Neurourology concerns nervous system control of the genitourinary system, and of conditions causing abnormal urination. Neurological diseases and disorders such as a stroke, multiple sclerosis, Parkinson's disease, and spinal cord injury can disrupt the lower urinary tract and result in conditions such as urinary incontinence, detrusor overactivity, urinary retention, and detrusor sphincter dyssynergia. Urodynamic studies play an important diagnostic role in neurourology. Therapy for nervous system disorders includes clean intermittent self-catheterization of the bladder, anticholinergic drugs, injection of Botulinum toxin into the bladder wall, and advanced and less commonly used therapies such as sacral neuromodulation. Less marked neurological abnormalities can cause urological disorders as well—for example, abnormalities of the sensory nervous system are thought by many researchers to play a role in disorders of painful or frequent urination (e.g. painful bladder syndrome also known as interstitial cystitis).