Eventual Brain Damage Observed to go Beyond Motor Neuron Death In ALS

Recent scientific observations have shown that Amyotrophic Lateral Sclerosis (ALS) patients who have progressed to an advanced stage of the disease experience difficulties in controlling their muscles. In the event where they have lost all voluntary movements, including the ability to communicate, they have destruction in multiple brain regions and this is not limited to motor neurons.

A study that evaluated the clinicopathological characteristics of ALS patients resulting in a totally locked-in state was conducted. It proposed that the brain damage mentioned above can be employed in singling out patients most vulnerable to progressing to complete paralysis.

It has been noted that specialists paying more attention to non-movement symptoms could prove significant in predicting the progress of ALS into a total locked-in stage. This is specific for ALS patients with a rapid disease course.
The past studies of ALS patients who have progressed to a totally locked-in stage have exhibited multiple forms of brain damage. In order to gain a more clearer perspective into this, researchers in Japan at the Tokyo Metropolitan Neurological Hospital evaluated the medical records of all locked-in patients from 320 ALS patients at two Japanese medical centres.

They discovered 11 patients who had progressed to a completely locked-in stage. However, none of them had exhibited signs of cognitive or behavioral difficulties before progressing to that stage. The patients had various protein aggregates inside their nerve cells.
The research team combined the findings in medical records to analyses of brain and spinal cord tissue following death of ALS patients. For 10 of the patients, the disease course was rapid in its progression with a need for tracheostomy with mechanical ventilation within a year after the onset of symptoms.

They noted that all patients developed paralysis, with limited eye movements with aided breathing of the Tracheostomy. Additionally, 4 patients had an extreme loss of brain tissue including structures in the brainstem and mid-brain while the remaining ones only has minimal damage to these brain structures.

All patients also had severe tissue loss in the spinal cord and in the medulla oblongata, which governs autonomic bodily functions such as the heart rate and breathing. In contrast, the optic nerve and a brain region relaying information from the eyes to the brain were intact.
Laying focus on neurons regulating movement, all patients had a loss of key nerve cells of the brain’s motor cortex. Most of the patients also showed activated glial cells in both the brain and spinal cord in regions controlling movement.

On a different note, the brain damage was not limited to areas controlling movement, and extensive damage was found in many other regions in the brains of the patients. The destruction in structures of the cerebellum was attributed to a more rapid progression toward death.

Despite the fact that the research team ascertained that some trends of neurodegeneration appeared to be associated with the presence and spread of specific protein aggregates; the severe loss of neurons prevented them from analysing those relationships in an objective way.