The multiple sclerosis it is a progressive disease of the central nervous system characterized by a generalized lesion of the brain and spinal cord (Chiaravalloti, Nancy and DeLuca, 2008). It is classified within the demyelinating diseases of the central nervous system. These are defined by an inadequate formation of myelin or by an affectation of the molecular mechanisms to maintain it (Bermejo-Velasco, et al., 2011).
The clinical and pathological characteristics of multiple sclerosis were described, in France and later in England, during the second half of the 19th century (Compson, 1988).
However, the first anatomical descriptions of Multiple Sclerosis were made at the beginning of the 20th century (Poser and Brinar, 2003) by Crueilhier and Carswell. It was Charcot who, in 1968, offered the first detailed description of the clinical and evolutionary aspects of the disease (Fernández, 2008).
Article index
Although the exact cause of multiple sclerosis is not yet known, it is currently thought to be the result of immunological, genetic, and viral factors (Chiaravalloti, Nancy, & DeLuca, 2008).
However, the most widely accepted pathogenic hypothesis is that multiple sclerosis is the result of the conjunction of a certain genetic predisposition and an unknown environmental factor..
When appearing in the same subject, they would originate a wide spectrum of alterations in the immune response, which in turn would be the cause of the inflammation present in multiple sclerosis lesions. (Fernández, 2000).
Multiple sclerosis is a progressive disease with a fluctuating and unpredictable course (Terré-Boliart and Orient-López, 2007), with variability being its most significant clinical characteristic (Fernández, 2000). This is because the clinical manifestations vary depending on the location of the lesions..
The most characteristic symptoms of multiple sclerosis include motor weakness, ataxia, spasticity, optic neuritis, diplopia, pain, fatigue, sphincter incontinence, sexual disorders, and dysarthria.
However, these are not the only symptoms that can be observed in the disease, since epileptic seizures, aphasia, hemianopia and dysphagia can also appear (Junqué and Barroso, 2001).
If we refer to statistical data, we can point out that motor-type alterations are 90-95% the most frequent, followed by sensory alterations in 77% and cerebellar alterations in 75% (Carretero-Ares et al, 2001).
Research since the 1980s has indicated that cognitive decline is also related to multiple sclerosis (Chiaravalloti, Nancy & DeLuca, 2008). Some studies show that these alterations can be found in up to 65% of patients (Rao, 2004).
Thus, the most common deficits in multiple sclerosis affect the evocation of information, working memory, abstract and conceptual reasoning, information processing speed, sustained attention and visuospatial skills (Peyser et al, 1990 ; Santiago-Rolanía et al, 2006).
On the other hand, Chiaravalloti and DeLuca (2008) point out that although most studies indicate that general intelligence remains intact in patients with multiple sclerosis, other investigations have detected slight but significant decreases.
The pathological anatomy of multiple sclerosis is characterized by the appearance of focal lesions in the white matter, called plaques, characterized by the loss of myelin (demyelination) and the relative preservation of the axons.
These demyelinating plaques are of two types depending on the activity of the disease:
Regarding their location, they are selectively distributed throughout the central nervous system, the most affected regions being the periventricular regions of the brain, nerve II, the optic chiasm, the corpus callosum, the brain stem, the floor of the fourth ventricle and the pyramidal route (García-Lucas, 2004).
Likewise, plaques may appear in the gray matter, generally subpial, but are more difficult to identify; neurons are usually respected (Fernández, 2000).
Taking into account the characteristics and evolution of these plaques with the progress of the disease, the accumulation of axonal loss can cause irreversible damage to the central nervous system and neurological disability (Lassmann, Bruck, Luchhinnetti, & Rodríguez, 1997; Lucchinetti et al. ., 1996; Trapp et al., 1998).
Multiple sclerosis is the most common chronic neurological disease in young adults in Europe and North America (Fernández, 2000), with most cases being diagnosed between 20 and 40 years of age (Simone, Carrara, Torrorella, Ceccrelli and Livrea, 2000 ).
The incidence and prevalence of multiple sclerosis in the world has increased at the expense of women, without this being due to a decrease in the incidence and prevalence in men, which has remained stable since 1950-2000.
Studies on the natural history of the disease have shown that in 80-85% of patients it starts with outbreaks (De Andrés, 2003).
These outbreaks, according to Poser's definition, can be considered as the appearance of symptoms of neurological dysfunction for more than 24 hours and that, as they recur, they leave a sequel.
According to the Advisory Committee for Clinical Trials in Multiple Sclerosis of the US National Multiple Sclerosis Society (NMSS), four clinical courses of the disease can be distinguished: recurring-sender (EMRR), progressive primary (EMPP), progressive secondary (EMSP) and finally, progressive- recurring (EMPR).
Chiaravalloti and DeLuca (2008), define multiple sclerosis recurring-sender characterized by periods in which symptoms worsen, although recovery of outbreaks is observed.
About 80% of people with RRMS develop later progressive secondary. In this type the symptoms gradually worsen with or without occasional relapses, or minor remissions..
Multiple sclerosis progressive recurring characterized by a progressive worsening after the onset of the disease, with some acute periods.
Lastly, multiple sclerosis progressive primary or chronic progressive has a continuous and gradual worsening of symptoms without exacerbation or remission of symptoms.
For its diagnosis, the diagnostic criteria described by Charcot were initially used, based on anatomopathological descriptions of the disease. However, these have now been superseded by the criteria described by McDonald in 2001 and revised in 2005..
McDonald's criteria are fundamentally based on the clinic, but they incorporate magnetic resonance imaging (MRI) in a leading place, allowing to establish spatial and temporal dissemination, and therefore, an earlier diagnosis (ad hoc Committee of the group of demyelinating diseases , 2007).
The diagnosis of multiple sclerosis is made taking into account the existence of clinical criteria of spatial dissemination (presence of symptoms and signs that indicate the existence of two independent lesions in the central nervous system) and of temporal dispersion (two more episodes of neurological dysfunction ) (Fernández, 2000).
In addition to the diagnostic criteria, the integration of information from the medical history, neurological examination and complementary tests is required..
These complementary tests are aimed at ruling out the differential diagnoses of multiple sclerosis and demonstrating the findings that are characteristic of it in cerebrospinal fluid (intrathecal secretion of immunoglobulins with oligoclonal profile) and in magnetic resonance imaging (MRI) (ad-hoc Committee demyelinating diseases group, 2007).
Globally, the therapeutic objectives in this disease will be to improve acute episodes, slow the progression of the disease (using immunomodulatory and immunosuppressive drugs), and the treatment of symptoms and complications (Terré-Boliart and Orient-López, 2007).
Due to the symptomatic complexity that these patients may present, the most appropriate treatment framework will be within an interdisciplinary team (Terré-Boliart and Orient-López, 2007).
Starting with memory, it must be considered that this is one of the neuropsychological functions most sensitive to brain damage and, therefore, one of the most evaluated in people with multiple sclerosis (Tinnefeld, Treitz, Haasse, Whilhem, Daum & Faustmann, 2005 ; Arango-Laspirilla et al., 2007).
As numerous studies indicate, memory deficit seems to be one of the most frequent disorders associated with this pathology (Armstrong et al., 1996; Rao, 1986; Introzzini et al., 2010).
Such deterioration usually compromises long-term episodic memory and working memory (Drake, Carrá & Allegri, 2001). However, it seems that not all memory components would be affected, since semantic memory, implicit memory and short-term memory seem not to be affected..
On the other hand, it is also possible to find alterations in the visual memory of patients with multiple sclerosis, as the results obtained in the studies of Klonoff et al, 1991; Landro et al, 2000; Ruegggieri et al, 2003; and Santiago, Guardiola and Arbizu, 2006.
The first works on memory impairment in multiple sclerosis suggested that the difficulty in recovering from long-term storage was the main cause of the memory deficit (Chiaravalloti and DeLuca, 2008).
Many authors believe that memory disorder in multiple sclerosis derives from a difficulty in “retrieving” information, rather than a storage deficit (DeLuca et al., 1994; Landette and Casanova, 2001).
More recently, however, research has shown that the primary memory problem is in the initial learning of information..
Multiple sclerosis patients require more repetitions of information to reach a predetermined learning criterion, but once the information has been acquired, recall and recognition reach the same level as healthy controls (Chiaravalloti and DeLuca, 2008; Jurado , Mataró and Pueyo, 2013).
The deficit in carrying out new learning causes errors in decision-making and seems to affect potential memory capacities.
Several factors have been associated with poor learning ability in people with multiple sclerosis, such as impaired processing speed, susceptibility to interference, executive dysfunction, and perceptual deficits. (Chiaravalloti and DeLuca, 2008; Jurado, Mataró and Pueyo, 2013).
Information processing efficiency refers to the ability to hold and manipulate information in the brain for a short period of time (working memory), and the speed with which that information can be processed (the speed of processing ).
The reduced speed of information processing is the most common cognitive deficit in multiple sclerosis. These deficits in processing speed are seen in conjunction with other cognitive deficits that are common in multiple sclerosis, such as deficits in working memory and long-term memory..
The results of recent studies with large samples have shown that people with multiple sclerosis have a significantly higher incidence of deficits in processing speed, rather than in working memory, particularly in patients who have a progressive secondary course.
According to Plohmann et al. (1998), attention is possibly the most prominent aspect of cognitive impairment in some patients with multiple sclerosis. This is usually one of the first neuropsychological manifestations in people with multiple sclerosis (Festein, 2004; Arango-Laspirilla, DeLuca and Chiaravalloti, 2007).
Those affected by multiple sclerosis present a poor performance in those tests that evaluate both sustained and divided attention (Arango-Laspirilla, DeLuca and Chiaravalloti, 2007).
Typically, basic care tasks (eg, repeating digits) are not affected in patients with multiple sclerosis. The deterioration in sustained attention is more common and specific affectations have been described in divided attention (that is, tasks in which patients can attend to several tasks) (Chiaravalloti and DeLuca, 2008)
There is empirical evidence that indicates that a high proportion of patients with multiple sclerosis present alterations in their executive functions (Arnett, Rao, Grafman, Bernardin, Luchetta et al., 1997; Beatty, Goodkin, Beatty and Monson, 1989).
They argue that frontal lobe injuries, caused by demyelization processes, can lead to a deficit in executive functions such as reasoning, conceptualization, task planning or problem solving (Introzzi, Urquijo, López-Ramón, 2010 )
Difficulties in visual processing in multiple sclerosis can have a detrimental effect on visual-perceptual processing, despite the fact that perceptual deficits are found independent of the primary visual disturbances..
Visuoperceptual functions not only include the recognition of a visual stimulus, but also the ability to perceive the characteristics of this stimulus accurately.
Although up to a quarter of people with multiple sclerosis may have a deficit in visual perceptual functions, little work has been done on the processing of visual perception.
The first phase of managing cognitive difficulties comprises assessment. The assessment of cognitive function requires several neuropsychological tests focused on specific fields such as memory, attention and processing speed (Brochet, 2013).
Cognitive deterioration is usually evaluated using neuropsychological tests, which have made it possible to verify that said deterioration in patients with multiple sclerosis is already present in the early stages of this disease (Vázquez-Marrufo, González-Rosa, Vaquero-Casares, Duque, Borgues and Left, 2009).
Currently there are no effective pharmacological treatments for cognitive deficits related to multiple sclerosis..
Another type of treatment arises, non-pharmacological treatments, among which we find cognitive rehabilitation, whose ultimate goal is to improve cognitive function through practice, exercise, compensation strategies and adaptation to maximize the use of residual cognitive function (Amato and Goretti, 2013).
Rehabilitation is a complex intervention that poses many challenges for traditional research designs. Unlike a simple pharmacological intervention, rehabilitation includes a variety of different components.
Few studies have been conducted on the treatment of cognitive deficits and several authors have highlighted the need for additional effective neuropsychological techniques in the rehabilitation of multiple sclerosis..
The few cognitive rehabilitation programs for multiple sclerosis aim to improve attention deficits, communication skills, and memory impairments. (Chiaravalloti and De Luca, 2008).
To date, the results obtained in the cognitive rehabilitation of patients with multiple sclerosis are contradictory.
Thus, while some researchers have not been able to observe an improvement in cognitive function, other authors, such as Plohmann et al., Claim to have demonstrated the efficacy of some cognitive rehabilitation techniques (Cacho, Gamazo, Fernández-Calvo and Rodríguez-Rodríguez, 2006).
In a comprehensive review, O'Brien et al. Concluded that, while this research is still in its infancy, there have been some well-designed studies that may provide a basis from which to advance in the field (Chiaravalloti and De Luca, 2008).
The rehabilitation program will focus on the consequences of the disease rather than on the medical diagnosis and the main objective will be to prevent and reduce disabilities and handicaps, although in some cases they can also eliminate deficits (Cobble, Grigsb and Kennedy, 1993; Thompson , 2002; Terré-Boliart and Orient-López, 2007).
It should be individualized and integrated within an interdisciplinary team, so therapeutic interventions should be carried out on various occasions with different objectives given the evolution of this pathology (Asien, Sevilla, Fox, 1996; Terré-Boliart and Orient-López, 2007).
Along with other therapeutic alternatives available in multiple sclerosis (such as immunomodulatory and symptomatic treatments), neurorehabilitation should be considered an intervention that complements the rest and that is aimed at a better quality of life for patients and their family group (Cárceres, 2000).
The realization of a rehabilitative treatment can suppose an improvement of some indices of the quality of life, both in the field of physical health, social function, emotional role and mental health (Delgado-Mendilívar, et al., 2005).
This can be key, since most patients with this disease will live more than half of their life with it (Hernández, 2000).
Yet No Comments