Essential tremor

What is it?

Essential tremor is involuntary shaking – usually of the hands, but sometimes also of the neck, jaw, voice or legs.

It can affect balance, walking, hearing and cognition, and can get worse over time. People with essential tremor run almost twice the risk of developing Alzheimer’s.

Essential tremor only appears with movement. If people let their hands sit still, they don’t tremble.

What causes it?

The cause remains a mystery, although it seems to run in families. People of any age or sex can have the condition, but it’s more common as people grow older. Roughly 4% of 40-year-olds have essential tremor compared with about 20% of 90-year-olds.

What’s the treatment?

Two medications – the beta blocker propranolol and the epilepsy drug primidone – can reduce tremors by 10-30%, but they work only in about half of patients.

Deep brain stimulation – implanting electrodes into the brain to override faulty electrical signals – has been shown to markedly reduce hand tremor severity.

But the treatment can worsen cognitive and balance problems, and it doesn’t actually cure the underlying disease.