Freezing of gait and executive functions in patients with Parkinson's disease

Freezing of gait (FOG) is a frequent, disabling symptom of Parkinson's disease (PD). FOG usually lasts a few seconds. It refers to brief paroxysmal events during which a subject is unable to start or continue locomotion. Despite its frequency, FOG pathophysiology is unclear. Because a frontal lobe dysfunction or a disconnection between the frontal lobe and basal ganglia has been implicated in FOG, we explored frontal functions in PD patients using neuropsychological tests. Thirteen early‐stage PD patients [Hoehn & Yahr score (H&Y) ≤ 2.5] with freezing during “on ” state (FOG+), and 15 age‐, H&Y score‐, and disease‐duration‐matched PD patients without freezing (FOG?) were investigated. No patient was demented or depressed. Assessment included the Unified Parkinson's Disease Rating Scale (UPDRS), FOG questionnaire, Mini Mental State Examination (MMSE), frontal assessment battery (FAB), phonemic verbal fluency, Stroop test (parts II and III), and ten‐point clock test (TPCT). UPDRS and MMSE scores did not differ between the two groups. FAB, verbal fluency, and TPCT scores were significantly lower in FOG+ patients than in FOG? patients (FAB: P = 0.008; phonemic verbal fluency: P = 0.011; TPCT: P = 0.024). FOG correlated with lower scores at frontal tests in patients with early‐stage PD. © 2007 Movement Disorder Society     

Bilateral subthalamic nucleus stimulation and quality of life in advanced Parkinson's disease.

We examined the impact of the subthalamic nuclei (STN) deep brain stimulation (DBS) on the health-related quality of life (QoL) of patients with advanced Parkinson's disease (PD). Seventeen consecutive patients with refractory motor fluctuations and dyskinesia were included in the study (mean age, 60.9 +/- 7.7 years [range, 43-74 years]; disease duration, 16.4 +/- 8.5 years [range, 7-38 years]; mean off-medication Hoehn and Yahr stage, 4.23 +/- 0.66 [range, 2.5-5]). Each patient's assessment was carried out using common rating scales, following the Core Assessment Program for Intracerebral Transplantation (CAPIT) protocol. Dyskinesia and emotional state were evaluated through the Abnormal Involuntary Movement Scale (AIMS) and the Hospital Anxiety and Depression Scale (HAD). QoL was assessed by means of the Parkinson's Disease Questionnaire Spanish version (PDQ-39). Significant benefit was obtained in the motor manifestations and complications of disease, as well as in the functional state and mood (P < 0.001). Some QoL dimensions (mobility and activities of daily living) and the PDQ-39 Summary Index (PDQ-39SI) showed a significant improvement (P < 0.001). Benefit was modest (P < 0.05) for three other domains (emotional well-being, stigma, bodily discomfort) and nil for the rest. There was no correlation between the change obtained in the QoL (PDQ-39SI) and in the other variables. As measured by the PDQ-39, STN-DBS significantly improves important aspects of QoL in patients with advanced PD.     

Freezing in Parkinson's disease: a spatiotemporal motor disorder beyond gait

Freezing of gait (FOG) is an incapacitating problem in Parkinson's disease that is difficult to manage therapeutically. We tested the hypothesis that impaired rhythm and amplitude control is a common mechanism of freezing which is also present during other rhythmic tasks. Therefore, we compared the occurrence and spatiotemporal profiles of freezing episodes during upper limb motion, lower limb motion, and FOG. Eleven freezers, 12 non-freezers, and 11 controls performed a rhythmic bilateral finger movement task. The triggering effect of movement speed, amplitude, and coordination pattern was evaluated. Regression slopes and spectral analysis addressed the spatial and temporal kinematic changes inherent to freezing episodes. The FOG Questionnaire score significantly predicted severity of upper limb freezing, present in 9 freezers, and of foot freezing, present in 8 freezers. Similar to gait, small-amplitude movements tended to trigger upper limb freezing, which was preceded by hastened movement and a strong amplitude breakdown. Upper limb freezing power spectra were broadband, including increased energy in the "freeze band" (3-8 Hz). Contrary to FOG, unilateral upper limb freezing was common and occurred mainly on the disease-dominant side. The findings emphasize that a core motor problem underlies freezing which can affect various movement effectors. This deficit may originate on the disease-dominant body side and interfere with amplitude and timing regulation during repetitive limb movements. These results may shift current thinking on the origins of freezing as being not exclusively a gait failure.     

Determinants of quality of life in Brazilian patients with Parkinson's disease.

Our objective was to identify determinants of health-related quality of life (HRQoL) in a cohort of Brazilian patients with Parkinson's disease (PD). Patients were evaluated by means of the Hoehn and Yahr staging (H&Y), Unified Parkinson's Disease Rating Scale (UPDRS), Schwab and England scale (S&E), Mini-Mental State Exam, Geriatric Depression Scale, and Hospital Anxiety and Depression Scale (HADS). HRQol was assessed using the MOS-Short-Form 36 (SF-36), the Parkinson's disease Questionnaire (PDQ-39), and the Scales for Outcomes in Parkinson's Disease-Psychosocial Questionnaire (SCOPA-PS). 144 patients were evaluated (mean age 62 years; 53.5% men; mean duration of illness 6.6 years; median H&Y, 2 (range: 1-4). Mean SCOPA-PS and PDQ-39 Summary Index (SI) were 39.2 and 40.7, respectively. Both, PDQ-39 and SCOPA-PS SIs correlated at a moderate level (r = 0.30-0.50) with H&Y, S&E, total UPDRS, HADS subscales, and SF-36 Physical and Mental Components. PDQ-39 and SCOPA-PS were closely associated (r = 0.73). HRQoL significantly deteriorated as H&Y progressed, as a whole. Mood disturbances, disability, motor complications, and education were independent predictors of HRQoL in the multivariate analysis model. In PD Brazilian patients, HRQoL correlated significantly with diverse measures of severity. Depression showed to be the most consistent determinant of HRQoL, followed by disability, motor complications, and education years. There was a close association between the PDQ-39 and SCOPA-PS summary scores.     

Quality of life in Polish patients with long-lasting Parkinson's disease.

The objective of this study was to evaluate possible relationships between quality of life (QoL) of Polish patients with long-lasting Parkinson's disease and various demographic and clinical factors. The study comprised 141 patients of Movement Disorders outpatient clinics in Warsaw and Gdansk with at least 5 years of the disease duration. Mean age of patients was 68.09 +/- 8.51 years, mean duration of disease was 11.87 +/- 5.14 years. To assess the quality of life, the Parkinson's Disease Questionnaire (PDQ-39) was used. Additional questions concerned duration of disease, initial and current treatment and expenses associated with therapy. Self-perceived symptoms of depression were in our study the most important factor determining QoL. Duration of the disease and expenses related to the treatment also have a significant impact on the QoL. Patient's age and presence of dyskinesia seem to be irrelevant to the quality of life.     

Proxy reports in Parkinson's disease: caregiver and patient self-reports of quality of life and physical activity.

We evaluated patient-proxy agreement in a population of veterans with Parkinson's disease and compared levels of agreement by patient subgroups. Patient and caregiver pairs completed questionnaires composed of standard measures and additional demographic and activity questions. Participants completed the Center for Epidemiologic Studies Depression Scale (CES-D), the PD Questionnaire 39 (PDQ-39), and three questions regarding physical activity. Caregivers completed proxy forms of the PDQ-39 and the physical activity questionnaire. The proxy forms asked caregivers to choose the answers that best described their "friend's/patient's situation." The results of our comparison of patient and proxy reports of quality of life were consistent with findings in other diseases. On average, proxies rated patient disability higher and quality of life lower than did patients. However, our comparison of patient and proxy reports of frequency of exercise diverged from previously published work. Less agreement was observed between patient and proxy reports of physical activity, even though this is a more objective variable than are the domains measured by the PDQ-39. Proxy reports may diverge appreciably from patient self-reports. These differences should be considered in research design and clinical decision making. Alternative approaches to the measurement of patient relevant outcomes could supplement traditional, retrospective self-reports.     

Assessing quality of life in Parkinson's disease: Can a short‐form questionnaire be useful?

Various instruments with good psychometric properties have been developed for the assessment of health-related quality of life (HRQoL) in Parkinson's disease, (PD); however, in everyday practice a brief questionnaire is needed for quick screening of patients. We present the process of development and validation of the Greek version of PD questionnaire-8 (PDQ-8(GrV)), which is an 8-item scale derived from a well-known measure for the evaluation of HRQoL in PD, the PD questionnaire (PDQ-39). PDQ-8 (GrV) was applied to 228 nondemented Greek PD patients. Data from PDQ-39 were also collected from these patients for comparisons between the total scores of the two scales. Detailed statistical analysis showed that PD-8(GrV) has psychometric properties analogous to its parent questionnaire.     

Development and testing of the Parkinson's disease quality of life scale.

We report on the development and results of preliminary psychometric testing of a disease specific health-related quality of life (HRQoL) scale intended for use in individuals diagnosed with idiopathic Parkinson's disease (PD). Results from an initial qualitative study provided content for item development and scale construction of the Parkinson's disease quality of life scale (PDQUALIF). The 33-item instrument includes seven domains: social/role function, self-image/sexuality, sleep, outlook, physical function, independence, and urinary function, plus one item of Global HRQoL. Initial psychometric testing of the instrument was conducted in 233 outpatient clinic attendees with physician-confirmed idiopathic PD. Factor structure, reliability and validity of the scale have been established in this cross-sectional study. Continuing development of the PDQUALIF will be directed at enhancing the psychometric properties, establishing responsiveness and determining appropriateness in culturally diverse samples.     

Quality of life outcomes following surgical treatment of Parkinson's disease.

We assessed the impact of surgical treatment of Parkinson's disease on quality of life using generic quality of life instruments and utility scores. The Medical Outcomes Study short form health survey SF-36 and Parkinson's Disease Questionnaire PDQ-39 were used before and 3-6 months after surgery to assess quality of life, and the results were converted into utility valuations. Ninety-seven patients were studied; 33 underwent unilateral thalamotomy, 33 unilateral pallidotomy, 20 bilateral pallidotomy, six subthalamic nucleus (STN) lesions, four mixed lesions, and in one case bilateral STN stimulation. All dimensions of the SF-36 except role mental and mental health showed statistically significant improvement following surgery. The PDQ-39 recorded significant improvements in the mobility, stigma, and bodily discomfort dimensions. The rating scale and time trade-off scales showed statistically significant gains in utility of 8% and 3%, respectively. Gains were particularly marked in the bilateral pallidotomy group. Differences in patient characteristics and selection made direct comparisons between procedures unreliable. Quality of life in patients with advanced Parkinson's disease is amenable to measurement; such measurement provides tentative evidence of significant gains in quality of life following some neurosurgical procedures.     

Oral festination in Parkinson's disease: biomechanical analysis and correlation with festination and freezing of gait.

In Parkinson's disease (PD), festination corresponds to a tendency to speed up when performing repetitive movements. First described in gait (and then in handwriting and speech), festination is one of the most disabling axial symptoms. To establish the phenomenology of oral festination (OF) and the condition's potential links with other axial disorders, we submitted a simple, rhythmic, repetitive, vocal motor task to 40 PD patients and 20 controls. Forty-five percent of the 40 patients presented OF, which was strongly associated with gait festination but not with the severity of freezing of gait (FOG) or dysarthria. With respect to the two pathophysiological hypotheses that have been put forward, a possible link with tremor (as previously suggested in tapping) was not confirmed in this study and so, in view of the significant increase in variability observed, we conclude that OF shares the same pathophysiology as gait disorders.     

Rasagiline improves quality of life in patients with early Parkinson's disease.

The objective of this study was to determine the effects of rasagiline as monotherapy on quality of life (QOL) in patients with early Parkinson's disease (PD). Rasagiline, a potent, second-generation, irreversible, selective monoamine oxidase B inhibitor improves PD symptoms in patients with early PD. Patients with early untreated PD were randomly assigned to once-daily rasagiline 1 mg/day, rasagiline 2 mg/day, or placebo in a 6-month, double-blind trial (n=404). At the end of 6 months, patients entered the preplanned, active-treatment phase in which those receiving 1 mg/day and 2 mg/day of rasagiline continued on their previously assigned dosages and those receiving placebo switched to rasagiline 2 mg/day, while maintaining blinding to treatment assignments. QOL was measured with the Parkinson's Disease Quality of Life questionnaire (PDQUALIF) at 0, 14, 26, and 52 weeks after randomization. Analysis of the change in PDQUALIF scores from baseline to 6 months showed adjusted treatment effects (with 95% confidence interval) favoring rasagiline over placebo of -2.91 units (-5.19, -0.64, P=0.01) for the 1 mg/day group and -2.74 units (-5.02, -0.45, P=0.02) for the 2 mg/day. Subscore analysis attributed most of this benefit to the self-image/sexuality domain. At 12 months (n=266), with all groups receiving rasagiline for at least 6 months, no significant differences in PDQUALIF scores were seen between groups. Rasagiline improved QOL compared with placebo. This QOL improvement appears to be accounted for primarily by the symptomatic benefit of rasagiline.     

Health-related quality of life in patients with advanced Parkinson's disease treated with deep brain stimulation of the subthalamic nuclei.

Parkinson's disease (PD) is a progressive neurodegenerative disorder for which there is as yet no cure. It affects many aspects of patients' lives, only some of which can be monitored by available clinical rating scales. In the past decade, there has been a new emphasis on the use of health-related quality of life (HRQOL) measures to describe patient response to treatment. We describe patient-reported HRQOL in subjects who underwent bilateral deep brain stimulation (DBS) of the subthalamic nuclei (STN) for the treatment of PD, compared with a similar group of subjects who did not receive surgical treatment. A consecutive series of patients (n = 11) with advanced idiopathic PD were treated with DBS of the STN. This surgically treated group was compared prospectively with a similar group of patients (n =13) awaiting surgery. Self-reported HRQOL, measured by the Parkinson's Disease Questionnaire (PDQ-39) was evaluated at three time periods T(0), T(3), and T(6). The surgery group was evaluated according to the Unified Parkinson's Disease Rating Sale (UPDRS) before (T(0)), 3 (T(3)), and 6 months (T(6)) after surgery. HRQOL, UPDRS part II and III, duration of off periods, and dyskinesias improved significantly from T(0) to T(3) and from T(0) to T(6) for the surgery group but not for the nonsurgery group. Ten of the 11 patients treated with DBS of the STN reported a lower summary score (indicating better HRQOL) 6 months after surgery. The results of this prospective controlled study suggest that patients with advanced idiopathic PD treated with DBS of the STN obtain significant improvements in patient reported HRQOL and in clinical outcomes 3 and 6 months after surgery.     

Validation of the freezing of gait questionnaire in patients with Parkinson's disease

To revalidate the Freezing of Gait Questionnaire (FOG‐Q), patients with Parkinson's disease (PD) were randomly assigned to receive rasagiline (1 mg/day) (n = 150), entacapone (200 mg with each dose of levodopa) (n = 150), or placebo (n = 154). Patients were assessed at baseline and after 10 weeks using the FOG‐Q, Unified Parkinson's Disease Rating Scale (UPDRS), Beck Depression Inventory (BDI), and Parkinson's Disease Questionnaire (PDQ‐39). FOG‐Q dimensionality, test–retest reliability, and internal reliability were examined. Convergent and divergent validities were assessed by correlating FOG‐Q with UPDRS, BDI, and PDQ‐39. Comparisons between FOG‐Q item 3 and UPDRS item 14 were also made. Principal component analysis indicated that FOG‐Q measures a single dimension. Test–retest reliability and internal reliability of FOG‐Q score was high. FOG‐Q was best correlated to items of the UPDRS relating to walking, general motor issues, and mobility. Correlations between baseline and endpoint suggested that FOG‐Q item 3 is at least as reliable as UPDRS item 14. At baseline, 85.9% of patients were identified as “Freezers” using FOG‐Q item 3 (≥1) and 44.1% using UPDRS item 14 (≥1) (P < 0.001). FOG‐Q was a reliable tool for the assessment of treatment intervention. FOG‐Q item 3 was effective as a screening question for the presence of FOG. © 2007 Movement Disorder Society     

Health-related quality of life evaluation by proxy in Parkinson's disease: approach using PDQ-8 and EuroQoL-5D.

Patient- and caregiver-based scores were compared and agreement levels ascertained to determine the reliability of proxy evaluation of Parkinson's Disease (PD) patients' health-related quality of life (HRQoL) using the EuroQoL and PD questionnaire (PDQ)-8. Of 72 patient-caregiver pairs, 64 (88.88%) returned the questionnaires. The degree of agreement varied for individual dimensions. Proxy evaluation of PD patients' HRQoL showed limitations mainly with assessments using the EuroQoL and especially in patients with severe disease and depression.     

Effects of caffeine on the freezing of gait in Parkinson's disease.

Caffeine is a nonselective competitive blockade of adenosine A1 and A2A receptors. In this report, we studied the efficacy of 100 mg of caffeine per day on the freezing of gait (FOG) for patients with Parkinson's disease. Different subtypes of FOG showed different therapeutic responses to caffeine. Caffeine improved "total akinesia" type of FOG, but had no effect on "trembling in place." Tolerance developed to the beneficial effect of caffeine on FOG within a few months, but a 2-week caffeine withdrawal period could restore the effect of caffeine.     

Freezing of gait in Parkinson's disease: The paradoxical interplay between gait and cognition

BackgroundFreezing of gait is a disabling episodic gait disturbance common in patients with Parkinson's disease. Recent evidences suggest a complex interplay between gait impairment and executive functions.Aim of our study was to evaluate whether specific motor conditions (sitting or walking) influence cognitive performance in patients with or without different types of freezing.MethodsEight healthy controls, eight patients without freezing, nine patients with levodopa-responsive and nine patients with levodopa-resistant freezing received a clinical and neuropsychological assessment during two randomly performed conditions: at rest and during walking.ResultsAt rest, patients with levodopa-resistant freezing performed worse than patients without freezing on tests of phonological fluency (p = 0.01). No differences among the four groups were detected during walking. When cognitive performances during walking were compared to the performance at rest, there was a significant decline of verbal episodic memory task (Rey Auditory Verbal Learning Test) in patients without freezing and with levodopa-responsive freezing. Interestingly, walking improved performance on the phonological fluency task in patients with levodopa-resistant freezing (p = 0.04).ConclusionsCompared to patients without freezing, patients with levodopa-resistant freezing perform worse when tested while seated in tasks of phonological verbal fluency. Surprisingly, gait was associated with a paradoxical improvement of phonological verbal fluency in the patients with levodopa-resistant freezing whilst walking determined a worsening of episodic memory in the other patient groups.     

Nonmotor symptoms are independently associated with impaired health‐related quality of life in Chinese patients with Parkinson's disease

We performed a cross‐sectional study of 82 Chinese patients with Parkinson's disease (PD) enrolled during an 18‐month period using a clinical interview to assess the prevalence of nonmotor symptoms (NMS), the association with disease severity and motor status, and the impact on patients' health‐related quality of life (Hr‐QoL). The patients' NMS, Hr‐QoL, disease severity, and motor status were assessed by the Nonmotor Symptoms Scale (NMSS), the 39‐item Parkinson's Disease Questionnaire (PDQ‐39), the modified Hoehn and Yahr staging scale (H&Y) and the Unified Parkinson's Disease Rating Scale part III (UPDRS III), respectively. We found that 100% of patients with PD presented with NMS. The NMSS significantly correlated with disease duration (Spearman's r_S = 0.276, P = 0.012), H&Y (r_S = 0.230, P = 0.038), and UPDRS III (r_S = 0.350, P = 0.001). Similarly, the PDQ‐39 SI significantly associated with the disease duration (r_S = 0.258, P = 0.019), H&Y (r_S = 0.340, P = 0.002), and UPDRS III (r_S = 0.453, P < 0.001). NMS domains that influenced the PDQ‐39 SI were sleep/fatigue, mood, gastrointestinal, urinary, and miscellaneous symptoms. This strongly suggested that the five domains played a key role in the manifestation of Hr‐QoL. NMSS explains more of the variability in Hr‐QoL than UPDRS III, when both are the model (stepwise multiple linear regression analysis R² change, 47.8% vs. 5.87%, respectively). Therefore, these findings demonstrate that NMS are independently and negatively associated with Hr‐QoL in PD and that improving NMS should be viewed as an important part in the management of PD. © 2010 Movement Disorder Society     

Translation and validation of the standard Chinese version of PDQ-39: a quality-of-life measure for patients with Parkinson's disease.

PDQ-39 has been widely used in the research and clinical management of Parkinson's disease. It has been translated into and validated in various non-English languages. We report here on the validity and reliability results for the translated standard Chinese PDQ-39 questionnaire. Fifty-four patients were recruited from a movement disorder clinic and two regional patient groups, and data were collected by direct interview. Nineteen patients had the tests repeated 4 weeks later to assess the test-retest and interrater reliability. The standard Chinese version of PDQ-39 demonstrated acceptable internal consistency (Cronbach's alpha = 0.54-0.90) and was comparable to versions in other languages. Further analysis showed good construct validity and test-retest reliability. Implications and limitations of the study are discussed.     

Heart rate changes during freezing of gait in patients with Parkinson's disease

Freezing of gait (FOG) is one of the most disabling symptoms that affect patients with Parkinson's disease (PD). Although the pathophysiology underlying FOG largely remains an enigma, several lines of evidence suggest that the autonomic nervous system might be involved. To this end, we tested the hypothesis that heart rate (HR) increases during FOG and, further, that HR increases just before FOG. To evaluate these hypotheses, 15 healthy older adults, 10 patients with PD who experienced FOG, and 10 patients who did not were studied. Patients with PD were tested during their “off” medication state. HR and HR variability were measured as subjects carried out tasks that frequently provoke FOG; 120 FOG episodes were evaluated. During FOG, HR increased (P = 0.001) by an average of 1.8 bpm, compared with HR measured before the beginning of FOG. HR also increased just before FOG, by 1 bpm (P < 0.0001). In contrast, during sudden stops and 180° turns, HR decreased by almost 2 bpm (P < 0.0001). HR variability was not associated with FOG. To our knowledge, these findings are the first to document the association of FOG to autonomic system activation, as manifested by HR dynamics. One explanation is that the changes in HR before and during FOG may be a sympathetic response that, secondary to limbic activation, contributes to the development of freezing. Although further studies are needed to evaluate these associations, the current results provide experimental evidence linking impaired motor blockades to autonomic nervous system function among patients with PD. © 2010 Movement Disorder Society