Monitor neuroactivity efficiently and safely

Friendship Europe offers a broad selection of accessories primarily for neurosurgeons and neurophysiologists to measure muscle activity (EMG), brain activity (EEG) and intraoperative monitoring and stimulation (IOM). Our product portfolio also includes products for Evoked Potentials (EP).

EMG – Electromyography

EMG is a diagnostic technique that gives a good understanding of the functional state of muscle, muscle fibers and their associated nerve centers. For this reason, it is often used to identify neuromuscular diseases.

EMG measures and assesses the electrical signals sent by motor neurons that cause muscles to contract. It is typically performed using monopolar or concentric needles. Signals are made up of superimposed motor unit action potential from several motor units and can be analyzed with a connected electromyograph.

A nerve conduction velocity (NCV) test – also called a nerve conduction study (NCS) – measures how fast an electrical impulse moves through a nerve. The NCS/NCV study is typically used to identify nerve damage. During the test, the nerve is stimulated using surface electrodes attached to the skin.

EEG – Electroencephalography

Electroencephalography (EEG) is a non-invasive diagnostic procedure most often used to diagnose epilepsy, as well as sleep disorders, depth of anesthesia, coma, encephalopathies and brain death. EEG can also be used as first-line method of diagnosis for tumors, stroke and other focal brain disorders. This makes it a valuable tool for research and diagnosis.

EEG measures spontaneous electrical activity over a period of time in the brain. It is typically carried out using multiple cup electrodes positioned on the scalp according to international standards, typically using the 10-20 system. EEG can also be carried out with scalp or subdermal needle electrodes.

EP – Evoked Potential

Evoked Potential (EP) is part of EEG and used to measure the electrical activity in certain areas of the brain and spinal cord. It measures a specific low-amplitude potential from the brain using electrical, visual or auditory stimuli. There are three kinds of evoked potentials in widespread clinical use:
Auditory Evoked Potentials (AEP) are usually monitored from the scalp but originate at brainstem level. Stimulation typically comes through earphones.
Visual Evoked Potentials (VEP) use stimulation from flashing lights or changing patterns on a monitor.
Somatosensory Evoked Potentials (SEP) come from electrical stimulation of the peripheral nerve.
SEP is often used to locate lesions on a peripheral nerve or the spinal cord. VEP and AEP can be used as a supplement to neuroimaging to detect diseases like multiple sclerosis.

In all EP tests, the low-amplitude potentials disappear in the background of ongoing EEG, ECG, EMG or ambient noise. To monitor them, an averaging technique is usually required. As the EP signal from the repetitive stimulation is time-locked to the stimulus and most of the background noise or EEG occurs randomly, the EP signal will be isolated and detectable after averaging.

IOM – Intraoperative Monitoring

Intraoperative monitoring (IOM) – also called Intraoperative Neuro Monitoring (IONM) – refers to the use of electrophysiological monitoring methods, such as EEG,EMG and EP to monitor certain neural structures of the central and peripheral nervous system during surgery. This type of monitoring reduces the risk of iatrogenic damage to the patient’s nervous system by providing ongoing information to the surgeon and anesthesiologist.

During IOM, a member of the surgical team trained in neurophysiology obtains and co-interprets triggered and spontaneous electrophysiologic signals from the patient. The signals received change depending on factors, such as anesthesia, tissue temperature, surgical stage and tissue stress. If any risk to the nervous system is detected, corrective measures can be taken immediately.

IOM is typically carried out by spine surgeons. However, neurosurgeons, vascular, orthopedic, otolaryngologists and urology surgeons also make use of it.