Cognitive Impairment and MS
Cognitive impairment is an area of MS that is often overlooked, as the common deficits caused by the condition concern motor skills and vision, despite cognitive impairment showing prevalence rates of 43% to 70% at earlier and later stages of the condition. Cognitive problems can appear independently of the physical problems caused by MS, which further complicates their identification. (continue reading below video block)
Cognitive functions affected by MS include:
- Long-term memory
- Attention
- Efficiently processing information
- Executive functioning (ability to plan and anticipate outcomes in complex goal-orientated tasks)
- Deficits in processing speed
Processing speed, visual learning, and memory are thought to be the most commonly affected areas in MS.
Long-Term Memory
Long-term memory is most commonly impaired cognitive function in MS with rates of 40% to 65%. Recent research has shown that the main cause for long-term memory impairment is less to do with difficulties in the retrieval of information, and more to do with the initial learning of the information. Patients with MS require information to be repeated more, but once the information has been learned, they can recall the information at the same levels as patients without MS. Other factors related to learning abilities affected by MS include slow processing speeds and difficulty to disregard irrelevant information or stimuli.
Attention
The processes identified under ‘attention’ are very varied, and as such concrete conclusions about the effect of MS on attention, processes have been difficult to make. Maintaining sustained attention is typically affected, as well as the ability to multitask.
Fatigue is also a factor that can affect attention processes, in particular, the ability to hold attention for long periods of time, but is often overlooked.
Information Processing
Problems with information processing have been seen across the disease course and are one of the most commonly seen cognitive symptom of MS. The ability to maintain information for a short period of time, also known as working memory, is negatively affected by MS. Impairment in information processing is usually seen concurrently with the other cognitive deficits in MS. Processing speed can be used to predict a patient’s long-term cognitive decline and also predict their performance in everyday tasks.
Executive Functioning
Defined as the cognitive abilities necessary for goal-directed tasks and complex decision making and adaptation to changes in the environment, executive functioning is one of the less frequent deficits seen in patients with MS.
Executive tasks include:
- Abstract and conceptual thinking.
- Planning and organization.
- Fluency.
- Anticipate outcomes.
Deficits in fluency see patients struggle with both phonemic (letter and word fluency) and semantic fluency (word category fluency). Depression affects the measurement of executive functioning and should be taken into account when examining and interpreting a patient’s performance in executive functioning.
Processing Speed
A reduction in processing speed is the most common cognitive area affected by MS, and deficits are seen concurrently with other areas of decline. The effect on a patient’s working memory is less than on their processing speed there is a positive correlation between increased demand on working memory and deficits in processing speed.
A sensitive test of cognitive dysfunction is a paced auditory serial addition test (PASAT), which tests working memory that puts a high demand on a patient’s processing speed.
Treatment of Cognitive Impairments in MS
……………………..
Visit our MS Learning Channel on YouTube: http://www.youtube.com/msviewsandnews