Table 1.

Comparison between symptoms, EMG and therapy in essential tremor and cortical myoclonus.

Syndrome	Localization	Frequency	EMG pattern	Therapy	Other features
Essential tremor	UE with or without other locations (voice; LE), predominantly bilateral	4–12 Hz	rhythmic; commonly synchronized	Propranolol, Primidone, Topiramate	No further neurological signs (if further neurological signs occur [e. g., ataxia] the classification is “essential tremor plus”)
Cortical myoclonus	UE (unilateral or bilateral)	9–18 Hz	arrhythmic bursts of around 15 to 60 ms	AED (e. g., Levetiracetam, sodium valproate)	Cortical excitability (giant SEP, jerk locked EEG changes)

UE, upper extremities; LE, lower extremities; AED, antiepileptic drugs; Hz, hertz; SSEP, somatosensory-evoked potentials; EEG, electroencephalography