Neurological disorders may affect Safety Critical Work through their effect on cognitive function, vision, sensation, motor function or balance, and sudden incapacity such as an intracranial bleed is especially relevant to Category 1. Balance is needed for walking or running on ballast and climbing into cabs, onto rolling stock or up to signals, and may be affected by cerebellar, spinal cord and vestibular disorders; vertigo can arise suddenly and with sufficient severity make Safety Critical Work impossible, compounded by oscillopsia. A worker with a neurological disorder is examined for the functions required for safe working, with referral for functional or practical assessment where the health professional is concerned. The fitness criteria in Table 17 address, in alphabetical order, unruptured intracranial aneurysms and vascular malformations, neuromuscular conditions, transient ischaemic attacks, space-occupying lesions including brain tumours and other lesions such as abscesses and chronic subdural haematomas, and subarachnoid haemorrhage, with the advice on intracranial surgery applying where a craniotomy has been performed and the seizure criteria applying where seizures have occurred; unless stated otherwise the criteria apply to both Category 1 and Category 2 workers, with individual assessment of the impairment against the task, and determinations generally rest on specialist opinion and defined review.
The graph holds this control, the 0 it maps to, and the evidence behind each claim, over MCP and REST.