Electrodiagnostic Evaluation of Peripheral Nervous System Changes in Patients with Multiple Sclerosis

Background: There is supportive evidence that multiple sclerosis (MS) could potentially affect the peripheral nervous system. We assessed peripheral sensory and motor nerve involvement in patients with MS by a nerve conduction velocity test. Methods: We studied 75 patients who had a relapsing-remitting or secondary progressive pattern. We measured amplitude, latency, conduction velocity, Hoffmann reflex (H-Reflex), and F-Waves. Results: The amplitude of the right tibial, right proneal, left tibial, left proneal, and left median motor nerves was less than the mean for the normal population. Right ulnar sensory conduction in the patients showed an amplitude that was less than that of the normal population; there was no significant change in the amplitude of other sensory nerves. Latencies of the right and left median and right proneal motor nerves and left ulnar sensory nerves were statistically less than that of the normal population. Mean motor conduction velocity and F-wave conduction did not differ significantly from the normal population. H-reflex latencies of the right and left lower limbs were significantly more prolonged than those of the normal population. Conclusion: Our results suggest possible peripheral motor nerve abnormalities in MS patients, especially with the amplitude of the motor nerves; however, our results do not demonstrate any significant difference among the nerve conduction velocity parameters of sensory nerves between MS patients and the normal population.

Epidemiology and characteristics of Guillain-Barre syndrome in the northwest of Iran

Little is known about the incidence of Guillain-Barre syndrome [GBS] in Iran. We determined the incidence and evaluated prognostic factors for GBS in a prospective, population-based study. We evaluated and followed all patients with a diagnosis of GBS admitted to three referral neurology centers in East Azerbaijan province over a 1-year period [2003]. Clinical and electrophysiological characteristics of cases were reviewed and analyzed. A total of 76 patients were found, corresponding to a crude annual incidence rate of 2.11/100 000 population. Six patients [7.9%] died acutely within 21 days from the onset of the disease. Acute mortality was due to respiratory involvement, sepsis and acute autonomic system dysfunction. The persistence of disability after the acute phase was related to axonal involvement [OR=3.19, 95%CI, 1.65 to 6.16]. There was a significant correlation between a history of diarrhea and a further need for mechanical ventilation [P<0.05]. Mechanically ventilated patients had a low GBS disability score on discharge compared with patients not mechanically ventilated [P=0.05]. The incidence rates of GBS in our province is similar to that in other countries. Acute mortality in GBS was mostly due to poor respiratory care of patients and infective complications, but disability and probably late mortality were due to axonal nerve injury