Translational neurophysiology

The activity of this research unit started with the development of methods for studying spinal nociceptive reflexes (the RIII nociceptive flexion reflex in particular) and techniques for studying polysynaptic reflexes at trigeminal-facial level. Recently, more innovative assessment methods for thermal and pain sensitivity have been introduced thanks to the acquisition of instrumentation for ‘quantitative sensory testing’ (QST). Through specific QST paradigms (QST implemented with ‘conditioned pain modulation’ techniques) it is also possible to evaluate the function of the endogenous pain control system in different physiological and pathological conditions (including headache syndromes, extrapyramidal diseases, multiple sclerosis, stroke).

These methods may be also useful for evaluating the mechanism of action of pharmacological and non-pharmacological therapies used in the treatment of pain in patients with various neurological diseases (e.g., treatment with botulinum toxin in patients with spasticity or neuropathic pain).

More recently, we have pursued several new lines of research and new instrumentation has been acquired:

– study protocols based on the use of non-invasive brain stimulation techniques with high neuromodulatory potential, such as transcranial magnetic and electrical stimulation (respectively, TMS and tDCS). These techniques are widely used for both basic and therapeutic research purposes. In the basic research setting, they allow us to study the pathophysiological mechanisms (including adaptive or maladaptive cortical plasticity responses) involved in numerous neurological disorders, such as primary headaches, Parkinson’s disease, multiple sclerosis and cerebrovascular diseases. On the therapeutic side, the potential of these techniques has been successfully demonstrated in numerous conditions, for example in syndromes characterized by chronic pain, including migraine, in patients with neurogenic dysphagia, and in brain damage of various origins; in the latter case they are used with the aim of enhancing the brain plasticity mechanisms underlying the recovery of motor, sensory and cognitive functions;

– development of an electrokinesiographic (EKG) system for swallowing assessment, to allow objective and detailed study of different aspects of the oral and pharyngeal phases of swallowing, both in physiological conditions and in different pathological conditions that impair the swallowing function;

– studies have been carried out in patients with extrapyramidal syndromes (i.e., progressive supranuclear palsy, multisystem atrophy) in order to characterize, through electromyographic study of ‘special’ muscles with some autonomic innervation (intrinsic laryngeal muscles, external anal sphincter), peculiar pathogenetic aspects that might be useful in the early differential diagnosis versus Parkinson’s disease;

– the Unit performs clinical and electrophysiological studies in patients with neuromuscular disorders, in particular peripheral nerve disorders (ganglionopathies, chronic inflammatory demyelinating polyradiculoneuritis, multifocal motor neuropathy), also in the context of national multicenter studies.

– finally, for both research and clinical purposes, various techniques for studying evoked potentials (visual, acoustic, somatosensory, vestibular, laser stimulus evoked potentials) are available along with neuro-ophthalmological methods including campimetry, electroretinography, techniques for evaluating ocular alignment and for the study of optic nerve fibers and the ganglion layer of the retina.

Specialized equipment:

• Medelec Synergy electromyograph
• Medoc Q-Sense (Conditioned-Pain-Modulation version)
• Cambridge Electronic CED 1401 Data Acquisition Unit
• Somedic algometer with control unit
• AUDIOSTIM stimulator with auditory stimulation module
• 6 direct current electrical stimulation devices (2 of which  for home use by the patient)
• CO₂laser stimulator
• MagVenture transcranial magnetic stimulator (MagPro X100 with MagOption)
• Instruments for recording of multimodal evoked potentials including cervical  and ocular vestibular evoked myogenic potential (cVEMP and oVEMP) recording
• HD-OCT Cirrus 5000 for studying optic nerve fibers and the ganglion layer of the retina
• Hess screen for assessing ocular alignment
• Humphrey-Zeiss visual field analyzer