Working Memory Training in Huntington's Disease
Condition: Huntington's Disease
MeSH terms: Huntington Disease
Study type: Interventional

Summary: 
      There is a paucity of investigation into effective interventions to enhance cognitive
      function and/or mitigate cognitive decline in individuals with Huntington disease (HD). This
      study targeted working memory (WM), which is the ability to actively hold information in the
      mind in order to perform complex mental tasks, given reports of WM dysfunction in patients
      with HD. The investigators examined the feasibility of conducting a 5-week WM training
      program (Cogmed). Patient adherence and treatment tolerance were assessed. In addition,
      preliminary evidence for the efficacy of this training program on targeted cognitive
      abilities was examined. Nine patients with pre-manifest or early stage HD underwent training.
      Patients were assessed before the intervention and one week after completion.
    

Detailed description: 
      Huntington disease (HD) is associated with a variety of cognitive deficits, with prominent
      difficulties in working memory (WM). WM deficits are notably compromised in early-onset and
      prodromal HD patients. This study aimed to determine the feasibility of a computer-ized WM
      training program (Cogmed QM), novel to the HD population. Nine patients, aged 26-62, with
      early stage HD underwent a 25-session (5 days/week for 5 weeks) WM training program (Cogmed
      QM). Training exercises involved the manipulation and storage of verbal and visuospatial
      information, with difficulty adapted as a function of individual performance.
      Neuropsychological testing was conducted before and after training, and performance on
      criterion WM measures (Digit Span and Spatial Span) and near-transfer WM measures (Symbol
      Span and Auditory WM) were evaluated. Post-training inter-views about patient experience were
      thematically analyzed using NVivo software. Seven of nine patients demonstrated adherence to
      the training and completed all sessions within the recommended timeframe of 5 weeks. All
      adherent patients reported that they found training helpful (n=7), and almost all felt that
      their memory improved (n=6). Compared to baseline scores, patients showed significant
      improvement on the neuropsychological measures of verbal WM, including Digit Span (p = .047)
      and Auditory WM (p = .041). This pilot study provides support for feasibility of computerized
      WM training in early-stage patients with HD. Results suggest that HD patients can improve WM
      with intensive training, though a full-scale intervention project is needed to understand the
      reliability of changes over time.
    

Intervention name(s): Cogmed QM
Intervention type(s): Behavioral
Intervention description(s): The intervention consisted of 25 Cogmed sessions, typically completed over a five week period (i.e. 5 days per week), with each session lasting between 40-50 minutes per day. The program consists of 12 exercises that target visuo-spatial or verbal working memory. At each training session, participants completed 8 of the 12 exercises (order selected by the user), with 15 trials per exercise. Cogmed QM is an adaptive program, wherein task difficulty is adjusted to performance on each trial. The level of difficulty adjusts continuously and automatically, ensuring that each session provides an engaging, challenging level of WM capacity. Breaks were permitted, and encouraged, at the participants' discretion throughout the session.
Intervention model: Single Group Assignment
Masking: None (Open Label)
Primary purpose: Treatment
Keywords: Huntington disease; cognitive rehabilitation; cognitive dysfunction