Management of detrusor external sphincter dyssynergia in neurogenic bladder

Spinal cord injury (SCI) affects 11.5 to 53.4 individuals per million of the population in developed countries each year. SCI is caused by trauma, although it can also result from myelopathy, myelitis, vascular disease or arteriovenous malformations and multiple sclerosis. Patients with complete lesions of the spinal cord between spinal cord level T6 and S2, after they recover from spinal shock, generally exhibit involuntary bladder contractions without sensation, smooth sphincter synergy, but with detrusor striated sphincter dyssynergia (DESD). Those with lesions above spinal cord level T6 may experience, in addition, smooth sphincter dyssynergia and autonomic hyperreflexia. DESD is a debilitating problem in patients with SCI. It carries a high risk of complications, and even life expectancy can be affected. Nearly half of the patients with untreated DESD will develop deleterious urologic complications, due to high intravesical pressures, resulting in urolithiasis, urinary tract infection (UTI), vesicoureteral reflux (VUR), hydronephrosis, obstructive uropathy, and renal failure. The mainstay of treatment is the use of antimuscarinics and catheterization, but in those for whom this is not possible external sphincterotomy has been a last resort option. External sphincterotomy is associated with significant risks, including haemorrhage; erectile dysfunction and the possibility of redo procedures. Over the last decade alternatives have been investigated, such as urethral stents and intrasphincteric botulinum toxin injection. In this review, we will cover neurogenic DESD, with emphasis on definition, classifications, diagnosis and different therapeutic options available.