Reported personal story
Mia Lucas — the test that was never done
What happened
Mia Maisie Lucas was 12, from Arnold in Nottinghamshire, when she changed over the months around Christmas 2023: visual hallucinations (men in black overalls, a "vampire" figure), voices telling her to do things and threatening her family if she refused, extreme mood swings, punching and spitting at her mother, an attempt to grab the steering wheel of a moving car, and, on 31 December 2023, taking a knife and saying the voices told her to kill herself and "go to heaven." On 4 January 2024 she was detained under Section 2 of the Mental Health Act as an "acute psychotic episode" and transferred on 9 January to the Becton Centre, a children's psychiatric unit in Sheffield.
What it looked like
A severe psychosis in a previously healthy child. At the hospital it was agreed that organic causes should be ruled out first — but the workup stopped early. Her MRI on 3 January was normal; an EEG was discussed but never completed; a lumbar puncture was never attempted. A blood test for NMDA-receptor antibodies, requested on 8 January, came back negative — and the spinal-fluid test that might have shown more was never done. Between 17 and 29 January there were four ligature incidents and one self-harm incident at the unit.
What the labs found
Only after her death. Post-mortem examination (2 February 2024) found inflammation patterns in her brain — perivascular lymphoid infiltrates in the temporal and frontal lobes and hypothalamus. A blood sample taken at post-mortem was sent for further testing on 24 September 2025, and it tested positive for the NMDA receptor antibody: autoimmune encephalitis was diagnosed. The recorded cause of death was 1a compression to neck, 1b acute psychosis, 1c autoimmune encephalitis. The inquest jury found that the failure to undertake a lumbar puncture meant potential indicators were missed and possibly contributed to her death. Mia was found unresponsive in her room late on 29 January 2024 and pronounced deceased on 30 January 2024. No immunotherapy was ever given, because the condition was never diagnosed in her lifetime.
What changed
Her mother, Chloe Hayes, had challenged the unit over Mia's safety while she lived; after the diagnosis emerged she campaigned for national testing guidance. The hospital trusts accepted that a lumbar puncture should have been done and apologised; the coroner's Prevention of Future Deaths report (February 2026) told NHS England there is no national guidance on when to consider or how to diagnose autoimmune encephalitis, and national guidance is now in development. This entry is printed plainly as what it is: the too-late end of the shape. Her family is not recorded as having requested antibody testing in her lifetime — the failure the coroner identified was the system's, and it is not dressed up here as anything else.
The test that told the story
Post-mortem NMDA-receptor antibody testing — and, in life, the lumbar puncture that was never attempted.
Sources: Senior Coroner's Regulation 28 Prevention of Future Deaths report (Tanyka Rawden, ref 2026-0070, 2 February 2026), a primary legal record resting on the inquest evidence and post-mortem testing; Channel 4 News inquest reporting, including interviews with her mother; PA Media inquest reporting.