Startle Response in Progressive Myoclonic Epilepsy. (March 2017)

• Record Type: Journal Article
• Authors: Kızıltan, Meral E.; Gündüz, Ayşegül; Coşkun, Tülin; Delil, Şakir; Pazarcı, Nevin; Özkara, Çiğdem; Yeni, Naz
• Is Part Of: Clinical EEG and neuroscience. Volume 48:Number 2(2017)
• Page Start: 123
• Page End: 129
• Publication Date: 2017-03
• Subjects: progressive myoclonic epilepsy -- Lafora disease -- neuronal ceroid lipofuscinosis -- Unverricht-Lundborg disease -- auditory startle response -- startle response to somatosensory stimuli; Electroencephalography -- Periodicals; Neurosciences -- Periodicals; 616.8047547
• DOI: 10.1177/1550059416646292
• Languages: English
• ISSNs: 1550-0594

Abstract

Cortical reflex myoclonus is a typical feature of progressive myoclonic epilepsy (PME) in which it is accompanied by other types of mostly drug-resistant seizures and progressive neurological signs. Although PME is characterized by cortical hyperexcitability, studies have demonstrated atrophy and degenerative changes in the brainstem in various types of PME. Thus, we have questioned whether any stimuli may trigger a hyperactive response of brainstem reticular formation in PME and investigated the startle reflex in individuals with PME. We recorded the auditory startle response (ASR) and the startle response to somatosensory inputs (SSS) in patients with PME, and compared the results with healthy volunteers and patients with other types of drug-resistant epilepsy. All patients were using antiepileptic drugs (AEDs), 12 were on multiple AEDs. The probability of ASR was significantly lower and mean onset latency was longer in patients with PME compared with other groups. SSS responses over all muscles were low in both the PME and drug-resistant epilepsy groups; however, the differences were not statistically significant. The presence of a response over the biceps brachii muscle was zero in the PME group and showed a borderline difference compared with the other groups. Decreased probability and prolonged latencies of ASR in PME indicate inhibition of reflex circuit. A trend for decreased responses of SSS suggests hypoactive SSS in both PME and other epilepsy groups. Hypoactive ASR in PME and hypoactive SSS in both PME and other epilepsies may be attributed to the degeneration of pontine reticular nuclei in PME and functional inhibition by AEDs in both disorders.