Table 1 Clinical and electrophysiological findings in 9 patients with myoclonic ataxia and Coeliac disease

50/M

EPC right face and tongue (5-6 Hz). Episodes of Jacksonian march, spreading from face into platysma and right shoulder, occasionally leading to secondary generalised tonic-clonic seizures. EPC attenuated during sleep.

Normal EEG, SEPs, no LLRs. JLBA, revealed that right facial/tongue twitching was EPC (Figure 2). Normal blink reflex studies and no signs of denervation on affected facial and tongue muscles. Ten years from onset of neurological symptoms, axonal PN on EMG & NCS.

60/F

Continuous myoclonic tremor at around 5 Hz of the right arm. Occasional myoclonus of the right leg. The left arm developed asynchronous (5-7 Hz) myoclonic tremor at a later stage. A single secondary generalised seizure.

Standard EEG unremarkable, SEPs (only left hand) within normal limits. JLBA, cortical myoclonic tremor of right UL (Additional file 1: Figure S1). JLBA at a later stage revealed cortical myoclonic tremor on the left UL. Normal NCS.

63/M

Continuous myoclonic jerks/action myoclonus of the right UL (5 Hz). Two years later, deterioration with facial twitching and prominent action myoclonus (R leg)

Mild excess of widespread theta and occasionally delta range activity, maximal in the temporal and centrotemporal regions. JLBA, continuous cortical myoclonus (right hand). ‘Giant’ SEPs, right leg, but no LLR (Additional file 2: Figure S2). Normal NCS.

53/M

Very frequent irregular spontaneous, action and reflex myoclonic tremor of left UL. Later on, episodes of Jacksonian march and secondary generalisation.

JLBA, spontaneous and action induced cortical myoclonus. Giant SEPs from ULs with LLRs, better formed on the right, clinically less affected side (Figure 4).

76/M

Irregular myoclonic action tremor of both ULs (L > R). Spontaneous and reflex myoclonic tremor of the intrinsic hand muscles (L > R at ~5-6 Hz).

JLBA, cortical origin of the very frequent spontaneous myoclonus of the right intrinsic hand muscles and forearm. Low amplitude LLR from left UL (Additional file 2: Figure S2). NCS & EMG, axonal sensorimotor PN.

46/F

Irregular spontaneous but mainly action and reflex myoclonic tremor of both UL and LL.

‘Giant’ cortical SEPs and LLRs from both median and the right tibial nerves. JLBA, cortical origin of spontaneous and action induced myoclonus (Figure 4).

61/M

Myoclonic status epilepticus with twitching of L UL and LL.

Standard EEG, PLEDs in the right posterior quadrant with irregular not time-locked asynchronous myoclonic jerks of the left upper and lower limb. JLBA, cortical generator for the myoclonus (Figure 1).

52/F

Spontaneous, action and reflex myoclonus of ULs (L > R at ~10 Hz).

JLBA, spontaneous and action induced cortical myoclonus. ‘Giant’ SEPs from both ULs (L > R) and LLRs (Figure 4).

74/M

Mainly action and reflex myoclonus of LLs (L > R at ~ 4 Hz)

JLBA, mainly action and reflex cortical myoclonus. ‘Giant’ SEPs only from left LL plus LLRs (Additional file 3: Figure S3).