Science

This image is of a slide of brain cells showing a Lewy body.

Lewy bodies are microscopic protein deposits in the brain associated with the death of cells. It is not yet known whether the Lewy bodies are the cause or effect of degeneration of brain cells, but they are thought to be the result of the misfolding of the protein alpha-synuclein. They are present in the brains of people with DLB and Parkinson’s disease.

Click on the hotspots to reveal the information.

A significant difference between the two diseases is the location of the Lewy bodies in the brain. In Parkinson’s they are found mainly in the substantia nigra which is in the mid-brain, whereas in DLB they are more widely distributed throughout the cerebral cortex . Clinically DLB closely resembles the dementia typically associated with Parkinson’s (PDD). If the physical symptoms precede the cognitive symptoms by one year, a diagnosis of Parkinson’s will be made; if the onset of cognitive symptoms precedes or starts at the same time the physical symptoms start it is considered to be DLB.

DLB was thought to be rare until the late 1980s, when advances were made in staining techniques for neurological studies. Lewy bodies were revealed in 10-15 percent of cases of dementia in older people. In 1995 a consortium of international scientists met in Newcastle, England, to agree on clinical and diagnostic criteria for DLB [1]. A second report [2] published in 1999 somewhat modified the criteria. In order to improve diagnostic reliability and sensitivity, the consortium met again in 2005 and agreed to significant amendments [3] in the guidelines. Recommendations for treatment were made and the concept of DLB being part of a spectrum of alpha-synuclein pathologies was postulated. Finally in 2006 the consortium published new guidelines with revised criteria [4].

Lewy bodies are named after Dr Friedrich Heinrich Lewy (1885-1950), a German-born neurologist. In 1912, two years out of medical school and in his first year as Director of the Neuropsychiatric Laboratory at the University of Breslau (now Wroclaw, Poland) Medical School he discovered ‘spherical […] neuronal inclusions’ [5] in the brain of a deceased Parkinson’s patient. Although he had loyally served Germany in World War I in charge of field hospitals in France, Russia, and Turkey, he was later persecuted by his native country for being a Jewish person. With the help of the American Friends Service Committee he and his wife, Flora, emigrated to the United States in 1934. Soon established as an eminent neurologist, he was appointed professor at the University of Pennsylvania and was a founder of the American Neurological Society. Dr Lewy became an US citizen, changed his name to Frederick Henry Lewey and served in the US army against Germany in the Second World War.

References

  1. McKeith I.G., Perry E.K. and Perry R.H. Report of the second dementia with Lewy body international workshop, Neurology 53(5) (1999), 902-905
  2. McKeith I.G., Dickson D., Emre M. et al., Dementia with Lewy Bodies: Diagnosis and Management: Third Report of the DLB Consortium, Neurology 65 (12) (2005), 1863-1872
  3. McKeith I.G., Consensus guidelines for the clinical and pathologic diagnosis of dementia with Lewy bodies (DLB): Report of the Consortium on DLB International Workshop, J Alzheimers Dis (2006) Aug:9 (3 Suppl), 417-23
  4. Lewy F.H., Paralysis agitans: pathologische Anatomie. Handbuch der Neurologie (Springer:Berlin, 1912) 3, 920-33