cliot (version 1.0.0)

calculate_edss: Expanded Disability Status Scale (EDSS) Calculator

Description

Calculates the EDSS score based on Kurtzke's Functional Systems Scores (FSS) and ambulation status. The scale ranges from 0.0 (normal) to 10.0 (death). Steps 0-4.5 are determined by FSS combinations, while steps 5.0-9.5 are defined primarily by impairment to ambulation.

Usage

calculate_edss(pyramidal, cerebellar, brainstem, sensory, bowel_bladder,
               visual, cerebral, ambulation_code)

Value

A list containing:

EDSS_Score

The calculated Expanded Disability Status Scale score.

Inputs

A record of the provided functional scores and ambulation status.

Arguments

pyramidal

Numeric (0-6). Pyramidal function score.

cerebellar

Numeric (0-5). Cerebellar function score.

brainstem

Numeric (0-5). Brainstem function score.

sensory

Numeric (0-6). Sensory function score.

bowel_bladder

Numeric (0-6). Bowel and Bladder function score.

visual

Numeric (0-6). Visual function score.

cerebral

Numeric (0-5). Cerebral (Mental) function score.

ambulation_code

Numeric (0-11). Ambulation status code: 0: Unrestricted / Walks > 500m without aid. 1: Walks > 300m without aid (Step 4.5 range). 2: Walks > 200m without aid (Step 5.0 range). 3: Walks > 100m without aid (Step 5.5 range). 4: Unilateral assistance >= 100m (Step 6.0). 5: Bilateral assistance >= 20m (Step 6.5). 6: Restricted to wheelchair, can transfer/wheel self (Step 7.0). 7: Restricted to wheelchair, needs help transferring (Step 7.5). 8: Restricted to bed/chair, retains self-care (Step 8.0). 9: Restricted to bed, some effective arm use (Step 8.5). 10: Helpless bed patient, can communicate (Step 9.0). 11: Totally helpless, unable to communicate (Step 9.5).

References

Kurtzke JF. Rating neurologic impairment in multiple sclerosis: an expanded disability status scale (EDSS). Neurology. 1983;33(11):1444-1452. doi:10.1212/wnl.33.11.1444

Examples

# Example 1: Mild Disability (Ambulatory)
# Pyramidal 2, others 0/1, Walks >500m
calculate_edss(2, 1, 0, 1, 0, 0, 0, 0)

# Example 2: Moderate Disability (Walking impaired)
# Pyramidal 3, Cerebellar 2, Walks 150m without aid
# Code 3 (>100m no aid) corresponds to 5.5
calculate_edss(3, 2, 1, 0, 1, 0, 0, 3)

# Example 3: Severe Disability (Wheelchair)
# Multiple high FSS, Wheelchair restricted (can transfer)
# Code 6 -> 7.0
calculate_edss(4, 3, 2, 3, 3, 1, 1, 6)