A Caucasian male who suffers from a severe neurological disease dies of an overwhelming respiratory infection. Autopsy shows an atrophic precentral gyrus and thin anterior roots of the spinal cord. Light microscopy reveals a severe loss of neurons in the anterior horn of the spinal cord and in the hypoglossal and ambiguous cranial nerve nuclei; corticospinal tracts stain only faintly, indicating demyelinization. The patient most likely suffered from which of the following?

Question

A Caucasian male who suffers from a severe neurological disease dies of an overwhelming respiratory infection.  Autopsy shows an atrophic precentral gyrus and thin anterior roots of the spinal cord.  Light microscopy reveals a severe loss of neurons in the anterior horn of the spinal cord and in the hypoglossal and ambiguous cranial nerve nuclei; corticospinal tracts stain only faintly, indicating demyelinization.  The patient most likely suffered from which of the following?

Quizplus · Accepted Answer

Amyotrophic lateral sclerosis (ALS) is the most common motor neuron disease. Combined upper motor neuron (UMN) and lower motor neuron (LMN) lesions are characteristic: damage to motor neurons of the anterior horns (LMN lesion) and demyelination of the corticospinal tracts (UMN lesion) are present. The result is denervation atrophy of the muscles (amyotrophy). The disease manifests in middle-aged people and has a progressive course. Most patients die within 5 years of diagnosis. Respiratory complications (such as aspiration pneumonia) are the most common cause of death. Important information about ALS is summarized in the table below. 11ec160b_39aa_357a_9249_a197b8d01a3a_MD0001_00 (Choice B) Poliomyelitis is an enteroviral infection that damages motor neurons of the anterior horns. It is a pure lower motor neuron (LMN) disease. Clinical features include flaccid paralysis, atrophy, areflexia, and fasciculation. (Choice C) The prodromal phase of rabies infection is characterized by fever, pharyngitis, and pain around the bite site. Acute encephalitis develops later. Ultimately, paralysis, confusion or hyperactivity, focal neurologic deficits, and coma occur. (Choice D) Huntington disease is an autosomal dominant disorder that leads to atrophy of the caudate nucleus and putamen. It causes progressive dementia, behavioral changes, and choreiform movements. (Choice E) Friedrich ataxia is an autosomal recessive disorder that manifests in children 5-15 years old. The main symptom is difficulty walking (ataxia). This disease is associated with hypertrophic cardiomyopathy, kyphoscoliosis, foot abnormalities, and diabetes mellitus. (Choice F) Vitamin B 12 deficiency causes subacute combined degeneration of the dorsal (posterior) and lateral spinal columns. Educational objective: Amyotrophic lateral sclerosis (ALS) causes both upper and lower motor neuron lesions. Loss of neurons of the anterior horns of the spinal cord (LMN lesion) causes muscle weakness and atrophy. Demyelination of the lateral corticospinal tract (UMN lesion) leads to spasticity and hyperreflexia.

A Caucasian Male Who Suffers from a Severe Neurological Disease