measurement of the postural corrective responses to perturbations backwards and forwards showed that the reaction time measured from the initiation of the force plate translation, and the amplitude of the body sway was significantly greater in the patient group than in the control group. We conclude that patients with a continuing chronic ACL insufficiency several years after injury have an impaired postural control in the antero-posterior direction in single-limb stance on their injured leg. They also show a greater body sway and a prolonged reaction time when subjected to antero-posterior perturbations when standing on their injured leg.

Adolescent↗

PubMed1998

No Effects of Acute Alcohol Ingestion on Subjective Visual Horizontal Determination During Eccentric Rotation.

Evaluating the function of the vestibular part of the inner ear comprises more than the classic analysis of the lateral semicircular canal function. In healthy subjects, positional alcohol nystagmus may be seen after acute alcohol ingestion. Posturography has shown a deteriorated equilibrium after even moderate doses of alcohol, which speculatively could be an effect of otolith disturbance or a central integrative effect. We tested the possibility of an otolith effect by using linear acceleration in the lateral direction by means of eccentric rotation, stimulating mainly the outermost ear's otolith organ. The subject is seated eccentrically in a rotatory chair facing the direction of rotation. Thus, the otolith organs are stimulated in steady-state rotation. The subject experiences a lateral tilt and, in darkness, is instructed to put a short light bar in the position thought to be that of a water surface, which is identical to the perceived tilt. Twenty healthy subjects (10 men, 10 women) aged 20-29 years were tested before and approximately 1 hour after ingestion of alcohol, the amounts consumed corresponding to an approximate blood alcohol level of 0.05%, well above the maximum permissible level for driving in Sweden. No significant effects of alcohol were found. The otolith function probably is not affected by moderate alcohol intoxication levels. From this point of view, equilibrium deterioration due to alcohol ingestion in the erect position is caused by a central integrative deficit and not by an otolith effect.

Journal Article↗

PubMed1998

Temperature Order Effects in the Caloric Reaction.

Does it matter in what order the four irrigations are conducted in the caloric test? It has been suggested that warm water (44 degrees C) elicits stronger reactions than does cold water (30 degrees C), which might be explained simply by slight differences in water temperatures. However, if it can be shown that starting with cold water diminishes the difference between the warm and cold irrigations, it might be worthwhile to apply the cold irrigations first. Binaural, bithermal caloric irrigation was conducted in darkness using electrooculography. Maximum slow-phase velocity was measured. One hundred and eighteen consecutive patients from our laboratory were tested with warm water first and then with cold irrigations. In a second run, 108 subjects were irrigated with cold water before the warm. Employing cold irrigations first produces a smaller difference between the warm and the cold irrigations than does the opposite order. However, the lateral and directional preponderances, according to the formulas of Jongkees, are not affected by this change of irrigation order. The fact that initial warm-water irrigations cause the temperature effect differences to be larger than do initial cold-water irrigations is a phenomenon having only marginal clinical implications.

Journal Article↗

PubMed1998

Subjective Visual Horizontal Determination During Otolith Stimulation by Eccentric Rotation in Conservatively Treated Meniere's Disease.

Peripheral vestibular equilibrium disorders may originate in various parts of the labyrinth or of the vestibular nerve. Traditionally, the function of the lateral semicircular canals has been assessed by caloric irrigation and has been interpreted (sometimes falsely) as demonstrating a vestibular nerve lesion. The vertical semicircular canals are not assessed easily. Caloric testing with the head in various positions is not very helpful, but the canals may be tested in pairs using specific rotational techniques. Often, the otolith organs, detecting linear acceleration forces, are forgotten as a source of vertigo and dizziness. The extent of otolith involvement in Meniere's disease is not well understood. The tested subject is seated eccentrically in a rotatory chair and faces the direction of rotation. Thus, the otolith organs are stimulated in steady-state rotation. The subject experiences a lateral tilt and, in darkness, is instructed to point a short light bar in the position that he or she thinks a water surface would have (identical to the perceived tilt). Patients with conservatively treated unilateral Meniere's disease were tested. In the eccentric rotation test, the patients with unilateral Meniere's disease showed highly variable, sometimes even paradoxical, responses. No correlation was noted between the eccentric otolith test and pure-tone audiometry or the side difference of the caloric responses. Otolith and lateral semicircular canal functions may differ in patients with Meniere's disease, the nature of which remains to be elucidated in further studies.

Journal Article↗

PubMed1998

Three-Dimensional Fast Spin-Echo T2-Weighted Magnetic Resonance Images of the Cerebellopontine Angle.

In patients experiencing dizziness and hearing disorders, it is essential to rule out the possibility of an intracranial affection, typically a cerebellopontine angle (CPA) process. Clinically, this often is accomplished using audiology and otoneurology and by interpreting the time course of the symptoms. However, in many cases, we must resort to imaging of the skull base and the CPA. The use of thin-section, fast spin-echo, heavily T2-weighted images can eliminate the need for gadolinium contrast administration, offering a cheaper and quicker investigation as compared with the customary T1-weighted images using gadolinium. With three-dimensional volume sampling, slice thickness can be reduced to 0.7 mm. Data reconstruction in every desired direction is possible. Ninety-two patients with hearing and balance disorders were examined using this method. In subjects free of tumor in the CPA, the seventh and eighth nerves could be followed accurately from the internal auditory meatus to the brainstem. The tumors could be outlined with reasonable accuracy even without gadolinium contrast. Three-dimensional, fast spin-echo, T2-weighted images are useful in evaluating the CPA in cases of suspected tumor. Most often the use of gadolinium can be avoided. This seems to be a cheap alternative for magnetic resonance screening of patients experiencing dizziness and hearing disorders.

Journal Article↗

PubMed1998

Dynamic and randomized perturbed posturography in the follow-up of patients with polyneuropathy.

BACKGROUND: The purpose of the study was to investigate and follow the equilibrium performance of patients with chronic polyneuropathy using Dynamic Posturography (DP) and Randomized Perturbed Posturography (RPP). METHODS: Fourteen patients with chronic polyneuropathy, aged 53-83 years, were evaluated by clinical investigation, vibrametry, DP and RPP in a six-year follow-up. The patient group was compared to 14 healthy volunteers, aged 63-80 years. The DP comprises a sensory organization (SO) part in which the platform and visual surround are stable or referenced to the patient sway, with eyes open or closed. In a movement coordination (MC) part, the platform makes active movements. In RPP, the platform moves randomly in the anteroposterior direction. RESULTS: Comparison between the first and second study of the patient group showed decreased equilibrium scores under stable conditions and when vision was excluded. Compared with controls, the patients showed significantly lower scores in most of the SO test conditions except when the platform was sway referenced with stable surround; in the MC part, the patients showed prolonged muscular response latencies, and in the RPP, the patients showed increased sway areas. CONCLUSIONS: The results are further evidence that proprioception is probably the single most important sensory input for postural control in humans. Posturography proved to be an objective method to study and follow the equilibrium performance in patients with PN.

Aged↗