# Neurologically predominant fat embolism syndrome in an octogenarian with dementia: diagnostic challenges and prolonged recovery

## TL;DR

An elderly man with dementia showed neurological symptoms of fat embolism syndrome, diagnosed via MRI and managed with supportive care leading to partial recovery.

## Contribution

Highlights the rare occurrence of neurologically predominant fat embolism syndrome in elderly dementia patients and its diagnostic and therapeutic challenges.

## Key findings

- MRI with DWI and SWI confirmed cerebral fat embolism despite absence of respiratory symptoms.
- Prolonged neurological recovery was achieved with supportive care in an elderly patient with dementia.
- Persistent microhemorrhages on follow-up MRI did not hinder significant clinical improvement.

## Abstract

Neurologically predominant fat embolism syndrome (FES) without respiratory involvement is very rare in elderly patients with pre-existing dementia. Diagnosis is challenging as symptoms may be misattributed to delirium.

We report the case of an 82-year-old man with dementia with Lewy bodies who developed progressive altered consciousness following a femoral neck fracture. Despite the absence of respiratory symptoms, brain magnetic resonance imaging revealed the characteristic findings of cerebral fat embolism, including multiple hyperintense lesions on diffusion-weighted imaging(DWI) and numerous hypointense lesions on susceptibility-weighted imaging(SWI) of the corpus callosum, cerebellum, and cerebrum. The patient’s clinical stability indicated conservative management was appropriate. Comprehensive supportive care included enteral nutrition, prevention of immobility-related complications, and rehabilitation. Corticosteroid therapy was not indicated. Gradual neurological improvement occurred over 84 days, with the patient achieving partial functional recovery including functional communication and mobility. Follow-up MRI at 2 months showed persistent microhemorrhages with minimal interval change, despite significant clinical improvement.

This case highlights the diagnostic challenges of neurologically predominant FES in elderly patients with dementia, where symptoms may easily be confused with hypoactive delirium. Advanced MRI sequences (DWI and SWI) are essential for diagnosis. Despite advanced age and pre-existing cognitive impairment, prolonged neurological recovery is possible with sustained supportive care, emphasizing the importance of avoiding premature therapeutic nihilism in this vulnerable population.