The HSE has insisted that it never intended to withdraw any discretionary medical cards or any other health services or supports from people who developed narcolepsy allegedly as a result of being immunised with the swine flu vaccine, Pandemrix.

Narcolepsy is a chronic neurological disorder caused by the brain's inability to regulate sleep/wake cycles normally. There is no cure for it and symptoms can include excessive daytime sleepiness, cataplexy (sudden loss of muscular/postural tone), vivid hallucinations during sleep or after wakening and brief episodes of total paralysis at the beginning or end of sleep.

In September 2011, a group of Irish parents who believed their children developed the condition as a result of receiving the Pandemrix vaccine officially launched the support group, SOUND (Sufferers of Unique Narcolepsy Disorder).

Their fears were confirmed in April 2012, when a report by the Health Protection Surveillance Centre (HPSC) found that people who received the Pandemrix vaccine in the 2009/10 swine flu pandemic had a 13-fold higher risk of developing narcolepsy.

These findings were similar to results reported in Sweden and Finland at the time.

Last month, a letter was sent to some families telling them that the HSE would no longer continue to pay the medical expenses of those with narcolepsy if they sued the State.

It was suggested that this letter was written following advice from the State Claims Agency.

However, the HSE has since made a statement insisting that health services and supports were never going to be withdrawn from affected families and that the letter ‘never stated that the State Claims Agency advised the HSE of any requirement to alter its approach in this regard'.

"The interpretation of the letter by some media may have given an impression that the HSE had intended to withdraw such medical support," the HSE commented.

It added that the Director General of the HSE, Tony O'Brien, wanted to make it ‘absolutely clear that he has given a direction that medical supports and services will not be withdrawn for this category of narcolepsy sufferers'.

He also apologised if the letter had caused ‘any distress or upset to any person, family or group'.

Meanwhile, Fianna Fail's health spokesperson, Billy Kelleher, has called for the Minister of Health, Dr James Reilly, to clarify his role in the issuing of the letter.

He said that while he is happy that Mr O'Brien ‘moved swiftly to clarify the situation for the families concerned...it is important we know what role Minister Reilly played'.

"The fact that the HSE chief executive seems to have been utterly unaware of this is very disturbing and points to the continuing chaos and confusion in the health service under Minister Reilly. I am calling on the Minister to state clearly his role on this matter and how this issue transpired," Mr Kelleher said.