Somatosensory Evoked Potentials with High Cortical Amplitudes: Clinical Data in 31 Children

Abstract

Between 1989 and 1993, somatosensory evoked potentials (SEP) were recorded as part of the diagnostic work-up in 282 children with different neurologic disorders. In thirty-one children with N20/P25/N35 amplitudes were enhanced compared to our control group (highest amplitude 14.1 microV). Four children had amplitudes > 40 microV ("giant"), fifteen between 20-39.9 microV ("elevated") and twelve between 14-19.9 microV ("borderline"). Enhanced cortical SEPs were seen in all patients with neuronal ceroid lipofuscinosis (5 late-infantile NCL > 20 microV, 1 juvenile NCL 14.7 microV). In addition, five of six NCL children showed bilaterally prolonged cervico-cortical conduction times, otherwise only seen in a 4-month-old child following hypoxia. "Borderline" and "elevated" SEPs occurred in patients with heterogeneous neurologic disorders. Follow-up recordings showed inconsistent results: seven children had amplitudes > 14 microV in all recordings, six only at the first examination, and six only at follow-up. In six children with hemiparesis enhanced SEPs were recorded over both (n = 2) or only over the unaffected hemisphere (n = 4). Myoclonic seizures were observed only in five children with NCL. Similar to other SEP parameters, enhanced amplitudes are an unspecific indicator of an ongoing neurologic disorder. However, in neuronal ceroid lipofuscinosis, enhanced SEP amplitudes may be a useful diagnostic criterium.

Electroclinical spectrum of the neuronal ceroid lipofuscinoses associated with CLN6 mutations

“…Indeed, the finding of giant SEPs is extremely rare in childhood and considered to be mostly associated with NCL. 37 On the basis of our observations, the concurrent presence of PPR and giant SEPs in childhood can be a feature suggestive of NCL, to which attenuated ERG can add further confidence in indicating the likelihood of finding a CLN6 mutation.…”

Late infantile neuronal ceroid lipofuscinosis: A case report with review of literature

“…The characteristic feature include biphasic, nearly monophasic, very high voltage complexes (cortical components of SEP). [12] Although, it is of diagnostic importance for NCL, SEP abnormalities are found less consistently than an enlarged VEP. A study by Veneselli et al ., observed that occurrence of pseudoperiodic discharges on EEG can be useful in early diagnosis of late infantile NCL.…”

Parameters of Somatosensory Evoked Potentials in Patients with Primary Sjӧgren’s Syndrome: Preliminary Results

“…Such observations have not been described for pSS so far. However, in patients with myoclonic epilepsy, high amplitude of N20/P25 complex, so-called gigantic SEP, was observed [ 27 , 28 ]. The pathomechanism of this phenomenon is unclear.…”