Risk factors of respiratory failure in children with Guillain Barre syndrome

Guillain Barre Syndrome is the most common peripheral neuropathy causing respiratory failure, and about 10-30% of these patients require mechanical ventilation sometimes during their illness. Ninety one children under 15 years old with GBS were studied over a period of 3 years. Thirteen [14.4%] of these patients required assisted ventilation. A comparison was made between the clinical, electrodiagnostic, and laboratory data from patients who required mechanical ventilation and those who did not. Progression to respiratory failure necessitating mechanical ventilation was highly likely to occur in those with younger age [p=0.001], cranial nerve involvement [p=0.03], and loss of deep tendon reflexes in upper limbs [p=0.04], lack of motor unit action potential [p=0.009] or presentation of fibrillation potentials [p<0.0001] on electromyography and markedly attenuated [>80%] CMAP amplitude on nerve conduction study [p<0.0001] were significantly more common in the ventilated group. While inherently unpredictable, the clinical course of patients with severe GBS may be predictable to some extent, on the basis of clinical information and electrodiagnostic findings

Electrodiagnostic changes in patient with subclinical hypothyroidism

Electrodiagnostic changes typical of peripheral polyneuropathy have been reported in patients with over hypothyroidism. There are controversial reports regarding the effects of subclinical hypothyroidism on peripheral nervous system function. The aim of the present study is to investigate the possible effects of subclinical hypothyroidism of peripheral nervous system function by electrodiagnostic studies. A total of 28 patients [56 extremities] with subclinical hypothyroidism [defined as high serum TSH in the presence of normal free thyroxin by appropriate methods] including 25 adult females and 3 males [mean age of 46.07 +/- 6.87y] and 30 normal subjects as control group [60 extremities]. 27 females and 3 males [mean age 45 +/- 8.7y] had normal thyroid function tests enrolled in the study. Exclusion criteria were presence of diabetes mellitus, neuromuscular disorder, pregnancy, other disorders or drugs affecting neuromuscular function in all patients and control group. Electrodiagnostic studies including motor nerve conduction velocity [motor NCV], motor distal latency, CMAP Amplitude performed from tibial, median, peroneal and ulnar nerves bilaterally. Sensory function tests including sensory nerve conduction velocity, SNAP amplitude and sensory distal latency from median, ulnar and sural nerves bilaterally were studied by standard methods. Minimal f-response was studied from tibial, median and ulnar nerves bilaterally. Mean of sensory NCV, SNAP amplitude and sensory distal latency from median, ulnar and sural nerves and motor NCV, motor distal latency and CMAP amplitude from median, ulnar, personeal and tibial nerves and mean of minimal F-response of tibial, median and ulnar nerves were not significantly different in patients and control group. The results of this study shows that there is no functional impairment in peripheral nerves in subclinical hypothyroidism at the time of diagnosis