What is Pseudobulbar Palsy?
In 1837, a Doctor named Magnus reported the first case of a condition known as pseudobulbar palsy, which happened to a patient who had multiple strokes. Later in 1877, another Doctor, Lepine, coined the term pseudobulbar palsy to better differentiate it from other conditions. A more precise term for this condition could be “upper nerve damage paralysis”, which refers to a condition where the signals in the brain that control certain muscle movements are disturbed on both sides.
These signals, known as corticobulbar tracts, regulate movement in our head and neck. They start from special cells in the brain’s motor cortex region, called Betz cells, and end in areas in the brain stem connected to cranial nerve nuclei. These areas are the ones controlling processes such as chewing, swallowing, and talking.
Pseudobulbar palsy is recognized by symptoms like speech difficulties, swallowing difficulties, weakness in the face and tongue, and emotional instability. Any condition that harms both sides of these corticobulbar pathways in the brain can lead to pseudobulbar palsy.
What Causes Pseudobulbar Palsy?
Pseudobulbar palsy isn’t a disease itself; instead, it’s a collection of symptoms caused by conditions that affect the nerves in the brain (known as corticobulbar tracts) on both sides. Various health problems can lead to pseudobulbar palsy, including brain damage from a serious injury, tumors, blood vessel issues, metabolic problems, or brain diseases. One of the serious complications of cerebrovascular diseases, which affect the blood vessels in the brain, is pseudobulbar palsy.
Sometimes, pseudobulbar palsy can be caused by certain nerve disorders like amyotrophic lateral sclerosis (commonly called ALS or Lou Gehrig’s disease), Parkinson’s disease, and progressive supranuclear palsy. Other reasons might include having a stroke, conditions that cause the protective covering of nerve cells to be damaged like multiple sclerosis, and birth defects of certain parts of the brain.
There are also some less common causes of pseudobulbar palsy:
- Central pontine myelinolysis, a condition that damages the protective covering of nerves.
- Bilateral thalamic infarction, which is a rare type of stroke.
- Reaction to a drug called methotrexate, which can cause neurological symptoms including pseudobulbar palsy.
- Progressive multifocal leukoencephalopathy, a rare brain disorder that occasionally causes pseudobulbar symptoms.
- Cerebral malaria, which can cause pseudobulbar palsy due to damage to the protective covering of nerves.
- Bacterial endocarditis, an infection of the heart that can sometimes lead to pseudobulbar palsy.
- Syphilis, a sexually transmitted infection that requires a test of the fluid surrounding the brain and spinal cord, can also manifest as pseudobulbar palsy.
- Meningioma, a type of tumor in the brain or spinal cord, can present similar symptoms to pseudobulbar palsy.
- Neurocysticercosis, a parasitic infection of the brain.
This list points out that an early detection of antibodies to thyroperoxidase, which is seen in conditions like autoimmune encephalitis and Hashimoto encephalopathy, can be very important in someone with pseudobulbar palsy.
Risk Factors and Frequency for Pseudobulbar Palsy
Pseudobulbar palsy is a condition that affects the brain pathway known as the corticobulbar pathway. The frequency of pseudobulbar palsy can vary based on its cause. According to research, the possibility of developing this condition, or any motor neuron disease, increases notably after the age of 50. More men than women are affected by pseudobulbar palsy across all age categories.
Additionally, pseudobulbar apathy, a particular form of this condition, appears in about 1 out of every 5 patients who have recently had a stroke, and in about 1 out of every 8 patients who have had a stroke a long time ago.
Signs and Symptoms of Pseudobulbar Palsy
Pseudobulbar palsy is a medical condition caused by damage to certain fibers in the brain known as the corticobulbar pathways in the pyramidal fibers. This damage affects several aspects of normal movement and speech. Some of the most common effects include:
- Dysarthria, or difficulty speaking
- Dysphagia, difficulty swallowing, and drooling
- Dysphonia, having a voice that sounds nasal and slurred, like Donald Duck. There may also be changes in voice rhythm and tone.
- Glossplegia, or weakened tongue movement caused by damage to certain nerves in the brain. This can result in the tongue not functioning properly.
- Weakness in chewing and facial muscles.
Additionally, people with pseudobulbar palsy may have what’s called emotional lability, or pseudobulbar affect. This is characterized by uncontrollable, involuntary bouts of laughter or crying, despite having a limited range of facial expressions. This effect has also been associated with certain types of brain tumors, particularly those in the pons and midbrain regions. Acute pseudobulbar palsy may also present with trismus, a condition characterized by difficulty opening the mouth due to muscle stiffness.
During a physical examination, healthcare practitioners often observe a brisk jaw jerk, exaggerated facial reflexes, and changes to the position of the mouth and tongue. However, unlike another condition called lower motor neuron bulbar palsy, pseudobulbar palsy does not cause muscle wasting or twitching, and does not affect emotions. In children with this condition, cognitive impairment and seizures may also be present.
Testing for Pseudobulbar Palsy
Pseudobulbar palsy, a condition that affects brain signals to nerves, is usually diagnosed based on the symptoms a patient is experiencing. Then, the goal is to understand what’s causing this condition. triggers for the sudden onset of pseudobulbar palsy can include things like cancer, inflammation, multiple sclerosis, or a condition that affects nerve signals in your muscles.
Your doctor may ask about your medical history, including questions about any previous strokes, as part of the evaluation process. Also, a neurological examination might be performed, including the Mini-Mental State Examination (MMSE), which is a method used to assess mental status.
Depending on your symptoms, various tests could be ordered. These might be:
- A complete blood count, metabolic profile, and serology – these are typical blood tests that can highlight general health and possible disease.
- An electroencephalogram – this is a test that monitors the electrical activity of your brain.
- A CSF analysis – this test checks your cerebrospinal fluid (the clear fluid that surrounds the brain and spinal cord) for any abnormalities, especially for the presence of unique proteins called oligoclonal bands.
Additionally, imaging studies could also be performed, such as a CT scan or an MRI of your brain. This could help identify problems in specific areas of your brain that are commonly associated with pseudobulbar palsy. For children, there is often an underdevelopment seen in the region around the Sylvian fissure of the brain.
Further tests might include a videofluoroscopic swallowing study (VFSS) or a Fiberoptic Endoscopic Evaluation of Swallowing (FEES). These are ways for your doctor to see what happens when you swallow, helping reveal any swallowing difficulties you might have, otherwise known as dysphagia.
Last but not least, a speech assessment and a cognitive assessment may be performed, and a consultation with a psychiatric expert could also be recommended for your comprehensive care.
Treatment Options for Pseudobulbar Palsy
Dysphagia, or difficulty swallowing, can be managed through various methods. These include:
- Compensation therapy, which includes adjusting eating postures, modifying food characteristics, and using specific eating tools.
- Swallowing function training that works on strengthening swallowing muscles.
- Physiotherapy that involves electrical, magnetic, or heat stimulation.
- Alternative therapy like acupuncture, transcranial magnetic stimulation (using magnetic fields to stimulate nerve cells in the brain), or balloon dilation (expanding certain areas to aid swallowing).
- Medications such as nifedipine and metoclopramide.
- Behavioral interventions like making changes to the way one behaves while eating.
However, not all interventions work for everybody, and studies are mixed about how effective therapies like acupuncture or exercise-based therapies can be for dysphagia.
Dysarthria, which is a condition that affects speech correctness, is usually managed:
- At an impairment level through non-verbal and oro-motor exercises (like using ice packs and electrical stimulation).
- At an activity level through speech rate control techniques and the use of communication aids such as alphabet charts or text-to-speech computer devices.
- At a participation level by involving the patient in social activities.
There is no concrete evidence about the long-term benefits of these techniques on the patient’s everyday speech. However, for those with spastic dysarthria (a form of dysarthria where speech muscles may be weak), relaxation techniques and methods to control speech rate can be beneficial.
Emotional incontinence, a type of pseudobulbar effect characterized by uncontrollable episodes of crying and laughing, can be managed with a specific medication combination. This is presently the only FDA-approved treatment for pseudobulbar affect which helps in reducing the intensity and frequency of such emotional outbursts.
Other management techniques for pseudobulbar syndrome include cognitive therapy, and surgical procedures for cases involving recurrent bouts of falling (drop attacks) or problematic drooling.
What else can Pseudobulbar Palsy be?
If someone is showing signs of pseudobulbar palsy, it can sometimes be tricky to work out if this is the actual issue or something different. The symptoms can often appear like those seen in alcohol withdrawal seizures or delirium tremens. Metabolic encephalopathy is another condition that may have similar symptoms.
Pathological laughter, which is an uncontrollable type of laughter that doesn’t match with the person’s feelings, can also be linked with different types of tumors. Some examples include large tumors in the back part of the skull, posterior fossa meningiomas, a type of skin tumor called epidermoid tumors, and neurinomas on a nerve in the eye called the trochlear nerve. Other types of tumors that can cause pathological laughter include hypothalamic glioblastoma multiforme, pontine glioblastoma multiforme, and metastatic melanomas.
In the case of bulbar palsy – a condition that affects nerve cells in the brain and leads to muscle weakness and disability – there are different conditions that can be mistaken for it, including:
- Myasthenia gravis – a chronic autoimmune disease that leads to varying degrees of skeletal muscle weakness
- Progressive muscular atrophy – a rare disease causing damage to certain nerve cells in the brain and spinal cord
- Syphilis – a sexually transmitted infection that in its bulbar variant, can cause symptoms similar to bulbar palsy
What to expect with Pseudobulbar Palsy
The outlook for pseudobulbar palsy is largely determined by the cause of the condition itself.
Possible Complications When Diagnosed with Pseudobulbar Palsy
Pseudobulbar palsy may result in some complications:
- Aspiration pneumonia, a type of lung infection
- Severe dysphagia, which is difficulty swallowing
- Social withdrawal due to difficulty in speaking and swallowing
Preventing Pseudobulbar Palsy
Patients living with pseudobulbar palsy and their caregivers need to understand what causes the condition and what they might expect in the future. For instance, the treatment plan can vary for patients who’ve had a stroke or brain injury. In such cases, they might experience a slow recovery over a certain period, with neurological functions gradually improving. However, conditions like multiple sclerosis, Parkinson’s disease, and amyotrophic lateral sclerosis, which worsen over time and can’t be reversed, require ongoing collaborative care from different healthcare professionals.
