Multiple sclerosis (MS) can cause progressive walking impairment that contributes to disability and reduced quality of life. Dalfampridine, a voltage-dependent potassium channel blocker, has been shown to improve walking in patients with MS, as demonstrated by an increase in walking speed.
Dalfampridine is approved as symptomatic treatment of impaired mobility in MS patients. Recently, it has been published dalfampridine could have an effect on other functional systems (FS) not directly related to ambulation.
To demonstrate the dalfampridine effect on different FS.
To identify wether the impact on the different FS stabilizes the EDSS.
To establish correlations between different scales used to measure dalfampridine effectiveness and FS scores.
We collected 22 patients diagnosed of either relapsing-remitting, secondary progressive or primary progressive MS according Mc Donald´s criteria 2010 responsers to dalfampridine for at least one year.
Dalfampridine effectiveness was evaluated by Timed 25 foot-walk (T25-FW), Timed Up and GO (TUG), and Two minutes walk test (2MWT).
EDSS was performed every 3 months.
Median, interquartile ranges and p values were evaluated by Friedman test.
- The mean of follow-up was 19,5 months (13 - 26)
- Outcomes on functional systems were:
Visual functions: at start treatment 0,0 (0.0 - 1.0); at 12 months 0,0 (0.0 - 0.0); at last visit: 0,0 (0.0 - 0.0) p= 0,069
Brainstem functions: at start treatment 0,0 (0.0 - 2.0); at 12 months 0,0 (0.0 - 2.0); at last visit: 0,0 (0.0 - 2.0) p= 0,368
Pyramidal functions: at start treatment 3,0 (2.0 - 3.0); at 12 months 3,0 (2.0 - 3.0); at last visit: 3,0 (2.0 - 3.0) p= 1,000
Cerebellar functions: at start treatment 2,0 (2.0 - 3.0); at 12 months 2,0 (1.0 - 2.0); at last visit: 2,0 (1.0 - 2.0) p= 0,670
Sensory functions: at start treatment 2,0 (2.0 - 3.0); at 12 months 2,0 (2.0 - 3.0); at last visit: 2,0 (2.0 - 3.0) p= 0,867
Bowel and Bladder functions: at start treatment 1,0 (0.0 - 1.0); at 12 months 1,0 (1.0 - 1.0); at last visit: 1,0 (1.0 - 1.0) p= 1,000
Cerebral functions: at start treatment 1,0 (0.0 - 2.0); at 12 months 0,0 (0.0 - 0.0); at last visit: 0,0 (0.0 - 0.0) p= 0,005
Ambulation score: at start treatment 6,0 (2.0 - 7.0); at 12 months 6,0 (3.0 - 7.0); at last visit: 6,0 (5.0 - 8.0) p= 0,323
- The EDSS mean at the start of dalfampridine was 5,61 (4.0 - 6.5), at 12 months 5,5 (3.5 - 7.0) p= 0,339 and at the last visit 5,45 (2.0 - 7.0) p= 0,441.
- There was a negative correlation between sphincter and sensory functions and 2MWT.
We could obtain a relevant effect of dalfampridine on cerebral functions measured over more than a year. Nonetheless, we can not conclude if this outcome is directly related with an effect over cognition or it is related with improvement of fatigue and depression.
EDSS remained stable over more than a year in dalfampridine responsers.
We can not explain why patients who are responsers to dalfampridine had worsening of sphincter and sensory functions at the same time.