What is the management approach for a 60-year-old female with rapidly progressing quadriparensis, ptosis, dysarthria, dysphagia, and cranial nerve involvement, initially diagnosed as a cerebrovascular accident (CVA) but with normal computed tomography (CT) brain scans?

Rapidly Progressive Neuromuscular Crisis: Myasthenia Gravis Management

This patient requires immediate treatment for myasthenia gravis with pyridostigmine bromide 60 mg orally and urgent neurology consultation, as the clinical presentation of rapidly progressive quadriparesis with ptosis, dysarthria, dysphagia, fasciculations, and multiple cranial nerve involvement with normal CT imaging is pathognomonic for myasthenic crisis, not cerebrovascular accident.

Critical Diagnostic Clarification

The normal CT brain scans effectively rule out CVA as the primary diagnosis 1. The clinical constellation demands immediate reconsideration:

• Myasthenia gravis presents with ptosis, diplopia, dysarthria, dysphagia, and limb weakness 2, 3, 4
• Dysarthria and dysphagia can be the presenting features of generalized myasthenia gravis, though this is uncommon and often misdiagnosed as stroke in elderly patients 3
• The rapidly progressive nature with fasciculations and quadriparesis indicates impending myasthenic crisis, which can lead to respiratory failure and death if untreated 5

Immediate Management Algorithm

Step 1: Airway Protection and Respiratory Assessment

• Assess respiratory function immediately - myasthenic crisis involves respiratory muscles and can lead to death 5
• Prepare for potential intubation if respiratory distress develops, maintaining systolic blood pressure >110 mmHg 6
• Monitor oxygen saturation continuously, maintaining SaO2 >90% 6

Step 2: Diagnostic Confirmation

• Perform edrophonium chloride (Tensilon) test to differentiate myasthenic crisis from cholinergic crisis 5
• Order electromyography and autoantibody profiling (acetylcholine receptor antibodies, anti-MuSK antibodies) to confirm myasthenia gravis 2
• Obtain baseline pulmonary function tests including vital capacity and negative inspiratory force 5

Step 3: Pharmacologic Intervention

• Initiate pyridostigmine bromide 60 mg orally if able to swallow safely 5, 2
• For extended-release formulation: 180 mg tablets once or twice daily with at least 6-hour intervals between doses 5
• Symptoms should improve within days if myasthenia gravis is the correct diagnosis 2

Step 4: Monitor for Cholinergic Crisis

• Distinguish myasthenic crisis from cholinergic crisis - both present with extreme muscle weakness 5
• Cholinergic crisis requires immediate withdrawal of all anticholinesterase drugs and administration of atropine 5
• Increasing weakness despite pyridostigmine may indicate overdosage, not underdosage - this is a critical pitfall 5

Key Clinical Pitfalls to Avoid

Do not increase anticholinesterase doses if weakness worsens - this could represent cholinergic crisis and lead to grave consequences including death 5. The differential diagnosis between myasthenic crisis (needs more medication) and cholinergic crisis (needs drug withdrawal) requires edrophonium testing and clinical judgment 5.

Do not dismiss this as CVA based solely on initial presentation - myasthenia gravis in elderly patients with dysphagia and dysarthria is frequently misdiagnosed as stroke, leading to delayed treatment of a highly treatable condition 3. The normal CT scans should have prompted immediate reconsideration of the diagnosis 1.

Laryngeal myasthenia gravis requires differentiation from stroke - computerized voice analysis may be necessary when encountering atypical presentations 2.

Alternative Diagnosis Consideration

While biotin-responsive basal ganglia disease can present with subacute encephalopathy, dysarthria, dysphagia, supranuclear facial palsy, external ophthalmoplegia, and quadriparesis 7, this typically shows bilateral caudate and putamen necrosis on MRI, which is absent in this case. However, if myasthenia gravis is ruled out, consider empiric biotin 5-10 mg/kg/day as symptoms reverse within days 7.

Urgent Neurology Consultation

Immediate neurology consultation is mandatory for suspected myasthenic crisis, as this condition requires specialized management including potential plasmapheresis or intravenous immunoglobulin if respiratory failure develops 5. The presence of fasciculations, multiple cranial nerve involvement, and rapidly progressive quadriparesis indicates severe disease requiring intensive monitoring 5, 2.