Osserman and Genkins separated patients with myasthenia gravis into different clinical groups based on the extent and progression of muscle involvement. This correlates with the response to therapy and prognosis.
|
Class |
Findings |
Adult Group |
|
asymptomatic |
no signs or symptoms |
0 |
|
ocular involvement only |
localized to ocular muscles, and may involve only 1 eye ptosis and diplopia usually present if there is no spread to other muscles groups after 2 years from onset, then usually nonprogressive |
I |
|
mild generalized |
slow onset presentation often with ocular symptoms gradual progression to involve bulbar and skeletal muscles respiratory muscles are not involved |
IIA |
|
moderate generalized |
gradual onset presentation often with ocular symptoms progression to a more severe generalized involvement of the bulbar and skeletal muscles respiratory muscles are not involved |
IIB |
|
acute fulminating |
rapid onset of severe bulbar and skeletal muscle weakness; disease progresses over a few months early involvement of the respiratory muscles |
III |
|
late severe |
severe, progressive symptoms starting at least 2 years after the onset of myasthenia |
IV |
where:
• The common thread for Group IIA and IIB is the absence of respiratory muscle involvement.
• Bulbar symptoms include dysarthria, dysphagia, chewing weakness and dyspnea.
|
Adult Group |
Prognosis |
|
0 |
excellent |
|
I |
excellent |
|
IIA |
mortality very low, with good response to drug therapy |
|
IIB |
mortality low; response to drug therapy may be suboptimal |
|
III |
mortality high and response to drugs is poor |
|
IV |
mortality high and response to drugs is poor |
A modification of the classification (Abt et al, 2001) uses the same groups but assigns a different Roman numeral, as follows:
|
Original Group |
Modified Group |
|
0 |
0 |
|
I |
I |
|
IIA |
II |
|
IIB |
III |
|
III |
IV |
|
IV |
V |
Pediatric types:
(1) transient neonatal: a self-limited condition in infants born to myasthenic mothers that may last up to 6 weeks after delivery before disappearing, due to transplacental passage of antibodies from the mother
(2) juvenile: myasthenia is not present in the mother, but may be present in siblings or close relatives; this is classified similar to adult onset myasthenia
Purpose: To classify a myasthenic patient using the stages of Osserman and Genkins.
Specialty: Immunology/Rheumatology
Objective: severity, prognosis, stage, response to therapy, disease progression, comorbid conditions
ICD-10: G70,
