Evaluation of olfactory dysfunction in neurodegenerative diseases.

It is known that the olfactory dysfunction is involved in various neurological diseases, such as Parkinson's disease, Alzheimer's disease, multiple sclerosis, Huntington's disease and motor neuron disease. In particular, the ability to identify and discriminate the odors, as well as the odor threshold, can be altered in these disorders. These changes often occur as early manifestation of the pathology and they are not always diagnosed on time. The aim of this review is to summarize the major neurological diseases which are preceded or accompanied by olfactory dysfunction. In addition, new instrumental approaches, such as psychophysical testing, olfactory event-related potentials (OERPs) and functional magnetic resonance imaging (fMRI) measurements, supported by olfactometer for the stimuli delivery, and their combination in evaluation of olfactory function will be discussed. In particular, OERPs and fMRI might to be good candidates to become useful additional tools in clinical protocols for early diagnosis of neurological diseases.

Predictive biomarkers of recovery in traumatic brain injury.

Recent advances in medicine, intensive care and diagnostic imaging modalities have led to a pronounced reduction in deaths and disability resulting from traumatic brain injury. However, there are not sufficient findings to evaluate and quantify the severity of the initial and secondary processes destructive and therefore there are not effective therapeutic measures to effectively predict the outcome. For this reason, in recent decades, researchers and clinicians have focused on specific markers of cellular brain injury to improve the diagnosis and the evaluation of outcome. Many proteins synthesized in the astroglia cells or in the neurons, such as neuron-specific enolase, S100 calcium binding protein B, myelin basic protein, creatine kinase brain isoenzyme, glial fibrillary acidic protein, plasma desoxyribonucleic acid, brain-derived neurotrophic factor, and ubiquitin carboxy-terminal hydrolase-L1, have been proposed as potential markers for cell damage in central nervous system. Usually, the levels of these proteins increase following brain injury and are found in increasing concentrations in the cerebrospinal fluid depending on the injury magnitude, and can also be found in blood stream because of a compromised blood-brain barrier. In this review, we examine the various factors that must be taken into account in the search for a reliable non-invasive biomarkers in traumatic brain injury and their role in the diagnosis and outcome evaluation.

Magnetic resonance imaging markers for early diagnosis of Parkinson's disease.

Parkinson's disease (PD) is a neurodegenerative disorder characterized by selective and progressive degeneration, as well as loss of dopaminergic neurons in the substantia nigra. In PD, approximately 60-70% of nigrostriatal neurons are degenerated and 80% of content of the striatal dopamine is reduced before the diagnosis can be established according to widely accepted clinical diagnostic criteria. This condition describes a stage of disease called "prodromal", where non-motor symptoms, such as olfactory dysfunction, constipation, rapid eye movement behaviour disorder, depression, precede motor sign of PD. Detection of prodromal phase of PD is becoming an important goal for determining the prognosis and choosing a suitable treatment strategy. In this review, we present some non-invasive instrumental approaches that could be useful to identify patients in the prodromal phase of PD or in an early clinical phase, when the first motor symptoms begin to be apparent. Conventional magnetic resonance imaging (MRI) and advanced MRI techniques, such as magnetic resonance spectroscopy imaging, diffusion-weighted and diffusion tensor imaging and functional MRI, are useful to differentiate early PD with initial motor symptoms from atypical parkinsonian disorders, thus, making easier early diagnosis. Functional MRI and diffusion tensor imaging techniques can show abnormalities in the olfactory system in prodromal PD.