Cauda Equina Syndrome (CES) is a condition whereby damage to a group of nerves below the end of the spinal cord known as cauda equina can lead to a spinal injury. CES can cause a number of medical problems for the person affected including loss of bowel & bladder control, numbness in the legs and back, sexual dysfunction, and gait disturbance.
One of the most distressing symptoms of cauda equina syndrome is urinary dysfunction, which is manifest as inability to pass urine or inability to control urinary leakage. It is essential that a urologist is involved in the early management of all CES cases and subsequently involved in monitoring and treating complications and difficulties.
The importance of prevention cannot be over-emphasised. At presentation the presence of saddle anaesthesia, which is a change in sensation in the area around the bottom and genitals, in association with acute onset back pain and abnormalities of sensation and motor function in the legs, is an absolute indication for an urgent MRI scan (hours not days) to establish spinal compression with the prospect of immediate surgical decompression.
If decompression occurs before the onset of incontinence or inability to pass urine, the outlook for voiding is extremely good. Even if urinary symptoms are present, the outlook in the first 12 to 24 hours remains good. Failure of the medical staff to recognise this symptom complex, and provide urgent treatment and investigations is litigable negligence.
After the decompressive spinal surgery the ability to pass urine spontaneously with good bladder emptying must be closely monitored.
Inability to void with lack of sensation of bladder filling requires timely catheterisation. Overdistention of the bladder at this stage may lead to permanent bladder damage. After a short period of an indwelling catheter, a trial without catheter should determine whether or not there are any problems. If there is no progress the teaching of clean intermittent catheterisation is vital by a member of the urology team before discharge with an appropriate appointment for a urologist specialising in urological complications of CES.
In the first six months such an inability to void is likely to continue being managed by intermittent self-catheterization. Importantly there is considerable prospect for improvement over an 18-month period following the spinal nerve decompression. This improvement may allow spontaneous voiding, but can also cause an important change from an atonic non-functional bladder to a hypertonic over-active bladder with incontinence. Both atonic and hypertonic bladders may suffer from stress incontinence (being wet when moving, laughing, coughing, or during sexual relationships).
A post cauda equina decompression symptomatic bladder is known as a neuropathic bladder. In order to divide these bladders into two groups, non-functional low pressure and over-active high-pressure bladder, video urodynamic tests are essential. These will determine the type of bladder and the most appropriate treatment.
Low-pressure Atonic Bladder (patient unable to void):
These bladders are managed by intermittent self-catheterisation usually four to six times in a 24-hour period. Most patients remain continent between episodes. Some may require a sling operation to correct stress incontinence caused by pelvic floor weakness. Infections are managed with culture-directed antibiotics if symptomatic. Multiple infections may require long-term low-dose treatments with antibiotics. These patients require yearly ultrasound tests and blood tests to establish normal kidney function. There is an increased risk of urinary tract stone disease. In the terminal years of life permanent urethral/suprapubic catheter are often deployed.
High-pressure Over-Active Bladders with Incontinence:
This group of patients is far more difficult to manage. In some, intermittent self-catheterisation can prevent the point at which the bladder becomes unstable which means that the bladder suffers from high-pressure contractions resulting in the irresistible need to void immediately, resulting in incontinence. Another important cause of incontinence is lack of the ability of the bladder to relax when filling (compliance) resulting in urgency and incontinence.
Many will benefit from anticholinergic drugs such as Solifenacin which dampens down bladder contractions, or the newer drug Mirabegron which can be used in combination with Solifenacin.
Failure to respond to these measures will lead to the use of Botox injections, which are applied by day case cystoscopic injection on a 9 to 12-monthly basis.
At best these will restore reasonable voiding, at worst intermittent self-catheterisation will be required because the bladder is fully paralysed, but the patient is usually continent in the interval between catheterisations.
In cases which fail these treatments, posterior tibial nerve stimulation, sacral nerve stimulation and ileocystoplasty operations can provide an improved quality of life. Both these treatments are available at specialist centres for the relatively small group of patients who will require such treatment.
All patients who suffer from a hypertensive over-active bladder will require annual assessments and further urodynamic tests when symptoms change.
The implantation of an artificial urinary sphincter can replace the loss of function of the external urinary sphincter which controls continence in patients who suffer from sphincter weakness incontinence. The operation involves the placement of an inflatable cuff which occludes the urethra which can be opened by activating a control device. Once again, this operation is available at specialist urology centres.
Unlike spinal injury patients, because CES patients are able to walk and appear normal it is unlikely they will receive the specialist help in a rehabilitation centre which can make such difference to coping with urinary and faecal incontinence, sexual problems and psychiatric issues. I would urge all CES patients to seek such help. All such centres (National Rehabilitation Centre Republic of Ireland) have excellent urological expertise available.
The objective of all urological treatment is to provide continence in a low-pressure bladder thus preserving kidney function while at the same time managing infections and the risk of urinary stone formation. All such patients should remain under the supervision of the Urology Department and their knowledgeable and helpful urology nurse practitioners. In cases which have been negligently managed, a urologist is able to provide vital evidence to support proof of substandard treatment as well as defining the outcome, likely future problems and needs for those wishing to pursue a legal course of action.
Article written by Ronald A Miller MS FRCS FRGS
Consultant Urological Surgeon – Urology Chambers Limited
Hospital of St John and St Elizabeth (London)
Ronald Miller is a Consultant Urological Surgeon with more than 30 years’ experience at consultant level. He now works in private practice having previously been Head of Department at The Whittington Hospital, Honorary Consultant Urologist at University College Hospital and the Royal Free Hospitals in London, and Honorary Senior Lecturer at the Institute of Urology. For more information log onto www.ronaldmiller.com