Hand-arm vibration syndrome Clinical and Neuro-physiological studies

Hand-arm vibration syndrome (HAVS) is a group of symptoms caused by the use of vibrating hand-held tools. It appears to cause damage to both small blood vessels and small, unmyelinated nerve fibers, resulting in two specific diseases: vibration-induced white finger (VWF) and vibratory neuropathy. Aims: to assess VWF and carpal tunnel syndrome (CTS) in vibration exposed workers in three factories in Helwan, to investigate neural conduction in the upper limbs [somato sensory evoked potentials (SSEPs) and distal sensory latency (DSL) of the median nerve] in those patientsA further aim was to assess the efficacy of engineering control by application foundation and concrete for vibratory machines and protective measures for vibratory workers, as reassessment of VWF and SSEPs were done after one year. Methods: A total of 210 male workers were evaluated using Stages of Vibration White Finger (Taylor-Pelmear System). The upper limb SSEPs were done to 39 subjects with manifestation of VWF. Distal sensory latency (DSL) of the median nerve was done to 18 workers with clinical manifestation of CTS. After one year, from application protective measures, reassessment of stages of Vibration White Finger and upper limb SSEPs were done. Results: The study shows that 39 subjects had manifestations of VWF then reduced to 25 subjects after application protective measures. Upper limb SSEPs showed significant reduction at Erb's points, cervical and cortical points after implementation of protective measures. CTS is common in vibration exposed workers with manifestations of VWF (46%) and most of them showed increased DSL of the median nerve. Conclusions: VWF is common in workers exposed to vibration from metal grinding in some of Helwan factories and CTS is common among those workers with VWF. Assessments of upper limb SSEPs and DSL of the median nerve are important to detect early neural damage. Protective measures are important for those subjects.