Cryptogenic polyneuropathy: clinical and neurophysiological findings.

The purpose of this study was to describe the clinical and neurophysiological features of cryptogenic polyneuropathy in 168 patients in the neurological departments at three Swedish hospitals. The medical records of all patients aged 40-79 years with the diagnosis of cryptogenic polyneuropathy from 1993 to 2000 were analysed. One hundred and fourteen patients (68%) were men. The mean age at first symptom was 61 years and at diagnosis it was 64 years. Distal numbness (n = 115, 68%) was the most common symptom, but some patients complained of pain, pedal paresthesiae, and impairment of balance. The most common clinical findings were decreased or lost proprioception or sense of vibration (n = 135, 80%) and loss of ankle jerks (n = 131, 78%). Neurography in 139 patients showed mixed sensorimotor polyneuropathy of axonal or mixed axonal and demyelinating type in 97 (70%). Cryptogenic polyneuropathy is a slowly progressive sensorimotor nerve lesion of mainly axonal type. Men are more often affected than women. Most patients have a minor or moderate severe polyneuropathy.