I graduated from St Mary's Hospital Medical School (First Class BSc 1993, MB BS with Honours in 1996), and studied Neurology at the National Hospital for Neurology and Neurosurgery, Queen Square, and the Royal Free Hospital. I completed my MD at the Dementia Research Centre using MRI to track progression in Alzheimer's disease in 2004. I was appointed HEFCE Clinical Senior Lecturer at UCL & Honorary Consultant at UCLH in 2009; Reader in Clinical Neurology in 2004; and Professor of Neurology in 2007. 

I run a weekly multi-discliplinary Cognitive Disorders Clinic as part of the integrated Cognitive Disorders Service at Queen Square, and oversee the dementia CSF diagnostic service

I have published >330 papers on dementia and ageing. I co-edited the Oxford Textbook of Cognitive Neurology and Dementia - 2017 BMA Neurology Book of the Year - and authored the chapter on Alzheimer's disease and other dementias for the Oxford Textbook of Medicine. I have grant funding of >£50M, including >£10M as PI.

I am emeritus chair of the Advisory Council of the Alzheimer’s Association International Society to Advance Alzheimer’s Research and Treatment (ISTAART); Chair of the Association of British Neurologists (ABN) Cognitive Disorders Advisory Group; UK representative to the European Academy of Neurology Dementia panel; and serve on American Academy of Neurology Regional Conference Committee. I am Fellow of the EAN, Fellow of the AAN. 

I participated in the development and publication of European Guidelines for the co-prescription of cholinesterase inhibitors and Memantine in moderate-severe Alzheimer’s disease. I serve on a number of Pharmaceutical advisory boards.

In 2019 I was appointed as the inaugural Chief Medical Office to Alzheimer's Research UK, tEuope's biggest dementia research charity.