Rating scale for psychogenic movement disorders: Scale development and clinimetric testing

We developed and tested the clinimetric properties of a scale for psychogenic movement disorders (PMDs). PMDs are disabling but lack any generally accepted treatment strategies. To develop treatments, means of assessing disease severity must be provided. No scale to assess PMDs existed. The PMD scale developed here rates 10 phenomena (rest tremor, action tremor, dystonia, chorea, bradykinesia, myoclonus, tics, athetosis, ballism, cerebellar incoordination), 2 functions (gait, speech), and 14 body regions. To study interrater agreement, three movement disorder neurologists independently rated 88 videotapes of PMD patients. Data analysis was performed using a kappa coefficient of agreement, Kendall's coefficient of concordance, Spearman correlations, and intraclass correlation coefficients. Validity and scale responsiveness were tested as well. All phenomena and speech and gait dysfunction occurred in the patient sample. A wide range of affected body regions, severity, and incapacitation was captured. Ratings showed excellent interrater reliability for presence or absence of each phenomenon (kappa range, 0.63 to 0.86). Kendall's concordance coefficients for phenomenology, function, and total PMD scores were 0.92, 0.93, and 0.91. Spearman correlations between raters ranged from 0.86 to 0.90. The scale was responsive to changes that occurred as a result of a neuropsychiatric intervention. The PMD scale adequately captures the complex movements of PMDs and can be used to assess PMDs and test the efficacy of intervention strategies.

A responsive outcome for Parkinson's disease neuroprotection futility studies

Futility studies are designed to test new treatments over a short period in a small number of subjects to determine if those treatments are worthy of larger and longer term studies, or if they should be abandoned. An appropriate outcome measure for a neuroprotection futility study in Parkinson's disease (sensitive to tracking disease progression in the short-term) has not been determined. Data sets from three clinical trials were used to compare Parkinson's disease outcome measures. Total Unified Parkinson's Disease Rating Scale (UPDRS; Mentation + Activities of Daily Living + Motor) change and Motor plus Activities of Daily Living UPDRS change, measured in untreated patients, required the smallest sample sizes of all the outcome measures explored. Other outcomes (UPDRS Motor, UPDRS Activities of Daily Living, and time to need levodopa) required somewhat larger sample sizes. Futility designs in Parkinson's disease are feasible in terms of short duration and small sample size requirements, and this design is being applied in two ongoing Parkinson's disease studies to select agents for future larger and longer term neuroprotection studies.

Evidence-based medical review update: Pharmacological and surgical treatments of Parkinson's disease: 2001 to 2004

The objective of this study is to update a previous evidence-based medicine (EBM) review on Parkinson's disease (PD) treatments, adding January 2001 to January 2004 information. The Movement Disorder Society (MDS) Task Force prepared an EBM review of PD treatments covering data up to January 2001. The authors reviewed Level I (randomized clinical trials) reports of pharmacological and surgical interventions for PD, published as full articles in English (January 2001-January 2004). Inclusion criteria and ranking followed the original program and adhered to EBM methodology. For Efficacy Conclusions, treatments were designated Efficacious, Likely Efficacious, Non-Efficacious, or Insufficient Data. Four clinical indications were considered for each intervention: prevention of disease progression; treatment of Parkinsonism, as monotherapy and as adjuncts to levodopa where indicated; prevention of motor complications; treatment of motor complications. Twenty-seven new studies qualified for efficacy review, and others covered new safety issues. Apomorphine, piribedil, unilateral pallidotomy, and subthalamic nucleus stimulation moved upward in efficacy ratings. Rasagiline, was newly rated as Efficacious monotherapy for control of Parkinsonism. New Level I data moved human fetal nigral transplants, as performed to date, from Insufficient Data to Non- efficacious for the treatment of Parkinsonism, motor fluctuations, and dyskinesias. Selegiline was reassigned as Non-efficacious for the prevention of dyskinesias. Other designations did not change. In a field as active in clinical trials as PD, frequent updating of therapy-based reviews is essential. We consider a 3-year period a reasonable time frame for published updates and are working to establish a Web-based mechanism to update the report in an ongoing manner.

Movement Disorder Society Task Force report on the Hoehn and Yahr staging scale: status and recommendations

The Movement Disorder Society Task Force for Rating Scales for Parkinson's disease (PD) prepared a critique of the Hoehn and Yahr scale (HY). Strengths of the HY scale include its wide utilization and acceptance. Progressively higher stages correlate with neuroimaging studies of dopaminergic loss, and high correlations exist between the HY scale and some standardized scales of motor impairment, disability, and quality of life. Weaknesses include the scale's mixing of impairment and disability and its non-linearity. Because the HY scale is weighted heavily toward postural instability as the primary index of disease severity, it does not capture completely impairments or disability from other motor features of PD and gives no information on nonmotor problems. Direct clinimetric testing of the HY scale has been very limited, but the scale fulfills at least some criteria for reliability and validity, especially for the midranges of the scale (Stages 2-4). Although a "modified HY scale" that includes 0.5 increments has been adopted widely, no clinimetric data are available on this adaptation. The Task Force recommends that: (1) the HY scale be used in its original form for demographic presentation of patient groups; (2) when the HY scale is used for group description, medians and ranges should be reported and analysis of changes should use nonparametric methods; (3) in research settings, the HY scale is useful primarily for defining inclusion/exclusion criteria; (4) to retain simplicity, clinicians should "rate what you see" and therefore incorporate comorbidities when assigning a HY stage; and (5) because of the wide usage of the modified HY scale with 0.5 increments, this adaptation warrants clinimetric testing. Without such testing, however, the original five-point scales should be maintained.

Short-term and practice effects of metronome pacing in Parkinson's disease patients with gait freezing while in the ‘on’ state: randomized single blind evaluation

OBJECTIVE

In a randomized single blind parallel study, we tested the efficacy of an auditory metronome on walking speed and freezing in Parkinson's disease (PD) patients with freezing gait impairment during their 'on' function.

BACKGROUND

No pharmacological treatment is effective in managing 'on' freezing in PD. Like visual cues that can help overcome freezing, rhythmic auditory pacing may provide cues that help normalize walking pace and overcome freezing.

DESIGN/METHODS

Non-demented PD patients with freezing during their 'on' state walked under two conditions, in randomized order: unassisted walking and walking with the use of an audiocassette with a metronome recording. The walking trials were randomized and gait variables were rated from videotapes by a blinded evaluator. Outcome measures were total walking time (total trial time-total freezing time), which was considered the time over a course of specified length, freezing time, average freeze duration and number of freezes. All outcomes were averaged across trials for each person and then compared across conditions using Signed Rank tests.

RESULTS

Twelve non-demented PD patients with a mean age of 65.8 +/- 11.2 years, and mean PD duration of 12.4 +/- 7.3 years were included. The use of the metronome slowed ambulation and increased the total walking time (P < 0.0005) only during the first visit, without affecting any freezing variable. In the nine patients who took the metronome recording home and used it daily for 1 week while walking, freezing remained unimproved.

CONCLUSIONS

Though advocated in prior publications as a walking aid for PD patients, auditory metronome pacing slows walking and is not a beneficial intervention for freezing during their 'on' periods.

Altered cortical visual processing in PD with hallucinations: an fMRI study

OBJECTIVE

To compare fMRI activation during two visual stimulation paradigms in Parkinson disease (PD) subjects with chronic visual hallucinations vs PD patients who had never hallucinated.

METHODS

Twelve pairs of PD subjects, matched for age, PD duration, and dopaminergic drug exposure duration, participated in this study. The authors examined group differences in activation during stroboscopic (flashing) vs no visual stimulation and kinematic (apparent motion) vs stationary visual stimulation.

RESULTS

During stroboscopic stimulation, non-hallucinating PD subjects showed significantly greater activation in the parietal lobe and cingulate gyrus compared to hallucinating PD subjects. In contrast, the hallucinating subjects showed significantly greater activation in the inferior frontal gyrus and the caudate nucleus. During kinematic stimulation, non-hallucinating PD subjects showed significantly greater activation in area V5/MT, parietal lobe, and cingulate gyrus compared to hallucinating PD subjects. Hallucinating PD subjects showed significantly greater activation in the superior frontal gyrus.

CONCLUSIONS

PD patients with chronic visual hallucinations respond to visual stimuli with greater frontal and subcortical activation and less visual cortical activation than non-hallucinating PD subjects. Shifting visual circuitry from posterior to anterior regions associated primarily with attention processes suggests altered network organization may play a role in the pathophysiology of visual hallucinations in PD.

Repeated visual hallucinations in Parkinson's disease as disturbed external/internal perceptions: Focused review and a new integrative model

Visual hallucinations (VH) in Parkinson's disease (PD) are a chronic complication in 30 to 60% of treated patients and have a multifaceted phenomenology. Flickering, faultive impressions, and illusionary misperceptions precede the core syndrome of stereotyped, colorful images. The patient variably recognizes these images as hallucinations, being rarely irritated or frightened and more often amused as a bystander. Although studies on VH in PD focus on several research domains, no comprehensive, unified theory has been developed to study their pathophysiology. We have adapted Hobson's work on the states of consciousness and propose a model integrating seemingly disparate data on VH. We suggest that VH should be considered as a dysregulation of the gating and filtering of external perception and internal image production. Contributive elements and anatomical links for the model include poor primary vision, reduced activation of primary visual cortex, aberrant activation of associative visual and frontal cortex, lack of suppression or spontaneous emergence of internally generated imagery through the ponto-geniculo-occipital system, intrusion of rapid eye movement dreaming imagery into wakefulness, errative changes of the brainstem filtering capacities through fluctuating vigilance, and medication-related overactivation of mesolimbic systems. Different etiologies likely produce different phenomenologies and the prognosis may not be uniform. This new conceptual framework permits an anatomical view of VH and suggests new, testable hypotheses regarding their pathophysiology and therapy.

Genetic polymorphisms in Parkinson disease subjects with and without hallucinations: an analysis of the cholecystokinin system

BACKGROUND

Hallucinations in patients with Parkinson disease (PD), occurring in about one third of those receiving long-term dopaminergic therapy, contribute to morbidity and mortality. In matched Chinese PD subjects with and without hallucinations, the presence of the -45 C/T locus in the cholecystokinin (CCK) gene, particularly when combined with the CCK receptor, CCKAR (cholecystokinin A receptor), C polymorphism, was associated with increased hallucination risk. Because CCK gene polymorphisms vary across ethnic groups, the presence of similar associations in white PD subjects merits investigation.

OBJECTIVE

To determine whether polymorphisms of CCK and CCK receptor genes are associated with hallucinations in white PD subjects.

DESIGN

Case-control study of PD subjects with and without chronic hallucinations matched for age and dopaminergic medication. Genomic DNA was analyzed for CCK, CCKAR, and CCKBR (cholecystokinin B receptor) polymorphisms by polymerase chain reaction. Genotype distributions and allele frequencies were compared between groups and in matched pairs.

RESULTS

Comparing matched pairs, we found more frequent representation of the CCK T allele in hallucinating PD subjects, although this finding was not statistically significant (P =.06). Of 5 cases with both CCK T and CCKAR C alleles, 4 were hallucinators. Cases and controls did not differ in CCKAR or CCKBR polymorphisms.

CONCLUSIONS

Our study supports a previous association of hallucinations in PD subjects with the CCK T allele and the combined CCK T and CCKAR C allele, suggesting that the CCK system may influence the development of hallucinations in PD subjects. The lower representation of the T allele in our white sample limited our statistical power. Further assessment of the T allele as a risk factor for hallucinations would include longitudinal study of nonhallucinators to detect the evolution of hallucinations relative to T allele frequency.

Apolipoprotein E controls the risk and age at onset of Parkinson disease

BACKGROUND

Similarities between Alzheimer disease (AD) and Parkinson disease (PD) suggest a possible role for apolipoprotein E (APOE) in PD. Most previous studies seeking to establish such a link used case-control datasets and results have been inconsistent.

OBJECTIVE

To investigate APOE's role in PD using family-based association analyses.

METHODS

APOE functional polymorphisms were genotyped for 658 PD affected families, including 282 multiplex and 376 singleton families. The pedigree disequilibrium test (PDT) and the genotype-PDT were used to test the risk effect of APOE. The Monks-Kaplan test was used to evaluate the effect of APOE on age at onset of PD.

RESULTS

APOE was significantly associated with risk of developing PD. Stratified analysis revealed that APOE was most strongly associated with families with a positive PD family history (global p = 0.003). Like AD, the APOE-4 allele increases disease risk while the APOE-3 allele decreases risk. We detected a positive association of APOE-3 (p = 0.019) and a negative association of APOE-4 (p = 0.015) with age at onset in PD.

CONCLUSIONS

The APOE-4 allele increases risk and decreases age at onset of PD, an association that may not be dependent upon cognitive impairment.

The origins of scientific cinematography and early medical applications

OBJECTIVE

To examine the neurologic cinematographic contributions of Gheorghe Marinescu.

BACKGROUND

Near the end of the 19th century, cinematography developed and was immediately recognized as a new technique applicable to medical documentation. After studying with several prominent European neurologists and deeply influenced by Jean-Martin Charcot, Marinescu returned to Bucharest in 1897 and applied moving picture techniques to the study of neurologic patients.

METHODS

The Romanian State Archives were researched for original Marinescu films, and related publications were translated from Romanian and French.

RESULTS

Between 1899 and 1902, Marinescu perfected the use of cinematography as a research method in neurosciences and published five articles based on cinematographic documents. He focused his studies particularly on organic gait disorders, locomotor ataxia, and hysteria. He adapted Charcot's method of lining up several patients with the same disorder and showing them together to permit appreciation of archetypes and formes frustes. He decomposed the moving pictures into sequential tracings for publication. He documented treatment results with cases filmed before and after therapy. Processed and digitized excerpts of these films accompany this manuscript.

CONCLUSIONS

Marinescu's cinematographic studies led to several original contributions in clinical neurology. Remaining film archives include examples of many neurologic diseases, his examination techniques, and the working medical environment of the young founder of the Romanian school of neurology.

Medical-legal issues in Charcot's neurologic career

OBJECTIVE

Trace the medical-legal involvement of the 19th century clinical neurologist Jean-Martin Charcot.

BACKGROUND

The two major neurologic concerns of the 1800s that involved legal questions were topics of particular academic interest to Charcot: post-traumatic neurologic syndromes and the behavioral consequences of hysteria and hypnotism. Although Charcot's medical views influenced several nonmedical fields, including art, poetry, and drama, his impact on medical-legal issues has not been examined.

METHODS

Original documents from the Bibliothèque Charcot at the Salpêtrière Hospital in Paris, legal documents, and publications from Charcot's era were examined.

RESULTS

Although his involvement in medical-legal affairs was a modest element of Charcot's multifaceted career, he was involved in four different types of medical-legal activities: as a cited authority in the medical-legal literature, as an author of articles within medical-legal contexts, as a subpoenaed expert consultant, and as an expert examiner.

CONCLUSIONS

Charcot's involvement demonstrates the long tradition of an interface between neurology and legal medicine and provides a model for highly limited but authoritative involvement by academic neurologists in medical-legal affairs.

Fragile X-associated tremor/ataxia syndrome in sisters related to X-inactivation

Fragile X tremor/ataxia syndrome (FXTAS) is a recently described condition consisting of tremor, ataxia, parkinsonism, and executive dysfunction, presenting predominantly in male carriers of a fragile X mental retardation 1 premutation. In this report, we present premutation carrier sisters in whom severity of clinical signs correlated with a molecular pattern of X-inactivation favoring higher expression of the premutation allele. In these women with a common genetic background, we suggest that symptom severity may be dictated by X-inactivation, and thus a higher percentage of cells producing the premutation-containing mRNA result in increased toxicity and disease.

Assuring interrater reliability for the UPDRS motor section: Utility of the UPDRS teaching tape

We assessed rates of successful certification on the motor section of the Unified Parkinson's Disease Rating Scale (UPDRSm) after training with the UPDRS Teaching Tape. The most frequently used clinical scale for PD is the UPDRS, and most clinical trials rely on the motor examination as the primary outcome measure. Whereas the Movement Disorder Society's UPDRS Teaching Tape has been used widely as a training format, outcome data are lacking. We examined data sets from four multicenter studies that required raters to pass the certification exercise of the UPDRS Teaching Tape. Raters viewed the Teaching Tape showing examples of all rating levels for all items (38 minutes), and then took the certification exercise, rating 4 subjects with PD (20 minutes). Certification required scores on all 4 subjects that fit within the 95% confidence interval range established by three experts. We calculated the numbers of raters successfully certified after one or more rating attempts. Only one-half of 226 raters that participated successfully completed certification on their first attempt, but all completed by the third attempt. North American raters scored better than Europeans raters. The most difficult case to rate was the subject with the least impairment. Standardized methods for training UPDRSm application are essential to ensure that raters use the scale uniformly. Raters have the greatest difficulty with the mildest impairment, making training especially important to studies of early PD.

Glutathione S-transferase omega-1 modifies age-at-onset of Alzheimer disease and Parkinson disease

We previously reported genetic linkage of loci controlling age-at-onset in Alzheimer disease (AD) and Parkinson's disease (PD) to a 15 cM region on chromosome 10q. Given the large number of genes in this initial starting region, we applied the process of 'genomic convergence' to prioritize and reduce the number of candidate genes for further analysis. As our second convergence factor we performed gene expression studies on hippocampus obtained from AD patients and controls. Analysis revealed that four of the genes [stearoyl-CoA desaturase; NADH-ubiquinone oxidoreductase 1 beta subcomplex 8; protease, serine 11; and glutathione S-transferase, omega-1 (GSTO1)] were significantly different in their expression between AD and controls and mapped to the 10q age-at-onset linkage region, the first convergence factor. Using 2814 samples from our AD dataset (1773 AD patients) and 1362 samples from our PD dataset (635 PD patients), allelic association studies for age-at-onset effects in AD and PD revealed no association for three of the candidates, but a significant association was found for GSTO1 (P=0.007) and a second transcribed member of the GST omega class, GSTO2 (P=0.005), located next to GSTO1. The functions of GSTO1 and GSTO2 are not well understood, but recent data suggest that GSTO1 maybe involved in the post-translational modification of the inflammatory cytokine interleukin-1beta. This is provocative given reports of the possible role of inflammation in these two neurodegenerative disorders.

Standardized training tools for the UPDRS activities of daily living scale: Newly available teaching program

The Unified Parkinson's Disease Rating Scale (UPDRS) is the most widely used scale for evaluation of clinical impairment in PD. Whereas the motor section has been studied intensively for clinimetric properties and has an associated training tape, the Activities of Daily Living (ADL) section has been studied less rigorously. In preparation for a multicenter study that planned to use the UPDRS ADL score as an outcome, the authors reviewed the UPDRS ADL scale and designed a teaching program to provide a uniform technique for data acquisition without changing any wording of the primary scale. The teaching program is composed of four components: overall guidelines, clarifying points, recommended strategies, and a teaching videotape. The videotape shows examples of interviewers assessing each ADL item with patients of different disability levels and provides a complete ADL assessment of a single patient. Systematic training and utilization of this teaching program offer the potential for more uniformity in results of ADL assessments conducted in clinical practice and multicenter, international studies of PD. The written materials and videotape belong to the Movement Disorder Society and are available by contacting the MDS central office.

Objective assessments of longitudinal outcome in Gilles de la Tourette's syndrome

OBJECTIVE

To define the long-term outcome in Gilles de la Tourette syndrome (GTS) using objective rating measures.

BACKGROUND

Previous historical studies suggest spontaneous improvement of tic symptoms after adolescence, but objective longitudinal data are limited.

METHODS

The authors reviewed all videotapes in their database (1978 through 1991) of children with GTS (ages 8 to 14) who were seen in their tertiary care movement disorder center and underwent a standardized 5-minute filming protocol (n = 56). Through multiple contact methods, they successfully located 36 of these patients, who are now adults (age >20 years), and recruited 31 (28 men and 3 women) to volunteer for a second videotape and in-person assessment. A blinded rater evaluated the 62 tapes and rated five tic domains: body areas involved, motor and phonic tic frequency, and motor and phonic tic severity. Using standardized GTS videotape rating scale and Wilcoxon signed-rank tests with Bonferroni correction for multiple comparisons, the authors compared the two videotapes for each tic domain as well as the composite tic disability score.

RESULTS

Ninety percent of adult patients still had tics. Adult patients who considered themselves tic-free were often inaccurate in their self-assessment: 50% had objective evidence of tics. Mean objective tic disability diminished in comparison to childhood (mean composite tic disability score childhood 9.58 vs adulthood 7.52, p = 0.014). All domains improved by adulthood, and significant improvements occurred in motor tic severity (p = 0.008). The improvements in tic disability did not relate to medication use, as only 13% of adults received medications for tics, compared with 81% of children.

CONCLUSIONS

In GTS syndrome, tics objectively improve over time but most adults have persistent tics.

Impact of placebo assignment in clinical trials of Parkinson's disease

Informed consent procedures in placebo-controlled trials are developed to ensure that subjects entering studies clearly understand the possibility of placebo assignment. The extent of patient understanding and the impact of learning that they were assigned placebo treatment have not been extensively studied. By using a standardized questionnaire, we interviewed 50 consecutive placebo-treated patients from 14 placebo-controlled clinical trials of Parkinson's disease (PD) after completion of their involvement. All patients interviewed understood that their study contained a placebo arm. All had hoped to receive the study drug rather than placebo, and more than half the subjects believed they had improved clinically during their placebo exposure. Positive impressions of enrollment in placebo-controlled trials were more frequent than negative, included helping to advance science (86%); liking the experience, education, and attention associated with the clinical trial (90%); and participating in research for the benefit of other patients as well as for themselves (80%). If another placebo-controlled trial was offered, 88% expressed that they would possibly, likely, or definitely be interested in enrollment. PD patients clearly understand the concept of placebo-controlled trials they complete them, but they are inaccurate in assessing whether they received placebo treatment. Although most wish they received the active compound being tested, the overall view of participation in placebo-controlled trials is viewed very positively by PD patients.

Wheeled and standard walkers in Parkinson's disease patients with gait freezing

OBJECTIVES

Compare the efficacy of two walking assistance devices (wheeled walker and standard walker) to unassisted walking for patients with PD and gait freezing.

BACKGROUND

Although numerous walking devices are used clinically, their relative effects on freezing and walking speed have never been systematically tested.

METHODS

Nineteen PD patients (14 non-demented) walked under three conditions in randomized order: unassisted walking, standard walker, and wheeled walker. Patients walked up to three times in each condition through a standard course that included rising from a chair, walking through a doorway, straightway walking, pivoting, and return. Total walking time, freezing time and number of freezes were compared for the three conditions using mixed models (walking time) and Friedman's test (freezing). The wheeled walker was further studied by comparing the effect of an attached laser that projected a bar of light on the floor as a visual walking cue.

RESULTS

Use of either type of device significantly slowed walking compared to unassisted walking. Neither walker reduced any index of freezing, nor the laser attachment offered any advantage to the wheeled walker. The standard walker increased freezing, and the wheeled walker had no effect on freezing. Among the non-demented subjects (n=14), the same patterns occurred, although the walking speed was less impaired by the wheeled walker than the standard walker in this group.

CONCLUSIONS

Though walkers may stabilize patients and increase confidence, PD patients walk more slowly when using them, without reducing freezing. Because the wheeled walker was intermediate for walking time and does not aggravate freezing, if walkers are used for these subjects, this type of walker should be favored.

A double-blind controlled trial of bilateral fetal nigral transplantation in Parkinson's disease

Thirty-four patients with advanced Parkinson's disease participated in a prospective 24-month double-blind, placebo-controlled trial of fetal nigral transplantation. Patients were randomized to receive bilateral transplantation with one or four donors per side or a placebo procedure. The primary end point was change between baseline and final visits in motor component of the Unified Parkinson's Disease Rating Scale in the practically defined off state. There was no significant overall treatment effect (p = 0.244). Patients in the placebo and one-donor groups deteriorated by 9.4 +/- 4.25 and 3.5 +/- 4.23 points, respectively, whereas those in the four-donor group improved by 0.72 +/- 4.05 points. Pairwise comparisons were not significant, although the four-donor versus placebo groups yielded a p value of 0.096. Stratification based on disease severity showed a treatment effect in milder patients (p = 0.006). Striatal fluorodopa uptake was significantly increased after transplantation in both groups and robust survival of dopamine neurons was observed at postmortem examination. Fifty-six percent of transplanted patients developed dyskinesia that persisted after overnight withdrawal of dopaminergic medication ("off"-medication dyskinesia). Fetal nigral transplantation currently cannot be recommended as a therapy for PD based on these results.

Coping strategies for visual hallucinations in Parkinson's disease

We assessed the use of coping strategies in Parkinson's disease patients with visual hallucinations, using a semi-structured questionnaire. We found that 36 of our 46 Parkinson's disease subjects with hallucinations (78%) used coping strategies: cognitive techniques in 69%; interactive techniques in 62%; and visual techniques in 33%.