Medicine and Health Sciences Commons^™

Multifocal Myoclonus As A Presentation Of Levetiracetam Toxicity., Mei Bou Nasif, Shweta Varade, Mohamad Z. Koubeissi

Neurology Faculty Publications

No abstract provided.

Hypothalamic Hamartomas: Evolving Understanding And Management., Nathan T. Cohen, J Helen Cross, Alexis Arzimanoglou, Samuel F Berkovic, John F Kerrigan, Ilene Penn Miller, Erica Webster, Lisa Soeby, Arthur Cukiert, Dale K Hesdorffer, Barbara L Kroner, Clifford B Saper, Andreas Schulze-Bonhage, William D. Gaillard

Neurology Faculty Publications

No abstract provided.

Electromyographic And Joint Kinematic Patterns In Runner's Dystonia., Omar F Ahmad, Pritha Ghosh, Christopher Stanley, Barbara Karp, Mark Hallett, Codrin Lungu, Katharine Alter

Neurology Faculty Publications

Runner’s dystonia (RD) is a task-specific focal dystonia of the lower limbs that occurs when running. In this retrospective case series, we present surface electromyography (EMG) and joint kinematic data from thirteen patients with RD who underwent instrumented gait analysis (IGA) at the Functional and Biomechanics Laboratory at the National Institutes of Health. Four cases of RD are described in greater detail to demonstrate the potential utility of EMG with kinematic studies to identify dystonic muscle groups in RD. In these cases, the methodology for muscle selection for botulinum toxin therapy and the therapeutic response is discussed. Lateral heel whip, …

Why West? Comparisons Of Clinical, Genetic And Molecular Features Of Infants With And Without Spasms., Anne T Berg, Samya Chakravorty, Sookyong Koh, Zachary M Grinspan, Renée A Shellhaas, William D Gaillard, +Several Additional Authors

Neurology Faculty Publications

Infantile spasms are the defining seizures of West syndrome, a severe form of early life epilepsy with poorly-understood pathophysiology. We present a novel comparative analysis of infants with spasms versus other seizure-types and identify clinical, etiological, and molecular-genetic factors preferentially predisposing to spasms. We compared ages, clinical etiologies, and associated-genes between spasms and non-spasms groups in a multicenter cohort of 509 infants (

Absolute Lymphocyte And Neutrophil Counts In Neonatal Ischemic Brain Injury., Jessica M Povroznik, Elizabeth B Engler-Chiurazzi, Tania Nanavati, Paola Pergami

Neurology Faculty Publications

Objectives: This study aimed to identify differences in absolute neutrophils, lymphocytes, and neutrophil-to-lymphocyte ratio between neonates with two forms of ischemic brain injury, hypoxic-ischemic encephalopathy, and acute ischemic stroke, compared to controls. We also aimed to determine whether this neutrophil/lymphocyte response pattern is associated with disease severity or is a consequence of the effects of total-body cooling, an approved treatment for moderate-to-severe hypoxic-ischemic encephalopathy.

Methods: A retrospective chart review of 101 neonates with hypoxic-ischemic encephalopathy + total-body cooling (n = 26), hypoxic-ischemic encephalopathy (n = 12), acute ischemic stroke (n = 15), and transient tachypnea of the newborn (n = …

A Checklist For Clinical Trials In Rare Disease: Obstacles And Anticipatory Actions-Lessons Learned From The For-Dmd Trial, R Crow, K Hart, M Mcdermott, R Tawil, W Martens, Mathula Thangarajh, +Several Additional Authors

Neurology Faculty Publications

Background: Trials in rare diseases have many challenges, among which are the need to set up multiple sites in different countries to achieve recruitment targets and the divergent landscape of clinical trial regulations in those countries. Over the past years, there have been initiatives to facilitate the process of international study set-up, but the fruits of these deliberations require time to be operationally in place. FOR-DMD (Finding the Optimum Steroid Regimen for Duchenne Muscular Dystrophy) is an academic-led clinical trial which aims to find the optimum steroid regimen for Duchenne muscular dystrophy, funded by the National Institutes of Health (NIH) …

X-Linked Hypomyelination With Spondylometaphyseal Dysplasia (H-Smd) Associated With Mutations In Aifm1., Noriko Miyake, Nicole I Wolf, Ferdy K Cayami, Joanna Crawford, Annette Bley, Dorothy Bulas, Ryan J Taft, Adeline Vanderver, +Several Additional Authors

Neurology Faculty Publications

An X-linked condition characterized by the combination of hypomyelinating leukodystrophy and spondylometaphyseal dysplasia (H-SMD) has been observed in only four families, with linkage to Xq25-27, and recent genetic characterization in two families with a common AIFM1 mutation. In our study, 12 patients (6 families) with H-SMD were identified and underwent comprehensive assessment accompanied by whole-exome sequencing (WES). Pedigree analysis in all families was consistent with X-linked recessive inheritance. Presentation typically occurred between 12 and 36 months. In addition to the two disease-defining features of spondylometaphyseal dysplasia and hypomyelination on MRI, common clinical signs and symptoms included motor deterioration, spasticity, tremor, …

Ufm1 Founder Mutation In The Roma Population Causes Recessive Variant Of H-Abc., Eline M C Hamilton, Enrico Bertini, Luba Kalaydjieva, Bharti Morar, Dana Dojčáková, Adeline Vanderver, Recessive H-Abc Research Group.

Neurology Faculty Publications

OBJECTIVE: To identify the gene defect in patients with hypomyelination with atrophy of the basal ganglia and cerebellum (H-ABC) who are negative for TUBB4A mutations.

METHODS: We performed homozygosity mapping and whole exome sequencing (WES) to detect the disease-causing variant. We used a Taqman assay for population screening. We developed a luciferase reporter construct to investigate the effect of the promoter mutation on expression.

RESULTS: Sixteen patients from 14 families from different countries fulfilling the MRI criteria for H-ABC exhibited a similar, severe clinical phenotype, including lack of development and a severe epileptic encephalopathy. The majority of patients had a …

Clinician-Investigator Training And The Need To Pilot New Approaches To Recruiting And Retaining This Workforce., Alison K Hall, Sherry L Mills, P Kay Lund

Neurology Faculty Publications

Clinician–investigators, also called physician–scientists, offer critical knowledge and perspectives that benefit research on basic science mechanisms, improved diagnostic and therapeutic approaches, population and outcomes medicine, health policy, and health services, yet few clinically trained health professionals pursue a research career. Sustaining this workforce requires attention to the unique challenges faced by investigators who must achieve clinical and research competence during training and their careers. These challenges include the duration of required clinical training, limited or discontinuous research opportunities, high levels of educational debt, balancing the dual obligations and rewards of clinical care and research, competition for research funding, and the …

Application Of Rns In Refractory Epilepsy: Targeting Insula., Hai Chen, Patricia Dugan, Derek J Chong, Anli Liu, Werner Doyle, Daniel Friedman

Neurology Faculty Publications

Although responsive neurostimulation (RNS) is approved for treatment of resistant focal epilepsy in adults, little is known about response to treatment of specific cortical targets. We describe the experience of RNS targeting the insular lobe. We identified patients who had RNS implantation with at least one electrode within the insula between April 2014 and October 2015. We performed a retrospective review of preoperative clinical features, imaging, electrocardiogram (EEG), intraoperative electrocorticography (ECoG), and postoperative seizure outcome. Eight patients with at least 6 months of postimplant follow-up were identified. Ictal localization was inconclusive with MRI or scalp EEG findings. Intracranial EEG monitoring …

Functionally Pathogenic Ears2 Variants In Vitro May Not Manifest A Phenotype In Vivo, Nathan Mcneill, Alessia Nasca, Aurelio Reyes, Benjamin Lemoine, Brandi Cantarel, Adeline Vanderver, Raphael Schiffmann, Daniele Ghezzi

Neurology Faculty Publications

Objective: To investigate the genetic etiology of a patient diagnosed with leukoencephalopathy, brain calcifications, and cysts (LCC).

Methods: Whole-exome sequencing was performed on a patient with LCC and his unaffected family members. The variants were subject to in silico and in vitro functional testing to determine pathogenicity.

Results: Whole-exome sequencing uncovered compound heterozygous mutations in EARS2, c.328G>A (p.G110S), and c.1045G>A (p.E349K). This gene has previously been implicated in the autosomal recessive leukoencephalopathy with thalamus and brainstem involvement and high lactate (LTBL). The p.G110S mutation has been found in multiple patients with LTBL. In silico analysis supported pathogenicity …

A Defect In Myoblast Fusion Underlies Carey-Fineman-Ziter Syndrome, S Digioia, S Connors, N. Matsunami, J Cannavino, M Rose, N Gillette, Andrea Gropman, +Several Additional Authors

Neurology Faculty Publications

Multinucleate cellular syncytial formation is a hallmark of skeletal muscle differentiation. Myomaker, encoded by Mymk (Tmem8c), is a well-conserved plasma membrane protein required for myoblast fusion to form multinucleated myotubes in mouse, chick, and zebrafish. Here, we report that autosomal recessive mutations in MYMK (OMIM 615345) cause Carey-Fineman-Ziter syndrome in humans (CFZS; OMIM 254940) by reducing but not eliminating MYMK function. We characterize MYMK-CFZS as a congenital myopathy with marked facial weakness and additional clinical and pathologic features that distinguish it from other congenital neuromuscular syndromes. We show that a heterologous cell fusion assay in vitro and allelic …

Universal Connection Through Art: Role Of Mirror Neurons In Art Production And Reception., Bartlomiej Piechowski-Jozwiak, François Boller, Julien Bogousslavsky

Neurology Faculty Publications

Art is defined as expression or application of human creative skill and imagination producing works to be appreciated primarily for their aesthetic value or emotional power. This definition encompasses two very important elements—the creation and reception of art—and by doing so it establishes a link, a dialogue between the artist and spectator. From the evolutionary biological perspective, activities need to have an immediate or remote effect on the population through improving survival, gene selection, and environmental adjustment, and this includes art. It may serve as a universal means of communication bypassing time, cultural, ethnic, and social differences. The neurological mechanisms …

Presurgical Language Fmri: Mapping Of Six Critical Regions, Christopher Benjamin, Patricia Walshaw, Kayleigh Hale, William D. Gaillard, +Several Additional Authors

Neurology Faculty Publications

Language mapping is a key goal in neurosurgical planning. fMRI mapping typically proceeds with a focus on Broca's and Wernicke's areas, although multiple other language-critical areas are now well-known. We evaluated whether clinicians could use a novel approach, including clinician-driven individualized thresholding, to reliably identify six language regions, including Broca's Area, Wernicke's Area (inferior, superior), Exner's Area, Supplementary Speech Area, Angular Gyrus, and Basal Temporal Language Area. We studied 22 epilepsy and tumor patients who received Wada and fMRI (age 36.4[12.5]; Wada language left/right/mixed in 18/3/1). fMRI tasks (two × three tasks) were analyzed by two clinical neuropsychologists who flexibly …

A Murine Model To Study Epilepsy And Sudep Induced By Malaria Infection., Paddy Ssentongo, Anna E Robuccio, Godfrey Thuku, Derek G Sim, Ali Nabi, Fatemeh Bahari, Balaji Shanmugasundaram, Myles W Billard, Andrew Geronimo, Kurt W Short, Patrick J Drew, Jennifer Baccon, Steven L Weinstein, Frank G Gilliam, José A Stoute, Vernon M Chinchilli, Andrew F Read, Bruce J Gluckman, Steven J Schiff

Neurology Faculty Publications

One of the largest single sources of epilepsy in the world is produced as a neurological sequela in survivors of cerebral malaria. Nevertheless, the pathophysiological mechanisms of such epileptogenesis remain unknown and no adjunctive therapy during cerebral malaria has been shown to reduce the rate of subsequent epilepsy. There is no existing animal model of postmalarial epilepsy. In this technical report we demonstrate the first such animal models. These models were created from multiple mouse and parasite strain combinations, so that the epilepsy observed retained universality with respect to genetic background. We also discovered spontaneous sudden unexpected death in epilepsy …

Pediatric High-Grade Glioma: Biologically And Clinically In Need Of New Thinking., Chris Jones, Matthias A Karajannis, David T W Jones, Mark W Kieran, Michelle Monje, Suzanne J Baker, Roger J Packer, +Several Additional Authors

Neurology Faculty Publications

High-grade gliomas in children are different from those that arise in adults. Recent collaborative molecular analyses of these rare cancers have revealed previously unappreciated connections among chromatin regulation, developmental signaling, and tumorigenesis. As we begin to unravel the unique developmental origins and distinct biological drivers of this heterogeneous group of tumors, clinical trials need to keep pace. It is important to avoid therapeutic strategies developed purely using data obtained from studies on adult glioblastoma. This approach has resulted in repetitive trials and ineffective treatments being applied to these children, with limited improvement in clinical outcome. The authors of this perspective, …

Unmasking Of Myoclonus By Lacosamide In Generalized Epilepsy, Daniel Birnbaum, Mohamad Z. Koubeissi

Neurology Faculty Publications

Lacosamide is a new-generation antiseizure medication that is approved for use as an adjunctive treatment and monotherapy in focal epilepsy. Its use in generalized epilepsy, however, has not been adequately evaluated in controlled trials. We report a 67-year-old woman who experienced new-onset myoclonic seizures after initiation of lacosamide. We presume that she had an undiagnosed generalized epilepsy syndrome, likely juvenile myoclonic epilepsy. Myoclonic seizures were not reported before introducing lacosamide and completely resolved after lacosamide was discontinued. This suggests that lacosamide may have the potential to worsen myoclonus, similar to what has been reported with another sodium channel agent, lamotrigine, …

The Role Of Osteopontin And Its Gene On Glucocorticoid Response In Myasthenia Gravis., Yanchen Xie, Hai-Feng Li, Liang Sun, Linda L Kusner, Shuhui Wang, Yunxiao Meng, Xu Zhang, Yu Hong, Xiang Gao, Yao Li, Henry J Kaminski

Neurology Faculty Publications

Biomarkers that assess treatment response for patients with the autoimmune disorder, myasthenia gravis (MG), have not been evaluated to a significant extent. We hypothesized the pro-inflammatory cytokine, osteopontin (OPN), may be associated with variability of response to glucocorticoids (GCs) in patients with MG. A cohort of 250 MG patients treated with standardized protocol of GCs was recruited, and plasma OPN and polymorphisms of its gene, secreted phosphoprotein 1 (SPP1), were evaluated. Mean OPN levels were higher in patients compared to healthy controls. Carriers of rs11728697*T allele (allele definition: one of two or more alternative forms of a gene) were more …

Hemiataxia: A Novel Presentation Of Anti-Nmda Receptor Antibody Mediated Encephalitis In An Adolescent., Greg D Phillips, Gillian N Jones, Maureen Callaghan, Marc P Difazio

Neurology Faculty Publications

Anti-NMDA receptor antibody associated encephalitis as a cause of new-onset neuropsychiatric manifestations in children and adults can represent a significant diagnostic challenge for clinicians. Clinical signs often include encephalopathy, new-onset psychosis, and movement phenomenon. Although orofacial dyskinesias were initially identified as a characteristic movement phenomenon in this type of encephalitis, an expanded range of abnormalities has recently been reported, including isolated ataxia. We report a case of isolated hemiataxia in a young adult with mild initial psychiatric manifestations. A personal and family history of preceding neuropsychiatric symptoms produced diagnostic confusion and resulted in a significant diagnostic and therapeutic delay. Our …

Abnormal Glycosylation In Joubert Syndrome Type 10., Megan S Kane, Mariska Davids, Michelle R Bond, Christopher J Adams, Megan E Grout, Ian G Phelps, Gilbert Vezina, +Several Additional Authors

Neurology Faculty Publications

BACKGROUND: The discovery of disease pathogenesis requires systematic agnostic screening of multiple homeostatic processes that may become deregulated. We illustrate this principle in the evaluation and diagnosis of a 5-year-old boy with Joubert syndrome type 10 (JBTS10). He carried the OFD1 mutation p.Gln886Lysfs*2 (NM_003611.2: c.2656del) and manifested features of Joubert syndrome.

METHODS: We integrated exome sequencing, MALDI-TOF mass spectrometry analyses of plasma and cultured dermal fibroblasts glycomes, and full clinical evaluation of the proband. Analyses of cilia formation and lectin staining were performed by immunofluorescence. Measurement of cellular nucleotide sugar levels was performed with high-performance anion-exchange chromatography with pulsed amperometric …

Kcnq2 Encephalopathy, John Millichap, Kristen Park, Tammy N. Tsuchida, Bruria Ben-Zeev, Lionel Carmant, On Behalf Of The Rikee Consortium

Neurology Faculty Publications

Objective: To advance the understanding of KCNQ2 encephalopathy genotype–phenotype relationships and to begin to assess the potential of selective KCNQ channel openers as targeted treatments.

Methods: We retrospectively studied 23 patients with KCNQ2 encephalopathy, including 11 treated with ezogabine (EZO). We analyzed the genotype–phenotype relationships in these and 70 previously described patients.

Results: The mean seizure onset age was 1.8 ± 1.6 (SD) days. Of the 20 EEGs obtained within a week of birth, 11 showed burst suppression. When new seizure types appeared in infancy (15 patients), the most common were epileptic spasms (n = 8). At last follow-up, seizures …

Role Of Diffusion Tensor Imaging In Prognostication And Treatment Monitoring In Niemann-Pick Disease Type C1, Meghann Lau, Ryan Lee, Robin Miyamoto, Eun Sol Jung, Nicole Farhat, Shoko Yoshida, Susumu Mori, Andrea L. Gropman, Eva Baker, Forbes Porter

Neurology Faculty Publications

Niemann-Pick Disease, type C1 (NPC1) is a rapidly progressive neurodegenerative disorder characterized by cholesterol sequestration within late endosomes and lysosomes, for which no reliable imaging marker exists for prognostication and management. Cerebellar volume deficits are found to correlate with disease severity and diffusion tensor imaging (DTI) of the corpus callosum and brainstem, which has shown that microstructural disorganization is associated with NPC1 severity. This study investigates the utility of cerebellar DTI in clinical severity assessment. We hypothesize that cerebellar volume, fractional anisotropy (FA) and mean diffusivity (MD) negatively correlate with NIH NPC neurological severity score (NNSS) and motor severity subscores. …

The Clinical, Biochemical And Genetic Features Associated With Rmnd1-Related Mitochondrial Disease., Yi Shiau Ng, Charlotte L Alston, Daria Diodato, Andrew A Morris, Nicole Ulrick, Stanislav Kmoch, +Several Additional Authors

Neurology Faculty Publications

BACKGROUND: Mutations in the RMND1 (Required for Meiotic Nuclear Division protein 1) gene have recently been linked to infantile onset mitochondrial disease characterised by multiple mitochondrial respiratory chain defects.

METHODS: We summarised the clinical, biochemical and molecular genetic investigation of an international cohort of affected individuals with RMND1 mutations. In addition, we reviewed all the previously published cases to determine the genotype-phenotype correlates and performed survival analysis to identify prognostic factors.

RESULTS: We identified 14 new cases from 11 pedigrees that harbour recessive RMND1 mutations, including 6 novel variants: c.533C>A, p.(Thr178Lys); c.565C>T, p.(Gln189*); c.631G>A, p.(Val211Met); c.1303C>T, …

Adgrl3 (Lphn3) Variants Are Associated With A Refined Phenotype Of Adhd In The Mta Study, Maria T. Acosta, James Swanson, Annamarie Stehli, Brooke Molina, The Mta Team

Neurology Faculty Publications

Background

ADHD is the most common neuropsychiatric condition affecting individuals of all ages. Long-term outcomes of affected individuals and association with severe comorbidities as SUD or conduct disorders are the main concern. Genetic associations have been extensively described. Multiple studies show that intronic variants harbored in the ADGRL3 (LPHN3) gene are associated with ADHD, especially associated with poor outcomes.

Methods

In this study, we evaluated this association in the Multimodal Treatment Study of children with ADHD (MTA), initiated as a 14-month randomized clinical trial of 579 children diagnosed with DSM-IV ADHD-Combined Type (ADHD-C), that transitioned to a 16-year prospective observational …

Expert Opinion Regarding Invasive Monitoring: From Surface To Depth, Mohamad Z. Koubeissi

Neurology Faculty Publications

No abstract provided.

The Role Of Ng2 Proteoglycan In Glioma., Sridevi Yadavilli, Eugene I Hwang, Roger J. Packer, Javad Nazarian

Neurology Faculty Publications

Neuron glia antigen-2 ((NG2), also known as chondroitin sulphate proteoglycan 4, or melanoma-associated chondroitin sulfate proteoglycan) is a type-1 membrane protein expressed by many central nervous system (CNS) cells during development and differentiation and plays a critical role in proliferation and angiogenesis. 'NG2' often references either the protein itself or the highly proliferative and undifferentiated glial cells expressing high levels of NG2 protein. NG2 glia represent the fourth major type of neuroglia in the mammalian nervous system and are classified as oligodendrocyte progenitor cells by virtue of their committed oligodendrocyte generation in developing and adult brain. Here, we discuss NG2 …

Baseline Results Of The Neuronext Spinal Muscular Atrophy Infant Biomarker Study, Stephen J. Kolb, Christopher S. Coffey, Jon W. Yankey, Kristin Krosschell, David Arnold, Mathula Thangarajh, +20 Additoinal Authors, Neuronext Clinical Trial Network

Neurology Faculty Publications

Objective

This study prospectively assessed putative promising biomarkers for use in assessing infants with spinal muscular atrophy (SMA).

Methods

This prospective, multi-center natural history study targeted the enrollment of SMA infants and healthy control infants less than 6 months of age. Recruitment occurred at 14 centers within the NINDS National Network for Excellence in Neuroscience Clinical Trials (NeuroNEXT) Network. Infant motor function scales and putative electrophysiological, protein and molecular biomarkers were assessed at baseline and subsequent visits.

Results

Enrollment began November, 2012 and ended September, 2014 with 26 SMA infants and 27 healthy infants enrolled. Baseline demographic characteristics of the …

Spatial And Temporal Homogeneity Of Driver Mutations In Diffuse Intrinsic Pontine Glioma., Hamid Nikbakht, Eshini Panditharatna, Leonie G Mikael, Rui Li, Tenzin Gayden, Alan Siu, Roger J. Packer, Javad Nazarian, +16 Additional Authors

Neurology Faculty Publications

Diffuse Intrinsic Pontine Gliomas (DIPGs) are deadly paediatric brain tumours where needle biopsies help guide diagnosis and targeted therapies. To address spatial heterogeneity, here we analyse 134 specimens from various neuroanatomical structures of whole autopsy brains from nine DIPG patients. Evolutionary reconstruction indicates histone 3 (H3) K27M-including H3.2K27M-mutations potentially arise first and are invariably associated with specific, high-fidelity obligate partners throughout the tumour and its spread, from diagnosis to end-stage disease, suggesting mutual need for tumorigenesis. These H3K27M ubiquitously-associated mutations involve alterations in TP53 cell-cycle (TP53/PPM1D) or specific growth factor pathways (ACVR1/PIK3R1). Later oncogenic alterations arise in sub-clones and often …

Differential Rna Expression Profile Of Skeletal Muscle Induced By Experimental Autoimmune Myasthenia Gravis In Rats, Henry J. Kaminski, Keiichi Himuro, Jumana Alshaikh, Bendi Gong, Georgiama Cheng, Linda L. Kusner

Neurology Faculty Publications

The differential susceptibility of skeletal muscle by myasthenia gravis (MG) is not well understood. We utilized RNA expression profiling of extraocular muscle (EOM), diaphragm (DIA), and extensor digitorum (EDL) of rats with experimental autoimmune MG (EAMG) to evaluate the hypothesis that muscles respond differentially to injury produced by EAMG. EAMG was induced in female Lewis rats by immunization with acetylcholine receptor purified from the electric organ of the Torpedo. Six weeks later after rats had developed weakness and serum antibodies directed against the AChR, animals underwent euthanasia and RNA profiling performed on DIA, EDL, and EOM. Profiling results were validated …

Levels Of Glycosaminoglycans In The Cerebrospinal Fluid Of Healthy Young Adults, Surrogate-Normal Children, And Hunter Syndrome Patients With And Without Cognitive Impairment., Christian J Hendriksz, Joseph Muenzer, Adeline Vanderver, Jonathan M Davis, Barbara K Burton, Nancy J Mendelsohn, Nan Wang, Luying Pan, Arian Pano, Ann J Barbier

Neurology Faculty Publications

In mucopolysaccharidoses (MPS), glycosaminoglycans (GAG) accumulate in tissues. In MPS II, approximately two-thirds of patients are cognitively impaired. We investigated levels of GAG in cerebrospinal fluid (CSF) in different populations from four clinical studies (including NCT00920647 and NCT01449240). Data indicate that MPS II patients with cognitive impairment have elevated levels of CSF GAG, whereas those with the attenuated phenotype typically have levels falling between those of the cognitively affected patients and healthy controls.