Parkinsonism-dementia complex on Guam — Overview of clinical aspects


Parkinsonism-dementia complex (PDC) is the second most common neurodegenerative disorder in Guam, after amyotrophic lateral sclerosis (ALS). PDC was first described by Hirano 1961. A familial appearance is seen among some PDC cases, which may also include ALS, and vice versa, but subsequent research including pedigree analysis, prospective case control registries, and the search for specific gene markers has failed to yield a satisfactory genetic explanation. Important diagnostic indicators of the illness include rigido-akinetic type Parkinsonism and severe dementia.

In PDC, rigidity is so marked that postural deformities such as a generally flexed posture become rather prominent. Gait disturbances are a common initial symptom. Hyperreflexia and spinal muscular atrophy, developing mainly in the distal extremities, are frequently observed. These mixedsyndrome patients can be seen as clear support for the view that Guam ALS and PDC constitute a single mixed disease entity with a spectrum of clinical expression.

The present paper offers an overview and description of the clinical features of PDC.


  1. 1.

    Chen KM: The history of Guam ALS/PDC, 1900–1998 (1998) Annotated chronological bibliography

  2. 2.

    Chen KM, Chase TN (1985) Parkinsonism-dementia In: Vinken PJ, Bruyn GW (eds) Handbook of Clinical Neurology. Extrapyramidal Disorders, Elsevier Science, Amsterdam 49: 167–183

    Google Scholar 

  3. 3.

    Elizan TS, Hirano A, Abrams BM etal. (1966) Amyotrophic lateral sclerosis and Parkinsonism-dementia complex of Guam: Neurologic reevaluation. Arch Neurol 14: 356–368

    PubMed  CAS  Google Scholar 

  4. 4.

    Hirano A, Kurland LT, Krooth RS, Lessel S (1961) Parkinsonism-dementia complex: an endemic disease on the island of Guam. I. Clinical Features. Brain 84: 642–661

    PubMed  Article  CAS  Google Scholar 

  5. 5.

    Hirano A, Malamud N, Kurland LT (1961) Parkinsonism-dementia complex: an endemic disease on the island of Guam. II. Pathological Features. Brain 84: 662–679

    PubMed  Article  CAS  Google Scholar 

  6. 6.

    Kurland LT, Mulder DW (1954) Epidemiologic investigations of amyotrophic lateral sclerosis. I. Preliminary report on geographic distribution, with special reference to Mariana Islands, including clinical and pathologic observation. Neurology 4: 355–378

    PubMed  CAS  Google Scholar 

  7. 7.

    Mulder DW, Kurland LT, Irriarte LLG (1954) Neurologic disease on the island of Guam. U.S. Armed Forces Med J 5: 1724–1739

    PubMed  CAS  Google Scholar 

  8. 8.

    Murakami N (1980) A study on the natural history of amyotrophic lateral sclerosis in Japan and Guam. Nagoya-Igaku 103: 154–163

    Google Scholar 

  9. 9.

    Yase Y, Chen KM, Brody JA, Toyokura Y (1978) An historical note on the Parkinsonism-dementia complex of Guam. Neuro Med (Tokyo) 8: 583–589

    Google Scholar 

Download references

Author information



Corresponding author

Correspondence to N. Murakami.

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Murakami, N. Parkinsonism-dementia complex on Guam — Overview of clinical aspects. J Neurol 246, II16–II18 (1999).

Download citation

Key words

  • Parkinsonism-dementia complex (PDC)
  • Amyotrophic lateral sclerosis (ALS)
  • Lytico-Bodig