65 patients with SCA were invited to take part in the study but only 50 accepted to complete the assessments. Of these, 4 patients were affected by SCA1, 5 by SCA2, 13 by SCA3, 17 by SCA6 and 5 by SCA7.
30 patients (60%) self-reported urinary complaints during the clinical assessment, with a higher prevalence of bladder symptoms in patients with SCA7 (83.3%) and SCA3 (61.5%) compared to SCA1 and SCA2 (50%). The median duration of urinary symptoms was 5.0 years, being higher in SCA7 and SCA6 groups (13.0 and 9.0 years, respectively).
With regards to USP questionnaire, only 9 patients (18% - 4 affected by SCA2 , 2 by SCA3, 2 by SCA6 and 1 by SCA7) had a score of 0, indicating absence of any urinary symptoms. The median scores of the different sections of USP were the following: stress incontinence 0.9, overactive bladder (OAB) 4.71 and low stream (LS) 1.1. 40 patients (81.6%) scored at least 1 point in the OAB score, and 18 patients (36,7%) in the LS score. Urinary frequency and urgency were the most common complaints (both n=33, 67.3%), followed by incontinence and nocturia (both n=15, 30.6%).
9 patients underwent pressure flow urodynamic studies; of these, 2 were affected by SCA 7 and 7 by SCA3. With regards to patients with SCA3: detrusor overactivity was found in 6 (85.7%) and acontractile detrusor in 1 patient; mean detrusor pressure at maximum flow (Pdet at Qmax) was 36.33 cmhH2O (SD 20.89), mean bladder capacity was 307.4 ml (SD 199.29), mean volume at first desire to void (FDV) was 153.75 ml (SD 97.1). Free uroflowmetry showed mean PVR of 90.29 ml (SD 121.1), mean Qmax 20.15 ml/s (SD 8.77) and mean voided volume 221.62 ml (SD 185.25). According to the bladder outlet obstruction (BOO) index, three patients were categorized as equivocal and three as unobstructed (data were not available for one patient). With regards to patients with SCA7: no detrusor overactivity was found; mean detrusor pressure at maximum flow (Pdet at Qmax) was 46.5 cmH2O (SD 17.68), mean bladder capacity was 222 ml (SD 124.45), mean volume at first desire to void (FDV) was 175.5 ml (SD 99.7). Free uroflowmetry showed mean PVR of 58.75 ml (SD 85.62) and mean voided volume 127.3 ml (SD 86.07). One patient was categorized as obstructed according to the BOO index (data were not available for one patient).
Patients with self-reported LUTS were significantly older (61.83 vs 51.70, p=0.021) and their ataxia was more severe (mean SARA score 15.793 vs 9.525, p=0.05).
Linear regression analysis showed that duration of ataxia was a determinant in severity of LUTS (p=0.024). Bowel complaints were less common (n=6; 12 %) and, when present, were mild in severity (mean NBD score 0.82; SD 1.6). Mean score of SF Qualiveen was 1.08 (SD 1.22); patients with SCA2, SCA 6 and SCA7 had lower scores (0.45, 0.7 and 1.10 respectively), indicating better quality of life, while those with SCA1 and 3 had higher scores (3.03 and 1.43 respectively).
Management of LUTS included oral medications (antimuscarinics (n=9; 18%) or Mirabegron (n=1; 2%), tamsulosin, (n=1; 2%)), percutaneous tibial nerve stimulation (n=1; 2%) and intermittent self catheterisation (n=1; 2%), non-pharmacological measures (n=19, 38%).