Skip to main content

Unusual cause of dementia in an immunocompetent host: toxoplasmic encephalitis


A 69-year-old male was presented with a 2-month history of cognitive decline. The most profound deficit was observed in short-term verbal and visual memory and recognition. He was otherwise healthy, apart from atrial fibrillation diagnosed 5 months before. Brain MRI revealed T2 hyperintensities in the left thalamus, right pulvinar thalami, both putamina and right head of caudate nucleus without diffusion restriction on DWI sequences. CSF examination revealed elevated proteins. He was HIV negative. The course of the disease was complicated with gram negative sepsis and the patient died 14 days later. Autopsy revealed the brain lesions to have been caused by toxoplasmic encephalitis. Toxoplasmic encephalitis is an extremely rare cause of rapidly progressive dementia in immunocompetent patients. In patients with multiple lesions, hyperintense on T2 and hypointense on T1 weighted sequences, without diffusion restriction and some expansive effect, infectious causes should be considered, even in the absence of classical signs of infectious diseases and CSF pleocythosis.

This is a preview of subscription content, access via your institution.

Fig. 1
Fig. 2
Fig. 3


  1. Habek M, Brinar VV, Mubrin Z, Barun B, Zarkovic K (2007) Bilateral thalamic astrocytoma. J Neurooncol 84:175–177

    PubMed  Article  Google Scholar 

  2. Hochberg FH, Baehring JM, Hochberg EP (2007) Primary CNS lymphoma. Nat Clin Pract Neurol 3:24–35

    PubMed  Article  CAS  Google Scholar 

  3. Colosimo C, di Lella GM, Tartaglione T, Riccardi R (2002) Neuroimaging of thalamic tumors in children. Childs Nerv Syst 18:426–439

    PubMed  Article  Google Scholar 

  4. Almeida OP, Lautenschlager NT (2005) Dementia associated with infectious diseases. Int Psychogeriatr 17(Suppl 1):S65–S77

    PubMed  Article  Google Scholar 

  5. World Health Organization (2004) The revision of the surveillance case definition for variant Creutzfeldt–Jakob Disease: report of a WHO Consultation, Edinburgh. World Health Organ Tech Rep Ser 2004; (vCJD)

  6. Zeidler M, Sellar RJ, Collie DA et al (2000) The pulvinar sign on magnetic resonance imaging in variant Creutzfeldt–Jakob disease. Lancet 355:1412–1418

    PubMed  Article  CAS  Google Scholar 

  7. Shiga Y, Miyazawa K, Sato S et al (2004) Diffusion-weighted MRI abnormalities as an early diagnostic marker for Creutzfeldt–Jakob disease. Neurology 63:443–449

    PubMed  CAS  Google Scholar 

  8. Macfarlane RG, Wroe SJ, Collinge J, Yousry TA, Jäger HR (2007) Neuroimaging findings in human prion disease. J Neurol Neurosurg Psychiatry 78:664–670

    PubMed  Article  CAS  Google Scholar 

  9. Montoya JG, Liesenfeld O (2004) Toxoplasmosis. Lancet 363:1965–1976

    PubMed  Article  CAS  Google Scholar 

  10. Chong-Han CH, Cortez SC, Tung GA (2003) Diffusion-weighted MRI of cerebral toxoplasma abscess. AJR Am J Roentgenol 181:1711–1714

    PubMed  Google Scholar 

  11. Mueller-Mang C, Mang TG, Kalhs P, Thurnher MM (2006) Imaging characteristics of toxoplasmosis encephalitis after bone marrow transplantation: report of two cases and review of the literature. Neuroradiology 48:84–89

    PubMed  Article  CAS  Google Scholar 

  12. Vastava PB, Pradhan S, Jha S, Prasad KN, Kumar S, Gupta RK (2002) MRI features of toxoplasma encephalitis in the immunocompetent host: a report of two cases. Neuroradiology 44:834–838

    PubMed  Article  CAS  Google Scholar 

  13. Camacho DL, Smith JK, Castillo M (2003) Differentiation of toxoplasmosis and lymphoma in AIDS patients by using apparent diffusion coefficients. AJNR Am J Neuroradiol 24:633–637

    PubMed  Google Scholar 

  14. Couvreur J, Thulliez P (1996) Acquired toxoplasmosis of ocular or neurologic site: 49 cases. Presse Med 25:438–442

    PubMed  CAS  Google Scholar 

  15. Grant SC, Klein C (1987) Toxoplasma gondii encephalitis in an immunocompetent adult. A case report. S Afr Med J 71:585–587

    PubMed  CAS  Google Scholar 

  16. Lescop J, Brinquin L, Schill H, Soulie D, Sarrazin JL, Cordoliani YS (1995) Diffuse toxoplasmic encephalitis in a non-immunosuppressed patient. J Radiol 76:21–24

    PubMed  CAS  Google Scholar 

  17. Doffoel M, Coumaros D, Levy P, Jacques C, Saada K, Laidoudi A, Bockel R, Himy-Dahan R, Kien T (1980) Neurotoxoplasmosis. Description of a case of an acquired meningoencephalitis. Sem Hop 56:788–790

    PubMed  CAS  Google Scholar 

  18. Kaushik RM, Mahajan SK, Sharma A, Kaushik R, Kukreti R (2005) Toxoplasmic meningoencephalitis in an immunocompetent host. Trans R Soc Trop Med Hyg 99:874–878

    PubMed  Article  Google Scholar 

  19. Silva LA, Vieira RS, Serafini LN, Carlotti CG Jr, Figueiredo JF (2001) Toxoplasmosis of the central nervous system in a patient without immunosuppression: case report. Rev Soc Bras Med Trop 34:487–490

    PubMed  CAS  Google Scholar 

  20. Bach MC, Armstrong RM (1983) Acute toxoplasmic encephalitis in a normal adult. Arch Neurol 40:596–597

    PubMed  CAS  Google Scholar 

Download references

Author information

Authors and Affiliations


Corresponding author

Correspondence to Mario Habek.

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Habek, M., Ozretić, D., Žarković, K. et al. Unusual cause of dementia in an immunocompetent host: toxoplasmic encephalitis. Neurol Sci 30, 45–49 (2009).

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI:


  • Toxoplasmic encephalitis
  • Dementia
  • Immunocompetent