What are the causes and management of bulbar or pseudo bulbar palsy with convulsions?

Causes of Bulbar or Pseudobulbar Palsy with Convulsions

The most common causes of bulbar or pseudobulbar palsy presenting with convulsions include bilateral cerebrovascular lesions (particularly lacunar strokes affecting both corticobulbar tracts), neurocysticercosis, perisylvian cortical dysplasia, and bilateral thalamic infarctions, with management requiring immediate seizure control followed by treatment of the underlying etiology and supportive care for bulbar dysfunction. 1, 2, 3, 4

Primary Etiologies

Vascular Causes

• Bilateral lacunar strokes affecting both internal capsules can produce pseudobulbar palsy with dramatic clinical presentations despite relatively small lesion size, often leading to mislocalization as brainstem pathology 1
• Bilateral thalamic infarctions involving specific nuclei can manifest as acute pseudobulbar palsy, particularly in younger patients with risk factors such as oral contraceptives and smoking 2
• Consecutive strokes affecting contralateral corticobulbar tracts create cumulative deficits that may precipitate seizures due to cortical irritation 1

Infectious/Parasitic Causes

• Neurocysticercosis represents an unusual but documented cause of pseudobulbar palsy with seizures, presenting with multiple small cysts with scolex in both cerebral hemispheres and potentially giant intraparenchymal cysts 3
• This etiology is particularly important as it responds well to standard antiparasitic treatment combined with antiepileptics 3

Developmental/Structural Causes

• Unilateral perisylvian cortical dysplasia can progress to bilateral opercular syndrome with pseudobulbar palsy and seizures, manifesting as biopercular status epilepticus with diffusion of discharges from the dysplastic area to the contralateral hemisphere 4
• These episodes can last from one hour to one month and may resolve spontaneously or with medical treatment 4

Other Neurological Conditions

• Guillain-Barré syndrome can present with bulbar palsy and requires monitoring for swallowing difficulties, coughing impairment, and autonomic dysfunction, though seizures are not a typical feature 5
• Wilson disease may present with pseudobulbar palsy, transfer dysphagia, and neurological manifestations, though seizures are infrequent 5

Management Approach

Immediate Seizure Control

• Administer benzodiazepines as first-line therapy for active convulsions, followed by second-line agents (phenytoin 18-20 mg/kg IV at 50 mg/min, fosphenytoin 18-20 mg/kg PE IV at 150 mg/min, or valproate 30 mg/kg IV at 6 mg/kg/hour) if seizures persist 6
• For refractory status epilepticus, escalate to levetiracetam 30 mg/kg IV at 5 mg/kg/min, propofol 1-2 mg/kg IV bolus followed by 2-10 mg/kg/hour infusion, or phenobarbital 20 mg/kg IV at 50-100 mg/min 6
• Consider emergent EEG monitoring to detect nonconvulsive status epilepticus, especially in patients with persistent altered consciousness 6

Bulbar Dysfunction Assessment

• Perform immediate swallow screening before initiating any oral intake of fluids or food 7
• If swallow screening is abnormal, conduct a complete bedside swallow examination by a speech-language pathologist 7
• Patients with positive bedside screening or high aspiration risk (brainstem involvement, pseudobulbar palsy) require videofluoroscopy swallowing study (VFSS) or fiberoptic endoscopic evaluation of swallowing (FEES) 7
• Assess for specific bulbar signs: dysphagia, dysarthria, nasal voice, drooling, impaired gag reflex, lip closure, tongue strength and mobility, chewing capacity, and palatal movement 7

Respiratory Monitoring

• Monitor respiratory function using the "20/30/40 rule": patient is at risk of respiratory failure if vital capacity <20 ml/kg, maximum inspiratory pressure <30 cmH₂O, or maximum expiratory pressure <40 cmH₂O 5, 7
• Serial pulmonary function testing should continue every 6 months with non-invasive ventilation offered when FVC <80% of normal, FVC <50% predicted, or awake PaCO₂ >45 mmHg 7
• Patients with significant bulbar impairment may not tolerate non-invasive ventilation adequately, requiring alternative approaches 7

Diagnostic Workup

• Obtain urgent brain MRI to identify bilateral lesions affecting corticobulbar tracts, thalamic infarctions, neurocysticercosis, or cortical dysplasia 1, 2, 3, 4
• Extensive laboratory investigations should exclude neoplastic, inflammatory, demyelinative, and myasthenic causes of acute pseudobulbar palsy 2
• For suspected Wilson disease, check ceruloplasmin levels, 24-hour urinary copper, and perform slit-lamp examination for Kayser-Fleischer rings 5
• Consider lumbar puncture if meningitis is suspected, particularly in patients with fever, complex convulsions, or those under 18 months of age 5

Nutritional Management

• Implement regular nutritional status assessment (BMI, weight loss) every 3 months to detect early malnutrition 7
• Provide nutritional interventions including fractionating and enriching meals, texture modification of foods and liquids, and oral nutritional supplementation 7
• Consider percutaneous endoscopic gastrostomy placement before respiratory function significantly deteriorates 7

Specific Treatment Based on Etiology

• For neurocysticercosis: Administer standard antiparasitic treatment (albendazole or praziquantel) combined with corticosteroids and antiepileptics 3
• For perisylvian dysplasia with status epilepticus: Valproate treatment has shown efficacy in controlling myoclonic absences and biopercular status epilepticus 4
• For bilateral vascular lesions: Focus on secondary stroke prevention, risk factor modification, and supportive care 1, 2

Critical Complications to Monitor

Aspiration and Respiratory Complications

• Aspiration pneumonia occurs in 11.4-13% of cases with bulbar dysfunction and represents a major cause of morbidity and mortality 7, 8
• Bulbar muscle weakness prevents adequate peak cough flows to clear airway debris, increasing infection risk 8
• Abnormal respiratory patterns during swallowing (inspiration after swallow, prolonged swallow apnea, multiple swallows per bolus) are common 8

Nutritional Complications

• Weight loss and malnutrition occur in 0-21% of patients at diagnosis and are detrimental to survival and quality of life 7
• Chronic malnutrition secondary to bulbar muscle weakness has considerable bearing on respiratory muscle function and survival 8

Autonomic and Other Complications

• Monitor for autonomic dysfunction via electrocardiography and monitoring of heart rate, blood pressure, and bowel and bladder function 5
• Assess for psychological symptoms including pain, hallucinations, anxiety, and depression, which can have major impact on wellbeing 5
• Implement eye protection measures for patients with impaired eye closure due to facial weakness 7

Common Pitfalls to Avoid

• Do not mislocalize lesions: Patients with pseudobulbar palsy often present with dramatic bulbar symptoms that mimic brainstem lesions, but imaging may reveal bilateral supratentorial lesions affecting corticobulbar tracts 1
• Do not delay swallow assessment: All patients must undergo swallow screening before any oral intake to prevent aspiration 7
• Do not overlook treatable causes: Neurocysticercosis responds well to treatment and should be considered in endemic areas 3
• Do not underestimate respiratory risk: Up to two-thirds of deaths occur during the recovery phase from cardiovascular and respiratory dysfunction, requiring continued vigilance 5