ABSTRACT
Electrodiagnosis of carpal tunnel syndrome (CTS) were prospectively studied in 95 hands. The following techniques were studied in all hands and when at least one abnormal value was found (onset-measured), it was included on results: 1. wrist-index finger latency (WIF), abnormal > or = 2.8 ms, 140 mm; 2. palm-wrist latency (PW), abnormal > or = 1.8 ms, 80 mm; 3. comparison median/ulnar palm-wrist latency (CPW), abnormal > or = 0.4 ms; 4. comparison median/ulnar latency, wrist-ring finger (CMU), abnormal > or = 0.5 ms, 140 mm; 5. comparison median/radial latency, wrist-thumb (CMR), abnormal > or = 0.4 ms, 100 mm. All 95 CTS hands selected have the WIF < or = 3.5 ms (mild CTS). We found the CMR (97.8%) technique the most sensitive for mild CTS electrodiagnosis and the only comparative method with all potentials recordable when compared to CPW (88.4%), PW (84.2%), CMU (72.6%) and WIF (68.4%).
Subject(s)
Carpal Tunnel Syndrome/diagnosis , Hand/physiopathology , Median Nerve/physiopathology , Neural Conduction , Orthopedic Procedures/methods , Adult , Aged , Carpal Tunnel Syndrome/physiopathology , Electrodiagnosis , Female , Humans , Male , Median Nerve/physiology , Middle Aged , Prospective StudiesABSTRACT
Periodic paralysis is a rare disease, characterized by transient weakness associated with abnormal levels of serum potassium. Muscle biopsy may show a wide range of abnormalities, vacuoles being more specifically linked to the disease. We analysed 17 muscle biopsies from 14 patients with periodic paralysis (14 hypokalemic, 2 hyperkalemic). All of them showed at least one histological abnormality. Fourteen specimens showed vacuoles that were peripheral, single, frequent and preferentially found in type I fibers. Frequency or severity of attacks did not correlate with the presence of vacuoles but those were more easily found in patients with long term disease. Ten biopsies showed tubular aggregates, specially on the patients with frequent crises or long term disease. A second biopsy was done in three patients and in two we observed a worsening of the histopathologic picture. One patient manifested interictal weakness with evident myopathic changes on the muscle biopsy. Nonspecific changes were found in variable degrees in 15 biopsies. Our study shows that vacuoles and tubular aggregates are frequent changes in periodic paralysis and therefore helpful for the diagnosis. Important myopathic findings in the muscle biopsy suggest a permanent myopathy which probably develops after severe crises or long term disease.
