DATE OF STUDY: MM/DD/YYYY
INDICATION FOR STUDY: The patient is undergoing evaluation for the recent onset of left leg pain, paresthesias, and weakness. She has a history of diabetes mellitus and reports problems with “neuropathy.” She has never had symptoms similar to this involving one extremity however. MRI of the lumbar spine reportedly is unremarkable.
DESCRIPTION OF STUDY: Nerve conduction studies were carried out in the lower extremities in the peroneal and posterior tibial motor nerves bilaterally. The left peroneal motor nerve evoked amplitudes are reduced. The left peroneal motor nerve distal latency is within normal limits, but the nerve conduction velocity is slowed at 34 m/sec.
The F-wave latency is somewhat prolonged at 64.8 ms. The right peroneal motor nerve evoked amplitudes are within normal limits as is the distal latency. The nerve conduction velocity is mildly slowed at 39 m/sec. The F-wave response could not be elicited.
The left posterior tibial motor nerves evoked amplitude is within normal limits, the distal latency is mildly prolonged, and the F-wave latency is prolonged as well. No response could be elicited on stimulation behind the knee.
In the right posterior tibial motor nerve, the distal latency is mildly prolonged, the evoked amplitude is within normal limits, and no response could be elicited on stimulation behind the knee. Likewise, the F-wave response could not be elicited.
Needle examination was deferred due to the brief duration of symptoms (three to four days).
INTERPRETATION: These findings are consistent with a diffuse polyneuropathy involving at least motor innervation in the lower extremities with a combination of demyelinative and axonal features such as may be seen with diabetes mellitus.
Other etiologies cannot be entirely ruled out. No significant right to left asymmetries are observed to explain the patient’s left leg weakness and diffuse numbness.
Followup examination in three to six weeks might be helpful if clinically indicated with electromyography at that time.
