A five-year-old boy has been diagnosed with a peculiar condition which causes him headaches when he giggles.
The youngster, from the west of Ireland, was taken to Mayo University Hospital in Castlebar, County Mayo, after suffering from the painful headaches for a year.
The case was featured in the Irish Medical Journal, which said the pain feels light a tightening sensation around his head, and lasts several seconds each time, reports Galway Beo.
Whenever the headaches happen, the boy grasps his head with both hands and sits or lays down on the floor.
By the time he was seen at hospital he was having them every day.
Laughing was the only thing that would cause the pain - while other actions such as sneezing and coughing, for example, didn't.
Brain X-rays and examinations initially found nothing out of the ordinary, but an MRI scan showed that the boy had Chiari Malformation and a referral was made to a tertiary neurological centre for further management.
Chiari Malformation is where the lower part of the brain pushes down into the spinal canal.
It is often asymptomatic but can result in headaches that lessen over time for most patients.
At the time of the review, the young boy's headaches were becoming less frequent but more severe.
His parents were told to keep a diary recording the frequency and severity.
The report says that laughter is a rare trigger for headaches and that it is the first case of it they have seen happen in a child so young.
More about Chiari Malformation
According to nhs.co.uk, there are 4 main types of Chiari Malformation, but type 1, called Chiari I, is the most common.
"In someone with Chiari 1, the lowest part of the back of the brain extends into the spinal canal. This can put pressure on the brainstem, spinal cord, and obstruct the flow of fluid."
Chiari 1 malformations are not considered life threatening.
As well as headaches, symptoms can also include neck pain, hearing and balance problems, dizziness, and difficulty swallowing or speaking
There is a chance of developing syringomyelia (where a fluid-filled cavity called a syrinx develops in the spinal cord), which can damage the spinal cord if not treated promptly
The NHS website explains that surgery can usually stop the symptoms getting worse and can sometimes improve them, although some problems may remain.
