1. or multiple system atrophy (MSA)
Figure 1 Neural circuitry relevant to micturition in Parkinson disease (PD)
or multiple system atrophy (MSA)
Figure 1 | Neural circuitry relevant to micturition in Parkinson disease (PD) or multiple system atrophy (MSA). The lower urinary tract consists of two major components: the bladder and the urethra. The bladder receives innervation from the parasympathetic pelvic nerve. The urethra receives sympathetic innervation from the hypogastric nerve and somatic innervation from the pudendal nerve. Bladder relaxation during urine storage is dependent on the reflex arc of the sacral spinal cord. The storage reflex, which is predominantly restricted to the spinal cord, is facilitated in regions of the brain including the pontine storage centre, the hypothalamus, the cerebellum, the basal ganglia and the frontal cortex. Micturition is dependent upon activation of the reflex arc of the brainstem and spinal cord, which involves the midbrain periaqueductal grey (PAG) and the pontine micturition centre (PMC), which is located in or adjacent to the locus coeruleus (LC). Voiding function is initiated by signals in the hypothalamus and prefrontal cortex, which overlap with the storage-facilitating area. PD (blue line) is primarily induced by degeneration of dopaminergic neurons in the substantia nigra pars compacta (SNC), which reduces the activity of γ-aminobutyric acid (GABA)-releasing neurons projecting from the striatum to the PAG, thus, inhibiting the micturition reflex. The loss of dopaminergic neurons induces motor dysfunction and detrusor overactivity. In MSA (red lines), neuronal degeneration in the striatum including in the caudate nucleus and putamen (MSA-Parkinson) and in the cerebellum (MSA-cerebellar) induces PD-like symptoms and ataxia, respectively. In addition, neuronal degeneration in the brainstem and in the spinal cord induces autonomic dysfunction (MSA-autonomic) including detrusor underactivity and neurogenic sphincter dysfunction, constipation, postural hypotension and/or erectile dysfunction. DA, dopamine; GABA, γ-amino butyric acid; IML, intermediolateral cell column; L, lumbar; S, sacral; SPN, sacral parasympathetic nucleus; Th, thoracic.
Ogawa, T. et al. (2016) Prevalence and treatment of LUTS in patients with Parkinson disease or multiple system atrophy
Nat. Rev. Urol. doi: /nrurol