Brain degeneration, including that caused by traumatic brain injury (tBI) often leads to severe bladder dysfunction, including incontinence and lower urinary tract symptoms; with the causes remaining unknown. Male C57BL/6J mice underwent repetitive moderate brain injury (rmdTBI) or sham injury, then mice received either cis p-tau monoclonal antibody (cis mAb), which prevents brain degeneration in TBI mice, or control (IgG). Void spot assays revealed age-dependent incontinence in IgG controls 8 months after injury, while cis mAb treated or sham mice showed no dysfunction. No obvious bladder pathology occurred in any group. Urodynamic cystometry in conscious mice revealed overactive bladder, reduced maximal voiding pressures and incontinence in IgG control, but not sham or cis mAb treated mice. Hyperphosphorylated tau deposition and neural tangle-like pathology occurred in cortical and hippocampal regions only of IgG control mice accompanied with post-traumatic neuroinflammation and was not seen in midbrain and hindbrain regions associated with bladder filling and voiding reflex arcs. In this model of brain degeneration bladder dysfunction results from rostral, and not hindbrain damage, indicating that rostral brain inputs are required for normal bladder functioning. Detailed analysis of the functioning of neural circuits controlling bladder function in tBI should lead to insights into how brain degeneration leads to bladder dysfunction, as well as novel strategies to treat these disorders. Overactive bladder, incontinence and other bladder symptoms often occur in patients with neurodegenerative disease or brain injury, and can lead to significant debility, striking loss of self-esteem, depression, and the need for long term institutionalization 1-4. At present the mechanisms by which neurodegenerative diseases lead to severe bladder dysfunction remain entirely unclear. Although severe or/and moderate injuries most frequently sustained from single events falls, assaults, or roadside traffic accidents, which can lead to early death and profound disability 5,6 , military and sport-related injuries have received increasing attention in the past decade 7-10. Military-based brain injuries result in several