Dizziness is not an uncommon medical problem in children. When a child develops various physical symptoms in addition to dizziness, clinicians should include orthostatic dysregulation (OD) in their diagnosis. OD is composed of four different subsets, instantaneous orthostatic hypotension (INOH), postural tachycardia syndrome (POTS), neurally-mediated syncope and delayed orthostatic hypotension, and the former two are dominant. INOH involves dysfunction of the high-pressure system in the neural baroreflex pathway, and the low-pressure system in the case of POTS. Children with OD show a decrease in cerebral blood flow compared with unaffected children, and this might be associated with the mechanism responsible for dizziness. Further studies are anticipated in relation to OD and vestibular function.
This report is a preparatory study for a new dynamic equilibrium examination, the “Foulage test”. Subjects step on the center of a stabilometer, keeping both toes constantly in contact with the plate, and lifting up only the heels alternately. Subjects had to accurately keep up a tempo of 120 beats per minute (BPM120) as set by an electric metronome. The examination time was 60 seconds, 120 steps, with eyes open and closed. Sixteen healthy volunteers (8 men, 8 women, 24 to 55 years old, mean 36 years old) were tested with their eyes in the open and closed condition, changing the height of heels, from lower than 1 cm to almost 12 cm. 12 subjects were tested 5 times, 3 subjects were tested 6 times and also one volunteer, a 45-year-old healthy man, performed the test 16 times to get fine data. As the heels rose up, the locus was enlarged side to side and bent at the center like an inverted ‘V'rsquo; shape (Λ). The locus length was enlarged as the heels were raised higher, believed to reflect the activity of the subject. On the other hand the width of the locus band, front to back, was almost the same under conditions of stepping stably. However, if the subject swayed, this distance might increase. The total locus length (L) and the environed area (A) were investigated. The long length of the locus “Λ” shaped band was nearly the distance of one step. The subjects were stepping 120 times, therefore the mean distance of one step was almost L/120, and was nearly the length of the long axis of the locus band. The locus band was like a long square bent at the center, so the width, front to back, could be approximately presumed as A/(L/120)=120A/L.. Under stable stepping conditions, 400 cm<L<1400 cm, the width (120A/L) reached a plateau even when the height of the heels was changed. This could be a new parameter for the body sway, named FT. Ninety-four data sets were sampled by all 16 volunteers. Under stable condition (400<L<1400), the FT value plateaued. The mean of 70 data sets with open-eye-FT was 2.92 cm (SD 0.42), and the mean of 72 data sets with closed-eye-FT was 3.87 cm (SD 0.57). FT increased significantly with the eyes closed (p<0.01 paired t-test), and the dynamic Romberg's rate was 1.37 in normal healthy subjects under stable conditions. Under the condition of 1400<L, the heels were too much high, some subjects began to sway and the FT value increased. In conclusion, L (also L/120) reflects the height of stepping heels and it can be a parameter of activity: under the condition of 120 BPM, 60 seconds, 120 steps, 400<L<1400, FT=120A/L can possibly evaluate sway.
We examined the cerebral blood flow in 6 patients with acute stage vestibular neuritis using single photon emission computed tomography (SPECT). SPECT images of cerebral blood flow were analyzed using an easy Z-score imaging system (eZIS), a method for statistical image analysis. The analysis results showed cerebral blood flow to be increased in the parieto-insular vestibular cortex (PIVC) contralateral to the affected side, whereas blood flow was decreased bilaterally in the visual cortex and Brodmann area 40 (BA40). These results were identical to those obtained in patients with acute stage vestibular neuritis using PET by Bense et al. However, in our present analysis, increased cerebral blood flow was occasionally not detected in PIVC, rendering some cases unevaluable. Blood flow lowering in BA40 tended to be predominantly left hemispheric, regardless of the diseased side. Although SPECT is considered to be inferior to PET in spatial resolution and quantifiability, we found that cerebral blood flow in patients with acute stage vestibular neuritis can be sufficiently evaluated using eZIS analysis.
The direction of geotropic or ageotropic direction changing positional nystagmus in patients with lateral semicircular canal benign paroxysmal positional vertigo (LSC-BPPV) is reversed between the supine and prone positions. This reversal is also seen in other peripheral vestibular disorders. In this study, the positional nystagmus in the prone position was investigated in the patients with peripheral vestibular disorders except for BPPV. The positional nystagmus in the supine position was seen in 62 cases diagnosed as having peripheral vestibular disorders. They consisted of 33 with Ménière's disease (MD), 10 with sudden deafness (SD), 5 with vestibular neuritis (VN), 3 with Hunt syndrome (HS) and the remaining 11 cases with other lesions (OL). In these cases, the positional nystagmus in the prone position was investigated. When the direction of nystagmus was reversed in the prone position, it was defined as the reversal of nystagmus (RN). RN was seen in 27/33 MD (81.8%), 9/10 SD (90%) and 6/11 OL(54.5%). No RN was seen in VN and HS. In MD, SD and OL, all cases with canal paresis showed RN except 1 OL case. The cause of RN is suspected to be an inner ear disorder. Positional nystagmus in the prone position can assist in the diagnosis of peripheral vestibular disorders.
‘Cervical vertigo’ comprises a symptomatic group of vertiginous diseases whose pathogenesis is believed to be in the neck region. The diagnosis of cervical vertigo is difficult, mainly because no examinations are particularly useful for the purpose. In this study, we examined whether any features —especially stabilometry with or without neck tilting, torsion, or extension— are occasionally observed in patients with cervical vertigo. The subjects were 10 patients with putative cervical vertigo, seven patients with unilateral peripheral vestibular disorders, and 17 healthy individuals. With regard to oculomotor symptoms, five of seven patients with peripheral vestibular disorders showed some pathological nystagmus. In contrast, only one out of seven patients with cervical vertigo showed pathological nystagmus. From an analysis of stabilometry, the control group exhibited some tottering only in the head-extended position. This tendency was also observed, though mildly, in patients with peripheral vestibular disorders. Most of the patients with cervical vertigo, however, readily displayed tottering in any neck position. Further, the difference in the tottering in cervical vertigo patients between those in the neck-tilted or extended position and those not in such a position was significantly greater than in the control group and in patients with peripheral vestibular disorders, however there was no clear difference in the results between subjects in the control group and those with peripheral vestibular disorders. These results indicate the following. First, an oculomotor phenotype is not necessarily exhibited in patients with cervical vertigo. Second, stabilometry with and without neck extension or tilting provides valuable information in the diagnosis of cervical vertigo.
We report herein on psychiatric comorbidity in patients with dizziness in a psychiatric hospital with an otolaryngologist. Psychiatric comorbidity was revealed in 270 (68.9%) of 392 patients with dizziness. Of 270 patients with dizziness and psychiatric comorbidity, anxiety disorders were revealed in 149 (55.2%), mood disorders in 36 (13.3%), somatoform disorders in 5 (1.9%) and adjustment disorders or post-traumatic stress disorder in 15 (5.5%) but in addition organic mental disorders were also seen in 21 (7.8%) and schizophrenia in 15 (5.6%). Phobic postural vertigo was diagnosed in 30 (7.7%). These patients were not only treated by otolaryngologists, but also received psychiatric therapy or were prescribed psychotropic drugs. We believe that cooperation between psychiatrists and otolaryngologists in hospitals or regions can improve the mental condition and quality of life in patients suffering from dizziness with psychiatric comorbidity.
The control of extraocular and neck movements relies on the information from the vestibular organs. The brainstem and cerebellum are in charge of these processes. Further, the higher-order processing of vestibular information is mediated by the posterolateral part of the thalamus (“vestibular thalamus”), which in turn projects to multiple cortical areas including the parieto-insular vestibular cortex and thus constitutes the “thalamo-cortical vestibular system”. Recent advances in neuroimaging techniques have enabled researchers to visualize brain activity changes in the thalamo-cortical vestibular system in response to unilateral vestibular perturbation by means of electric or caloric stimulation. Clinically, neuroimging studies on peripheral vestibular disorders have shown abnormal responses of the thalamo-cortical vestibular system to vestibular perturbation. Studies have also revealed anatomo-functional reorganization of non-vestibular cortical areas (such as visual or somatosensory cortices) in peripheral vestibular disorders. Moreover, such reorganization may be correlated with functional recovery after peripheral vestibular disorders. Studies on cerebrovascular disorders involving the vestibular thalamus support the importance of this area for controlling posture. These imaging studies have begun to cast light on the otherwise unknown pathophysiology and compensatory mechanisms of vestibular disorders, although many issues still remain to be answered.
Neurorehabilitation for patients with intractable persistent dizziness is a specific treatment modality to decrease dizziness and balance problems and to increase safety and independence in patients with vestibular and balance disorders The neurorehabilitation treatment program in this study consisted of vestibular balance rehabilitation therapy specified in Nara Medical University (VBRT-NMU) to advance the central vestibular adaptation process and to substitute visual and somatosensory input for the impaired vestibular function, and a new therapy using the sensory substitution system with a human (brain)-machine interface which substitutes for diminished vestibular input by transmitting information about the patient's head position to the tongue. The clinical trials were performed to investigate how effective VBRT-NMU was for chronic balance disorders in subjects with unilateral vestibular loss and whether the new sensory substitution training could become a new treatment tool for severe balance problems intractable to VBRT-NMU. Some interventions for rehabilitation were selected and customized for each patient in accordance with the level of their compensation for postural control and their sensory dependence. Dynamic gait function and quality of life (QOL) assessments were tested using Functional Gait Assessment (FGA) and the Dizziness Handicap Inventory (DHI), respectively, before and after all training sessions. Improvements in the DHI and FGA were respectively noted in 88.9% and 90.7% of all subjects with unilateral vestibular loss examined in the VBRT-NMU program. All subjects for whom the VBRT-NMU failed showed pronounced improvements in their balance performance due to the vestibular sensory substitution training. The average scores of FGA and DHI significantly improved from 16.2 to 25.6 and 49.2 to 25.7, respectively, in 8 weeks. These results suggests that the program-based approach to vestibular rehabilitation such as an individualized VBRT-MNU could provide a beneficial effect in the treatment of balance disorder for patients who have a long term history of unilateral peripheral vestibular etiologies, and the vestibular substitution device is a possible new rehabilitation tool for subjects with a persistent severe problem in posture and mobility, intractable to any treatment.