Dr Eileen Mc Manus is an Advanced Trainee in Neurology working at Waikato General Hospital, Hamilton, New Zealand. She was born and trained in Ireland, gaining both MBChB and Neuroscience MSc from Trinity College Dublin 2013. She moved to New Zealand in 2015, working first in Thames Hospital and then Waikato General Hospital. In her spare time, she is an avid hiker and loves the outdoors including landscape photography.
Extended Interval Dosing Natalizumab and Ccognitive Function in Relapsing Remitting Multiple Sclerosis Patients: A Retrospective Audit
Cognitive impairment is frequently reported in Relapsing Remitting Multiple Sclerosis (RRMS). Multiple cognitive domains including processing speed, episodic memory and executive function can be impaired. Natalizumab (NTX) is a well-established therapy which has been shown to reduce annualised relapse rate (ARR) and cognitive impairment in RRMS. It is usually administered at 4 weekly intervals known as Standardised Interval Dosing (SID). In recent years, Extended Interval Dosing (EID) has been introduced to reduce the risk of progressive multifocal encephalopathy (PML). Although EID NTX has been shown to be non-inferior to SID NTX in reducing ARR, the impact on cognition has not yet been studied.
To investigate whether EID NTX improves cognition in RRMS.
A retrospective, monocentric single arm analysis of 34 RRMS patients on EID NTX was performed. A neuropsychological assessment was performed pre and (on average 28 months) post NTX infusion. A battery of 20 cognitive screening tests along with the Hospital Anxiety and Depression Scale (HADS) were applied at both neuropsychological assessments. A univariate analysis of pre and post NTZ neuropsychological test scores was performed. Raw data was converted into Z scores. A non-parametric Wilcoxon test was applied (p<0.05).
14/20 cognitive parameters showed improvement with 5/14 reaching statistical significance namely: Trails A (visual attention/information processing speed), Line-orientation (visual spatial attention), Picture-naming (word finding), Digital-Span (attention, executive function and memory) and Story-recall (memory). Depression and anxiety HADS scores remained unchanged.
Our data suggests that NTX EID leads to an improvement in deficits in executive function, memory, attention and information processing speeds; cognitive domains known to be particularly affected in RRMS patients. However, an observational prospective analysis is warranted.