Under-rated neuro-otological symptoms: Hoffman and Brookler 1978 revisited

Virtual reality versus optokinetic stimulation in visual vertigo rehabilitation

BACKGROUND

Visual vertigo (VV) is a condition at which there is worsening or triggering of vestibular symptoms in certain visual environments with large size (full field) repetitive or moving visual patterns as shopping malls.

PURPOSE

This work was designed to study effect of virtual reality and optokinetic stimulation on rehabilitation of VV.

METHOD

A total of 60 subjects divided into 2 groups that were simply randomized by the concealed envelope method: Group I consisted of 30 VV patients underwent vestibular rehabilitation using virtual reality. Group II consisted of 30 VV patients underwent vestibular rehabilitation using optokinetic stimulation.

RESULTS

Significant improvement in performance in the two groups after rehabilitation with no statistically significant difference when comparing both groups.

CONCLUSIONS

A combined intense rehabilitation program including OPK stimulation or VR rehabilitation combined with home-based exercises appeared to be equally effective for management of patients with VV and improving their quality of life.

Multisensory integration in balance control

This chapter provides an introduction to the topic of multisensory integration in balance control in, both, health and disease. One of the best-studied examples is that of visuo-vestibular interaction, which is the ability of the visual system to enhance or suppress the vestibulo-ocular reflex (VOR suppression). Of clinical relevance, examination of VOR suppression is clinically useful because only central, not peripheral, lesions impair VOR suppression. Visual, somatosensory (proprioceptive), and vestibular inputs interact strongly and continuously in the control of upright balance. Experiments with visual motion stimuli show that the visual system generates visually-evoked postural responses that, at least initially, can override vestibular and proprioceptive signals. This paradigm has been useful for the study of the syndrome of visual vertigo or vision-induced dizziness, which can appear after vestibular disease. These patients typically report dizziness when exposed to optokinetic stimuli or visually charged environments, such as supermarkets. The principles of the rehabilitation treatment of these patients, which use repeated exposure to visual motion, are presented. Finally, we offer a diagnostic algorithm in approaching the patient reporting oscillopsia - the illusion of oscillation of the visual environment, which should not be confused with the syndrome mentioned earlier of visual vertigo.

Psychiatric comorbidity and psychosocial impairment among patients with vertigo and dizziness

BACKGROUND

Vertigo and dizziness are often not fully explained by an organic illness, but instead are related to psychiatric disorders. This study aimed to evaluate psychiatric comorbidity and assess psychosocial impairment in a large sample of patients with a wide range of unselected organic and non-organic (ie, medically unexplained) vertigo/dizziness syndromes.

METHODS

This cross-sectional study involved a sample of 547 patients recruited from a specialised interdisciplinary treatment centre for vertigo/dizziness. Diagnostic evaluation included standardised neurological examinations, structured clinical interview for major mental disorders (SCID-I) and self-report questionnaires regarding dizziness, depression, anxiety, somatisation and quality of life.

RESULTS

Neurological diagnostic workup revealed organic and non-organic vertigo/dizziness in 80.8% and 19.2% of patients, respectively. In 48.8% of patients, SCID-I led to the diagnosis of a current psychiatric disorder, most frequently anxiety/phobic, somatoform and affective disorders. In the organic vertigo/dizziness group, 42.5% of patients, particularly those with vestibular paroxysmia or vestibular migraine, had a current psychiatric comorbidity. Patients with psychiatric comorbidity reported more vertigo-related handicaps, more depressive, anxiety and somatisation symptoms, and lower psychological quality of life compared with patients without psychiatric comorbidity.

CONCLUSIONS

Almost half of patients with vertigo/dizziness suffer from a psychiatric comorbidity. These patients show more severe psychosocial impairment compared with patients without psychiatric disorders. The worst combination, in terms of vertigo-related handicaps, is having non-organic vertigo/dizziness and psychiatric comorbidity. This phenomenon should be considered when diagnosing and treating vertigo/dizziness in the early stages of the disease.

Dizziness after traumatic brain injury: Results from an interview study

BACKGROUND

Dizziness is a commonly reported sequel to traumatic brain injury (TBI).

OBJECTIVE

To better define the nature of the symptomatology and the impact that dizziness has on the TBI survivor.

SETTING

A community brain injury rehabilitation programme and a community access programme for TBI survivors.

METHOD

Focus groups with TBI survivors and individual interviews with TBI survivors and some of their carers.

RESULTS

The data confirmed that dizziness is difficult for TBI survivors to define and describe and it consists of multiple symptoms. Dizziness also appears to be associated with significant functional difficulties. Additionally, many of the participants of this study reported falling. Carers reported a number of observable signs of dizziness and indicated that they believed they were able to tell when the person they cared for was dizzy.

CONCLUSION

The results provide information which will help in the development of more appropriate outcome measurement tools for dizziness after a TBI.

Field Dependency and the Sense of Object-Presence in Haptic Virtual Environments

Virtual environment (VE) users often report having a sense of being present in the virtual place or a sense that the virtual object is present in their environment. This sense of presence depends on both the technological fidelity (e.g., in graphics, haptics) and the users' cognitive/ personality characteristics. This study examined the correlation between user's cognitive style on the field-dependency dimension and the level of object-presence they reported in a haptic VE. Results indicated that field-independent individuals reported higher presence ratings compared to field-dependent participants. We hypothesize that field-independents' advantage in reorganizing the perceptual field and constructing it according to their previously acquired internal knowledge enables them to cognitively reconstruct the VE experience more efficiently by selectively attending only to the relevant cues and by filling in the gap of missing information with their previous knowledge and creative imagination. This active and creative cognitive process may be behind the enhanced sense of presence. In addition, we raise a possible linkage between field dependency, the sense of presence, and simulator sickness phenomenon.

Postural control in otolith disorders

It was the aim of the present paper to investigate the influence of otolith disorders on human postural control by different methods. The 33 patients of our study had undergone a minor head injury and suffered subsequently from an utricular or sacculo-utricular disorder as evidenced by vestibular evoked myogenic potential recordings and eccentric rotation recordings of the otolith-ocular responses. Postural control was assessed by performing stance/gait tests (standard balance deficit test, SBDT) and by evaluating trunk sway (using angular velocity sensors). Moreover, classical tests of the posterior column of the spinal tract (Romberg/Unterberger) and the dynamic posturography (sensory organization test, SOT) were included. It could be shown that SBDT tasks with reduced proprioceptive and visual cues (e.g. standing on foam, eyes closed) are most sensitive for an otolith disorder. The patients showed an increased trunk sway in the pitch plane (i.e. linear motion as adequate utricular stimulus) and an increase in sway velocities (i.e. tilting movements as adequate saccular stimulus) compared to controls. The SOT was most sensitive for combined (sacculo-utricular) otolith disorders (78%) while vestibulospinal tests are not enough sensitive. In essence, otolith disorders evidently impair human postural control and have been possibly underestimated as a source of posttraumatic postural imbalance as yet.

Ipsilesional visual field dependency for patients with vestibular schwannoma

Vestibular schwannoma patients have a non-homogenous vestibular function and compensation, and might rely more on visual cues for balance control. Using the rod and frame test, visual field dependence was investigated in 17 patients with vestibular schwannoma who had a normal subjective visual horizontal and vertical (0.8 +/- 1.4 degrees). Findings were correlated with tumor size, age, and other parameters of vestibular compensation and compared with field dependency results of 28 healthy subjects. Vestibular schwannoma patients showed greater deviation in the rod and frame test when the frame was tilted towards the lesioned ear (mean 8.2 +/- 4.9 degrees), than towards the healthy ear (mean 5.5 +/- 6.0 degrees; p=0.013). The results indicate a unilateral visual field dependency for patients with vestibular schwannoma that predicts the lesioned side.