http://brainblogger.com/2013/01/05/r...ymptoms-early/
pre-motor symptoms

The paradox is that by the time these overt symptoms develop and a confirmed diagnosis is arrived at based on them, the patient’s motor abilities are already significantly compromised. The loss of motor control results into loss of personal independence altering the quality of life considerably. Therefore the search for early symptoms of Parkinson’s disease which precede loss of motor functions is a vital topic in current neuroscience research.

A long-term research study, known as the Honolulu-Asia Aging Study (HAAS) has helped to shed some light on the development and early signs of Parkinson’s disease. In this study, 8,006 Japanese-American men were examined periodically for 40 years. From 1991, cases of Parkinson’s disease started emerging in this group. Patients were diagnosed as Parkinson’s patients based on the independent diagnoses provided by two neurologists. Brain autopsies have also been performed on deceased patients to ascertain the formation of incidental Lewy bodies — a characteristic cellular feature of Parkinson’s disease.

The study has helped to identify some behavioral patterns in patients that precede the motor symptoms of PD. Excessive day time sleepiness and loss of the sense of smell emerged as two characteristics of patients who developed PD later in life. Constipation was also identified as a feature that indicated greater risk for development of PD in this groups of patients.

One of the major findings from this prospective study:Low LDL cholesterol is associated with increased risk of PD:


Mov Disord. 2008 May 15;23(7):1013-8. doi: 10.1002/mds.22013.
Low LDL cholesterol and increased risk of Parkinson's disease: prospective results from Honolulu-Asia Aging Study.
Huang X, Abbott RD, Petrovitch H, Mailman RB, Ross GW.

Low-density lipoprotein cholesterol (LDL-C) levels are suggested to be associated inversely with Parkinson's disease (PD). To test the hypothesis that LDL-C levels may increase PD risk, we studied a prospective cohort of 3,233 men (Honolulu-Asia Aging Study) for whom the LDL-C from fasting lipid profiles was obtained during 1991 to 1993. The cohort was followed longitudinally until 2001 for incident Parkinson's cases. During follow-up, 41 men developed PD (18.4/10,000 person-years). Although the incidence of PD increased with decreasing LDL-C in a dose-dependent manner, the association was only significant for men aged 71 to 75 years. In the latter group, risk of PD declined from 38.5/10,000 person-years in men with LDL-C levels <80 mg/dl to less than 9/10,000 person-years for concentrations that were > or =140 mg/dl. After adjustment for age, smoking, coffee intake, and other factors, the relative odds of PD for men at the 80th versus the 20th percentile of LDL-C (135 vs. 85 mg/dl) was 0.4 (95% confidence interval: 0.2, 0.9). This prospective study supports the hypothesis that low LDL-C is associated with an increased risk of PD. Although confirmation is required, the underlying mechanisms may be useful in understanding key aspects of PD.
PMID: 18381649 [PubMed - indexed for MEDLINE]