The characteristics of juvenile myasthenia gravis among South Africans.
OBJECTIVE
To report the characteristics of juvenile-onset (<20 years) myasthenia gravis (MG) in Africa.


METHODS
Six South African centres collected data which included acetylcholine receptor-antibody (AChR-ab) status, delay before diagnosis, MG Foundation of America grade at onset, maximum severity and severity at last visit, therapies, outcomes and complications.


RESULTS
We report on 190 individuals with a 4-year median follow-up (interquartile range (IQR) 1 - 8). The median age at symptom onset was 7 years (IQR 4 - 14). Ocular MG (26%) occurred among younger children (mean 5.1 years), compared with those developing generalised MG (74%) (mean 10.2 years) (p=0.0004). Remissions were obtained in 45% of generalised and 50% of ocular MG patients, of whom the majority received immunosuppressive treatment, mainly prednisone. Children with post-pubertal onset had more severe MG, but deaths were infrequent. Thymectomies were performed in 43% of those with generalised MG who suffered greater maximum disease severity (p=0.002); there was a trend towards more remissions in the thymectomy group compared with the non-thymectomy group (p=0.057). There was no racial variation with respect to AChR-ab status, maximum severity, or use of immunosuppression. However, 23% of children of African genetic ancestry developed partial or complete ophthalmoplegia as a complication of generalised MG (p=0.002).


CONCLUSIONS
Younger children developed ocular MG and older children generalised MG. Persistent ophthalmoplegia developing as a MG complication is not uncommon among juveniles of African genetic ancestry. A successful approach to the management of this complication that causes significant morbidity is, as yet, unclear.
Division of Neurology, Department of Medicine, Groote Schuur Hospital. jeanine.heckmann@uct.ac.za
Jeannine M
JM
Heckmann
Perrin
P
Hansen
Ronald
R
Van Toorn
Elsabeth
E
Lubbe
Elmarie
E
Janse van Rensburg
Jo M
JM
Wilmshurst
D000293:Adolescent; D000328:Adult; D017668:Age of Onset; D000704:Analysis of Variance; D000906:Antibodies / Q000097:blood; D002648:Child; D002675:Child, Preschool; D005128:Eye Diseases / Q000175:diagnosis / Q000453:epidemiology* / Q000628:therapy; D005260:Female; D006801:Humans; D016756:Immunoglobulins, Intravenous / Q000627:therapeutic use; D007155:Immunologic Factors / Q000627:therapeutic use; D007166:Immunosuppressive Agents / Q000627:therapeutic use; D007223:Infant; D008297:Male; D009157:Myasthenia Gravis / Q000175:diagnosis / Q000453:epidemiology* / Q000628:therapy*; D010951:Plasma Exchange; D011241:Prednisone / Q000627:therapeutic use; D011950:Receptors, Cholinergic / Q000276:immunology; D012074:Remission Induction; D013019:South Africa / Q000453:epidemiology; D018709:Statistics, Nonparametric; D013934:Thymectomy; D016896:Treatment Outcome; D055815:Young Adult
D000906:Antibodies; D016756:Immunoglobulins, Intravenous; D007155:Immunologic Factors; D007166:Immunosuppressive Agents; D011950:Receptors, Cholinergic; D011241:Prednisone