Bulbar palsy
Encyclopedia
Bulbar palsy refers to impairment of function of the cranial nerves
IX, X, XI and XII, which occurs due to a lower motor neuron lesion either at nuclear or fascicular level in the medulla oblongata
or from lesions of the lower cranial nerves outside the brainstem.
In contrast, pseudobulbar palsy describes impairment of function of cranial nerves IX-XII due to upper motor neurone lesions of the corticobulbar tracts in the mid-pons. For clinically evident dysfunction to occur, such lesions must be bilateral as these cranial nerve nuclei receive bilateral innervation.
Bulbar Palsy is an assortment of signs and symptoms, not the name of a precise disease.
The occular muscles are spared and this differentiates it from myasthenia gravis.
Pseudobulbar palsy
is a clinical syndrome similar to bulbar palsy but the damage is occurred in upper motor neurons, that is the nerves cells come down from the cerebral cortex inervating the motor nuclei in the medulla.
This is usually caused by stroke.
Cranial nerves
Cranial nerves are nerves that emerge directly from the brain, in contrast to spinal nerves, which emerge from segments of the spinal cord. In humans, there are traditionally twelve pairs of cranial nerves...
IX, X, XI and XII, which occurs due to a lower motor neuron lesion either at nuclear or fascicular level in the medulla oblongata
Medulla oblongata
The medulla oblongata is the lower half of the brainstem. In discussions of neurology and similar contexts where no ambiguity will result, it is often referred to as simply the medulla...
or from lesions of the lower cranial nerves outside the brainstem.
In contrast, pseudobulbar palsy describes impairment of function of cranial nerves IX-XII due to upper motor neurone lesions of the corticobulbar tracts in the mid-pons. For clinically evident dysfunction to occur, such lesions must be bilateral as these cranial nerve nuclei receive bilateral innervation.
Bulbar Palsy is an assortment of signs and symptoms, not the name of a precise disease.
Causes
- Genetic: Kennedy's disease, Acute Intermittent PorphyriaAcute intermittent porphyriaAcute intermittent porphyria is a rare autosomal dominant metabolic disorder affecting the production of heme, the oxygen-binding prosthetic group of hemoglobin. It is characterized by a deficiency of the enzyme porphobilinogen deaminase. Acute intermittent porphyria is the second most common...
- Vascular causes: medullary infarction
- Degenerative diseases: motor neuron disease, syringobulbiaSyringobulbiaSyringobulbia is a medical condition when syrinxes, or fluid filled cavities, affect the brainstem. This defect normally results from congenital abnormality, trauma or tumor growth....
- Inflammatory/infective: Guillain-Barré syndromeGuillain-Barré syndromeGuillain–Barré syndrome , sometimes called Landry's paralysis, is an acute inflammatory demyelinating polyneuropathy , a disorder affecting the peripheral nervous system. Ascending paralysis, weakness beginning in the feet and hands and migrating towards the trunk, is the most typical symptom...
, poliomyelitisPoliomyelitisPoliomyelitis, often called polio or infantile paralysis, is an acute viral infectious disease spread from person to person, primarily via the fecal-oral route...
, Lyme diseaseLyme diseaseLyme disease, or Lyme borreliosis, is an emerging infectious disease caused by at least three species of bacteria belonging to the genus Borrelia. Borrelia burgdorferi sensu stricto is the main cause of Lyme disease in the United States, whereas Borrelia afzelii and Borrelia garinii cause most... - Malignancy: brain-stem gliomaGliomaA glioma is a type of tumor that starts in the brain or spine. It is called a glioma because it arises from glial cells. The most common site of gliomas is the brain.-By type of cell:...
- Toxic: botulismBotulismBotulism also known as botulinus intoxication is a rare but serious paralytic illness caused by botulinum toxin which is metabolic waste produced under anaerobic conditions by the bacterium Clostridium botulinum, and affecting a wide range of mammals, birds and fish...
Symptoms
These include:- dysphagiaDysphagiaDysphagia is the medical term for the symptom of difficulty in swallowing. Although classified under "symptoms and signs" in ICD-10, the term is sometimes used as a condition in its own right. Sufferers are sometimes unaware of their dysphagia....
(difficulty in swallowing) - difficulty in chewing
- nasal regurgitation
- slurring of speech
- choking on liquids
- Dysphonia (defective use of the voice)
- Dysarthria (difficulty in articulating words due a CNS problem)
- Dysphasia (difficulty in using or understanding words due to injury or disease of the brain)
Signs
These include:- Nasal speech lacking in modulation and difficulty with all consonants
- Tongue is atrophic and shows fasciculations.
- Dribbling of saliva.
- Weakness of the soft palate, examined by asking the patient to say aah.
- The jaw jerkJaw jerk reflexThe jaw jerk reflex or the masseter reflex is a stretch reflex used to test the status of a patient's trigeminal nerve . The mandible—or lower jaw—is tapped at a downward angle just below the lips at the chin while the mouth is held slightly open. In response, the masseter muscles will jerk the...
is normal or absent. - The gag reflexGag reflexThe pharyngeal reflex or gag reflex is a reflex contraction of the back of the throat, evoked by touching the soft palate or sometimes the back of the tongue. It prevents something from entering the throat except as part of normal swallowing and helps prevent choking...
is absent. - In addition, there may be lower motor neuronLower motor neuronLower motor neurons are the motor neurons connecting the brainstem and spinal cord to muscle fibers, bringing the nerve impulses from the upper motor neurons out to the muscles...
lesions of the limbs.
The occular muscles are spared and this differentiates it from myasthenia gravis.
Pseudobulbar palsy
Pseudobulbar palsy
Pseudobulbar palsy results from an upper motor neuron lesion to the corticobulbar pathways in the pyramidal tract. Patients have difficulty chewing, swallowing and demonstrate slurred speech...
is a clinical syndrome similar to bulbar palsy but the damage is occurred in upper motor neurons, that is the nerves cells come down from the cerebral cortex inervating the motor nuclei in the medulla.
This is usually caused by stroke.