Table 1. Characteristics of the 125 Study Cases.

Table lists general study characteristics, including demographics, birth history, and neurological exam at presentation. Sum of individual brain injuries sum to >34 due to N = 5 cases with multiple subtypes (E.G. head injury with subsequent meningitis). Miscellaneous brain injuries include infarction (N = 4), periventricular leukomalacia (N = 3), and N =1 each of ruptured aneurysm, traumatic brain injury from motor vehicle accident, prenatal methamphetamine exposure, and hypoglycemic brain injury. In 1 case of HIE and 1 case of encephalitis, a variant of unknown significance was also identified on genetic testing. The case of prenatal drug exposure ultimately had no abnormalities noted on MRI. Non-focal motor difficulties included changes in motor tone or coordination. Follow-up duration, age at onset, and gestational age are reported as median (IQR); all other variables shown as N (%).

General Study Population Characteristics Total N = 125
Male / Female	61 (48.8%) / 64 (51.2%)
Duration Follow-up	10.9 years (6.2, 19.3)
Age Onset	7 months (2.0, 15.5)
Gestational Age	40 weeks (37.0, 40.0)
Early Pre-term Births (<34 wks)	15 (12.0%)
Late Pre-term Births (34 to 36 6/7)	9 (7.2%)
Prenatal Complications Requiring Hospitalization	15 (12.0%)
Postnatal Complications Requiring ≥ 7 Days in NICU	48 (38.4%)
Presence of Neonatal Seizures	28 (22.4%)
Presence of Febrile Seizures	16 (12.8%)
Family History of Seizures in 1st Degree Relative	18 (14.4%)
Brain Injury	34 (27.2%)
Hypoxic-Ischemic Encephalopathy	14 (11.2%)
Intraventricular Hemorrhage	8 (6.3%)
Head Injury	1 (0.8%)
Meningitis	3 (2.4%)
Encephalitis	2 (1.6%)
Miscellaneous	11 (8.8%)
Abnormal Findings on Neurologic Exam	64 (51.2%)
Quadriparesis	27 (21.6%)
Hemi/paraparesis	20 (16.0%)
Extrapyramidal Signs	2 (1.6%)
Non-focal Motor Difficulties	15 (12.0%)