Epileptic spasm

What it means

A sudden flexion, extension, or mixed extension-flexion of predominantly proximal and truncal muscles that is usually more sustained than a myoclonic movement but not as sustained as a tonic seizure. Limited forms may occur: Grimacing, head nodding, or subtle eye movements. Epileptic spasms frequently occur in clusters. Infantile spasms are the best known form, but spasms can occur at all ages

The maximum age of onset is between 3 and 12 months, the peak being at 6 months. However, spasms may start from birth, or appear long after the age of 12 months, including into adulthood. Infantile spasms represent a specific type of seizure seen in an epilepsy syndrome of infancy and childhood known as West Syndrome. West Syndrome is characterized by infantile spasms, developmental regression, and hypsarrhythmia (as demonstrated by electroencephalography).

Rare diseases that can present with this22

The range is how often this sign appears among people diagnosed with each disease — it is not a probability of having any of them. Many of these signs also occur in common, non-rare conditions, and Orphanet separately records 1 disease where this sign is specifically absent. A sign on this page is a conversation to have with a clinician, not a conclusion.

Part of the broader category

Also called: Epileptic spasms · Salaam convulsion · Salaam convulsions · Salaam seizure · Salaam seizures · West syndrome