Secondary Logo

Journal Logo

RESEARCH ARTICLE

Measurement of Health Status in Patients with Dizziness and a History of Migraine

Wrisley, Diane M. PhD, PT, NCS1,3,4; Whitney, Susan L. PhD, PT, NCS, ATC1,2,3; Furman, Joseph M. MD, PhD1, 2

Author Information
Journal of Neurologic Physical Therapy: June 2004 - Volume 28 - Issue 2 - p 84-90
doi: 10.1097/01.NPT.0000281188.71512.f5

Abstract

INTRODUCTION

Vestibular dysfunction can result in an illusionary sense of motion, vertigo, gaze instability, gait dysfunction, and imbalance.1–4 These impairments often result in functional limitations including decreased ability to perform activities of daily living and work.5 These physical symptoms can result in a perceived lower quality of life, or perceived hand-icap.6 In a previous study we demonstrated that patients with vestibular dysfunction with a history of migraine had a greater perceived handicap due to their dizziness than patients with vestibular disorders without a history of migraine.7 If patients with vestibular disorders and a history of migraine have a greater perceived handicap and lower perceived quality of life they may require that physical therapists provide specific emotional and psychological support during vestibular rehabilitation.

Patient perceived health status or quality of life has come to be regarded as an important factor in determining the effectiveness of health care.8, 9 Both generic and disease-specific measures of health status have been developed. The MOS Short-Form 36 (SF-36) Health Survey was developed to evaluate the impact of disease on well-being and functional status.8 It is a generic questionnaire that consists of 36 items, scored on a nominal or ordinal scale, measuring 8 health domains.10 Internal consistency and reliability have been demonstrated across socioeconomic status, diagnosis, and disease severity groups.10 Test-retest reliability and internal consistency were found to be adequate for all dimensions (r > 0.75, Cronbach's a > 0.85).11 The extensive use of this questionnaire in previous research allows for comparison with the general public and with groups with other medical conditions.

The Dizziness Handicap Inventory (DHI) is a 25-item disease-specific questionnaire that was developed to measure an individual's feelings about the impact dizziness and dysequilibrium have on their life.12 Higher scores on the DHI indicate greater perceived handicap. The DHI has been shown to be reliable and valid for use with patients with vestibular disorders.12 Disease-specific questionnaires are thought to be more responsive to change than generic questionnaires.6, 13 The DHI has been shown to be more responsive to change following vestibular physical therapy than the SF-36.6 Moderate correlations were demonstrated between the DHI and the SF-36 dimensions of physical functioning, role limitations-physical, and social function in persons with vestibular dysfunction.6

Use of a self-perception quality of life measure is especially appropriate when assessing patients with conditions that are more difficult to quantify such as migraine or vertigo.14 Several studies have compared SF-36 scores of patients with migraine to the general population.9, 14–22 Patients with migraines demonstrated lower scores in the role functioning, social function, bodily pain, vitality, and mental health dimensions compared to the general public.9, 17, 18, 21 Physical function scores were similar to the general population.9, 17, 18, 21 Patients with migraine demonstrated lower scores on the SF-36 even between attacks.14 Patients with vestibular disorders demonstrated decreased scores on all dimensions of the SF-36 compared with the general population.6, 23 In patients with multiple medical conditions the impact of the individual conditions on the SF-36 scores appears to be additive14 so it would be expected that patients with vestibular disorders and a history of migraine would have lower SF-36 scores than patients with either a vestibular disorder or migraine alone.

Migraines are commonly associated with dizziness. The incidence of dizziness and motion sensitivity is approximately twice as common in people with migraine than in the general public.24 True vertigo is reported by 25% of people with migraine25, 26 and may present as the only symptom of migraine, as the aura or in association with the headache.1,4,24,25,27 Although dizziness may be a component of migraine, patients with migraine may have concomitant vestibular pathology. Previously we presented a retrospective study of physical therapy outcomes in patients with vestibular disorders with a history of migraine compared to historical controls matched by diagnosis, age, and vestibular function tests without a history of migraine.7 The patients with a history of migraine demonstrated less change in their DHI scores than patients without a history of migraine. In addition, fewer of the patients with a history of migraine demonstrated clinically significant changes on all assessment measures recorded than those in the control group.

Generic questionnaires like the SF-36 provide a broader picture of multiple aspects of health than do disease-specific questionnaires and may illuminate differences between groups that will influence diagnosis or treatment. The SF-36 has previously been used to discriminate between patients with migraine and the general public, 9,14,17,18,21 to evaluate the effectiveness of migraine medication, 16, 22 and to predict the response to pharmacological therapy.14, 28 In patients with vestibular dysfunction, the SF-36 has been used to discriminate patients with vestibular dysfunction from the general public and has been used to evaluate the response to vestibular physical therapy.6 Exploring the differences in self-perceived health status prior to vestibular physical therapy in patients with vestibular disorders with and without a history of migraine may provide insight as to why patients with migraine demonstrate less improvement following vestibular physical therapy, lead to a means of predicting outcome, and may direct therapeutic intervention. We hypothesized that patients with vestibular disorders and a history of migraine would have the self-perception of a poorer quality of life than those with vestibular disorders alone. To test this hypothesis we compared scores on the SF-36 prior to vestibular physical therapy between patients with vestibular disorders with and without a history of migraine and to compare our scores with previously reported SF-36 scores for healthy control subjects, subjects with migraine, and subjects with vestibular dysfunction. A secondary purpose was to look at the relationship between scores on the SF-36 prior to vestibular physical therapy and scores on the Dizziness Handicap Inventory before vestibular physical therapy in patients with vestibular dysfunction with and without a history of migraine.

METHODS

Subjects

The subjects for this study were a subset of those reported in a previous study (Table 1).7 All subjects were identified through a retrospective chart review of patients seen for vestibular physical therapy between January 1998 and June 2000. Subjects were included in the history of migraine (HM) group if they had a diagnosis of vestibular disorder other than Migraine-related Vestibulopathy (MRV)1, 4, 25, 29 and had been diagnosed with migraine by a physician. A patient was considered to have a diagnosis of MRV if the diagnosis was provided by the physician. A diagnosis of MRV was based on the criteria of having a diagnosis of migraine, episodic or fluctuating vestibular symptoms, at least one migraine symptom during at least 2 attacks of vertigo.1, 3, 4, 29 Twenty-one subjects who had completed the SF-36 during the initial physical therapy visit were included in the present study. Subjects in the HM group were matched with historical controls also from a retrospective chart review of patients seen for vestibular physical therapy. Controls had no history of migraine and were matched by age (± 5 years) and vestibular diagnosis.

Table 1
Table 1:
Characteristics of Patients with Vestibular Disorders with and without a History of Migraine (mean ± standard deviation)

Patients were referred with a diagnosis of peripheral or central vestibular dysfunction. Specific vestibular diagnoses for subjects in the HM and control groups are listed in Table 1. All patients had undergone a neurological or otological examination before referral and the diagnoses were provided by the referring physician. One hundred percent of the patients with a history of migraine and 85% of subjects without a history of migraine completed vestibular function testing (electronystagmography, earth vertical axis rotation, positional or ocular motor testing) as part of the diagnostic process (Table 2). Abnormal findings in at least one of the vestibular function tests were found in 75% of the patients with a history of migraine and 88% of the patients without a history of migraine. The diagnoses of the 3 patients without a history of migraine who had not completed vestibular function testing were BPPV (2) and central vestibular dysfunction (1).

Table 2
Table 2:
Percentage of Patients with Abnormal Vestibular Laboratory Results

The Medical Outcome Study Short-Form-36 Health Status Survey (SF-36) was completed by patients prior to the initiation of physical therapy as a generic quality of life measure. The 8 dimensions of the SF-36 were scored individually and transformed according to methods described by Ware et al (1993), 30 resulting in a score ranging from 0 to 100. Lower scores on the SF-36 indicate that the subject perceives that their health interferes with activities or causes greater psychological or emotional stress.31 During this same visit and at each re-evaluation the patients completed the Dizziness Handicap Inventory (DHI) as a disease specific measure.6, 12

Data Analysis

Differences in SF-36 scores between patients with vestibular disorders with and without migraine were compared using the Wilcoxin matched-pairs signed-ranks test. The Spearman rank order correlation coefficient was used to determine if there was a relationship between scores on the 8 dimensions of the SF-36 and the DHI completed prior to beginning vestibular physical therapy for each patient group (SPSS for Windows Release 10).The criteria used for interpreting the correlation coefficients was: 0-0.25 little to no relationship, 0.25 to 0.50 fair degree of relationship, 0.50 to 0.75 moderate to good relationship, and 0.75 to 1.00 good to excellent relationship.32 Cochran's Q-statistic was used to compare the summary effect between SF-36 scores obtained during the current study and those obtained in previous studies using different patient populations.

The standardization of scoring the SF-36 allows for comparison between the current study and previously published SF-36 scores for the general population (Figure 1), 30 for patients with vestibular disorders (Figure 2), 6 and for patients with migraine (Figure 3).18 The mean SF-36 scores of the total group of patients with vestibular disorders were significantly lower than those reported by Ware et al30 for the general population (range 8–53 points, p <0.01) (Figure 4). When scores for the general population were compared to the HM and control groups from the current study, the HM group demonstrated statistically significant differences in all dimensions except general health while the patients without a history of migraine demonstrated statistically significant differences in physical function, role limitations-physical, and vitality dimensions (Figures 1 and 4). The mean scores of our total group were not statistically different from those reported by Enloe et al6 for their group of patients with vestibular disorders in all dimensions except for role limitations-emotional (Figure 2, p < 0.01). The HM group demonstrated statistically significantly lower scores than those previously reported for patients with migraine in the physical functioning, role limitations-physical, social function, and vitality dimensions (Figure 3, p < 0.01).

Figure 4
Figure 4:
Differences in mean SF-36 dimension scores between the general population and patients with vestibular disorders with and without a history of migraine. A negative score indicates a score less than the population mean indicative of poorer function.
Figure 3
Figure 3:
Comparison of patients with vestibular disorders with a history of migraine from the current study with patients with a history migraine from a previous study. History of migraine (HM): patients with vestibular disorders with a history of migraine from the current study, Migraine patients: patients who met the International Headache Society (IHS) diagnostic criteria for migraine18 Error Bars represent 1 standard deviation * Significant difference (p < 0.01)
Figure 2
Figure 2:
Comparison of patients with vestibular disorders from the current study with patients with vestibular disorders from a previous study. Previous Study: Patients diagnosed with vestibular dysfunction by an otolaryngologist in a previous study (n=95)6 Current study: Combined Scores of patients with vestibular disorders with and without a history of migraine from the current study. Error Bars represent 1 standard deviation *Significant difference (p < 0.01)
Figure 1
Figure 1:
Comparison of mean SF-36 dimension scores between the general public (population means), history of migraine (HM) and control group from the current study. Higher scores on the SF-36 indicate less impairment. Population means: general population reported by Ware et al,25 History of migraine (HM): patients with vestibular disorders without a history of migraine from the current study, Error Bars represent 1 standard deviation *Significant difference between HM and general population means (p<0.01 †Significant difference between control group and population means (p<0.01)

RESULTS

Descriptive information concerning the composition of both groups is listed in Table 1. Statistically significant differences were not identified between the groups in age, gender, duration of symptoms, number of treatment visits, or treatment duration. Similar to the gender distribution of people with migraines in the general public, there were a higher proportion of females in the HM group compared to the control group.

Mean SF-36 values for the HM and control groups are listed in Table 3. As a group, the patients with a history of migraine scored lower on all 8 dimensions of the SF-36 than the patients without a history of migraine. Significant differences were seen between the 2 groups in the role limitations – emotional (p<0.05), social functioning (p<0.05), mental health (p<0.05), and role limitations- physical (p<0.05) dimensions.

Table 3
Table 3:
Means and standard deviations for the 8 dimensions of the SF-36 for patients with vestibular disorders with and without a history of migraine. Significance level of the Wilcoxin matched-pairs signed ranks test between patients with vestibular disorders with and without a history of migraine.

The Spearman Rho correlation coefficients between the SF-36 dimension scores and the initial total DHI are listed in Table 4. Moderate to good correlations were found between the initial total DHI and the social functioning dimension of the SF-36 in both the HM and control groups. Moderate to good correlations were found between the initial total DHI and physical functioning, mental health, and general health perception dimensions in the HM group while moderate to good correlations were found between the initial total DHI and the role limitations (physical) and vitality in the control group.

Table 4
Table 4:
Spearman Rho Correlation coefficients between initial SF-36 dimension scores and initial Total Dizziness Handicap Inventory (DHI) scores in patients with vestibular disorders with and without a history of migraine.

DISCUSSION

Based on their scores on the SF-36, the patients with vestibular disorders with a history of migraine perceived that they had greater problems with work, social, or other activities due to emotional problems (role limitations-emotional) and a lower sense of well-being (mental health) than patients without a history of migraine prior to beginning physical therapy. However, there was no statistically significant difference in the scores between groups on the perception of general health on the SF-36 or on the initial scores of the total DHI.

The increased perception of difficulties with social, work, and other activities due to emotional problems may explain the lower levels of improvement in patients' perception of disability due to dizziness reported in an earlier study.7 The patients with vestibular disorders with a history of migraine demonstrated less change following physical therapy in their total DHI scores than the patients without a history of migraine.7

Both the HM and the control groups demonstrated SF-36 scores that were lower than those reported for the general public. The greatest difference between the population means and the scores of the patients were seen in the role limitations-physical. This finding is not unexpected as patients with vestibular disorders find it difficult to complete their daily activities due to their dizziness and/or balance impairments. The patients with vestibular disorders with a history of migraine demonstrated significantly lower scores across all dimensions of the SF-36 than patients without a history of migraine. However, the patients with vestibular disorders without a history of migraine demonstrated scores that were similar to those reported for the general public for the role limitations-emotional, bodily pain, and mental health dimensions. This difference adds support to the theory that having a history of migraine, in addition to a vestibular disorder, contributes to the perception that one's activities are limited due to emotional problems.

The patients in the HM group demonstrated stronger correlations between the total DHI and the SF-36 dimensions of mental health and general health perception than did the patients in the control group (Table 3). This may indicate that for patients with a history of migraine their perception of their disability due to dizziness is also influenced by their mental health and perception of general health perception, dimensions that may be significantly influenced by the presence of migraines. It would have been interesting to see if the correlation was stronger in patients with uncontrolled or active migraines or if there was a correlation with frequency or severity of migraines.

Increased levels of anxiety and signs of emotional distress are often seen in people who complain of dizziness.33 The relationship between anxiety and vertigo may be mediated physiologically through connections in the autonomic nervous sys-tem34 or through a neuro-chemical link.35–37 There is increasing evidence that the extent to which dizziness becomes a chronic problem relates to the patient's psychological response to the symptoms.38 People with a lower threshold to becoming anxious or those who have a tendency toward becoming passive and dependent appear to be more likely to exhibit behaviors that perpetuate dizziness such as inactivity and avoidance of symptom-provoking situ-ations.39 People who are experiencing increased stress due to life situations may also be more likely to have an increased response to dizziness.39 This leads one to question whether the low scores on the emotional components of the SF-36 seen in this study are due to the pathology causing dizziness and/or migraine or that the patients had increased complaints of dizziness because of their emotional profile. The patients in this study represent the more severely and chronically involved patients with dizziness who were treated at a tertiary care center and frequently have failed medical management. Thus, the sample may be biased to include people with lower SF-36 scores or a different emotional profile due to their more severe illness.

Patients with migraine have been represented as having distinct personality traits of increased anxiety, insecurity, rigidity, compulsiveness, irritability, and decreased tolerance.40 Although this stereotypic migraine personality has been questioned because the research was based on observations of biased patient samples from headache specialty clinics, 40 the co-morbidity of migraine with panic disorder and depression has been demonstrated through recent population based studies.40–42 In addition, recent studies have questioned the theory that depression is a psychological reaction to the disability caused by migraine attacks and have theorized that the association between migraine and psychopathology is due to common pathophysiological mechanisms.40, 43–45 The similar autonomic and neuro-chemical pathology that are thought to be responsible for the association between anxiety and dizziness may also be responsible for the association between migraine and depression and migraine and panic disorder.37, 40, 46

As with the patients in our study, a high proportion of patients with dizziness complain of fatigue (SF-36 Vitality dimension) and avoid social activities (SF-36 Social Function dimension).38 Fatigue and decreased concentration are frequently seen as signs of depression. However, these symptoms also may result from the mental overload caused by the conflict between their normal daily demands for mental activity and the increased concentration needed to maintain their balance.38 Patient's fears about vertigo have been found to be the principal reason that they limit activities.47 Fear of having a migraine attack in addition to the fear of experiencing dizziness may contribute to the patients in the HM group scoring lower in the role-emotional and well-being dimensions of the SF-36.

Patients who experience migraine may perceive themselves as having more disability and less function based on the combination of their experience with migraines and dizziness. It has been demonstrated that in patients with multiple medical conditions the impairment of the SF-36 scores appears to be cumulative.14 The patients in the HM group demonstrated lower scores on all dimensions of the SF-36 than previously reported for either patients with migraine, 18 or patients with vestibular disorders6 supporting the concept that the SF-36 score may be cumulative for multiple impairments.

Patients with a vestibular disorder and a history of migraine perceive that they have greater disability and greater functional impairment, as evidenced by higher total DHI scores and lower scores on SF-36 dimensions of physical functioning, role limitations-emotional, and social dysfunction, than patients without a history of migraine although their physical function is similar following physical therapy.7 Patients with vestibular disorders and a history of migraine may have a difficult time separating the disability due to the migraine from the disability due to the dizziness and may require additional emotional support and encouragement during their physical therapy treatment that helps them to recognize that their symptoms of dizziness are improving and to continue with the treatment. The clinician needs to be aware of the symptoms and complications from the history of migraine in patients who present with dizziness.It appears to be important that the migraine is adequately managed before significant improvements will be seen in a patient's balance and vestibular function.2 Medications to reduce the symptoms so that patients can tolerate vestibular rehabilitation may improve physical therapy outcomes.2, 48

CONCLUSION

Patients with vestibular disorders with a history of migraine perceive greater handicap (higher total DHI scores), physical and emotional role limitations, and decreased social function than patients with vestibular disorders without a history of migraine. Patients with a history of migraine may benefit from enhanced emotional support and encouragement while undergoing vestibular physical therapy.

ACKNOWLEDGEMENTS

Supported in part by NIDCD grant DC04784 and the Neurology Section APTA (DMW). Designated as exempt from Human Subjects Review by the University of Pittsburgh's Institutional Review Board.

REFERENCES

1 Cass SP, Furman JM, Ankerstjerne JKP, Balaban C, Yetiser S, Aydogan B. Migraine-related vestibulopathy. Ann Otol Rhinol Laryngol. 1997;106:182–189.
2 Johnson GD. Medical management of migraine-related dizziness and vertigo. Laryngoscope. 1998;108:1–28.
3 Marcus DA, Whitney SL, Furman JM. Treatment of migrainous vertigo. Expert Rev Neurotherapeutics. 2003;3:307–316.
4 Furman JM, Marcus DA, Balaban CD. Migrainous vertigo: development of a pathogenic model and structured diagnostic interview. Curr Opin Neurol. 2003;16:5–13.
5 Cohen HS, Kimball KT, Adams AS. Application of the vestibular disorders activities of daily living scale. Laryngoscope. 2000;110:1204–1209.
6 Enloe LJ, Shields RK. Evaluation of health-related quality of life in individuals with vestibular disease using disease-specific and general outcome measures. Phys Ther. 1997;77:890–903.
7 Wrisley DM, Whitney SL, Furman JM. Vestibular rehabilitation outcomes in patients with a history of migraine. Otology and Neurotology. 2002;23:483–487.
8 Ware JE, Sherbourne CD. The MOS 36-item Short-Form Health Survey (SF-36) I. Conceptual framework and item selection. Med Care. 1992;30:473–483.
9 Wang S, Fuh J, Lu S, Juang K. Quality of life differs among headache diagnoses: analysis of SF-36 survey in 901 headache patients. Pain. 2001;89:285–292.
10 McHorney CA, Ware JE, Lu JE, Sherbourne CD. MOS 36-item Short-Form Health Survey (SF-36): Tests of data quality, scaling assumptions, and reliability across divers patient groups. Med Care. 1994;32:40–66.
11 Brazier JE, Harper R, Jones NMB, O'Cathain A, Thomas KJ, Usherwood T et al. Validating the SF-36 health survey questionnaire: new outcome measure for primary care. Br Med J. 1992;305:160–164.
12 Jacobson GP, Newman CW. The development of the dizziness handicap inventory. Arch Otolaryngol Head Neck Surg. 1990;116:424–427.
13 Patrick DL, Deyo RA. Generic and disease-specific measures in assessing health status and quality of life. Med Care. 1989;27:S217-S232.
14 Solomon GD. Evolution of the measurement of quality of life in migraine. Neurology. 1997;48:S10-S15.
15 Dahlof C. Assessment of health-related quality of life in migraine. Cephalalgia. 1993;13:233–237.
16 Lofland JH, Johnson NE, Batenhorst AS, Nash DB. Changes in resource use and outcomes for patients with migraine treated with sumatriptan: a managed care perspective. Arch Intern Med. 1999;159:857–863.
17 Monzon MJ, Lainez MJ. Quality of life in migraine and chronic daily headache patients. Cephalalgia. 1998;18:638–643.
18 Osterhaus JT, Townsend RJ, Gandek B, Ware JE, Jr. Measuring the functional status and well-being of patients with migraine headache. Headache. 1994;34:337–343.
19 Passchier J, de Boo HZA, Brienen JA. Health-related quality of life of chronic headache patients is predicted by the emotional component of their pain. Headache. 1996;36:556–560.
20 Solomon GD, Skobieranda FG, Gragg LA. Quality of life and well-being of headache patients: measurement by the medical outcomes study instrument. Headache. 1993;33:351–358.
21 Solomon GD, Skobieranda FG, Gragg LA. Does quality of life differ among headache diagnoses? Analysis using the medical outcomes study instrument. Headache. 1994;34:143–147.
22 Solomon GD, Skobieranda FG, Genzen JR. Quality of life assessment among migraine patients treated with sumatriptan. Headache. 1995;35:449–454.
23 Fielder H, Denholm SW, Lyons RA, Fielder C P. Measurement of health status in patients with vertigo. Clin Otolaryngol. 1996;21:124–126.
24 Kuritzky A, Ziegler DK, Hassanein R. Vertigo, motion sickness, and migraine. Headache. 1981;21:227–231.
25 Baloh RW. Neurotology of migraine. Headache. 1997;37:615–621.
26 Ishiyama A, Jacobson KM, Baloh RW. Migraine and benign positional vertigo. Ann Otol Rhinol Laryngol. 2000;109:377–380.
27 Kayan A, Hood JD. Neuro-otological manifestations of migraine. Brain. 1984;107:1123–1142.
28 Litaker DG, Solomon GD, Genzen JR. Using pretreatment quality of life perceptions to predict response to suma-triptan in migraineurs. Headache. 1997;37:630–634.
29 Neuhauser H, Lempert T. Vertigo and dizziness related to migraine: a diagnostic challenge. Cephalalgia. 2004;24:83–91.
30 Ware JE, Snow K, Kosinski M, Gandek B. SF-36 Health Survey: Manual and Interpretation Guide. Boston, Mass: The Health Institute, New England Medical Center; 1993.
31 Ware JE, Kosinski M, Bayliss M, McHorney CA, Rogers WH, Raezek AE. Comparison of methods for the scoring and statistical analysis of SF-36 health profile and summary measures: summary of results from the medical outcomes study. Med Care. 1995;33:AS264-AS279.
32 Portney LG, Watkins M P. Foundations of Clinical Research: Applications to Practice. Norwalk, Conn: Appleton and Lange; 1993.
33 Eagger S, Luxon LM, Davies RA, Coelho A, Ron MA. Psychiatric morbidity in patients with peripheral vestibular disorder: a clinical and neuro-otological study. J Neurol Neurosurg Psychiatry. 1992;55:383–387.
34 Yardley L, Masson E, Verschuur C, Haacke N, Luxon L. Symptoms, anxiety and handicap in dizzy patients: development of the vertigo symptom scale. J Psychosom Res. 1992;36:731–741.
35 Balaban CD, Porter JD. Neuroanatomic substrates for vestibulo-autonomic interactions. J Vestib Res. 1998;8:7–16.
36 Balaban CD. Vestibular autonomic regulation (including motion sickness and the mechanism of vomiting). Curr Opin Neurol. 1999;12:29–33.
37 Balaban CD, Thayer JF. Neurological bases for balance-anxiety links. J Anxiety Disord. 2001;15:53–79.
38 Yardley L, Burgneay J, Nazareth I, Luxon L. Neuro-oto-logical and psychiatric abnormalities in a community sample of people with dizziness: a blind, controlled investigation. J Neurol Neurosurg Psychiatry. 1998;65:679–684.
39 Yardley L. Overview of psychiologic effects of chronic dizziness and balance disorders. Otolaryngol Clin North Am. 2000;33:603–616.
40 Silberstein SD, Lipton RB, Breslau N. Migraine: association with personality characteristics and psychopathology. Cephalalgia. 1995;15:358–369.
41 Merikangas KR. Association betwen psychopathology and headache syndromes. Curr Opin Neurol. 1995;8:248–251.
42 Stewart W, Breslau N, Keck PJ. Comorbidity of migraine and panic disorder. Neurology. 1994;44 (Suppl) 7:S23-S27.
43 Breslau N, Davis GC, Schultz LR, Peterson EL. Migraine and major depression: a longitudinal study. Headache. 1994;7:387–393.
44 Jarman J, Fernandez M, Davies PTG, et al. High incidence of endogenous depression in migraine: confirmation by tyramine test. J Neurol Neurosurg Psychiatry. 1990;53:573–575.
45 Breslau N, Davis GC. Migraine, major depression and panic disorder: a prospective epidemiologic study of young adults. Cephalalgia. 1992;112:85–89.
46 Cutrer FM, Baloh RW. Migraine-associated dizziness. Headache. 1992;32:300–304.
47 Yardley L, Putnam J. Quantitative analysis of factors contributing to handicap and distress in vertiginous patients: a questionaire study. Clin Otolaryngol. 1997;17:231–236.
48 Whitney SL, Wrisley DM, Brown KE, Furman JM. Physical therapy for migraine-related vestibulopathy and vestibular-dysfunction with history of migraine. Laryngoscope. 2000;110:1528–1534.
© 2004 Neurology Section, APTA