Table 1

Episodic tremor syndromes

SyndromeAge at onsetCausePhenotypeDurationRecurrenceTriggers
Limb shakingAdulthood.Vascular: severe carotid stenosis (>80%).Typically unilateral, upper limb jerking tremor.Transient—may last several minutes.Episodes occur monthly or up to several times per day.Orthostatic positional change, hypotension, hyperventilation, neck extension or walking.
Hereditary chin tremorAdolescence.AD linked to chromosome 9q13-q21 in one family.Oscillatory rhythmic movements of the chin muscles, mainly the mentalis muscle.
Frequency varies between 2 and 11 Hz.
Seconds to hours.Daily.Emotion or anxiety.
Paroxysmal head tremorAdulthood.Heterogeneity: missense mutation in CACNA1A gene, encoding the calcium voltage-gated channel.Progressive disorder with ‘no-no’ pattern and frequency of 3–5 Hz involving the splenius and sternocleidomastoid muscles.5 and 60 min.Up to several times a week.No specific triggers.
Bobble-head doll syndromeChildhood.Expansion in the region of the III ventricle resulting from a suprasellar arachnoid or a cyst.Episodic 2–3 Hz ‘yes-yes’ tremor of the head with occasional ‘no-no’ movements.
Other areas: neck, shoulders, trunk or upper limbs.
Variable.Variable.Absent during sleep.
Amplitude increases with walking or excitement and decreases or disappears under volitional control or concentration.
Spasmus nutansChildhood.Idiopathic and benign.Head shaking, nystagmus, and abnormal head posture or torticollis.
Reminiscent of bobble-head doll syndrome.
Variable.Variable.Absent during sleep.
No triggers.
Shuddering attacksChildhood.Idiopathic and benign.Brief bursts of rapid, shivering-like movements of the head and both arms.Seconds.Up to 100 episodes per day.No triggers.
  • AD, autosomal dominant.