Overactive bladder is a is a prevalent condition than may cause a negative impact on patients quality of life. According to the International Continence Society (ICS) definition, OAB consists of urinary urgency with or without urge incontinence, often accompanied by frequency and nocturia. 

The treatment of these symptoms may be challenging for physicians. Lifestyle modifications and Behavioral therapies should be offered as first-line therapy. Second line therapy consists on the use of antimuscarinic and beta3-adrenoceptor agonist agents. 
In patients not responding to conservative therapies, more invasive treatments should be offered. 
Sacral neuromodulation,  Peripheral tibial nerve stimulation and Intradetrusor onabotulinumtoxin A (Botox) may be offered as third-line treatment in select patients who have symptoms that are severe and refractory to first and second-line treatments.

For patients who do not respond to conservative therapies Botulinum Toxin has been shown as an effective therapy for those with idiopathic overactive bladder refractory to drug treatment. 
Botulinum Toxin A blocks the presynaptic release of acetylcholine and urothelial sensory receptors expression causing chemical denervation of detrusor muscle. 
The onset of effect is one or two weeks and the average response to this treatment is set in 6 months. Treatment with Botulinum Toxin A seems to be very  tolerated with minimal injection site and systemic side-effects.

The aim of our study is to identify possible clinical or urodynamic features that predict a favourable response to onabotulinumtoxinA treatment.

Retrospective analysis of patients with idiopathic overactive bladder and urinary incontinence, who underwent for the first-time to Botulinum Toxin intradetrusor injection with accurate response, between January 2013 and October 2017 in our Hospital. 

Patients were divided in to groups, according to the duration of the effect. The group 1 consists of patients with a response time of less than 12 months. The group 2 consists of patients with a response equal or greater to 12 months. 

Descriptive and comparative analyses of the following variables was carried out: age, smoking, alcohol consumption, arterial hypertension, diabetes mellitus, dyslipidemia, obesity, neuromuscular disturbances, anxiety-depressive syndrome, history of delivering, maximum cistometric capacity, non-inhibited detrusor´s contractions magnitude, length of clinical manifestations, number of previous treatments and personal background of pelvic surgery or surgical treatment of urinary incontinence.

32 patients were included, 15 in group 1 and 17 in group 2. 
No differences were  found between the two groups for the variables analyzed: age (70,23 vs 63 years), smoking (11,8% vs 26,7%),  alcohol consumtion (5,9% vs 6,85%), arterial hypertension (64,7% vs 40%), diabetes mellitus (23,5% vs 6,7%), dyslipidemia (47,1% vs 26,7%), obesity (58,8% vs 46, 7%), neuromuscular disturbances (35,3% vs 60%), anxiety-depressive syndrome (64,7% vs 33,3%), history of delivery (58,8% vs 86,7%), maximum cistometric capacity (241, 2 vs 200,4 ml), non-inhibited detrusor´s contractions magnitude (18 cmH20 vs 26 cmH20), length of clinical manifestations (42 vs 45 months), number of previous treatments (2 in both groups) and personal background of pelvic surgery (41,2% vs 26,7%) or surgical correction of urinary treatment (5,9% vs 26,7%).

There are no similar trials published that support our results. 
Although we couldn´t find significant differences, patients included in group 1, show a tendency to present a higher percentage of hypertension, diabetes mellitus, dyslipidemia, obesity, anxiety-depression syndrome and personal background of pelvic surgery. 

Neither has been demonstrated other predictive factors for long-lasting response to OnabotulinumtoxinA for other medical uses. 
It would be necessary to develop more studies in this area, that support our results and it´s also necessary to research new factors related with a fulfilling response to botulinum toxin treatment.

We couldn´t identify any clinical or urodinamic feature that predicts a long-lasting response to the Botulinum toxin treatment.  There is no difference between both groups in any of the analyzed variables.