Sphingolipidoses | | | | | | |
GM2-Gangliosidosis | | | | | | |
Infantile type | Normal to slight decrease in amplitude | Normal early; abnormal to absent later with loss of definition of early components initially | Prolonged latencies | Peripheral components normal | Progressive slowing initially High then decreasing voltage Paroxysmal spike events may be infrequent | NI |
Late infantile type | Normal | Variable loss | Abnormal in 1/2 tested Prolonged I-V interval | NI | Similar to infantile type | Normal |
Juvenile type | Normal | Normal high-voltage response | Normal | NI | Normal to progressive diffuse slowing | Normal |
Adult type | Normal | NI | NI | NI | Normal to diffuse slowing | Normal |
Sandhoff type | Similar to infantile | Similar to infantile | Similar to infantile | NI | Similar to infantile | Normal |
GM1-Gangliosidosis | | | | | | |
Infantile/juvenile types | Normal | Abnormal | Normal in 1/1 tested | NI | Generalized slowing Occasionally with spike/wave | Normal |
Adult type | NI | NI | NI | NI | Normal | Normal |
Sphingomyelin Lipidosis | | | | | | |
Infantile type | Normal to reduced | Progressive decrease in amplitude | Normal to delayed | NI | Normal early May be epileptiform with slowing late | Normal to reduced |
Glucosylceramide Lipidosis | | | | | | |
Infantile type | NI | NI | Lengthening of peak latencies | NI | Diffuse slow waves and spike-wave discharges | NI |
| | | Progressive loss of waves III-V | | Abnormal sharp waves on photic stimulation | |
| | | Associated with loss of neurons in cochlear nuclei and hypoplastic superior olivary complex | | | |
Galactosylceramide Lipidosis | | | | | | |
Infantile type | Normal | Progressive decrease to no response in late stage | Only waves I and II noted rest absent | Delayed major component (P 100) | Normal early Moderate to severe generalized high-voltage slowing | Markedly reduced |
Sulfatide Lipidosis | | | | | | |
Late infantile type | Normal | Normal early; then prolonged latencies No response late | Prolonged latencies for waves I and V and I-V interval Absent waves III-V Delayed Wave I | Low amplitude Prolonged latencies to absent response | Normal early Progressive diffuse slowing Occasionally spike-and wave paroxysms late | Markedly reduced |
Juvenile type | Normal | Same as late infantile | Prolonged latencies | Prolonged latencies | Same as late infantile | Markedly reduced |
Adult type | NI | Normal to prolonged latencies | Normal | NI | Low voltage Diffusely slow | Normal to reduced |
Adrenoleukodystrophies | | | | | | |
Adrenoleukodystrophy | Normal | Normal early Prolonged latency later | Normal at onset Prolonged interwave intervals to absent response after wave I Prolonged in obligate heterozygotes | Prolonged latency Abnormal in 4/7 female relatives | Normal early Irregular high voltage delta More prominent posteriorly Loss of normal arousal response | Normal early Reduced later |
Adrenomyeloneuropathy | Normal | Normal | No waves after I or prolonged interwave intervals | Prolonged latency | Normal | Normal to mildly reduced |
Adrenoleukomyeloneuropathy | Normal | Normal | Prolonged I-III and III-V intervals | Prolonged latency | Normal to mild diffuse slowing | Normal early Reduced later Worse in lower extremities |
Neonatal adrenoleukodystrophy | Absent | Absent—info from one infant | Marked central pathway dysfunction | NI | Diffusely epileptiform Marked frontally Progresses from focal to multifocal spikes to burst suppression | Normal to reduced |
Neuronal Ceroid Lipofuscinoses |
Infantile type | Small to absent | Small to absent by age 3-4 | NI | NI | Slowing initially (normal 12-15 mo) with progressive decrease in amplitude, especially central, frontal, and temporal regions); no response to photic stimulation before 2 y; after age 3, isoelectric | Normal |
Late infantile type | Small to absent | Grossly enlarged response early Absent late | NI | Exaggerated response early with normal latency Later, little response within and rostral to brainstem | Loss of background rhythm Diffusely slow with temporal spike and wave spikes Exaggerated photic response | Usually normal |
Juvenile type | Small to absent Early | Small amplitude early Then absent | NI | Markedly reduced Amplitudes | Early diffuse slowing Increased amplitude Spike/wave discharges | Slight decrease especially in sensory fibers |
Sialidosis/Sialuria Complex |
Sialidosis I | Normal | Normal to decreased amplitude | Normal | NI | Normal early Decreased voltage with fast background Occasional generalized spike/wave | NI |
Sialidosis II | | | | | | |
Infantile type | NI | NI | NI | NI | Marked epileptiform activity | NI |
Juvenile type | Normal | Normal early Decreased amplitude later | NI | NI | Normal to diffuse fast activity early Irregular background with spike discharges later | Normal |
Sialuria | | | | | | |
Infantile type | Normal | Normal | Normal | NI | Multifocal spike discharges | Normal |
Salla type | Normal | Normal | Normal | NI | Progressive voltage decrease | Normal |
| | | | | With voltage decrease, no response to eye-opening or photic stimulation | |