Differences Between Progressive Supranuclear Palsy and ALS
Progressive supranuclear palsy (PSP) and amyotrophic lateral sclerosis (ALS) are both neurodegenerative diseases, but they affect different areas of the brain and have distinct symptoms. PSP primarily impacts balance and eye movements, while ALS affects voluntary muscle movement. The progression and prognosis of these diseases also differ, with ALS typically progressing more rapidly than PSP.
What Is Progressive Supranuclear Palsy?
Progressive Supranuclear Palsy (PSP) is a distinctive form of neurodegenerative disease. It belongs to the group of Frontotemporal Lobar Degeneration [1].
It primarily affects the brainstem and basal ganglia [1]. The cause of the neuronal loss in these regions is the accumulation of neurofibrillary tangles in these brain areas. These tangles are made up of a protein called tau, and their presence correlates with the progression of the disease [2].
The symptoms of PSP include supranuclear ophthalmoplegia, postural instability, and mild dementia [1] .
Supranuclear ophthalmoplegia is a condition that affects the movement of the eyes. This leads to problems with balance and coordination in the affected individual and can significantly impact their ability to carry out daily activities [1].
Further, patients show postural instability and experience problems with balance and coordination, which may lead to frequent falls. Postural instability is one of the first symptoms in the disease progression and is a crucial factor in diagnosing PSP [3].
As such, people with PSP typically need the care of a carer, who makes sure.
Another symptom of PSP is dementia. PSP patients often have difficulties with memory, thinking, and behaviour. These cognitive problems worsen over time and impact a person’s ability to function independently [4].
What is Amyotrophic Lateral Sclerosis?
Amyotrophic Lateral Sclerosis, also known under its acronym ALS, is a progressive neurodegenerative disease affecting the motor system.
It results from the neurodegeneration of upper and lower motor neurons in the brain and the spinal cord. Such loss then leads to muscle dysfunction. In particular, we observe patients with ALS to be experiencing muscle weakness and paralysis [5, 6].
As the disease progresses, it leads to extensive paralysis and results in death, usually due to respiratory failure [5, 7].
Typically, ALS develops in adulthood between the ages of 40 and 70. The life expectancy after diagnosis is usually 2-5 years, although this may differ significantly among individuals [8, 9].
ALS is believed to be caused by genetic and environmental factors. It can occur sporadically or as a familial form. While Familial ALS is inherited and usually associated with mutations in the SOD1 gene, sporadic ALS occurs randomly without any known familial link to the disease[10, 11, 12]. However, both of these forms of the disease have similar symptoms and progression [10].
What Are The Differences Between Progressive Supranuclear Palsy and Amyotrophic Lateral Sclerosis?
Progressive Supranuclear Palsy (PSP) and Amyotrophic Lateral Sclerosis (ALS) are both neurodegenerative diseases, but they present with different symptoms and affect different areas of the brain.
PSP is characterized by a disturbance of balance, a disorder of downward gaze, and parkinsonism (which, however, can't be cured by L-DOPA treatment). Cognitive impairment is another feature of PSP, with patients often experiencing visuospatial impairment and substantial frontal behavioural disturbances [13]. PSP is also associated with tau protein abnormalities, which lead to cell dysfunction and death [4].
On the other hand, ALS primarily affects the motor neurons in the brain and spinal cord, leading to muscle weakness and atrophy. The symptoms of ALS typically include difficulty speaking, swallowing, and breathing, as well as muscle cramps and twitching.
Unlike PSP, ALS does not typically cause problems with eye movement or balance. Regarding pathology, PSP is a tauopathy characterized by the accumulation of neurofibrillary tangles and tufted astrocytes in the brain [14]. ALS, however, is characterized by the degeneration of motor neurons in the brain and spinal cord.
In conclusion, while both PSP and ALS are neurodegenerative diseases, they have distinct clinical presentations and pathological features. PSP primarily affects balance, eye movement, and cognition, while ALS predominantly affects motor function.