Comparison of electrophysiological findings in axonal and demyelinating Guillain-Barre syndrome.

BACKGROUND: Incidence and predominant subtype of Guillain-Barre syndrome (GBS) differs geographically. Electrophysiology has an important role in early diagnosis and prediction of prognosis. This study is conducted to determine the frequent subtype of GBS in a large group of patients in Iran and compare nerve conduction studies in axonal and demyelinating forms of GBS. METHODS: We retrospectively evaluated the medical records and electrodiagnostic study (EDS) of 121 GBS patients who were managed in our hospital during 11 years. After regarding the exclusion criteria, patients classified as three groups: acute inflammatory demyelinating polyneuropathy (AIDP), acute motor axonal neuropathy (AMAN), and acute motor sensory axonal neuropathy (AMSAN). The most frequent subtype and then electrophysiological characteristic based on the time of EDS and their cerebrospinal fluid (CSF) profile were assessed. RESULTS: Among 70 patients finally included in the study, 67% were men. About 63%, 23%, and 14% had AIDP, AMAN, and AMSAN, respectively. AIDP patients represented a wider range of ages compared with other groups. Higher levels of CSF protein, abnormal late responses and sural sparing were more frequent in AIDP subtype. Five AMSAN patients also revealed sural sparing. Conduction block (CB) was observed in one AMAN patient. Prolonged F-wave latency was observed only in AIDP cases. CB and inexcitable sensory nerves were more frequent after 2 weeks, but reduced F-wave persistency was more prominent in the early phase. CONCLUSION: AIDP was the most frequent subtype. Although the electrophysiology and CSF are important diagnostic tools, classification should not be made based on a distinct finding.

Clinical and electrophysiological features of Guillain-Barré syndrome in Iran.

We evaluated the clinical and electrophysiological characteristics of 121 consecutive patients admitted with Guillain-Barré syndrome (GBS) to a tertiary referral hospital in Tehran, Iran, from 1997 to 2007. The mean age of patients was 38.9 (standard deviation 19.7) years. The predominant subtype of GBS was the demyelinating form. Miller Fisher syndrome was present in 3.3% of patients. There was no significant seasonal clustering among the three subtypes, but axonal variants tend to occur in summer. In contrast with other subtypes, the majority of patients with acute motor-sensory axonal neuropathy (AMSAN) were female (72.3%). AMSAN patients also had significantly longer hospitalization time (p=0.002) and intensive care unit (ICU) admission (p=0.017), while none of the acute motor axonal neuropathy patients needed ICU admission. Involvement of cranial nerves and symmetry of signs were significantly detected in the demyelinating variant (p=0.021 and p=0.040, respectively). The overall mortality was 3.3%.