Cerebral abscess

   September 1, 2020  Posted in Central Nervous System, Infection

Case contribution: Dr Radhiana Hassan

Clinical:

  • A 62 years old female
  • Underlying DM and HPT
  • Presented with worsening body weakness and facial asymmetry of few days
  • Later had altered consciousness
  • GCS at ED E3V5M5, BP=169/79mmHg and PR 69 bpm
  • Power right upper and lower limb 4/5, left side 1/5
  • One day after admission GCS E1V1M5

MRI findings:

  • There is ring-enhancing lesions in the right thalamus (red arrows)
  • The wall is smooth with regular enhancement.
  • Central part is hypointense on T1, hyperintense on T2/FLAIR and shows restricted diffusion on DWI/ADC sequences
  • Smaller lesion seen adjacent to it with similar characteristic
  • Another lesion with similar appearance but slightly irregular wall is seen at pons
  • It is associated with significant surrounding oedema
  • Leptomeningeal enhancement at left side of the cerebellar region (yellow arrows)
  • No hydrocephalus, no basal cistern enhancing lesion
  • MRS shows lactate peak

Diagnosis: Cerebral abscess

Discussion:

  • Cerebral abscess represent focal areas of infection within brain parenchyma.
  • It is usually pus-containing lesion with a thick capsule.
  • They typically have enhancing walls and can mimic a number of other significant pathologies.
  • It can occur at any age. Risk factors include immunocompromised (HIV & diabetes mellitus), existing infection (middle ear infection or bacteraemia) and IV drug use.
  • CT and MRI demonstrate similar features.
  • Typical appearance on CT include outer hypodense and inner hyperdense (double rims sign), ring of iso or hyperdense tissue of uniform thickness, central low attenuation region (pus/fluid), surrounding low density (vasogenic oedema), ventriculitis may be present. Obstructive hydrocephalus when intraventricular spread occured
  • MRI is more sensitive; T1WI with central hypodensity and peripheral oedema, T2/FLAIR central hyperintensity , peripheral vasogenic oedema, DWI/ADC shows restricted diffusion, MRS shows elevated lipid/lactate succinate and acetate

Progress of patient:

  • FBC: Hb 9.9, Plt 349 and TWBC 7.9 (all normal)
  • RP: Urea 5.9, Na 130, K 4.4, Creat 85 (normal)
  • LFT normal
  • HIV rapid test negative
  • CRP increased
  • Sputum for TB negative
  • CSF for TB no culture, no growth
  • Patient responded well to antibiotics given, GCS 15/15

 

Author: radhianahassan