David Hojnacki

Bio: David Hojnacki is an academic researcher from State University of New York System. The author has contributed to research in topics: Chronic cerebrospinal venous insufficiency & Multiple sclerosis. The author has an hindex of 33, co-authored 95 publications receiving 3079 citations. Previous affiliations of David Hojnacki include University at Buffalo.

Psychometrics and normative data for the Multiple Sclerosis Functional Composite: replacing the PASAT with the Symbol Digit Modalities Test

Abstract: The MS Functional Composite (MSFC) is a continuous scale of neurological disability for patients with multiple sclerosis (MS). Cognition is represented by the Paced Auditory Serial Addition Test (PASAT), although the Symbol Digit Modalities Test (SDMT) has been proposed as a promising alternative. MSFC scores were calculated using either the PASAT or the SDMT with the following reference populations: National Multiple Sclerosis Society (NMSS) Task Force, 400 MS patients, and 100 normal controls. A subgroup of 115 patients was followed longitudinally, with a test-retest interval of 2.3 +/- 1.2 years. Pearson correlations were calculated and analyses of variance (ANOVAs) were used to assess relationships among the MSFC components and composite scores, and differences in performance between patients and controls. Longitudinal changes were also assessed. Logistic regression was performed to determine which MSFC scores are most predictive of diagnosis, course, and work disability. All MSFCs had similar test-retest reliability and correlations with other measures including neurological disability, depression, and fatigue. The SDMT showed slightly better validity with respect to predicting diagnosis, course, and work disability, although the amount of variance accounted for was similar for each version of the MSFC. Our data, derived from a large sample of MS patients and normal controls, supports the validity of both PASAT and SDMT versions of the MSFC. Because the SDMT has slightly better predictive validity and has a relatively easier administration procedure, some clinicians and researchers may wish to replace the PASAT with the SDMT in future calculations of the MSFC using the calculation methods provided in this manuscript.

Prevalence, sensitivity, and specificity of chronic cerebrospinal venous insufficiency in MS

Abstract: Background: Chronic cerebrospinal venous insufficiency (CCSVI) was recently described in patients with multiple sclerosis (MS). A subject is considered CCSVI positive if ≥2 venous hemodynamic (VH) criteria are fulfilled. Objective: To determine prevalence of CCSVI in a large cohort of patients with MS, clinically isolated syndrome (CIS), other neurologic diseases (OND), and healthy controls (HC), using specific proposed echo-color Doppler (ECD) criteria. Methods: Transcranial and extracranial ECD were carried out in 499 enrolled subjects (289 MS, 163 HC, 26 OND, 21 CIS). Prevalence rates for CCSVI were calculated in 3 ways: first, using only the subjects for whom diagnosis was certain (i.e., borderline subjects were excluded); secondly, including the borderline subjects in the “no CCSVI” group; and finally, taking into account subjects who presented any of the VH criteria. Results: CCSVI prevalence with borderline cases included in the “no CCSVI” group was 56.1% in MS, 42.3% in OND, 38.1% in CIS, and 22.7% in HC ( p p p p = 0.004). Conclusions: Our findings are consistent with an increased prevalence of CCSVI in MS but with modest sensitivity/specificity. Our findings point against CCSVI having a primary causative role in the development of MS.

Upper and lower extremity motor function and cognitive impairment in multiple sclerosis

Abstract: Motor impairments and cognitive dysfunction are common in multiple sclerosis (MS). We aimed to delineate the relationship between cognitive capacity and upper and lower motor function in 211 MS patients, and 120 healthy volunteers. Lower and upper motor function were assessed with the Timed 25 Foot Walk (T25FW) and the Nine Hole Peg Test (NHPT) as implemented in the Multiple Sclerosis Functional Composite (MSFC). Subjects also underwent neuropsychological evaluation. Hierarchical linear regression analysis was conducted separately for the MS and healthy groups with the T25FW and NHPT serving as the outcome measures. Cognitive performance indices served as predictors. As expected, healthy subjects performed better than the MS group on all measures. Processing speed and executive function tests were significant predictors of lower and upper motor function in both groups. Correlations were more robust in the MS group, where cognitive tests predicted variability in motor function after controlling for disease duration and physical disability. In conclusion, we find evidence of higher order cognitive control of motor function that appears to be particularly salient in this large and representative MS sample. The findings may have implications for risk assessment and treatment of mobility dysfunction in MS.

Cardiovascular risk factors are associated with increased lesion burden and brain atrophy in multiple sclerosis

Abstract: Background Cardiovascular (CV) risk factors have been associated with changes in clinical outcomes in patients with multiple sclerosis (MS). Objectives To investigate the frequency of CV risks in patients with MS and their association with MRI outcomes. Methods In a prospective study, 326 patients with relapsing–remitting MS and 163 patients with progressive MS, 61 patients with clinically isolated syndrome (CIS) and 175 healthy controls (HCs) were screened for CV risks and scanned on a 3T MRI scanner. Examined CV risks included hypertension, heart disease, smoking, overweight/obesity and type 1 diabetes. MRI measures assessed lesion volumes (LVs) and brain atrophy. Association between individual or multiple CV risks and MRI outcomes was examined adjusting for age, sex, race, disease duration and treatment status. Results Patients with MS showed increased frequency of smoking (51.7% vs 36.5%, p=0.001) and hypertension (33.9% vs 24.7%, p=0.035) compared with HCs. In total, 49.9% of patients with MS and 36% of HCs showed ≥2 CV risks (p=0.003), while the frequency of ≥3 CV risks was 18.8% in the MS group and 8.6% in the HCs group (p=0.002). In patients with MS, hypertension and heart disease were associated with decreased grey matter (GM) and cortical volumes (p Conclusions Patients with MS with one or more CV risks showed increased lesion burden and more advanced brain atrophy.

Diagnosis of multiple sclerosis: 2017 revisions of the McDonald criteria

Abstract: The 2010 McDonald criteria for the diagnosis of multiple sclerosis are widely used in research and clinical practice. Scientific advances in the past 7 years suggest that they might no longer provide the most up-to-date guidance for clinicians and researchers. The International Panel on Diagnosis of Multiple Sclerosis reviewed the 2010 McDonald criteria and recommended revisions. The 2017 McDonald criteria continue to apply primarily to patients experiencing a typical clinically isolated syndrome, define what is needed to fulfil dissemination in time and space of lesions in the CNS, and stress the need for no better explanation for the presentation. The following changes were made: in patients with a typical clinically isolated syndrome and clinical or MRI demonstration of dissemination in space, the presence of CSF-specific oligoclonal bands allows a diagnosis of multiple sclerosis; symptomatic lesions can be used to demonstrate dissemination in space or time in patients with supratentorial, infratentorial, or spinal cord syndrome; and cortical lesions can be used to demonstrate dissemination in space. Research to further refine the criteria should focus on optic nerve involvement, validation in diverse populations, and incorporation of advanced imaging, neurophysiological, and body fluid markers.

Contributions to Neuropsychological Assessment

Abstract: on to develop full blown Parkinson's disease with rigidity and bradykinesia in the next few years. For those interested in the mechanisms of tremor, there are the customary authoritative reviews by Llinas, De Long, Lamarre, Rothwell and Deuschl, but uncertainty remains with respect to the relative importance of central autonomous generators and instability of peripheral reflex loops. Well written chapters are also included on primary orthostatic tremor and its relationship to essential tremor, writing tremor, neuropathic tremor, midbrain tremor and the increasingly acknowledged psychogenic tremors. Complex interrelationship between dystonia and postural tremor is also covered in depth. This cornucopia will be coveted and dipped into by those neurologists with a special interest in abnormal movement disorders, but who would not consider themselves to have a research interest in tremor. However, for the majority of clinicians involved in the hurly burly of clinical practice, I suspect that regrettably time and cost factors will conspire together to keep this excellent book out of reach. ANDREW LEES

Inflammation in neurodegenerative diseases

Abstract: Neurodegeneration, the slow and progressive dysfunction and loss of neurons and axons in the central nervous system, is the primary pathological feature of acute and chronic neurodegenerative conditions such as Alzheimer's disease and Parkinson's disease, neurotropic viral infections, stroke, paraneoplastic disorders, traumatic brain injury and multiple sclerosis. Despite different triggering events, a common feature is chronic immune activation, in particular of microglia, the resident macrophages of the central nervous system. Apart from the pathogenic role of immune responses, emerging evidence indicates that immune responses are also critical for neuroregeneration. Here, we review the impact of innate and adaptive immune responses on the central nervous system in autoimmune, viral and other neurodegenerative disorders, and discuss their contribution to either damage or repair. We also discuss potential therapies aimed at the immune responses within the central nervous system. A better understanding of the interaction between the immune and nervous systems will be crucial to either target pathogenic responses, or augment the beneficial effects of immune responses as a strategy to intervene in chronic neurodegenerative diseases.