Neurologic bases for comorbidity of balance disorders, anxiety disorders and migraine: neurotherapeutic implications.

The comorbidity among balance disorders, anxiety disorders and migraine has been studied extensively from clinical and basic research perspectives. From a neurological perspective, the comorbid symptoms are viewed as the product of sensorimotor, interoceptive and cognitive adaptations that are produced by afferent interoceptive information processing, a vestibulo-parabrachial nucleus network, a cerebral cortical network (including the insula, orbitofrontal cortex, prefrontal cortex and anterior cingulate cortex), a raphe nuclear-vestibular network, a coeruleo-vestibular network and a raphe-locus coeruleus loop. As these pathways overlap extensively with pathways implicated in the generation, perception and regulation of emotions and affective states, the comorbid disorders and effective treatment modalities can be viewed within the contexts of neurological and psychopharmacological sites of action of current therapies.

Visually induced postural sway in anxiety disorders.

Postural sensitivity to moving visual environments in patients with anxiety disorders was studied. We hypothesized that patients with anxiety disorders would have greater sway in response to a moving visual environment compared to healthy adults, especially if they have space and motion discomfort (SMD). Twenty-one patients with generalized anxiety without panic (NPA) and 38 patients with panic and agoraphobia (PAG) were compared to 22 healthy controls. SMD was evaluated in all subjects via questionnaire. Subjects stood on a force platform that was either fixed or rotating with the subject (i.e., sway referenced) during exposure to a sinusoidally moving visual surround. Center of pressure (COP) data were computed from force transducers in the platform as a measure of sway. Results showed that patients swayed significantly more in response to the moving visual scene compared to control subjects, with no differences between the NPA and PAG groups. SMD was a predictor of sway response in the patients: patients with high SMD swayed significantly more than both Controls and anxiety patients with low SMD. These results indicate that patients with anxiety disorders, particularly those with SMD, are more visually dependent for balance. This subgroup of patients may be amenable to treatment used for patients with balance disorders (i.e., vestibular rehabilitation) that focuses on sensory re-integration processes that address visual sensitivity.

Vestibulo-ocular function in anxiety disorders.

Previous studies of vestibulo-ocular function in patients with anxiety disorders have suggested a higher prevalence of peripheral vestibular dysfunction compared to control populations, especially in panic disorder with agoraphobia. Also, our recent companion studies have indicated abnormalities in postural control in patients with anxiety disorders who report a high degree of space and motion discomfort. The aim of the present study was to assess the VOR, including the semicircular canal-ocular reflex, the otolith-ocular reflex, and semicircular canal-otolith interaction, in a well-defined group of patients with anxiety disorders. The study included 72 patients with anxiety disorders (age 30.6 +/- 10.6 yrs; 60 (83.3% F) and 29 psychiatrically normal controls (age 35.0 +/minus; 11.6 yrs; 24 (82.8% F). 25 patients had panic disorder; 47 patients had non-panic anxiety. Patients were further categorized based on the presence (45 of 72) or absence (27 of 72) of height phobia and the presence (27 of 72) or absence (45 of 72) of excessive space and motion discomfort (SMD). Sinusoidal and constant velocity earth-vertical axis rotation (EVAR) was used to assess the semicircular canal-ocular reflex. Constant velocity off-vertical axis rotation (OVAR) was used to assess both the otolith-ocular reflex and static semicircular canal-otolith interaction. Sinusoidal OVAR was used to assess dynamic semicircular canal-otolith interaction. The eye movement response to rotation was measured using bitemporal electro-oculography. Results showed a significantly higher VOR gain and a significantly shorter VOR time constant in anxiety patients. The effect of anxiety on VOR gain was significantly greater in patients without SMD as compared to those with SMD. Anxiety patients without height phobia had a larger OVAR modulation. We postulate that in patients with anxiety, there is increased vestibular sensitivity and impaired velocity storage. Excessive SMD and height phobia seem to have a mitigating effect on abnormal vestibular sensitivity, possibly via a down-weighting of central vestibular pathways.

Acrophobia and pathological height vertigo: indications for vestibular physical therapy?

BACKGROUND AND PURPOSE: Acrophobia (fear of heights) may be related to a high degree of height vertigo caused by visual dependence in the maintenance of standing balance. The purpose of this case report is to describe the use of vestibular physical therapy intervention following behavioral therapy to reduce a patient's visual dependence and height vertigo. CASE DESCRIPTION: Mr N was a 37-year-old man with agoraphobia (fear of open spaces) that included symptoms of height phobia. Exposure to heights triggered symptoms of dizziness. Intervention. Mr N underwent 8 sessions of behavioral therapy that involved exposure to heights using a head-mounted virtual reality device. Subsequently, he underwent 8 weeks of physical therapy for an individualized vestibular physical therapy exercise program. OUTCOMES: After behavioral therapy, the patient demonstrated improvements on the behavioral avoidance test and the Illness Intrusiveness Rating Scale, but dizziness and body sway responses to moving visual scenes did not decrease. After physical therapy, his dizziness and sway responses decreased and his balance confidence increased. DISCUSSION: Symptoms of acrophobia and sway responses to full-field visual motion appeared to respond to vestibular physical therapy administered after completion of a course of behavioral therapy. Vestibular physical therapy may have a role in the management of height phobia related to excessive height vertigo.

Validation of a brief nurse-administered migraine assessment tool.

OBJECTIVE: To validate a brief tool for screening migraine. BACKGROUND: Migraine is a common, but underdiagnosed condition. Effective utilization of nonphysician personnel to reliably screen patients for migraine may improve identification of migraineurs for clinical treatment and research. METHODS: An 8-question Migraine Assessment Tool (based on International Headache Society criteria) was designed for administration by a nurse with no specialized headache training as a pre-assessment for the diagnosis of migraine for use in either a research or clinical environment. A community sample of 80 adults (71 women, 9 men; mean age, 33.7 years; 80% white, 14% African American, 2.5% Asian American) with self-reported headache was recruited through advertisements. A headache specialist independently diagnosed subjects using clinical assessment, and a nurse who works in a balance disorder clinic used the Migraine Assessment Tool. Agreement between physician and nurse-administered Migraine Assessment Tool diagnoses was determined. Each subject returned in 2 to 4 weeks for a second assessment, administered by the same nurse. Agreement between the 2 diagnoses from the Migraine Assessment Tool was calculated. RESULTS: Comparison between diagnosis by the physician versus the Migraine Assessment Tool revealed a positive predictive value of 0.85; negative predictive value, 0.84; sensitivity, 0.89; specificity, 0.79; and observed agreement, 0.85. Cohen's kappa reliability measure was 0.69, indicating good test reliability. Interestingly, in 8 of the 12 cases of disagreement, the examiner diagnosing nonmigraine diagnosed analgesic overuse headache. Comparing diagnoses assigned by the 2 separate administrations of the Migraine Assessment Tool revealed a Cohen's kappa of 0.69. Notably, 9 of the 12 cases of nonagreement on the 2 assessments were due to subjects endorsing analgesic overuse in only 1 of the 2 testing sessions. CONCLUSIONS: This study showed good reliability and stability of a new, brief, nurse-administered migraine questionnaire. In addition, the study also showed that consistency in self-reporting analgesic overuse within individuals with headache is poor. This suggests the need for repeat questioning about analgesic overuse on subsequent appointments to ensure absence of analgesic overuse headache.

Diagnosis of migrainous vertigo: validity of a structured interview.

BACKGROUND: Migraine and vestibular symptoms are co-morbid. Migraine is increasingly recognized as a cause of benign, recurrent vertigo. Although the International Headache Society does not currently include the diagnosis of migrainous vertigo, specific criteria have been proposed and utilized in clinical trials. MATERIAL/METHODS: Seventeen adult migraineurs were separately screened for the diagnosis of migrainous vertigo using a standardized structured interview for migrainous vertigo (SIM-V) and a clinical evaluation by an experienced neurotologist. The SIM-V was administered by a nurse who read and recorded subject responses, obtaining no additional information for the diagnosis of migrainous vertigo. Comparison of diagnoses between clinician and SIM-V was made using Cohen's kappa reliability testing. Subjects were asked to return for a second interview by the same nurse using the SIM-V, at least 2 weeks after the initial assessment. Testing stability was evaluated by comparing diagnoses obtained with each SIM-V administration. RESULTS: Cohen's kappa demonstrated excellent test validity (kappa=0.75). Fourteen subjects returned for repeat testing, with excellent retest stability (kappa=0.85). The additional three subjects could not be relocated or were not interested in attending a retest appointment. CONCLUSIONS: The SIM-V is an easy-to-administer screening tool for the diagnosis of migrainous vertigo. Diagnostic comparison to a standard clinical assessment shows good test validity. Retest stability was also demonstrated. The SIM-V may be a useful screening tool for migraineurs with an additional complaint of dizziness.

Does nondipping of blood pressure at night reflect a trait of blunted cardiovascular responses to daily activities?

BACKGROUND: Individuals who fail to show a decline in blood pressure (BP) when asleep or at night (labeled nocturnal nondippers) are at elevated risk for hypertension and associated target-organ damage. PURPOSE: We tested whether the well-established changes in BP exhibited in response to daily activities are also blunted in nocturnal nondippers. METHODS: Cross-sectional study of 41 women and 56 men, aged 27 to 71 years, residing in Benin, Nigeria, enrolled in a health survey of civil servants. Ambulatory 24-hr BP monitoring was performed with concurrent diary recordings of physical activity level, posture, location, state of mental activity, interpersonal interaction, and mood obtained during the waking hours. RESULTS: Nocturnal nondippers exhibited smaller cardiovascular responses to changes in posture (from lying to sitting or to standing, ps <.02), location (from home to work or to driving/riding in a car, ps <.02), mental activity (from relaxed to active, p =.02), and mood (from feeling mellow to feeling elated-happy, p =.05) than did dippers. Statistical controls for posture substantially reduced the effects of nondipping status on responses to other daily activities and mood. Lack of systolic BP responsiveness to postural changes during the day is a strong predictor of nondipping status. CONCLUSIONS: Nondipping at night appears to extend to decreased cardiovascular responses to changes in activities during daytime hours.

Depression and anxiety in parents of children with ADHD and varying levels of oppositional defiant behaviors: modeling relationships with family functioning.

This study investigated the relation between parental anxiety and family functioning. Parental anxiety and depression, child attention deficit hyperactivity disorder (ADHD), and oppositional defiant disorder (ODD) symptoms were all included as predictors of 3 measures of family functioning to examine the independent contributions of each. Using a self-report battery completed by 45 mother-father pairs, 3 family functioning factors were derived: Parental Warmth and Positive Involvement, Intrusiveness and Negative Discipline, and Social Distress. Multilevel modeling simultaneously estimated the unique contributions of parental and child symptoms on family functioning. Results indicated that parental anxiety was negatively associated with Parental Warmth and Positive Involvement, Intrusiveness and Negative Discipline, and Social Distress; parental depression was only negatively associated with Social Distress. Child ODD symptoms had independent associations with all outcomes; no relations were found with ADHD. Sex moderated the effects of parental anxiety on Parental Warmth and Positive Involvement such that only for mothers did greater anxiety lead to less Parental Warmth and Positive Involvement.

Hypertension Intervention Pooling Project.

Data from 12 independently designed and conducted randomized trials of behavioral interventions for hypertension, consisting principally of variants of relaxation and biofeedback therapies, were aggregated to assess current progress of research in this area. Meta-analytical methods revealed a statistically significant decrease in diastolic blood pressure for nonmedicated patients at the end of intervention. No significant improvement was detected in medicated patients, but potential differential effectiveness of prescribed medications and differences in compliance among patients prohibits separation of changes due to behavioral treatments alone. The need to devise criteria for selection of patients, and to establish the most appropriate patient-treatment match is emphasized.