Author response: Early weight loss in neurodegenerative disorders could be related to increased protein metabolism in the brain
Angus D.Macleod, Clinical Lecturer in Neurology, University of Aberdeen
Phyo K.Myint, Professor of Old Age Medicine, University of Aberdeen
Carl E.Counsell, Reader (Clinical) in Neurology, University of Aberdeen
Submitted April 13, 2018
We thank Dr. Marinelli for the comment on our article, [1] and agree that further research into the relationship between protein misfolding and weight loss in Parkinson disease (PD) is needed. Furthermore, several other potential mechanisms for weight loss deserve further study, including other aspects of brain metabolism, whole-body metabolic rate, appetite regulation, and food-related reward mechanisms.
Evidence for increased brain temperature in PD is limited. One study of 5 patients with PD of unusually young onset (mean age at onset = 33.8) showed increased brain temperature in several regions compared to controls; another study of 10 patients, from the same institution, demonstrated increased brain temperature in one brain region. [2,3] Both studies used MR spectroscopy to measure brain temperature which, to our knowledge, has not been validated in neurodegenerative diseases. Conceivably, other cerebral metabolic changes could explain the MR spectroscopy differences. Despite these caveats, we agree that further research into brain temperature and weight loss would be useful. We recommend these studies should include (i) appropriate validation brain temperature measurement methods, (ii) prospective analysis of weight loss, (iii) pre-specified analysis of specific sites of brain temperature measurement.
Advancing our understanding of the mechanisms of weight loss in PD may help design appropriate interventions to prevent or reverse weight loss for evaluation in randomized controlled trials.
1. Cumming K, Macleod AD, Myint PK, Counsell CE. Early weight loss in parkinsonism predicts poor outcomes: Evidence from an incident cohort study. Neurology 2017;89:2254-2261.
2. Rango M, Piatti M, Di Fonzo A, et al. Abnormal brain temperature in early-onset Parkinson's disease. Mov Disord 2016;31:425-426.
3. Rango M, Arighi A, Bonifati C, Bresolin N. Increased brain temperature in Parkinson’s disease. Neuroreport 2012;23:129-133.
We thank Dr. Marinelli for the comment on our article, [1] and agree that further research into the relationship between protein misfolding and weight loss in Parkinson disease (PD) is needed. Furthermore, several other potential mechanisms for weight loss deserve further study, including other aspects of brain metabolism, whole-body metabolic rate, appetite regulation, and food-related reward mechanisms.
Evidence for increased brain temperature in PD is limited. One study of 5 patients with PD of unusually young onset (mean age at onset = 33.8) showed increased brain temperature in several regions compared to controls; another study of 10 patients, from the same institution, demonstrated increased brain temperature in one brain region. [2,3] Both studies used MR spectroscopy to measure brain temperature which, to our knowledge, has not been validated in neurodegenerative diseases. Conceivably, other cerebral metabolic changes could explain the MR spectroscopy differences. Despite these caveats, we agree that further research into brain temperature and weight loss would be useful. We recommend these studies should include (i) appropriate validation brain temperature measurement methods, (ii) prospective analysis of weight loss, (iii) pre-specified analysis of specific sites of brain temperature measurement.
Advancing our understanding of the mechanisms of weight loss in PD may help design appropriate interventions to prevent or reverse weight loss for evaluation in randomized controlled trials.
1. Cumming K, Macleod AD, Myint PK, Counsell CE. Early weight loss in parkinsonism predicts poor outcomes: Evidence from an incident cohort study. Neurology 2017;89:2254-2261.
2. Rango M, Piatti M, Di Fonzo A, et al. Abnormal brain temperature in early-onset Parkinson's disease. Mov Disord 2016;31:425-426.
3. Rango M, Arighi A, Bonifati C, Bresolin N. Increased brain temperature in Parkinson’s disease. Neuroreport 2012;23:129-133.
For disclosures, please contact the editorial office at journal@neurology.org.