Factor analysis of carpal tunnel syndrome questionnaire in relation to nerve conduction studies

OBJECTIVE

This study aims to assess the Boston Carpal Tunnel Syndrome Questionnaire (BCTQ) structure and its relation to nerve conduction studies (NCS).

METHODS

A total of 403 patients with clinical and/or electrophysiological definition of CTS were evaluated with the instrument. The structure of the questionnaire was assessed by means of factor analysis. Factors obtained were compared with NCS.

RESULTS

Factor analysis showed that three factors represented nearly 60% of the variance of the instrument. Factor one is related to all the function domain questions and to the weakness and difficulty in grasping questions of the symptom domain; factor two to questions that assess numbness and tingling, and to the pain-awakening question of the symptom domain; and factor three, to pain questions of the symptom domain. Factor two had a stronger correlation with latencies of NCS and with the neurophysiological scale than the other two factors.

CONCLUSIONS

BCTQ assesses function and symptoms in patients with CTS by means of questions related to numbness and tingling sensation, pain and functional status. Questions related to numbness and tingling (factor two) better reflected the pathophysiology of the median nerve.

SIGNIFICANCE

Factor-2 sensory-related questions of BCTQ may be more useful in diagnosis, follow-up and assessing therapeutic outcome in CTS.

Motor recovery after Guillain-Barré syndrome in childhood

PURPOSE

To determine the clinical factors that modify the recovery time for gait after Guillain-Barré syndrome (GBS) in childhood.

METHOD

Medical records of patients admitted to Instituto de Ortopedia Infantil Roosevelt (IOIR) between years 1991 and 2001, were reviewed. Age, sex, cranial nerve impairment, requirement of assisted ventilation, number of days of assisted ventilation, muscular strength at day 10 of the disease, presence of quadriplegia, intravenous infusion of human gamma globulins (IVIG), were taken as independent variables. The number of needed days to reach Hughes State III was taken as the major outcome. First, univariate analysis was performed and with the factors that showed a statistically significant association with recovery time, multiple linear regression analysis and Cox regression were also performed.

RESULTS

Data of 332 children under 15 years old was collected. (Mean age: 7.1 years). A sample of 215 children was gathered for the study, all of them were regarded as functional states IV or V. Acute Motor Axonal Neuropathy (AMAN) was found in 30% of all cases. In the univariate analysis Cranial nerve impairment, requirement of assisted ventilation, presence of quadriplegia and presence of non-excitable motor nerves were associated with delayed motor recovery time. Patients who received IVIG reached Hughes state III faster than those who received only support treatment. This finding, that was more important in the presence of Acute Inflammatory Demyelinating Polyradiculoneuropathy (AIDP), lost its value in the Cox regression analysis. In the multivariate analysis, muscular strength, assessed at day 10 of the disease was the most important predictor to determine motor recovery. The presence of quadriplegia was strongly associated with a delayed recovery time. Relative risk: 3.3 (95% Confidence Interval 2.1 - 5.2).

CONCLUSIONS

Muscular strength at day 10 of the disease is the most useful clinical factor to determine prognosis of motor recovery in children who have suffered Guillain-Barré syndrome.