Article Text

Download PDFPDF
Unusual cause of progressively impaired cognitive function: Mycobacterium avium complex meningoencephalitis
  1. Yuji Okazaki and
  2. Yusuke Higashi
  1. Department of Internal Medicine, Akiota Hospital, Yamagata-gun, Hiroshima, Japan
  1. Correspondence to Dr Yuji Okazaki, ur8nibhc1{at}


Mycobacterium avium complex (MAC) is a rare cause of meningoencephalitis. Non-tuberculous mycobacterium meningoencephalitis including MAC meningoencephalitis is an important cause of rapidly progressive dementia. We present a case of MAC meningoencephalitis in an immunosuppressed woman who had progressively impaired cognitive function. An 83-year-old woman who had been taking glucocorticoid for myasthenia gravis developed cognitive dysfunction and visual hallucinations over a period of 2 weeks. Cerebrospinal fluid (CSF) findings were normal, but MAC was positive in CSF culture and M. avium and M. intracellulare were identified by PCR. She was treated with multiple antimycobacterial agents and her symptoms fully recovered. MAC meningoencephalitis is an unusual cause of progressively impaired cognitive function. The possibility of mycobacterial central nervous system infection cannot be excluded by normal CSF findings.

  • meningitis
  • infection (neurology)
  • memory disorders

Statistics from


  • Contributors All authors contributed to the development of this manuscript. YO was responsible for the literature search and writing of entire manuscript. YH was a supervisor.

  • Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.

  • Competing interests None declared.

  • Provenance and peer review Not commissioned; externally peer reviewed.

  • Patient consent for publication Not required.

Request Permissions

If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.