Demographic Characteristics.
| Etiology | Unknown | Cryptogenic | Symptomatic | Total |
|---|---|---|---|---|
| Gender | ||||
| Male | 4 (7.5) | 2 (3.7) | 18 (34) | 24 (45.2) |
| Female | 4 (7.5) | 5 (9.5) | 20 (37.8) | 29 (54.8) |
| Age at onset of spasms (months) | 7.8 | 8.0 | 7.4 | 7.8 |
| Age at start of treatment (months) | 8.5 | 9.6 | 8.8 | 9.0 |
| Delay in treatment (months) | 0.72 | 1.6 | 1.4 | 1.3 |