Neurology Quiz: Motor Neuron Lesions and Palsy

Lower Motor Neuron Lesions

• Associated with fasciculations
• Not associated with spasticity, clonus, or preserved reflexes in atrophic muscles

Bulbar Paralysis

• Refers to a lesion affecting cranial nerves 9-12
• Also refers to LMN lesion

Pseudobulbar Palsy

• Characterized by dysarthria, dysphagia, emotional lability
• Not characterized by hypoactive jaw jerk

Amyotrophic Lateral Sclerosis (ALS)

• Characterized by progressive atrophy and weakness of hands and forearms, spasticity of legs, brisk jaw jerk
• Neuroimaging shows increased signal in corticospinal tracts on T2-weighted MRI
• Also known as Lou Gehrig's disease
• Primary lateral sclerosis is a progressive isolated UMN disorder
• Familial ALS is caused by genetic mutations of superoxide dismutase
• Involves anterior horn cell and corticospinal tract
• Features include split-hand syndrome, frontotemporal dementia, dropped head syndrome, tongue fasciculations, and spastic dysarthria
• Confirmatory test of choice is none of the above
• Riluzole is the only drug known to improve survival in ALS
• Mechanism of action of riluzole includes inhibition of glutamate release, but not inhibition of GABA reuptake, NMDA glutamate receptor antagonism, or kainate glutamate receptor antagonism
• Edaravone is a novel free-radical scavenger approved for use in ALS

Ataxia

• Cerebellar ataxia characterized by dysdiadochokinesis, ataxia, and hypotonia, but not resting tremor
• Paraneoplastic cerebellar ataxia associated with carcinoma breast, Hodgkin's lymphoma, and non-small-cell lung cancer, but not carcinoma ovary
• Most common inherited ataxia is Friedreich's ataxia
• Vitamin B12 deficiency can give rise to paresthesia, optic atrophy, peripheral neuropathy, but not myopathy
• Subacute combined degeneration of spinal cord due to Vitamin B12 deficiency, involves posterior column and corticospinal tracts, and characterized by brisk deep tendon reflexes
• Tabes dorsalis characterized by ataxia, Argyll Robertson pupil, bladder dysfunction, but not hyperreflexia
• Ataxia telangiectasia presents in childhood, shows autosomal recessive mode of inheritance, and is characterized by ataxia, telangiectasia, and immunodeficiency

Test your knowledge on motor neuron lesions, bulbar paralysis, and palsy with these questions. Covers topics related to neurology and nervous system disorders.