Assessment of Balance Disorders and Falls Risk

in Persons with Parkinson’s Disease

(Intervention and Prevention)

Andrea L. Behrman, PhD, PT

Department of Physical Therapy, College of Public Health and Health Professions McKnight Brain Institute at UF

VA Brain Rehabilitation Research Center

University of Florida

Acknowledgements

Foundation for Physical TherapyVA Brain Rehabilitation and Research Center

Kathye Light, PhD, PT Dawn Bowers, PhD William Friedman, MD William Triggs, MD

James Cauraugh, PhD Philip Teitelbaum, PhD

Sheryl Flynn, PT, MHSMary Thigpen, PT, MHS, NCS

Jung Chang, PT, MHS

Non-PDRelated

Environment

Intrinsic

Inherent to PD

Extrinsic

Associated with Movement/Cognitive

Disorders-

1° Balance Disorder

Balance Difficulties

ADL, Task-

dependent

Medications

• 38% fall (Koller et al., 1989): person’s body involuntarily contacts the ground

• 18% suffer fractures

• Stage III Hoehn & Yahr, balance disorder

• Mid-Late in disease progression

• 13% fall more than 1x/week

Inherent to PD

1° Balance Disorder

• Appropriate use of sensory information for postural orientation – Sensory Organization Test - (reduced sway relative to cohort performance/M-L)

Nature of inherent postural disorder in PD(Horak et al. 1992; Pastor et al., 1993; Schieppati and Nardone, 1991)

• Appropriate coordination of postural movement patterns in response to displacements (hip vs. ankle

strategy) Program is intact.

• Inflexibility of postural response patterns adapting to changes in support conditions. Planning is impaired.

• Excessive antagonist activity.

• Precue/focus attention when change in environment expected (i.e. see crowd ahead, change from tile to carpet)

• Adapt environment to diminish changes (i.e. stripes on floor at areas that pose difficulty)

• Plan route if obstacles ahead, including stops ifa long distance or expect you will need to change direction

• Prepare mentally to recover balance by stepping; teach stepping response

• Prepare for probable events that will disturb balance (bus stops, elevator stops, train starts)

• Decreased walking speed, if < 0.6 m/sec decreased ground clearance trips FALLS

• Shuffling gait, decreased step length and ground clearance (< 0.8 cm)

• Sudden cessations of walking: freezing

• Turning difficulty (Thigpen et al., 2000)strategies; freezing during turn, progressively smaller steps and decreased ground clearance,> 20 steps in 360 degree turn (Lipsitz et al., 1991) • Difficulty terminating locomotion

Associated with

MovementDisorders

Inherent to PD

• Context-dependent/environment (ex. visual array: tile pattern change, door width / hallway / outdoors, barriers to movement, corners or furniture requiring change in direction)

• Difficulty performing 2 tasks at once (turn and talk; Bond et al., 2000)

• Impairment in problem-solving and planning. May increase incidence of behavior that is high-risk for persons with PD.

Inherent to PD

Associated with CognitiveDisorders

• Age-related changesSensory impairments: visual, vestibular, proprioceptive

• Weakness; inability to stand up from a chair without using one’s arms to push off (LE strength)

• Gender: Females have greater frequency of falls than males.

• Muscle tightness / inflexibility

• Pre-existing level of dependency: higher rate for falls – institutions vs. community

Non-PDRelated

Extrinsic

• Depress NS (sedatives, antidepressants)

• Lead to postural hypotension: a postural systolic BP decline > 20 mm Hg at one or three minutes of standing or an absolute systolic BP below 90 mm Hg(antihypertensives, antidepressants, diuretics)

Medications

Extrinsic

• OVERALL. Minimize balance requirements while performing ADLs and minimize cognitive tasks /conversation. Diminish balance requirement, focus on task. Break down task into steps.

ADL, Task-

dependent

• TOILETTING,compounded by urgency. • Walking in/out bathroom. Grab rails, raised toilet seats. Mark floor for consistency of stepsthrough doorway and in BR. Clock turn in BR.• Night light.• Bedside commode/urinal.• Bedside cues for getting out of bed.

• BATHING. Sit or support with rail while bathing / showering (remove balance as a factor, than can concentrate on bathing/drying, etc.) Use wash mitt.

• DRESSING. Organize closet/drawers for safety/access to clothes (diminish amount of reaching while standing). Sit down on stable chair when dressing, focus on buttons, etc. Clock turn out of closet.

Extrinsic

• Support surface on which person is standing: uneven, cracks, slippery, carpeted• Environment free of obstacles & clutter• Adequate lighting, night light in bedroom/halls• Appropriate shoes: low broad heel, lace up • Stairs: differentiation of edges and stairs • Home Safety Check List

Environment

Balance and Falls Risk – Falls Assessment

Performance in the clinic/lab on motor tasksvs.

Assessment under real-life circumstances

• Does performance in the clinic correlate with performance at home or in the community?

• Does performance in the clinic predict performance in the home?

• Are assessment tests reliable, sensitive, predictive?

Clinical Assessments of Balance

Standing balance (Smithson, Morris, & Iansek, 1998)

• Steady standing: feet apart, feet together, tandem stance, single limb stance• Self-initiated movements: arm raise, functional reach (1 reach), bend-reach, step test• External perturbation to upright stance: shoulder tug

• Differentiated persons with PD who have a hx of falls from 1) persons with PD and no hx of falls and from 2) control subjects (no hx of falls) • Reliable measures 1 week later

• Stage II and III, peak-dose of meds

Functional reach (Behrman et al., 2002)

Standing balance

• 1 practice with average of 3 test trials as test score• 1 practice with 1st test trial as test score

• Both scores differentiated persons with PD who have a hx of falls from

1) persons with PD and no hx of falls and from 2) control subjects (no hx of falls)

Functional Reach Group Means

05

101520253035404550

PD + Falls PD - Falls Control

Dist

ance

Rea

ched

(cm

)

(Behrman et al, 2002)

0

20

40

60

80

100

Per

cent

PD + Falls PD - Falls Control

% subjects reaching < 25.4 cm % subjects reaching = or > 25.4 cm

FR test validity: sensitivity, specificity, predictive value

Criterion for falls risk: reach < 25.4 cm (Duncan et al., 1992)

Hx of Falls (+) No Falls Hx (-) Total

Reach < 25.4* (+ Falls Risk) 9a 1b 10

Reach >/= 25.4* (- Falls Risk) 21c 12d 33

Total 30 13 43

Falls History in Individuals with PDSc

reen

ing

Tes

t

Sensitivity = a / (a + c) = 30% Specificity = d / (b + d) = 92%+ Predictive value = a / (a + b) = 90% - Predictive value = d / (c + d) = 36%

a = true positives, persons with a history of falls correctly identified as at risk;b = false positives, persons incorrectly identified as at risk for falls;c = false negatives, persons who are incorrectly identified as not at risk for falls;d = true negatives, persons with no history of falls correctly identified as not at risk. (adapted from Behrman et al., 2002)

Bogle Thorbahn & Newton, 1996

Residents of 2 independent life-care communities (n=66), M = 79.2 yrsMixed diagnoses: 38% orthopedic or neurologic impairment (n=5, PD)• 53% test sensitivity for predicting positive falls history with 45 / 56 as cutoff or criterion score for risk of falls• 96% test specificity

Standing, transitional movements, and functional tasks:Berg Balance test

(Behrman et. al, unpublished data)

Community-dwelling population, n= 66 with PD (reported incidence of falls, n=18 controls (- falls history)

• Test scores discriminated overall group with PD (= 48. 8) from controls (M = 55.7)

• Test scores discriminated group with PD/+falls hx (M = 47.2) from 1) group with PD/-falls hx (M = 52.4) and 2) controls (55.7)

• Comparing balance scores for individual items across the three groupsdetermined a significant group effect for only 3 / 14 test items

Berg Balance Test Items

1. Sitting to standing

2. Standing unsupported

3. Sitting unsupported

4. Standing to sitting

5. Transfers

6. Standing with eyes closed

7. Standing with feet together

8. Reaching forward with an outstretched arm

9. Retrieving object from floor

10. Turning to look behind

11. Turning 360°

12. Placing alternate foot on stool

13. Standing with one foot in front of the other foot

(tandem stance)

14. Standing on one foot

*

**

Postural response test (Pastor et al., 1996)

If clinician pull backwards on patient at shoulders, typical response is lack of a posterior stepping response and a rigid fall backwards into clinician’s arms. • Patient in stance with feet 10 cm apart.• “I am going to tap you off balance, and I won’t let you fall.”

0 Stays upright without taking a step1 Takes one step backwards but remains steady2 Takes more than one step backwards, followed by the need

to be caught3 Takes several steps backwards, followed by the need to be

caught4 Falls backwards without attempting to step

Use to quantify baseline performance and outcome of stepping training.

Timed Up and Go (Podsiadlo and Richardson, 1991; Morris & Morris, 2001)

> 20 steps in 360° turn (Lipsitz et al., 1991)

Turning difficulty (Thigpen et al., 2000)

Reliable: Practice Trial, Test trials 1-3Differentiates on/off medication performance andSubjects with PD and adults without PD

Fall while turning associated with increased hip fracture in the elderly.Evaluated turning strategy, time in turn, number of steps Differentiated persons with turning difficulty

Falls Records (Yekutiel, 1993 – 2 case studies)

• Context-dependent vs. lab/clinic-based assessments• Individual’s specific environment• Falls diary

• Draw plan of home to scale and copy• Mark each fall on the plan• Use 1 copy / day• Use during baseline period prior to initiating therapy, during therapy, and post-completion of therapy

Information accumulated:• Where do falls occur?• Under what circumstances/tasks?• Time of day, association with meds• Identify each individual’s particular problem

Plan intervention accordingly.Continual assessment over time, % reduction of

falls.Factors accounting for falls may change.

Non-PDRelated

Environment

Intrinsic

Inherent to PD

Extrinsic

Associated with Movement/Cognitive

Disorders-Context-dependent

Fear of

Falling

Balance Difficulties

ADL, Task-

dependent

Medications

Falls Efficacy Scale (Tinetti) Fear of

FallingMeasures a person’s confidence in doingADL without falling.

On a scale of 1 to 10 with 10 meaning NOT confident or sure at all, 5 being FAIRLY confident/sure, and 1 being COMPLETELY confident/sure, how confident/sure are you that you can do each of the following without falling?

1. Clean house (e.g. sweep or dust) 2. Get dressed/undressed3. Prepare simple meals (no carrying) 4. Take a bath/shower5. Simple shopping 6. Get in/out of car7. Go up and down stairs 8. Walk around neighborhood9. Reach into cabinets or closets 10. Hurry to answer the phone

Self-efficacy has a strong correlation with 1) frailty: person self-limits activities and 2) incidence of falls.

Progression of PD / Balance Impairments

Early -• Movement disorders that may affect balance

gait pattern: short stepsgait akinesia/hypokinesiafreezing

• Delayed stepping response to external perturbation in steady stance• No incidence of falls, yet difficulty with balance

Intervention: Attentional strategiesVisualization/verbal cuesVisual cuesStepping responseMaintain musculoskeletal and cardiovascular systems in good condition.

Mid: Impact of visual environment increased

Gait performance, shuffling

Falls occur

Assessments: TUG, Fxal Reach, tandem stance, turning, postural response test, STS, postural hypotension, Falls Efficacy scale, Home Safety Checklist

Intervention: Falls prevention emphasis. Restructure environment. Review falls hx, task analysis, impact of environment, pt/family education re: falls risk, falls diary: date, time, location, reason for fall.

Maintain musculoskeletal and cardiovascular systems in good condition.

Work within everyday tasks, home, and community.

F/up every 3 months or as necessary.

Prieto N & Light KE. (1999). Balance, Frailty, and Falls Assessment, and Intervention: Case study of a client with Parkinson’s disease.

Non-PDRelated

Environment

Intrinsic

Inherent to PD

Extrinsic

Associated with Movement/Cognitive

Disorders-Context-dependent

Fear of

Falling

Balance Difficulties

ADL, Task-

dependent

Medications

“A phenomenon like this makes me wonder: May psychological attitudes somehow influence the severity of Parkinsonian disabilities? Or, alternatively, may some nerve circuit situated deep in the more primitive part of our nervous system be capable when called upon under certain circumstances, of bypassing malfunctional striatal linkages, thereby making possible an instinctive, semi-automatic life-saving ability to walk? All of this forces another difficult question. If the skills for walking can be reactivated to serve a thoroughly disabled Parkinsonian patient, even if transiently, and under specific circumstances, can some way be discovered---whether by a trick of the will or by repetitive conditioning---of bringing still other neuronal pathways and connections back into dependable service?”

(McGoon, 1990)

“One must cease to regard all patients as replicas, and honour each one with individual attention, attention to how he is doing, to his individual reactions and propensities; and, in this way, with the patient as one’s equal, one’s co-explorer…one may find ways, tactics, which can be modified as occasion requires.”

(Sacks, 1982)

Correlates for Home-based Standardized Assessments – Problem Specific

Timed Functional Movement Battery (Light et al., self-selected, fast pace)adapt to functional activities in home

Time to dress

Distance walking / day

End of the day: Controversy or new

BWS-locomotor training

Locomotor training with BWS, treadmill, and manual assistance

Equilibrium during

propulsive movement

Adaptation to behavioral

goals and externalconstraints

Basic movement

synergy

Functional Walking: Control Requirements by the Nervous System

Adapted from Forssberg, 1982;

Barbeau et al., 1999

“Rehabilitation’s job is to take your body as it is and to maximize your capabilities within recognized limitations. This is a difficult acknowledgement. Rehabilitation seems only second best. To fully accept rehabilitation, for most of us, it is to effectively abandon recovery. Rehabilitation can give you strength, reeducation, skills and real improvement, but no cure.”

Corbet, 1980Editor, New Mobility, Spinal Network

Will I walk again?

LOCOMOTOR-SPECIFIC STIMULI

• Loading (Conway et al., 1987; de Guzman et al., 1987; Edgerton et al., 1991; Harkema et al., 1987; Visintin & Barbeau, 1994)

• Speed (Conway et al., 1987; de Guzman et al., 1987 --- Patel et al., 1998; Visintin & Barbeau, 1994)

• Hip position (Conway et al., 1987; Andersson et al., 1978; Grillner et al., 1978; Duysens et al., 1980)

Rehabilitation of Walking After SCI

Compensation Recovery

Apply “Recovery” to

Rehabilitation for Walking after SCI

Specificity of TrainingActivity-Dependent PlasticityLocomotor-Specific Stimuli

VIDEO

DISCOVERY: Improvements in Walking Function in Individuals with Incomplete SCI

Following Experimental Locomotor Training

• Developed the ability to walk overground• Improved their overground walking

velocity and kinematics• Some regained the ability to climb stairs (Visintin & Barbeau, 1989; Wernig et al., 1992, 1995, 1999; Trimble et

al., 1998; Behrman & Harkema, 2000)

Discovery

• Volitional motor control is not a prerequisite for the generation of stepping. (Wernig et al., 1992, 1995; Behrman & Harkema, 2000)

National Center for Medical Rehabilitation Research, NIH, PI: Andrea L. Behrman, PhD, PT

• ASIA C or D, UMN• < 3 yrs. post-SCI• Can walk minimum of 40’• Walks minimum of 30”/day

• Randomized to 1 of 2 training speeds with BWS and trainers• 45 sessions

• Overground gait velocity• Reflex modulation

“Rehabilitation’s job is to take your body as it is and to maximize your capabilities within recognized limitations. This is a difficult acknowledgement. Rehabilitation seems only second best. To fully accept rehabilitation, for most of us, it is to effectively abandon recovery. Rehabilitation can give you strength, reeducation, skills and real improvement, but no cure.”

One of rehabilitation’s jobs is to optimize your body’s capacity for plasticity in order to maximize recovery from injury.

Pharmacology

Regeneration

Transplantation

Rehabilitatio

n

DiscoveryRecovery

SCI