Michael D Fox

Michael D Fox
Brigham and Women's Hospital | BWH · Department of Neurology

MD, PhD

About

174
Publications
66,727
Reads
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Introduction
Michael Fox, MD, PhD, is the Director of the Center for Brain Circuit Therapeutics at Brigham and Women's Hospital and Associate Professor of Neurology at Harvard Medical School
Additional affiliations
January 2014 - present
Harvard Medical School
Position
  • Director of the Laboratory for Brain Network Imaging and Modulation
January 2014 - present
Harvard Medical School
Position
  • Assistant Professor of Neurology
January 2008 - present
Massachusetts General Hospital
Position
  • Research Neuroscientist

Publications

Publications (174)
Article
Full-text available
Brain stimulation, a therapy increasingly used for neurological and psychiatric disease, traditionally is divided into invasive approaches, such as deep brain stimulation (DBS), and noninvasive approaches, such as transcranial magnetic stimulation. The relationship between these approaches is unknown, therapeutic mechanisms remain unclear, and the...
Article
Recently, multifocal transcranial current stimulation (tCS) devices using several relatively small electrodes have been used to achieve more focal stimulation of specific cortical targets. However, it is becoming increasingly recognized that many behavioral manifestations of neurological and psychiatric disease are not solely the result of abnormal...
Article
Transcranial magnetic stimulation (TMS) to the left dorsolateral prefrontal cortex (DLPFC) is used clinically for the treatment of depression however outcomes vary greatly between patients. We have shown that average clinical efficacy of different left DLPFC TMS sites is related to intrinsic functional connectivity with remote regions including the...
Article
Transcranial magnetic stimulation (TMS) to the left dorsolateral prefrontal cortex (DLPFC) is used clinically for the treatment of depression. However, the antidepressant mechanism remains unknown and its therapeutic efficacy remains limited. Recent data suggest that some left DLPFC targets are more effective than others; however, the reasons for t...
Article
Full-text available
Drug addiction is a public health crisis for which new treatments are urgently needed. In rare cases, regional brain damage can lead to addiction remission. These cases may be used to identify therapeutic targets for neuromodulation. We analyzed two cohorts of patients addicted to smoking at the time of focal brain damage (cohort 1 n = 67; cohort 2...
Article
Objective Chronic tinnitus is a clinical symptom that affects 10% to 15% of the adult population. Repetitive transcranial magnetic stimulation (rTMS) is a promising treatment, but significant heterogeneity exists in the treatment outcomes and stimulation parameters. In this study, we perform a qualitative systematic review to determine if there is...
Chapter
Despite the prevalence of anhedonia across multiple psychiatric disorders, its relevance to treatment selection and prognostication can be unclear (Davey et al., Psychol Med 42(10):2071-81, 2012). Given the challenges in pharmacological and psychosocial treatment, there has been increasing attention devoted to neuroanatomically-targeted treatments....
Article
Full-text available
Lesion network mapping is a neuroimaging technique that explores the network of regions functionally connected to lesions causing a common syndrome. The technique uses resting state functional connectivity from large databases of healthy individuals, i.e., connectomes, and has allowed for important insight into the potential network mechanisms unde...
Article
Mapping human brain function is a long-standing goal of neuroscience that promises to inform the development of new treatments for brain disorders. Early maps of human brain function were based on locations of brain damage or brain stimulation that caused a functional change. Over time, this approach was largely replaced by technologies such as fun...
Article
Full-text available
There is growing evidence that placebo effects can meaningfully modulate the brain. However, there has been little consideration of whether these changes may overlap with regions/circuits targeted by depression treatments and what the implications of this overlap would be on measuring efficacy in placebo-controlled clinical trials. In this systemat...
Article
Objectives Delirium is common among patients with acute stroke and associated with worse outcomes. However, it is unclear which stroke locations or types are most associated with delirium. Materials and Methods We systematically reviewed studies of patients with acute stroke that reported stroke locations and types by delirium status. We included...
Preprint
Full-text available
Emotion regulation has been linked to specific brain networks based on functional neuroimaging. We found that damage to these networks was associated with emotion regulation impairment in patients following focal brain injury (n = 167). Next, we used this lesion dataset to derive a de novo brain network for emotion regulation, which was defined by...
Article
Stroke represents a considerable burden of disease for both men and women. However, a growing body of literature suggests clinically relevant sex differences in the underlying causes, presentations and outcomes of acute ischaemic stroke. In a recent study, we reported sex divergences in lesion topographies: specific to women, acute stroke severity...
Article
Background Repetitive transcranial magnetic stimulation (rTMS) is entering wider use as a therapeutic intervention for many psychiatric illnesses. The efficacy of this therapeutic intervention may depend on accurately localizing target brain regions. Recent work investigating whole-brain maps of circuits associated with depression and its successfu...
Article
Deep brain stimulation (DBS) is an effective treatment for Parkinson’s disease but can be complicated by side-effects such as cognitive decline. There is often a delay before this side-effect is apparent and the mechanism is unknown, making it difficult to identify patients at risk or select appropriate DBS settings. Here, we test whether connectiv...
Article
Deep brain stimulation (DBS) is an effective treatment for Parkinson’s disease but can be complicated by side-effects such as cognitive decline. There is often a delay before this side-effect is apparent and the mechanism is unknown, making it difficult to identify patients at risk or select appropriate DBS settings. Here, we test whether connectiv...
Article
Full-text available
Brain lesions are a rare cause of tic disorders. However, they can provide unique insights into tic pathophysiology and can also inform on possible neuromodulatory therapeutic targets. Based on a systematic literature review, we identified 22 cases of tics causally attributed to brain lesions and employed ‘lesion network mapping’ to interrogate whe...
Article
Background and Objectives Disorders of consciousness, EEG background suppression and epileptic seizures are associated with poor outcome after cardiac arrest. Our objective was to identify the distribution of diffusion MRI-measured anoxic brain injury after cardiac arrest and to define the regional correlates of disorders of consciousness, EEG back...
Chapter
Brain lesions, such as the ones caused by stroke or tumors, disrupt normal brain function and cause a wide spectrum of neurological and psychiatric symptoms. Studying brain lesions has formed the foundation for localization of symptoms throughout the history of neurology, providing unique causal evidence. In exceedingly rare cases, spontaneous brai...
Chapter
Deep brain stimulation (DBS) is just one of many ways to modulate brain circuits. Noninvasive brain stimulation tools, such as transcranial magnetic stimulation and transcranial direct current stimulation may provide insights that are relevant for understanding and improving DBS outcomes. These different brain stimulation modalities target differen...
Article
Objective Blindsight is a disorder where brain injury causes loss of conscious but not unconscious visual perception. Prior studies have produced conflicting results regarding the neuroanatomical pathways involved in this unconscious perception. Methods We performed a systematic literature search to identify lesion locations causing visual field l...
Article
Full-text available
Damage to specific brain circuits can cause specific neuropsychiatric symptoms. Therapeutic stimulation to these same circuits may modulate these symptoms. To determine whether these circuits converge, we studied depression severity after brain lesions (n = 461, five datasets), transcranial magnetic stimulation (n = 151, four datasets) and deep bra...
Article
Full-text available
At the group-level, deep brain stimulation leads to significant therapeutic benefit in a multitude of neurological and neuropsychiatric disorders. At the single-patient level, however, symptoms may sometimes persist despite “optimal” electrode placement at established treatment coordinates. This may be partly explained by limitations of disease-cen...
Article
Full-text available
Advances in computational neuroimaging techniques have expanded the armamentarium of imaging tools available for clinical applications in clinical neuroscience. Non-invasive, in vivo brain MRI structural and functional network mapping has been used to identify therapeutic targets, define eloquent brain regions to preserve, and gain insight into pat...
Preprint
Full-text available
At the group-level, deep brain stimulation leads to significant therapeutic benefit in a multitude of neurological and neuropsychiatric disorders. At the single-patient level, however, symptoms may sometimes persist despite "optimal" electrode placement at established treatment coordinates. This may be partly explained by limitations of disease-cen...
Book
Full-text available
The book is available here: https://www.elsevier.com/books/connectomic-deep-brain-stimulation/horn/978-0-12-821861-7
Article
Background Over 80% of the global population consider themselves religious with even more identifying as spiritual, but the neural substrates of spirituality and religiosity remain unresolved. Methods In two independent brain lesion datasets (N1=88; N2=105), we apply lesion network mapping to test whether lesion locations associated with spiritual...
Preprint
Full-text available
Introduction Disorders of consciousness, EEG background suppression and epileptic seizures are associated with poor outcome after cardiac arrest. The underlying patterns of anoxic brain injury associated with each remain unknown. Our objective was to identify the distribution of anoxic brain injury after cardiac arrest, as measured with diffusion M...
Article
Full-text available
The brain regions responsible for hallucinations remain unclear. We studied 89 brain lesions causing hallucinations using a recently validated technique termed lesion network mapping. We found that hallucinations occurred following lesions to a variety of different brain regions, but these lesion locations fell within a single functionally connecte...
Article
Full-text available
Whether antagonistic brain states constitute a fundamental principle of human brain organization has been debated over the past decade. Some argue that intrinsically anti-correlated brain networks in resting-state functional connectivity are an artifact of preprocessing. Others argue that anti-correlations are biologically meaningful predictors of...
Article
Objective Approximately 50% of patients with Tuberous Sclerosis Complex develop infantile spasms, a sudden‐onset epilepsy syndrome associated with poor neurological outcomes. While an increased burden of tubers confers an elevated risk of infantile spasms, it remains unknown whether some tuber locations confer higher risk than others. Here, we test...
Article
Interhemispheric inhibition (IHI) is a dual-site TMS protocol measuring inhibitory interactions between the primary motor cortices (M1). IHI is performed by applying an initial conditioning stimulus followed by a test stimulus to the contralateral M1. Conventionally, the response in the contralateral hand to the conditioning TMS pulse is either not...
Cover Page
Full-text available
Four deep brain stimulation electrodes implanted for treatment of obsessive compulsive disorder within the anterior limb of the thalamus and nucleus accumbens (blue) and anteromedial subthalamic nucleus (orange). Stimulation of fibertracts associated with positive clinical outcome are colored in red (anterior limb of the internal capsule, „associat...
Article
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This article is based on a consensus conference, promoted and supported by the International Federation of Clinical Neurophysiology (IFCN), which took place in Siena (Italy) in October 2018. The meeting intended to update the ten-year-old safety guidelines for the application of transcranial magnetic stimulation (TMS) in research and clinical setti...
Article
Full-text available
BACKGROUND Although mania is characteristic of bipolar disorder, it can also occur following focal brain damage. Such cases may provide unique insight into brain regions responsible for mania symptoms and identify therapeutic targets. METHODS Lesion locations associated with mania were identified using a systematic literature search (n = 41) and ma...
Article
Full-text available
The process of altering neural activity – neuromodulation – has long been used to treat patients with brain disorders and answer scientific questions. Deep brain stimulation in particular has provided clinical benefit to over 150,000 patients. However, our understanding of how neuromodulation impacts the brain is evolving. Instead of focusing on th...
Article
Full-text available
Transcranial magnetic stimulation (TMS) is an effective treatment for depression but is limited in that the optimal therapeutic target remains unknown. Early TMS trials lacked a focal target, and thus positioned the TMS coil over the prefrontal cortex using scalp measurements. Over time, it became clear that this method leads to variation in the st...
Article
Large-scale brain networks are often described using resting-state functional magnetic resonance imaging (fMRI). However, the blood oxygenation level-dependent (BOLD) signal provides an indirect measure of neuronal firing and reflects slow-evolving hemodynamic activity that fails to capture the faster timescale of normal physiological function. Her...
Article
Objective: Treatment of different depression symptoms may require different brain stimulation targets with different underlying brain circuits. The authors sought to identify such targets, which could improve the efficacy of therapeutic brain stimulation and facilitate personalized therapy. Methods: The authors retrospectively analyzed two indep...
Article
Inconsistent findings from migraine neuroimaging studies have limited attempts to localize migraine symptomatology. Novel brain network mapping techniques offer a new approach for linking neuroimaging findings to a common neuroanatomical substrate and localizing therapeutic targets. In this study, we attempted to determine whether neuroanatomically...
Article
Full-text available
Brain lesions can provide unique insight into the neuroanatomical substrate of human consciousness. For example, brainstem lesions causing coma map to a specific region of the tegmentum. Whether specific lesion locations outside the brainstem are associated with loss of consciousness (LOC) remains unclear. Here, we investigate the topography of cor...
Article
Full-text available
Damage to the right fusiform face area can disrupt the ability to recognize faces, a classic example of how damage to a specialized brain region can disrupt a specialized brain function. However, similar symptoms can arise from damage to other brain regions, and face recognition is now thought to depend on a distributed brain network. The extent of...
Article
Diverse but complementary methodologies are required to uncover the complex determinants and pathophysiology of freezing of gait. To develop future therapeutic avenues, we need a deeper understanding of the disseminated functional-anatomic network and its temporally associated dynamic processes. In this targeted review, we will summarize the latest...
Article
Full-text available
Objective: Holmes' tremor is a debilitating movement disorder with limited treatment options. Lesions causing Holmes' tremor can occur in multiple different brain locations, leaving the neuroanatomical substrate unclear. Here we test whether lesion locations that cause Holmes' tremor map to a connected brain circuit and whether this circuit might...
Article
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The annual deep brain stimulation (DBS) Think Tank aims to create an opportunity for a multidisciplinary discussion in the field of neuromodulation to examine developments, opportunities and challenges in the field. The proceedings of the Sixth Annual Think Tank recapitulate progress in applications of neurotechnology, neurophysiology, and emerging...
Article
Full-text available
Human memory is thought to depend on a circuit of connected brain regions, but this hypothesis has not been directly tested. We derive a human memory circuit using 53 case reports of strokes causing amnesia and a map of the human connectome (n = 1000). This circuit is reproducible across discovery (n = 27) and replication (n = 26) cohorts and speci...
Article
Background: Focal brain lesions can lend insight into the causal neuroanatomical substrate of depression in the human brain. However, studies of lesion location have led to inconsistent results. Methods: Five independent datasets with different lesion etiologies and measures of postlesion depression were collated (N = 461). Each 3-dimensional le...
Article
Full-text available
Dementia is a common and devastating symptom of Parkinson’s disease but the anatomical substrate remains unclear. Some evidence points towards hippocampal involvement but neuroimaging abnormalities have been reported throughout the brain and are largely inconsistent across studies. Here, we test whether these disparate neuroimaging findings for Par...