The relationship of pre- and postoperative median and ulnar nerve conduction measures to a self-administered questionnaire in carpal tunnel syndrome.

STUDY AIMS: Following carpal tunnel release (CTR), only very modest correlations have been found between subjective symptoms and function indexes compared to neurophysiological measures. The objective of this study was to evaluate this relationship by comparing the self-administered Boston symptom severity score and function severity score questionnaire against nerve conduction studies (NCS) before and after CTR using two different electrophysiological techniques. PATIENTS AND METHODS: Carpal tunnel release was performed in 51 patients (62 hands). Pre- and postoperative NCS were evaluated using both conventional neurophysiological methods and by means of a new hand-held device. RESULTS: Preoperatively there was almost no correlation between symptom severity and function scores and NCS results. Following surgery however, both symptom severity and function showed a modest, but significant improvement in their correlation to NCS (at highest r=0.405, P<0.01). This improvement in the relation of subjective measures to neurophysiological results was seen in both median nerve sensory and motor conduction as well as in ulnar nerve motor conduction. CONCLUSIONS: In addition to median-nerve dysfunction, it might be suggested that ulnar nerve changes can contribute to symptoms of carpal tunnel syndrome in patients. Several associations were found using a median-ulnar sensory latency difference in the finger-wrist segment and a sensory conduction difference in the palm to wrist segment. Significant correlations were established by both conventional NCS and the new hand-held device.

Brainstem size and function at term age in relation to later neurosensory disability in high-risk, preterm infants.

UNLABELLED: The aim of this study was to measure brainstem size on magnetic resonance imaging (MRI) scans of high-risk. preterm infants, to assess brainstem function by brainstem auditory-evoked potentials (BAEP) and to determine the predictive value of these measures for the neurosensory outcome. A total of 51 preterm infants (gestational age <34 wk, birthweight <1,500 g) underwent examinations at term age; neuromotor outcome and hearing were followed up until a corrected age of 18 mo. Fourteen (27%) infants had neurosensory disability. Those with a later neurosensory disability had a significantly smaller brain stem than those with a normal outcome. The preterm infants had significantly longer peak latency (L) V and interpeak latency (IPL) III-V than the full-term control infants. Most of the preterm infants with severe cerebral palsy or hearing loss had abnormal BAEP. Sensitivity of morphometric dimensions for predicting neurosensory disability was only 20-31%, but specificity was 97-100%. Abnormal L I and IPL III-V in BAEP predicted disability with a sensitivity of 93% and a specificity of 57-59%. CONCLUSION: We conclude that adverse events during the perinatal period may lead to morphofunctional changes in the brain stem in high-risk, preterm infants, and it seems that functional changes are accurate in predicting neurosensory disability in such patients.

Prediction of permanent hearing loss in high-risk preterm infants at term age.

UNLABELLED: The aim of this series was to assess hearing screenings; auditory brainstem responses (ABR), transient evoked otoacoustic emissions (TEOAE) and free field auditory responses (FF) for the prediction of permanent bilateral hearing loss in high-risk preterm infants at term post-conceptional age. A total of 51 preterm infants (gestational age < 34 weeks, birth weight < 1500 g) underwent examinations at term and hearing, speech and neurological development were followed up until a corrected age of 18 months. Significant hearing defects were verified by broader ABR examinations under sedation and by clinical ward observation including responsiveness to sounds and enhancement of hearing using an amplification device. Seven bilateral fails in ABR were found, together with nine bilateral fails in TEOAE and four fails in FF screening at term age. Six preterm infants were later confirmed to have a significant permanent bilateral hearing loss, four of whom had also cerebral palsy. Bilateral failure in ABR screening predicted hearing loss with a sensitivity of 100% and a specificity of 98%, TEOAE with a sensitivity of 50% and a specificity of 84% and in the FF examination at the levels of 50% and 98%, respectively. CONCLUSION: Transient evoked otoacoustic emissions alone seem not to be so applicable to the neonatal screening of hearing in high-risk preterm infants as shown earlier in full-term infants, possibly because a hearing defect may be due to retrocochlear damage. Consequently, auditory brainstem response screening seems to be more suitable for very low birth weight preterm infants.

Nerve lesions after therapy for childhood acute lymphoblastic leukemia.

BACKGROUND: The objective of the current study was to use somatosensory evoked potentials (SEP) to detect signs of nerve lesions in the peripheral nerve and in the central nervous system (CNS) after 3 years of treatment for childhood acute lymphoblastic leukemia (ALL). METHODS: The somatosensory potentials evoked by stimulation of the median nerve and posterior tibial nerve were recorded in 31 children with ALL after 3 years of therapy. All patients were examined clinically. The 14 standard risk patients had been treated with chemotherapy according to the Nordic regimen, and the 17 intermediate risk or high risk patients had been treated with chemotherapy and cranial irradiation according to the ALL BFM-83 protocol. RESULTS: A decrease in amplitudes was observed at the brachial plexus and spinal cord (C7) in the median SEP, and at the knee, spinal cord (Th12), and cortex in the tibial SEP, indicating axonal injury within the entire CNS in the patients with ALL compared with healthy age-, gender-, and height-matched controls. Prolongation of the SEP latencies was found within the spinal cord, indicating demyelination. These SEP changes had persisted for 2 years since the last injection/infusion of vincristine or methotrexate, which are the principal neurotoxic drugs used in chemotherapy for ALL. Clinical signs of nerve injury such as depressed deep tendon reflexes and gross or fine motor difficulties were found in approximately 33% of the patients and dysdiadochokinesia in 50%. CONCLUSIONS: Treatment of ALL in children principally with vincristine and methotrexate causes long-standing axonal injury throughout the nervous system and demyelination within the spinal cord. These changes are associated with clinical neurologic findings.