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Amyotrophic Lateral Sclerosis (ALS) cases are broadly categorized into two main etiological types: familial and sporadic.
Sporadic ALS constitutes 90-95% of all cases; its underlying cause remains unknown, and no significant family history is observed in these instances.
Familial ALS is a progressive neurological disease affecting multiple members within the same family, accounting for 5-10% of all ALS cases.
Beyond etiological classification, ALS is also divided into various subtypes based on its clinical presentation:
Classic ALS: This is a progressive neurological disease characterized by the degeneration of both upper and lower motor neurons. It accounts for over two-thirds of all ALS patients.
Primary Lateral Sclerosis (PLS): A progressive neurological disease primarily affecting upper motor neurons. If lower motor neurons remain unaffected within two years, the disease typically progresses as a pure upper motor neuron disorder. Primary Lateral Sclerosis is the rarest among all ALS forms.
Progressive Bulbar Palsy (PBP): This condition typically begins with difficulties in speech, chewing, and swallowing due to the degeneration of lower motor neurons. This subtype affects approximately 25% of all ALS patients.
Progressive Muscular Atrophy (PMA): A progressive neurological disease characterized by the degeneration of lower motor neurons. If upper motor neurons remain unaffected within a two-year period, the disease commonly continues as a pure lower motor neuron disorder.
What are the Classifications of ALS Disease?
Sporadic ALS constitutes 90-95% of all cases; its underlying cause remains unknown, and no significant family history is observed in these instances.
Familial ALS is a progressive neurological disease affecting multiple members within the same family, accounting for 5-10% of all ALS cases.
Beyond etiological classification, ALS is also divided into various subtypes based on its clinical presentation:
Classic ALS: This is a progressive neurological disease characterized by the degeneration of both upper and lower motor neurons. It accounts for over two-thirds of all ALS patients.
Primary Lateral Sclerosis (PLS): A progressive neurological disease primarily affecting upper motor neurons. If lower motor neurons remain unaffected within two years, the disease typically progresses as a pure upper motor neuron disorder. Primary Lateral Sclerosis is the rarest among all ALS forms.
Progressive Bulbar Palsy (PBP): This condition typically begins with difficulties in speech, chewing, and swallowing due to the degeneration of lower motor neurons. This subtype affects approximately 25% of all ALS patients.
Progressive Muscular Atrophy (PMA): A progressive neurological disease characterized by the degeneration of lower motor neurons. If upper motor neurons remain unaffected within a two-year period, the disease commonly continues as a pure lower motor neuron disorder.