memory; impact of small vessel disease on cognition; role of cerebrovascular disease in Alzheimer’s and other dementias; vitamin D and cogniton, cognitive sequelae of stroke and concussion
My research focuses primarily on the overlap between dementia and stroke and, in particular, trying to understand how disease affecting the small blood vessels in the brain (i.e., “small vessel disease”) and stroke risk factors contribute to the development of cognitive impairment and dementia. A recent paper (Pettersen JA et al Archives of Neurology 2008) examined the prevalence and topography of two markers of small vessel disease–microbleeds and white matter disease–and their relationship to cognition in patients with Alzheimer’s and revealed that both manifestations of small vessel disease are common, tend to co-occur, and are most pronounced in the posterior aspects of the brain, particularly the occipital lobes (i.e., towards the back of the brain). This latter revelation had not been described previously in an Alzheimer’s population and was cited in the recommendations paper on amyloid-related imaging abnormalities by the Alzheimer’s Assn. Research Roundtable Workgroup (Alzheimer’s & Dementia 2011;7:367-385). Another recent project revealed the novel finding that tortuosity of the internal carotid artery–related to atherosclerosis, or “hardening of the arteries”–can potentially impact and contribute to shrinkage of the cholinergic basal forebrain (i.e., an area of the brain which supplies acetylcholine, a neurotransmitter important for cognition) and is associated with worse cognition in Alzheimer’s patients, providing yet another way in which cerebrovascular disease (i.e., stroke) and Alzheimer’s dementia interact.
Another area of research concerns the role of vitamin D in cognition and dementia. A 3-phase pilot study is currently underway examining the association between vitamin D levels and cognitive functioning during the summer (1st Phase) and winter (2nd Phase) months among residents of Northern BC followed by a randomized trial of vitamin D supplementation (low dose vs high dose)(3rd Phase). The results of this study could have major implications for public health, particularly if supplementation is found to have a significant effect on cognitive functioning.
There is emerging evidence that regular exercise is associated with a decreased risk of cognitive decline. I practice what I preach and engage in regular activity including cross-country skiing, running, canoeing and cycling.
Published Refereed Papers
1.Sharp ME, Chew JB, Heran MKS, Pettersen JA. Delayed restricted diffusion in carbon monoxide leukoencephalopathy. Can J Neurol Sci 2012 In Press.
2.Pettersen JA, Patry DG, St George-Hyslop PH, Curry B. Variant Alzheimer disease with spastic paraparesis: A rare presenilin-1 mutation. Can J Neurol Sci 2011;38(4):659-661.
3.Alexander LD, Pettersen JA, Hopyan JJ, Sahlas DJ, Black SE. Long-term prediction of functional outcome after stroke using the Alberta Stroke Program Early Computed Tomography Score in the subacute stage. J Stroke Cerebrovas Dis 2011. In Press.
4.Friedman Y, Pettersen JA, Aviv RA, Murray BJ. The “eye sign” in acute stroke: Not necessarily poor outcome. JNNP 2009 Mar;80(3):291.
5.Huynh H, Murphy B, Pettersen JA, Mallia G, Tu H, Sahlas DJ, Black SE, Lee T, Aviv RI. The role of CT perfusion in quantifying extent of small vessel ischemia. AJNR 2008 Nov;29(10):1831-1836.
6.Pettersen JA, Sathiyamoorthy G, Gao FQ, Szilagyi G, Nadkarni NK, St. George-Hyslop P, Rogaeva E, Black SE. Microbleed Topography, Leukoaraiosis, and Cognition in probable Alzheimer disease from the Sunnybrook Dementia Study. Archives of Neurology June 2008;65(6).
7.Pettersen JA, Aviv RI, Black SE, Fox AJ, Lim A, Murray BJ. Global hemispheric CT hypoperfusion may differentiate headache with associated neurological deficits and lymphocytosis (HaNDL) from acute stroke. Stroke 2008;39(2):492-493.
8.Pettersen JA, Pexman JHW, Barber PA, Demchuk AM, Buchan AM, Hill MD on behalf of the CASES Investigators. Insular cortical ischemia does not independently predict acute hypertension or acute hyperglycaemia within three hours of onset. J Neurol, Neurosurg, Psych 2006;77:885-887.
9.Pettersen JA, Jones G, Worthington C, Krentz H, Keppler OT, Hoke A, Gill MJ, Power C. Sensory neuropathy in HIV/AIDS patients highly exposed to antiretroviral therapy: Protease inhibitor-mediated neurotoxicity. Ann Neurol. 2006;59:816-824.
10.Pettersen JA, Hill MD, Demchuk AM, Morrish W, Hudon ME, Hu W, Wong J, Barber PA, Buchan AM. Intra-arterial thrombolysis for retinal artery occlusion: The Calgary experience. Can J Neurol Sci, 2005;32:507-511.
11.Pettersen JA, Hudon ME. Hill MD. Intra-arterial thrombolysis in acute ischemic stroke: A review of pharmacologic approaches. Expert Rev Cardiovasc Ther, 2004 2(2): 89-103.
12.Pettersen JA, Zochodne DW, Bell RB, Martin L, Hill MD. Refractory neurosarcoidosis responding to infliximab. Neurology 2002, 59(10): 1660-1661.
13.Pettersen JA. Does rugby headgear prevent concussion?: Attitudes of Canadian players and coaches. Br J Sports Med, 2002; 36:19-22.
14.Pettersen JA, Skelton RW. Glucose enhances long-term declarative memory in mildly head-injured varsity rugby players. Psychobiology, 28(1): 81-89.
Published Abstracts / Notes (Last 5 years only)
1.Duke CL, Fontes S, Purnell J, Pettersen JA. Vitamin D insufficiency in northern BC and effects on cognition: D-COG 1st phase results. Can J Neurol Sciences 2011;38(3)(Suppl 1): S51.
2.Sharp ME, Pettersen JA. Prolonged restricted diffusion white matter changes in carbon monoxide delayed encephalopathy. Neurology 2011;76(9) Suppl 4:A313-4.
3.Chan PC, Navaranjan D, Philips AM, Pettersen JA, Ganda, A, Black SE. Serum biomarkers in white matter disease: A preliminary study. Clinical Biochemistry Journal 2011.
4.Sharp ME, Pettersen JA. Prolonged restricted diffusion white matter changes in carbon monoxide delayed encephalopathy. Can J Neurol Sciences 2010; 37(3;Suppl1):S54.
5.Pettersen JA, Black SE, Naqvi S, Jin S, Murray BJ. Nocturnal limb movements are correlated with cerebral white matter disease burden. Cerebrovascular Diseases 2009;27(suppl 6):201.
6.Pettersen JA, Black SE, Naqvi S, Jin S, Murray BJ. Objective sleep quality and nocturnal limb movements are correlated with cerebral white matter disease burden. Can J Neurol Sciences 2008 35(2; Suppl 1): S61.
7.Ramirez J, Pettersen JA, Black SE. Diffusion tensor imaging of normal appearing white matter in Alzheimer’s disease and normal controls: Working memory and white matter integrity in the parietal lobes. Brain and Cognition March 2008.
8.Pettersen JA, Gao F-Q, Black SE. Carotid artery bifurcation tortuosity as a possible contributor to substantia innominata atrophy and executive dysfunction in Alzheimer disease. Stroke 2008;39(2): 682-683.
9.Huynh H, Murphy B, Pettersen JA, Mallia G, Tu H, Sahlas DJ, Black SE, Lee T, Aviv RI. The role of CT perfusion in quantifying extent of small vessel ischemia. Stroke 2008;39(2):683.
10.Buck BH, Gladstone DJ, Mallia G, Black SE, Sahlas DJ, Hopyan J, Pettersen JA, Symons S, Aviv RI. Acute stroke CT perfusion imaging profiles for predicting outcome following early intravenous thrombolytic therapy. Stroke 2008;39(2):590.
11.Pettersen JA, Sathiyamoorthy G, Gao FQ, Szilyagi G, Nadkarni NK, St. George-Hyslop P, Rogaeva, E, Black SE. Microbleed topography, leukoaraiosis, and cognition in probable Alzheimer disease from the Sunnybrook dementia study. Geriatrics Today: Canadian Journal of Geriatric Medicine & Psychiatry Sept 2007.
12.Pettersen JA, Bilbao JM, Spence JD, Fox AJ, Aviv RI, Axelrod T, Black SE. Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) rapidly accelerated by hypotension post-trauma. Geriatrics Today: Canadian Journal of Geriatric Medicine & Psychiatry Sept 2007.
13.Pettersen JA, Sathiyamoorthy G, Gao FQ, Szilagyi G, Nadkarni NK, Black SE. Frequency and lobar topography of cerebral microbleeds in probable Alzheimer disease from the Sunnybrook Dementia Study. Stroke 2007;38(2):582.
14.Pettersen JA, O’Ferrall E, Al-Mekhlafi M, Pillay N, Zochodne DW, Hoyte K, Morrish W, Switzer N, Bell RB. Potential importance of MRI changes in diagnosing sporadic Creutzfeldt-Jakob disease. Can J Neurol Sciences 2006;33(Suppl 1):S37.