Long-term effects of antidepressants on balance, equilibrium, and postural reflexes

Differentiation in theta and gamma activation in weight-shifting learning between people with parkinson's disease of different anxiety severities

Anxiety and postural control deficits may be related in people with Parkinson's disease (PwPD). However, the association between anxiety levels and weight-shifting control remains ambiguous. This study investigated whether 1) weight-shifting control differed between PwPD with and without anxiety, and 2) the learning effect of weight-shifting differed between the two populations. Additionally, we evaluated cortical activities to investigate neural mechanisms underlying weight-shifting control. Twenty-eight PwPD (14 anxiety, 14 nonanxiety) participated in a 5-day weight-shifting study by coupling the bearing weight of their more-affected leg to a sinusoidal target at 0.25 Hz. We tested the weight-shifting control on day 1 (pretest), day 3 (posttest), and day 5 (retention test) with a learning session on day 3. The error and jerk of weight-shifting trajectory and the theta and gamma powers of electroencephalography in prefrontal, frontal, sensorimotor and parietal-occipital areas were measured. At the pretest, the anxiety group showed larger error and smaller jerk of weight-shifting with greater prefrontal theta, frontal gamma, and sensorimotor gamma powers than the nonanxiety group. Anxiety intensity was correlated positively with weight-shifting error and theta power but negatively with weight-shifting jerk. Reduced weight-shifting error with increased theta power after weight-shifting learning was observed in the nonanxiety group. However, the anxiety group showed decreased gamma power after weight-shifting learning without behavior change. Our findings suggest differential weight-shifting control and associated cortical activation between PwPD with and without anxiety. In addition, anxiety would deteriorate weight-shifting control and hinder weight-shifting learning benefits in PwPD, leading to less weight-shifting accuracy and correction.

Induced leg length inequality affects pelvis orientation during upright standing immediately following a sit-to-stand transfer: a pre-post measurement study

BACKGROUND

Leg length inequality (LLI) greater than 20 mm has been associated with low back pain (LBP) and its correction is clinically recommended. Much less is known about the biomechanical effects that LLI below 15 mm has on pelvis orientation.

METHODS

Twenty-two adult participants (8 female) aged between 18 and 30 years without LBP were enrolled in the study and completed a series of sit-to-stand trials with no heel-lift (0 mm baseline) and heel-lifts of varying heights (5, 9 and 12 mm) placed in their right shoe. Three-dimensional kinematic data were obtained from the lower extremities, pelvis and thorax. Additional kinematic data were obtained from the left and right sides of the pelvis. The global orientation of the whole pelvis and relative orientation between the left and right sides of the pelvis were obtained in upright standing immediately upon completion of the sit-to-stand movement. Repeated measures ANOVAs were used to detect differences in sample means across the different levels of heel-lift (0, 5, 9, and 12 mm). The tests for within-subject effects determined overall significant differences between the means at the different levels of heel-lift induced LLI. Partial Eta-Squared was used to express the size for the main effect of heel-lift height. For each level of heel-lift, the estimated marginal mean and 95% confidence interval (95%CI) values of pelvis angles were illustrated graphically.

RESULTS

Left frontal plane rotation of the pelvis increased (p = 0.001), that is, the left side of the pelvis was lower than the right side of the pelvis, and anterior tilt of the pelvis decreased (p = 0.020) with a heel-lift height (applied on the right) as low as 5 mm. A significant main effect of heel-lift was only observed for the norm of rotations about all three axes for relative-pelvis orientation (p = 0.034). Post-hoc analyses did not reveal any statistically significant differences between the heel-lifts and the 0 mm baseline (p≥0.072).

CONCLUSION

These findings suggest that correcting leg length inequality below the recommended threshold of 20 mm may influence pelvic orientation. Future work can investigate the effects of the altered orientations on spine loading and the clinical effects of corrections to minor leg length inequality.

Effect of transcranial magnetic stimulation on postural control of individuals with major depressive disorder: A case report

Accidental falls and major depressive disorder (MDD) are two common conditions associated with aging. Initial treatment of MDD often starts with administering antidepressants, followed by transcranial magnetic stimulation (TMS) for treatment-resistant individuals. The purpose of this case study was to determine the effect of repetitive TMS (rTMS) on postural control of an individual with MDD. A 44-year-old male with recurrent severe MDD was assessed for postural balance during eyes closed and eyes open conditions, pre and post three consecutive sessions receiving high-frequency rTMS (NeuroStar). Total excursion and velocity of sway significantly decreased following rTMS treatment when eyes were closed (p < 0.05). Power of the sway changed, but the changes were not statistically significant. The fractal dimension confidence circle area decreased significantly in eyes closed trials (p < 0.05). It appears that rTMS application can potentially impact postural steadiness in individuals with MDD. Our results warrant further studies with larger study samples.

Motor alterations in depression and anxiety disorders: A systematic review and meta-analysis

BACKGROUND

Psychomotor retardation has long been recognized as a major feature of depression, and anxiety disorders have been linked with freeze and flight motor responses. This systematic review and meta-analysis aimed a) to synthesize available evidence of motor alterations comparing individuals with depression and anxiety disorders to healthy individuals and b) to evaluate the effect of experimental manipulations of motor displays within these clinical groups.

METHOD

The databases PubMed and PsycINFO were searched for studies either assessing motor differences between clinical and healthy control groups or manipulating the motor system within a clinical group.

RESULTS

The literature search yielded 87 relevant papers, comprising 82 studies comparing a clinical group to a healthy group and 5 studies investigating motor manipulations within a clinical sample. The results of the meta-analysis (K = 71) indicated a statistically significant combined estimate of differences between healthy and clinical groups (g = 0.38 [0.31, 0.45], adjusted for publication bias g = 0.26 [0.19, 0.33]) of a small size. This effect did not vary according to type of disorder (anxiety vs. depression, p = .468). From a narrative review of experimental studies within clinical groups, four out of five studies reported statistically significant effects of manipulating the motor system on affective outcomes.

DISCUSSION

This synthesis adds to the accumulating empirical evidence of motor alterations in depression and anxiety disorders. Future research will need to investigate how individuals suffering from depression or anxiety disorders could benefit from psychological, behavioral, and physical interventions directly aimed at the motor system.

Instrumental assessment of balance and gait in depression: A systematic review

Psychomotor symptoms of depression are understudied despite having a severe impact on patient outcomes. This review aims to summarize the evidence on motor features of depression assessed with instrumental procedures, and examine age-related differences. We included studies investigating posture, balance and gait ascertained with instrumental measurements among individuals with depressive symptoms or disorders. Studies on subjects with specific physical illnesses were excluded. Methodological quality was assessed with the Newcastle - Ottawa Scale (NOS) and PRISMA guidelines were followed. 33 studies (13 case-control, five cross-sectional, nine longitudinal and six intervention) with overall low-medium quality were included. Different instruments were employed to assess posture (e.g. digital cameras), balance (balance, stepping platform) or gait (e.g. Six-Minute-Walking Test, instrumented walkways). Results suggest that depression in adults is associated with significant impairments of posture, balance and gait. Motor abnormalities among depressed older adults may depend on the interplay of physical diseases, cognitive impairment and mood. Very few intervention studies measured motor symptoms as outcome. Available evidence suggests, however, that antidepressant drugs and physical exercise may be beneficial for motor abnormalities. Despite the lack of high-quality studies, instrumental assessments confirm the presence and importance of motor abnormalities in depression, with potential age-related differences in their pathophysiology.

Postural Stability in Obese Preoperative Bariatric Patients Using Static and Dynamic Evaluation

INTRODUCTION

Globally, 300 million adults have clinical obesity. Heightened adiposity and inadequate musculature secondary to obesity alter bipedal stance and gait, diminish musculoskeletal tissue quality, and compromise neuromuscular feedback; these physiological changes alter stability and increase injury risk from falls. Studies in the field focus on obese patients across a broad range of body mass indices (BMI >30 kg/m2) but without isolating the most morbidly obese subset (BMI ≥40 kg/m2). We investigated the impact of obesity in perturbing postural stability in morbidly obese subjects elected for bariatric intervention, harboring a higher-spectrum BMI.

SUBJECTS AND METHODS

Traditional force plate measurements and stabilograms are gold standards employed when measuring center of pressure (COP) and postural sway. To quantify the extent of postural instability in subjects with obesity before bariatric surgery, we assessed 17 obese subjects with an average BMI of 40 kg/m2 in contrast to 13 nonobese subjects with an average BMI of 30 kg/m2. COP and postural sway were measured from static and dynamic tasks. Involuntary movements were measured when patients performed static stances, with eyes either opened or closed. Two additional voluntary movements were measured when subjects performed dynamic, upper torso tasks with eyes opened.

RESULTS

Mean body weight was 85% (p < 0.001) greater in obese than nonobese subjects. Following static balance assessments, we observed greater sway displacement in the anteroposterior (AP) direction in obese subjects with eyes open (87%, p < 0.002) and eyes closed (76%, p = 0.04) versus nonobese subjects. Obese subjects also exhibited a higher COP velocity in static tests when subjects' eyes were open (47%, p = 0.04). Dynamic tests demonstrated no differences between groups in sway displacement in either direction; however, COP velocity in the mediolateral (ML) direction was reduced (31%, p < 0.02) in obese subjects while voluntarily swaying in the AP direction, but increased in the same cohort when swaying in the ML direction (40%, p < 0.04).

DISCUSSION AND CONCLUSION

Importantly, these data highlight obesity's contribution towards increased postural instability. Obese subjects exhibited greater COP displacement at higher AP velocities versus nonobese subjects, suggesting that clinically obese individuals show greater instability than nonobese subjects. Identifying factors contributory to instability could encourage patient-specific physical therapies and presurgical measures to mitigate instability and monitor postsurgical balance improvements.

Management of Late-Life Depression

Depression is a common disorder in late life that is associated with poor quality of life, increased disability, and increased all-cause mortality. Rates of completed suicide are the highest in older depressed men compared with any other age group. In this age group, depression is often concurrent with medical illness and it can aggravate the course of medical illness. Cognitive impairment is frequently present and may be the result of the depression itself or may be the consequence of a neurodegenerative disorder such as Alzheimer's disease. Evidence-based psychotherapies, antidepressants, and somatic treatments such as electroconvulsive therapy are employed in the treatment of older depressed adults. Treatment may be complicated by the presence of cognitive impairment, other comorbid medical disorders, and medications used to treat these disorders. Certain safety issues such as increased bleeding risk, hyponatremia, decreased bone density and falls may be associated with antidepressant treatment, may be more common in older depressed adults, and their consequences may be more severe in late life. These risks, however, need to be weighed against the hazards of untreated depression. With appropriate care, most older depressed patients can be successfully treated and a positive outcome can have a significant effect on the patient's quality of life.

The effect of alprazolam on acoustic stapedius reflex thresholds in healthy volunteers

Alprazolam, a widely used drug, has widespread, nonspecific depressant effects on the central nervous system, similar to other benzodiazepines. This inhibitor effect may cause changes in reflex thresholds by affecting the acoustic stapedial reflex (ASR) arc. This study was performed on 31 healthy volunteers. Initially, the basal ASR thresholds were measured and measured again 2 h after oral intake of 1 mg of alprazolam; by measuring the reflex thresholds once again the mean values of thresholds before and after the drug were compared. Only the left ipsilateral and contralateral 2,000 Hz increases were significantly different. The left ipsilateral and contralateral 500, 1000, and 4000 Hz, and the right ipsilateral and contralateral 500, 1000, 2000, and 4000 Hz measurements showed no differences. Although an increase in ART thresholds was generally observed after the intake of alprazolam, it was not significant. Its use in healthy adults does not statistically produce an additional risk of acoustic trauma at most of the frequencies, but its use with the agents potentiating the effect of alprazolam may increase this risk.

Antidepressants and falls in the elderly

Antidepressants have long been recognized as a contributory factor to falls and many studies show an association between antidepressants and falls. There are extensive data for tricyclic antidepressants (TCAs) and related drugs, and for selective serotonin reuptake inhibitors (SSRIs), but few data for other classes of antidepressants. Sedation, insomnia and impaired sleep, nocturia, impaired postural reflexes and increased reaction times, orthostatic hypotension, cardiac rhythm and conduction disorders, and movement disorders have all been postulated as contributing factors to falls in patients taking antidepressants. Sleep disturbance is a cardinal feature of depression, and all antidepressants have effects on sleep. TCAs and related drugs cause marked sedation with daytime drowsiness. SSRIs and related drugs have an alerting effect, impairing sleep duration and quality and causing insomnia, which may result in nocturia and daytime drowsiness. Daytime drowsiness is a significant risk factor for falls, both in untreated depression and in depression treated with antidepressants. Clinically significant orthostatic hypotension is common with TCAs and related drugs, the older monoamine oxidase inhibitors and serotonin-norepinephrine reuptake inhibitors (SNRIs). It occurs less commonly with SSRIs, and rarely with moclobemide and bupropion, and is not reported as a significant adverse effect of hypericum (St John's wort). Cardiac rhythm and conduction disturbances are well recognized with TCAs, tetracyclics and SNRIs, but have also been reported with SSRIs. The contribution of antidepressant-induced conduction and rhythm disturbances to falls cannot be assessed with current data. There are insufficient data to exonerate any individual antidepressant or class of antidepressants as a potential cause of falls. The magnitude of the increased risk of falling with an antidepressant is about the same as the excess risk found in patients with untreated depression.

Falls prevention in primary care

Each year 1.57 million older people fall more than three times and 70 000 fracture their hips. Falls can lead to disability and even death. The NSF for Older People identified falls prevention as a major health priority. This paper explains how primary care practitioners can contribute to falls prevention, reduce falls risk and improve quality of life for the older person.

Evaluation of postural stability after low-dose droperidol in outpatients undergoing gynaecological dilatation and curettage procedure

BACKGROUND

Low-dose droperidol is suggested to be cost-effective in preventing nausea and vomiting after ambulatory surgery. This clinical study evaluated patient postural stability using a computerized force platform after an i.v. dose of droperidol 0.625 mg in outpatients undergoing gynaecological dilatation and curettage procedures.

METHODS

After institutional approval and informed consent, 120 females were randomly assigned to receive either 0.9% saline (placebo) or droperidol 0.625 mg i.v. before surgery. Anaesthesia was induced with propofol 2-2.5 mg kg-1 and fentanyl 50-100 micrograms, and was maintained with intermittent boluses of propofol 25-50 mg and fentanyl 25-50 micrograms i.v. After operation, the Post-Anaesthesia Discharge Score (PADS), patient self-assessment scores for pain, nausea, drowsiness and dizziness, and extrapyramidal symptoms were recorded. Body sway velocity was measured while the patient was standing on a firm surface with eyes open then closed vs standing on a foam surface with eyes open then closed, at the time of arrival in the operation holding area (baseline), on achieving a PADS of 9 after surgery and on discharge home.

RESULTS

At the time of achieving a PADS of 9, body sway was significantly greater in the droperidol group than in the placebo group (overall 61% vs 33% above baseline). There were no differences between groups with respect to scores for pain, nausea, drowsiness and dizziness. Three patients (5%) in the droperidol group reported nervousness and restlessness postoperatively (not significant).

CONCLUSION

Low-dose droperidol 0.625 mg i.v. for anti-emetic prophylaxis can cause balance disturbances in females after gynaecological dilatation and curettage procedures.

The assessment of postural stability after ambulatory anesthesia: a comparison of desflurane with propofol

We designed this study to evaluate postural stability in outpatients after either desflurane or propofol anesthesia. After IRB approval, 120 consenting women undergoing gynecological laparoscopic procedures were randomly assigned to receive either desflurane or propofol-based general anesthesia. After surgery, patients' postural stability was measured as body sway velocity by using a computerized force platform in the following conditions: 1) standing on a firm surface with eyes open versus closed and 2) standing on a foam surface with eyes open versus closed. These measurements were made before anesthesia, immediately after the patient achieved a Post-Anesthesia Discharge Score of 9, and at actual discharge home. At the time patients first achieved a Post-Anesthesia Discharge Score of 9, the body sway in the Propofol group was significantly more than in the Desflurane group when patients were asked to stand on a foam surface with eyes closed (testing the ability of using vestibular information for balance control). We concluded that the desflurane-based anesthetic was associated with better postural control than the propofol-based anesthetic in the early recovery period after outpatient gynecological laparoscopic procedures.

IMPLICATIONS

The residual effects of the short-acting general anesthetics desflurane and propofol on patient's balance function during recovery after surgery were assessed with a computerized force platform. The results showed that desflurane seemed to be associated with better postural control than propofol in the early recovery period.

An experimental controlled study on postural sway and therapeutic exercise in subjects with low back pain

OBJECTIVES

To describe postural sway and its associations to background factors, low back pain and functional capacity. To evaluate the changes in postural sway after three months of therapeutic exercise in the gym or at home.

DESIGN

A one-year randomized experimental trial evaluated postural sway in three study groups: intensive training, home exercise and control group.

SETTING

Subjects were recruited from seven local occupational health care centres in Central Finland and were examined at Central Finland Hospital by medical doctors. Measurements and therapeutic exercise programmes were carried out in the Research Laboratory of Sport and Health Sciences at Jyväskylä University.

SUBJECTS

Initially, 49 male and 41 female subjects (aged 20-55 years) with nonspecific and subacute low back pain were examined.

MAIN OUTCOME MEASURES

Postural sway using a force platform, the Oswestry Index, as well as a measure of low back pain intensity were measured at the initial stage of the study, directly after interventions, as well as at three and nine months after the interventions.

RESULTS

The background variables were not strongly correlated with postural sway. No changes occurred in the amplitude of sway during the study, but the sway velocity of the home exercise group increased.

CONCLUSIONS

Postural sway measurements with a force platform may be suitable for detecting impairments of balance performance among subjects with pronounced functional or activity limitations and severe low back pain problems. In order to enhance balance performance, specific and customized exercise programmes are required.

Drugs and falls in older people: a systematic review and meta-analysis: I. Psychotropic drugs

OBJECTIVES

To evaluate critically the evidence linking psychotropic drugs with falls in older people.

DESIGN

Fixed-effects meta-analysis.

DATA SOURCES

English-language articles in MEDLINE (1966 - March 1996) indexed under accidents or accidental falls and aged or age factors; bibliographies of retrieved papers.

STUDY SELECTION

Systematic evaluation of sedative/hypnotic, antidepressant, or neuroleptic use with falling in people aged 60 and older.

DATA EXTRACTION

Study design, inclusion and exclusion criteria, setting, sample size, response rate, mean age, method of medication verification and fall assessment, fall definition, and the number of fallers and non-fallers taking specific classes of psychotropic drugs.

RESULTS

Forty studies, none randomized controlled trials, met eligibility criteria. For one or more falls, the pooled odds ratio (95% confidence interval) was 1.73 (95%CI, 1.52-1.97) for any psychotropic use; 1.50 (95%CI, 1.25-1.79) for neuroleptic use; 1.54 (95%CI, 1.40-1.70) for sedative/hypnotic use; 1.66 (95%CI, 1.4-1.95) for any antidepressant use (mainly TCAs); 1.51 (95%CI, 1.14-2.00) for only TCA use; and 1.48 (95%CI, 1.23-1.77) for benzodiazepine use, with no difference between short and long acting benzodiazepines. For neuroleptics in psychiatric inpatients, the pooled OR was 0.41 (95%CI, 0.21-.82); for all other patients, the pooled OR was 1.66 (95%CI, 1.38-2.00). Comparing > or =1 with > or = 2 falls, mean subject age <75 versus > or =75 years old, communities with <35% versus > or =35% fallers, or subject place of residence did not affect the pooled OR. Increased falls occurred in patients taking more than one psychotropic drug.

CONCLUSION

There is a small, but consistent, association between the use of most classes of psychotropic drugs and falls. The evidence to date, however, is based solely on observational data, with minimal adjustment for confounders, dosage, or duration of therapy. The incidence of falls and their consequences in this population necessitate that future large randomized controlled trials of any medication in older persons should measure falls prospectively as an adverse outcome event.

Antidepressants and the risk of falls among nursing home residents

BACKGROUND

In nursing home residents, the use of tricyclic and other heterocyclic antidepressants is associated with an increased risk of falls. The newer selective serotonin-reuptake-inhibitor antidepressants are largely free of the side effects of the tricyclic agents thought to cause falls and so have been hypothesized to be safer for those at high risk for falls.

METHODS

We retrospectively identified an inception cohort of 2428 nursing home residents in Tennessee who were new users of tricyclic antidepressants (665 subjects), selective serotonin-reuptake inhibitors (612 subjects), or trazodone (304 subjects) or nonusers of antidepressants (847 subjects). We ascertained the number of falls during therapy and during a similar follow-up period for nonusers, then calculated the rate ratios for falls with adjustments for an extensive set of potential confounding factors.

RESULTS

The new users of each type of antidepressant had higher rates of falls than the nonusers, with adjusted rate ratios of 2.0 (95 percent confidence interval, 1.8 to 2.2) for tricyclic antidepressants, 1.8 (1.6 to 2.0) for selective serotonin-reuptake inhibitors, and 1.2 (1.0 to 1.4) for trazodone. The rate ratios increased with the daily dose for tricyclic antidepressants, reaching 2.4 (95 percent confidence interval, 2.1 to 2.8) for doses of 50 mg or more of amitriptyline or its equivalent, and for the serotonin-reuptake inhibitors, reaching 1.9 (1.7 to 2.2) for 20 mg or more of fluoxetine or its equivalent. The elevated rates of falls persisted through the first 180 days of therapy and beyond.

CONCLUSIONS

In this large study of nursing home residents, there was little difference in rates of falls between those treated with tricyclic antidepressants and those treated with selective serotonin-reuptake inhibitors. Hence, the preferential use of the newer antidepressants is unlikely to reduce the higher rate of falls among nursing home residents taking antidepressants.