Hoehn and Yahr Scale

Original Editor - Shreya Pavaskar

Top Contributors - Shreya Pavaskar and Aminat Abolade

Introduction

Hoehn and Yahr was originally published in 1967 in the journal Neurology by Margaret Hoehn and Melvin Yahr and included stages 1 through 5. In 1983 Larsen et al. published an article entitled "Theoretical and practical issues in assessment of deficits and therapy in Parkinsonism," wherein they included a modification of the original Hoehn and Yahr scale. They added some minor alterations which did not substantially change the basic classification published in 1967. This scale is used along with Unified Parkinson's Disease Rating Scale for a better assessment of Parkinson's disease.

Purpose

The scale has been used for the staging of the functional disability associated with Parkinson's disease. It helps in describing the progression of the disease through various stages, thus allowing us to measure the severity of the case.

Technique

The assessment requires a medical examination and according to the history given by the patients and their caregivers, the scoring is done.

Stage	Hoehn and Yahr Scale	Modified Hoehn and Yahr Scale
1	Unilateral involvement only usually with minimal or no functional disability	Unilateral involvement only
1.5	-	Unilateral and axial involvement
2	Bilateral or midline involvement without impairment of balance	Bilateral involvement without impairment of balance
2.5	-	Mild bilateral disease with recovery on pull test
3	Bilateral disease: mild to moderate disability with impaired postural reflexes; physically independent	Mild to moderate bilateral disease; some postural instability; physically independent
4	Severely disabling disease; still able to walk or stand unassisted	Severe disability; still able to walk or stand unassisted
5	Confinement to bed or wheelchair unless aided	Wheelchair bound or bedridden unless aided

Evidence

In a review of the use of Hoehn and Yahr staging, the Movement Disorder Society concluded that the modified scale should not be used due to a lack of clinimetric testing, and that the broad categories of the original scale do not allow for detection of effective interventions. For these reasons, the scale is used in clinical trials to define inclusion and exclusion criteria, but not typically as an outcome measure.