Clinical diagnostics
The Headache Centre Hirslanden offers a wide range of additional diagnostic examinations such as ENMG, EEG, ultrasound or lumbar puncture. At the beginning of every treatment, however, a detailed discussion with the patients in order to carefully record their individual medical condition and to respond to any wishes and fears is required next to a comprehensive neurological examination.
If further Equipment based and technical diagnostics are required, this can be carried out directly on site by one of our specialists. For MRI diagnostics, we can rely on an excellent network of radiology specialists in close proximity of the practice.
Electroneuromyography (ENMG):
Electroneuromyography, ENMG for short, is used to examine nerves and muscles. It is of great importance in the examination of nerve and muscle diseases, because the ENMG examination provides information about the type and causes of a disease.
Depending on the aim of the examination, two different diagnostic methods are used:
Electroneurography (ENG):
In Electroneurography, the conductivity and conduction velocity of nerves are measured by means of current impulses. It is therefore investigated at what speed nerves transmit the information. This allows the analysis of the condition of nerves and the detection of any nerve damage.
In order to detect the conductivity of nerves, electrodes are glued to the skin or, in individual cases, fine needle electrodes are pierced into the skin and short and non-painful current pulses are repeatedly released. This neurological examination method is completely harmless, but can be perceived as unpleasant.
Electromyography (EMG):
Electromyography measures electrical activity and conductivity in muscles. The EMG assessment can be used to understand, whether the cause of a disease lies in the area of the muscle or in the nerve that supplies the muscle. A distinction is made between a needle EMG and a surface EMG. In most of the cases, a needle EMG is performed, as results are more indicative.
In needle EMG, a very fine needle electrode is pinched into the affected muscle to measure the action potentials of individual muscle fibres with the muscle being activated and relaxed. In surface EMG, on the other hand, electrodes are glued to the skin to detect the electrical activity of entire muscles or muscle groups.
The EMG assessment is harmless, but can also be perceived as unpleasant, especially when performing the needle EMG. Due to the puncture of the skin from the insertion of the thin needle electrode there is a slight risk of bleeding, which is why this examination should not be carried out with patients who are taking strong blood-thinning medication. As sterile myography needles are used and disinfection of the skin is performed before carrying out the examination, infections in the area of the puncture are very rare and, as such, a negligible examination risk.
Electroencephalography, EEG for short, is a neurological examination method, in which the electrical activity of the cerebral cortex is measured and recorded. An EEG is used, for example, in the diagnosis of epilepsy. The measurement and recording of brain activity is carried out through electrodes which are attached to the scalp. This examination method is completely harmless and not painful.
Evoked potentials, or EP for short, is a neurological examination method for testing the conductivity and functionality of a sensory organ or peripheral nerves to the brain.
There are different methods to conduct the examination:
Visually evoked potentials (VEP):
With VEP, the conduction of nerve impulses from the eye via the optic nerve to the visual cortex is being checked. The patient looks at a checkerboard pattern on a screen, which changes its pattern in short intervals. The resulting electrical potentials are detected by electrodes attached to the back of the patient’s head. This examination method is particularly important in the diagnosis of inflammatory or circulation-related optic nerve and visual tract changes.
Assessment of VEP takes about 20 minutes and is harmless and not painful. However, it may be perceived as unpleasant due to the electrical impulses.
Motor evoked potentials (MEP):
MEP are used to check the transmission of nerve impulses responsible for muscle movement, which goes from the cerebral cortex to the spinal cord and further through peripheral nerves to the muscles of the extremities (arms and legs). For this purpose, a magnetic field is generated over the head, neck or lumbar region of the patient. This magnetic field stimulates the part of the brain, which is responsible for movement. As a result, there are short, involuntary muscle twitches on arms and legs. Electrodes are used to measure strength and speed of the stimulus response of muscles.
The assessment of MEP takes about 30 minutes and is harmless and not painful. However, it may be perceived as unpleasant.
With neurovascular ultrasound and the use of Doppler and duplex sonography, brain leading blood vessels are examined. Thanks to colour coding, vascular wall and blood flow can be made visible. Circulatory problems in the blood vessels due to narrowing or occlusions (e.g. due to calcination of the arteries) can be fatal. Stroke due to a circulatory disorder of the brain leading blood vessels is the second most common cause of death. This makes it all the more important to use ultrasound to detect and treat relevant vascular changes and vascular diseases at an early stage. As a result, the risk of stroke can be significantly reduced.
The examination of brain leading blood vessels by means of ultrasound is harmless and not painful.
The aim of a lumbar puncture is to detect any inflammation or infection of cerebrospinal fluid (liquor). Therefore, a small amount of liquor (which is formed in the cavities of the brain) is extracted with a thin and hollow needle. Under sterile conditions, the spinal cord (also called dural sac) is punctured in the area of the lower back in order to extract the liquor. The spinal cord itself is not hit with the needle, as it already ends a few centimetres above the punctured area. This examination method is carried out if inflammatory diseases of the nervous system such as multiple sclerosis (MS) or infections are suspected.
Performing a lumbar puncture is sometimes described as unpleasant. Any risks such as post-puncture headaches or infections due to germ carry-over are rare to extremely rare, if the examination is carried out properly. A lumbar puncture should not be performed with patients who take strong blood-thinning drugs. Before carrying out the puncture, the blood’s ability to clot must be checked by means of blood sampling.
Outpatient sleep screening:
Breathing gaps, snoring, daytime tiredness, daytime sleepiness and morning headaches can all be signs of a sleep apnoea syndrome. By using outpatient sleep screening methods, unnoticed sleep-related breathing disorders can be detected. Patients therefore receive a device they can use at home, which measures flow of breathing air, movement of chest and abdomen, pulse rate and oxygen saturation in the blood during their sleep. The data obtained provide important clues as to whether sleep apnoea syndrome is present or not.
Actigraphy:
In actigraphy, a sensor is attached to the patient’s wrist or ankle. The sensor records all data regarding sleep-wake rhythm over several days, including phases of activity and resting as well as leg movements during sleep. These data provide important information for an individual and successful therapy.
Since there is no examination method, which can confirm the diagnosis of a migraine, keeping a headache calendar is vital: When and under what circumstances does the headache occur? What side effects do you have (nausea, vomiting, sensitivity to light, sound, smell, visual disturbances etc.)? The detailed description of headache symptoms helps the doctor to make a more precise diagnosis. Furthermore, the headache calendar also helps patients to better understand their own headache triggers and thus to avoid them in the future.
