Fat embolism showing restriction on diffusion sequence in brain magnetic resonance imaging

Restrição na sequência de difusão em imagem de ressonância magnética cerebral de embolia gordurosa

A 69 year-old female presented with bilateral amaurosis, headache, fever (38^oC) and dyspnea two days after a liposuction and abdominoplasty. A bilateral papilledema was observed in the clinical examination, without other neurological changes. Her ESR was 60mm/h and her platelet count was low (55.000mm³). Brain MRI revealed restriction of diffusion sequence in the right globus pallidus and both retinas (Figure 1). At spinal tap opening pressure was 16cmH2O. CSF examination was normal. Angio-MRI of the head and neck were also normal. Both transthoracic and transesophagic ecoDoppler examinations of the heart, the latter tailored to exclude left-to-right shunt were normal. The whole investigation of coagulopathy, vasculitis and idiopathic intracranial hypertension were negative. The retinal angiofluoresceinography demonstrated papilledema with venous congestion and retinal hemorrhages and no change in the arterial bed (Figure 2). Patient was submitted to anticoagulation with enoxaparine 1mg/kg subcutaneous bid without reversal of amaurosis.

Figure 1
Sign of restriction on the diffusion in both retinas (A) and the globus pallidus to the right (B).

Figure 2
Papilledema with venous congestion (A) and retinal hemorrhage with no change in arterial bed (B).

Papilledema leading may be seen in increased intracranial pressure, inflammatory optic neuropathy, infiltrative optic neuropathy, optic nerve tumours, compressive optic neuropathy, vasculopathies, intra-ocular disease venous obstruction; conditions associated with a massive increase in the protein content of CSF.

There are several mechanisms described for papilledema, such as a stasis of venous and lymphatic drainage secondary to increased pressure in the subarachnoid space, to an inflammatory condition, to venous obstruction by cloths or to mechanic obstruction. Optic nerve ischemia and impaired axoplasmic flow are also mentioned as determinates of a choked disk. In the case described above the sudden onset of the amaurosis, time-locked to the surgical procedure (liposuction) suggests a vascular phenomenon. Liposuction may determine small vessel rupture and adipocyte damage. Fat microfragments are drained by the venous circulation and surpass the pulmonary capillary bed, reaching the arterial system. Criteria for fat embolism were described by Gurd and Wilson (Table)¹.

Table
Gurd’s criteria for fat embolism.

Major criteria
Axillary or subconjunctival petechiae
Hypoxaemia (PaO2 < 60 mmHg; FIO2 = 0.4)
Central nervous system depression disproportionate to hypoxaemia
Pulmonary oedema
Minor criteria
Tachycardia < 110 bpm
Pyrexia < 38.5°C
Emboli present in the retina on fundoscopy
Fat present in urine
A sudden inexplicable drop in haematocrit or platelet values
Increasing ESR
Fat globules present in the sputum

We hypothesized that in this case papilledema was caused bilateral cilliary arteries obstruction by fat embolism. Similar cases of cerebral fat embolism were described. Surgeons, ophtalmologists, physicians, and neurologist should be aware of this condition².

References

• ¹
  Gurd AR, Wilson RI. The fat embolism syndrome. J Bone Joint Surg Br. 1974;56B(3):408-16.
• ²
  Wang HD, Zheng JH, Deng CL, Liu QY, Yang SL. Fat embolism syndromes following liposuction. Aesthetic Plast Surg. 2008;32(5):731-6. doi:10.1007/s00266-008-9183-1

• Erratum

  Fat embolism showing restriction on diffusion sequence in brain magnetic resonance imaging.
  Arq Neuropsiquiatr 2016;74(7):597-598. DOI: http://dx.doi.org/10.1590/0004-282X20160052
  The authors:
  Henry Koiti Sato¹, Pedro André Kowacs¹, Josep Dalmau², Paulo Sergio Faro Santos²
  Should be:
  Henry Koiti Sato¹, Pedro André Kowacs¹, Paulo Sergio Faro Santos¹
  The afiliation “2Universitat de Barcelona, Institut D’Investigacions Biomédiques August Pi I Sunyer, Hospital Clínic, Barcelona, Spain.” must be ignored.

Publication Dates

• Publication in this collection
  20 May 2016
• Date of issue
  July 2016

History

• Received
  20 Aug 2015
• Reviewed
  22 Dec 2015
• Accepted
  1 Mar 2016