Besinger et al developed a clinical score for evaluating patients with myasthenia gravis. This can be used to monitor a patient over time and to determine the effectiveness of a therapeutic intervention. The authors are from Technische Universitat Munich, Universitat Dusseldorf, and Universitat Munich.
The patient should be on optimal therapy at the time of testing.
Testing groups:
(1) muscles of limb and trunk (5): outstretch arms, outstretch legs, head lift, grip strength, lung vital capacity
(2) oropharyngeal muscles (3) : facial muscles, chewing, swallowing
|
Parameter |
Finding |
Points |
|
arms outstretched at 90° while standing |
> 240 seconds |
0 |
|
|
90 - 240 seconds |
1 |
|
|
10 - 89 seconds |
2 |
|
|
< 10 seconds |
3 |
|
leg outstretched at 45° while supine |
> 100 seconds |
0 |
|
|
30 - 100 seconds |
1 |
|
|
1 - 29 seconds |
2 |
|
|
0 seconds |
3 |
|
head lifted to 45° while supine |
> 120 seconds |
0 |
|
|
30 - 120 seconds |
1 |
|
|
1 - 29 seconds |
2 |
|
|
0 seconds |
3 |
|
grip strength after 10 minutes at maximal closure |
< 15% decrement (> 85% of initial) |
0 |
|
|
15 - 30% decrement (70 - 85% of initial) |
1 |
|
|
30.1 - 75% decrement (25 - 69.9% of initial) |
2 |
|
|
> 75% decrement (< 25% of initial) |
3 |
|
vital capacity, male |
> 3.5 liters |
0 |
|
|
2.5 - 3.5 L |
1 |
|
|
1.5 - 2.49 L |
2 |
|
|
< 1.5 L |
3 |
|
vital capacity, female |
> 2.5 liters |
0 |
|
|
1.8 - 2.5 L |
1 |
|
|
1.2 - 1.79 L |
2 |
|
|
< 1.2 L |
3 |
|
facial muscles |
normal |
0 |
|
|
mild weakness on lid closure, snarl |
1 |
|
|
incomplete lid closure |
2 |
|
|
no mimic expression |
3 |
|
chewing |
normal |
0 |
|
|
fatigue on chewing solid foods |
1 |
|
|
can only eat soft foods |
2 |
|
|
requires gastric tube |
3 |
|
swallowing |
normal |
0 |
|
|
fatigue on normal foods |
1 |
|
|
incomplete palatal closure, with nasal speech |
2 |
|
|
requires gastric tube |
3 |
where:
• The original grip strength testing used the Vigorimeter ™. Results are expressed as decrement from the initial reading rather than comparing to a particular grip strength.
• I will report grip strength in kilograms (for more on grip strength, see Chapter 12).
• The testing of arms and legs could be done (a) by left and right sides separately, (b) by both together. The first item specifies "arms" while the second "leg". This should be done consistently.
• While the method states that the grade is based on average of the measures tested, in the implementation I will assume that all of the measures are done.
total weakness grade =
= SUM(points for all measures tested) / (number of measures tested)
Interpretation:
• minimum weakness grade: 0
• maximum weakness grade: 3
• The higher the grade the greater the degree of weakness.
• Clinical improvement or deterioration is recorded as the change in score between assessments.
Purpose: To grade the degree of muscle weakness shown by a patient with myasthenia gravis using the clinical score of Besinger et al.
Specialty: Immunology/Rheumatology
Objective: severity, prognosis, stage, response to therapy, disease progression
ICD-10: G70,
