Signs of First Motor Neuron Injury
0 Spasticity
0 Increased deep tendon reflexes
0 Decreased superficial reflexes (abdominal skin and cremaster reflex)
0 Pathological reflexes (Babinski, positive clonus)
Second Motor Neuron Injury Signs
0 Atrophy
0 Muscle fasciculations (denervation hypersensitivity)
0 Decreased deep tendon reflexes
0 No pathological reflexes
Amyotrophic lateral sclerosis (ALS)
0 It is the disease of the famous physicist Stephen Hawking.
It is a progressive, fatal disease characterized by degeneration of motor neurons in the primary motor cortex, brainstem and spinal cord.
0 Corticospinal tracts, brainstem and spinal motor neurons are involved. Amyotrophic lateral sclerosis involves the lateral cord lower anterior horn motor neuron.
0 Bulbar involvement ALS is low before the age of 40 and is highest around the age of 70. It is more common in men.
Crossing over with the SOD (superoxide dismutase) gene is shown.
0 Examination reveals low soft palate, reduced gag reflex, decreased salivation, and tongue fasciculations.
0 The first prominent finding in patients is atrophy. Vivid deep tendon reflexes and pathological reflexes can be seen depending on the involvement of the first motor neuron.
0 There is no sensory deficit on examination. Extraocular muscles and sphincter involvement, autonomic and sensory manifestations are absent.
0 It progresses progressively and death develops within 3-5 years.
0 Most deaths are due to lung infections.
0 Bulbar involvement is worse than limited to the extremities.
0 Riluzole may delay mortality.
Primary Lateral Sclerosis
There is a pure upper motor neuron (corticospinal) deficit in the extremities. It has a much slower course compared to ALS.
Spinal Muscular Atrophy
0 It is an inherited disease of the second motor neurons.
0 It is the formation of lower motor neuron deficit in the extremities due to spinal cord anterior horn degeneration.
0 It shows autosomal recessive inheritance.
Pseudobulbar Paralysis
0 Usually in people with hypertension and atherosclerosis
0 In corticospinal and corticobulbar tracts
0 Clinical picture in which bilateral lacunar infarcts occur in the deep regions of the brain
0 There is no lesion in bulbus. Bulbar nuclei intact
9-10-11-12. cranial nerves are affected.
0 Difficulty in swallowing, dysarthria (speech) and walking with small steps are noted in the patient.
0 It is often accompanied by urinary incontinence and unexplained crying and laughing fits.
0 Tongue atrophy and fasciculation do not develop.
Bulbar palsy
It develops due to a lesion affecting the cranial nerve motor nucleus in the brain stem.
Other Diseases
Kennedy's Disease (Bulbbospinal Neuropathy)
• It is a disease characterized by large trinucleotide repeats in the androgen receptor gene.
• Tremor, fasciculations, cramps and proximal and distal weakness are characteristically seen.
• Dysphagia, dysarthria, gynecomastia and testicular atrophy may accompany this disease.