Applications

Elettromyography

The electromyographic study is based on two fundamental methods: electromyography (EMG) itself and electroneurography (ENG).

The EMG measures the electrical potentials detectable by muscle fibers both at rest and during voluntary or involuntary contraction. The potentials are caused by the depolarization of the fibers in response to the arrival of an impulse to the neuromuscular synapse. Electromyography provides information both on the functional state of muscles and muscle fibers and on the associated nerve centers and pathways.

ENG (electroneurography) is that part of the electromyographic examination that evaluates the nerve conduction velocity and amplitude of the conducted signal. It provides information on both the motor and sensory components of the nerve. It can be performed by recording from the nerve or muscle receiving the signal, either with surface electrodes or needle electrodes. An electrical stimulus is applied to a peripheral nerve at two points and the response at the corresponding muscle level is recorded.

Electroencephalography

Electroencephalography is the technique that allows the recording of the superficial electrical activity of the scalp, representing the intense neuronal activity of the underlying brain.

The recording of the EEG signal is done through specific electrodes positioned according to the international standard 10-20. These figures represent the distance expressed as a percentage between adjacent positions defined by the intersection of orthogonal lines of the ideal skull map drawn starting from the anteroposterior nasion – inion repère points.

From this derives the standard configuration that provides for the positioning of 19 electrodes, beyond reference and mass, for the recording of electroencephalographic traces. Variants of the 10-20 system allow defining multiple positions, for high-density EEG recordings.

Polisomnography

Polysomnography (PSG) is a multi-parametric test used in the study of sleep and as a diagnostic tool for many diseases of the central nervous system.

During the examination, specific sensors positioned on the patient record the trend and variations of some physiological parameters during the different phases of REM (Rapid Eye Movement) and non-REM sleep, such as brain activity, oxygen levels, heartbeat, breathing, snoring, limb movements, sometimes blood pressure. The number and type of signals that are studied will partially change depending on the sleeping disease to be studied.

The analysis of the evolution of the polygraphic parameters and of the sleep staging allows the discriminating diagnosis of pathologies linked to sleep disorders such as insomnia, narcolepsy, parasomnia, hypersomnia, sleepwalking, pavor nocturnus.

Evoked Potentials

Evoked Potentials are specific responses of the central nervous system related to external sensory stimuli (electrical, visual, acoustic), represented in modifications of the electroencephalographic trace. These potentials, of low amplitude compared to EEG, are detectable through the use of repetitive stimulations combined with the recording method called averager, which allows to isolate and amplify these responses from the remaining electrical activity. In relation to the sensory pathway stimulated and the mode of execution they are distinguished: Potential somato-sensory PESS, visual PEV, acoustic PEA, PEM motors, and cognitive CNV, ERP.

Intra Operative Neuro Monitoring

The IONM Intraoperative Neurophysiological Monitoring involves the integrated application of electrophysiological methods – such as EEG, EMG, EP – aimed at monitoring the functional integrity of the neural structures of the central and peripheral nervous system during surgery.

The aim of the IONM is to reduce the risk of iatrogenic damage to the nervous system for the patient by providing real-time physiological information such as nerve pathway integrity, identification of specific areas of the cerebral cortex, and evaluation of the depth of the anesthesia.