Magnetic resonance imaging of idiopathic carpal tunnel syndrome: correlation with clinical findings and electrophysiological investigation.
OBJECTIVE
To compare clinical evaluation, electrophysiological investigation and magnetic resonance findings in assessing the severity of idiopathic carpal tunnel syndrome.


METHODS
Seventy-four patients with idiopathic carpal tunnel syndrome were prospectively recruited. Clinical evaluation included symptoms severity score and two-point discrimination, sensory and motor nerve conduction velocities were determined by electroneuromyography and imaging parameters were obtained after wrist magnetic resonance. The Wilcoxon test was used to define the differences between measurements of median nerve area. The Pearson and Spearman correlation tests were used to determine the relationships between all the measured parameters.


RESULTS
Cross-sectional area of median nerve was smaller at hamate level than at radio-ulnar joint and pisiform levels (p<0.001). With exception of median nerve area at hamate level, there was a lower degree of correlation between MRI parameters and findings obtained by clinical assessments and electrophysiological measurements. The median nerve area at hamate level correlated negatively with duration of symptoms, two-point discrimination, symptoms severity score and positively with sensory nerve conduction velocity (p<0.01).


CONCLUSIONS
In patients with idiopathic carpal tunnel syndrome, median nerve area measured by wrist magnetic resonance at hamate level may be considered as a valuable indicator to grading the severity of disease.
Martins
R S
RS
Peripheral Nerve Unit, Department of Neurosurgery, Hospital Santa Marcelina, São Paulo, Brazil. robar@ig.com.br
Siqueira
M G
MG
Simplício
H
H
Agapito
D
D
Medeiros
M
M
D000200:Action Potentials / Q000502:physiology; D000328:Adult; D000367:Age Factors; D000368:Aged; D015992:Body Mass Index; D002349:Carpal Tunnel Syndrome / Q000150:complications / Q000473:pathology* / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008475:Median Nerve / Q000473:pathology* / Q000503:physiopathology; D008875:Middle Aged; D009431:Neural Conduction / Q000502:physiology*; D014459:Ulnar Nerve / Q000473:pathology* / Q000503:physiopathology