Studies have shown that patients of Amyotrophic Lateral Sclerosis (ALS) with cognitive difficulties exhibit brain damage in the brain regions that are necessary for thinking. This aspect has been attributed to the accelerated deterioration of the patients.
ALS is a motor neuron disease linked to a variety of cortical symptoms encompassing mild cognitive decline with behavioral changes. This proposes the involvement of extra-motor areas in the disease.
A study aimed at examining the structural explanation of poor prognosis in ALS in the non-demented state. It was published in the European Journal of Neurology. Its objective was to investigate the particular patterns of brain atrophy in Sporadic ALS patients who did not have commonly known genetic mutations. It reinforced the theory that the diseases processes of ALS would begin in the brain’s cortex or in the spinal cord.
In the recent years, studies demonstrating that ALS is a disease probably involving several brain regions, in addition to motor neurons, have been emerging by the day. ALS patients can have both cognitive and behavioral problems, and the condition usually co-exists with Frontotemporal Dementia.
The researchers at Hanyang University in Korea discovered that the neuropsychological differences in ALS patients may be reflected by damage to the comparable brain regions. The research team mobilized 47 patients with Sporadic ALS who did not have Dementia, and 28 healthy controls as subjects. The controls were matched with patients according to age, to enhance the validity of the analysis.
Following the testing of patients’ neurologic and cognitive abilities, the team split them up into three categories: patients with cognitive impairment, patients with behavioral problems, and those with distinct motor or movement difficulties associated with ALS.
In the process, all participants had their brains scanned with a magnetic resonance imaging (MRI) technique that was capable of assessing the volume of specific brain areas. To begin with, the team collated images between the different patient groups and controls to detect the affected brain regions. With time, it became clear that patients with cognitive problems demonstrated brain tissue loss in regions that were not affected in the other patient groups.
With more accuracy, only patients with cognitive difficulties showed gray matter tissue loss in the cerebellum and an area of the cortex responsible for cognitive processing. The researchers also discovered loss of white matter in regions processing visual signals in addition to the nerve pathways connecting the brain and spinal cord. In comparison, patients with behavioral problems or distinct ALS symptoms had no significant brain volume loss in contrast to the healthy controls.
The research team, in correlating brain imaging data with neuropsychological assessments it was established that patients with cognitive problems had volume loss in brain areas. This was in the regions involved in detecting and coordinating movement, including significant regions connecting different areas of the brain. ALS pathogenesis has a dual focality of onset with contiguous spread outwards. In addition, neuropsychological aspects could be a significant predictor of progression and survival rates in ALS.