Spinocerebellar Ataxia Type 7 (SCA7) is characterized by progressive cerebellar ataxia and cone-rod and retinal dystrophy with progressive central visual loss resulting in blindness. In our clinical experiences, patients with SCA7 also report lower urinary tract (LUT) symptoms. However there are a few reports about LUT symptoms in patients with SCA7. The presence of overactive bladder symptoms impairs quality of life and increase the risk for falls and fractures, particularly relevant to this cohort because of motor disability and visual disturbance. However, the pathophysiological basis for LUT dysfunction is poorly characterized in this group. The aim of this study is to evaluate the urodynamic findings in a cohort of patients with SCA7 reporting LUT symptoms.

Two SCA 7 patients with LUT symptoms were enrolled and investigated by urodynamic study (UDS).

Case 1: A 61 years old female with 20 years history of ataxia. She has moderate ataxia and severe visual loss. Her LUT symptoms are urgency, nocturia, urge and stress incontinence. UDS showed evidence for borderline reduced bladder capacity without abnormal detrusor contraction during the filling phase, and low and intermittent urinary flow, low detrusor pressure at maximum flow rate (Pdet at Qmax)(34 cmH2O) , prolonged detrusor contraction and equivocal AG number (30.0) during the voiding phase, although residual urine volume (PVR) is low (20ml). These UDS findings suggest increased bladder sensation without abnormal bladder contraction as a storage problem and detrusor underactivity with or without bladder outlet obstruction as a voiding problem.
Case 2: A 51 years old male with over 17 years history of ataxia. He has moderate ataxia and severe visual loss. His LUTS symptoms are urgency, frequency and urge incontinence. UDS showed reduced bladder capacity without abnormal detrusor contraction such as detrusor overactivity and low compliance bladder during the filling phase, and low and iregular urinary flow, low Pdet at Qmax (59 cmH2O) , prolonged detrusor contraction and high AG number (44.6) during the voiding phase, although PVR is low (23ml). These UDS findings suggest increased bladder sensation without abnormal bladder contraction as a storage problem and detrusor underactivity with bladder outlet obstruction as a voiding problem.

These UDS findings in both cases suggest that SCA 7 patients with LUT symptoms have both storage and voiding dysfunction such as increased bladder sensation without abnormal bladder contraction and detrusor underactivity with (or without) bladder outlet obstruction.

Significant pathophysiological changes in lower urinary tract control are detected in patient with SCA 7. Increased bladder sensation without abnormal bladder contraction during the bladder filling phase and detrusor underactivity with (or without) bladder outlet obstruction during voiding phase appears to be a common findings in patient with SCA 7. This implication may be useful in planning of the management for LUT symptoms in these patients.