There are two main types of neurogenic bladder dysfunction in SCI: 1) neurogenic detrusor overactivity, represented by overactive, reflexic or spastic detrusor muscle activity, usually associated with sphincter dysynergia (Detrusor Sphincter Dyssynergia, DSD); and 2) detrusor underactivity or acontractile detrusor, represented by reduced or absent detrusor activity. The former is also referred to a UMN bladder dysfunction while the latter is referred to as LMN bladder dysfunction. Occasionally, neurogenic detrusor overactivity secondary to SCI is seen without associated sphincter dyssynergia. This can also result in difficulty maintaining continence. Methods to improve continence in those with or without DSD are often similar and are addressed in the sections on enhancing bladder volumes in DSD.