What Is Bulbar Muscle Weakness

This bulbar weakness named for the nerves that originate from the bulblike part of the brainstem can cause difficulty with talking dysarthria chewing swallowing dysphagia and holding up the head.

What is bulbar muscle weakness.

Bulbar weakness or bulbar palsy refers to bilateral impairment of function of the lower cranial nerves ix x xi and xii which occurs due to lower motor neuron lesion either at nuclear or fascicular level in the medulla or from bilateral lesions of the lower cranial nerves outside the brain stem. Bulbar palsy is the result of diseases affecting the lower cranial nerves vii xii. Amyotrophic lateral sclerosis myasthenia gravis. Spinal and bulbar muscular atrophy sbma popularly known as kennedy s disease is a progressive debilitating neurodegenerative disorder resulting in muscle cramps and progressive weakness due to degeneration of motor neurons in the brainstem and spinal cord.

The former is a lower motor neuron lesion of the cranial nerves ix x xi and xii while the latter is an upper motor neuron lesion affecting ix x xi and xii cranial nerves. Bulbar weakness is often associated with difficulty in chewing weakness of the facial muscles. There are differences between bulbar palsy and pseudobulbar palsy. The bulbar als or bulbar onset is seen in about 25 of patients who are to develop als.

Spinal and bulbar muscular atrophy sbma or kennedy s disease is an x linked motor neuron disease typically presenting in adult men in the 3rd to 5th decades. Bulbar palsy vs pseudobulbar palsy. Bulbar als symptoms are seen in 75 to 80 of the patients with classic als symptoms. The causes of this are broadly divided into.

In contrast pseudobulbar palsy is a clinical syndrome similar to bulbar palsy but in which the damage is located in upper motor neurons of the corticobulbar tracts in the mid pons i e in the cranial nerves ix xii that is the nerve cells coming down from the cerebral cortex innervating the motor nuclei in the medulla. The condition is associated with mutation of the androgen receptor ar gene and is inherited in an x linked recessive manner. Weakness and fatigue in the neck and jaw also can occur early in mg. Muscles of the mouth and throat responsible for speech and swallowing.

Gradually almost all the muscles under voluntary control are affected and individuals lose their strength and the ability to speak eat move and even breathe. This is because the motor neuron cells in the spinal cord degenerate leading to their death due to als. About 15 of patients present with bulbar symptoms. A speech deficit occurs due to paralysis or weakness of the muscles of articulation which are supplied by these cranial nerves.

Bulbar relates to the medulla.