Klinisk Neurofysiologi Uppsala

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ultraljudNeuromuskulärt ultraljud
Neuromuskulärt ultraljud kan ibland vara ett bra komplement till neurografi och EMG vid diagnostik på neurofysiologiska mottagningen. Ultraljud av nerver och/eller muskler genomförs i tillägg till neurografi/EMG och selektionen av patienter för ultraljud utgår vanligtvis från resultat av dessa metoder. Några av indikationerna för neuromuskulärt ultraljud är nervskador, inflammatoriska polyneuropatier och primära muskelsjukdomar.
Nedan följer redogörelse på engelska för viktiga tolkningskriterier av nerv-ultraljud för att säkerställa god diagnostisk kvalitet.

Neuromuscular ultrasound at the Dept of Clinical Neurophysiology, Uppsala University hospital
Neuromuscular ultrasound is sometimes an important complement to nerve conduction study (NCS) and EMG. At the Uppsala lab the patient selection for ultrasound is usually based on findings from NCS and EMG.
Below follows some general recommendations for determining when the ultrasound investigation is defined as pathological at the dept of Clinical Neurophysiology in Uppsala. The ultrasound results are always interpreted in the context of clinical symtoms and the outcome of the neurography as well as EMG. Many times the clinical neurophysiologist (physician) also has to take into account special consideration in each individual case, and the recommendations are not claiming to cover all possible aspects of pathology and has to be used with good clinical interpretation and common sense.
Pathology in peripheral nerve is diagnosed if either one or several of the criteria below are fulfilled. Careful re-measurement of pathological values to exclude technical errors are of vital importance. Pathological segments of the nerve has to be evaluated both in transverse and longitudinal views, and preferably with several different probes. In cases of unusually tall patients, when you can expect generally larger nerve cross-sectional area (CSA) of the nerves as a normal finding, it is important to not only look at the absolute values, but also to evaluate ratios. Useful ratios include wrist/forearm ratio of the median nerve and elbow/forearm ratio of the ulnar nerve.

Criteria for diagnosing peripheral nerve pathology with ultrasound:

    1. The nerve is partially or completely severed with discontinuation of the epineurium. Many times in severe nerve injuries the intraneural appearance become anechoic (not only hypoechoic) at the injury level.
    2. The absolute value of CSA of the nerve is above reference value.
    3. CSA value > 2 times greater than the CSA at the same level in contralateral nerve.
    4. Median wrist/forearm ratio > 1.8.
    5. Ulnar elbow/forearm ratio >2.
    6. Individual nerve fascicle size is above reference value for fascicle.

För mer detaljerad information om våra metoder, se Metodboken