BLB Study Back or Leg Pain and Bladder Symptoms Study

Uro-neurological disorders are those in which there is a disturbance of bladder function related to a neurological cause. However, many patients with Uro-Neurological disorders are not found to have explanatory abnormalities despite adequate clinical and radiological investigation, so-called 'scan negative' patients. The BLB study will investigate this problem through an acute disorder, Cauda Equina Syndrome (CES), to provide a better understanding of scan-negative Uro-Neurological disorders.

CES is a devastating condition caused by compression of the cauda equina nerve roots resulting in bowel, bladder and sexual dysfunction with potential lower limb weakness. CES requires urgent surgery and has serious potential morbidity and medico-legal consequences1. Suspected acute CES has a minimum incidence of 11 per 100,000 making it twice as common as multiple sclerosis. However, in the two largest studies both retrospective and from Edinburgh, 43-48% of patients with clinical CES were 'scan-negative' and indeed received no other diagnosis 1,2.

Little is known about patients with 'scan negative' CES and nothing is known about their outcome. Our two studies in Edinburgh found basic clinical and demographic characteristics could not distinguish 'scan positive' and 'scan negative' groups 1,2. However, on the basis of clinical experience, and now prospective pilot data, the investigators hypothesise that many of these patients have either an acute functional disorder or, in some cases, sacral nerve damage not seen on imaging but detectable on anal sphincter EMG. Functional disorders, also called psychogenic/non-organic disorders, refer to genuinely experienced physical symptoms which can be positively identified as not related to underlying neurological disease3. Finding out about the diagnosis of patients with 'scan negative' CES would enable them to access treatment and improve their outcome as well as creating better service provision for them in the long term. There is also limited data on long term outcome in patients with 'scan positive' CES and a wish for knowledge from the medical community about what the priorities for patients with 'scan positive' CES are after discharge. The investigators have called the study subsection 'Back or Leg pain with Bladder symptoms' (BLB) study because this most accurately describes the symptoms patients have and we know that describing something negatively to patients (e.g. medically unexplained symptoms)is found by patients to be unhelpful.

The BLB study asks three main questions; do patients with 'scan negative' CES have symptoms of bowel, bladder, sexual dysfunction and lower limb weakness and sensory abnormalities due to a functional disorder?; do a proportion of patients with 'scan negative' CES have missed neurological disease?; what are the outcomes of patients with 'scan negative' and 'scan positive' CES after three months?