What is the recommended workup for a 42-year-old female with a history of tremor, skin cancer, and amblyopia, presenting with persistent diplopia and associated symptoms?

From the Guidelines

The recommended workup for a 42-year-old female with persistent diplopia and a history of tremor, skin cancer, and amblyopia should begin with a comprehensive neuro-ophthalmologic evaluation, including a detailed cranial nerve examination, ocular motility testing, and measurement of proptosis if present, as suggested by the most recent guidelines 1. This evaluation is crucial given the patient's complex presentation, which includes sudden onset of double vision, nausea, vomiting, and associated symptoms such as weakness, fatigue, and occasional headaches. The patient's history of tremor, skin cancer, and amblyopia further complicates the diagnosis, necessitating a thorough investigation into potential underlying causes.

Key Components of the Workup

• A detailed medical history, including the description of ocular misalignment, strabismus angle and direction, and history of chronicity, as outlined in the adult strabismus preferred practice pattern 1.
• Neuroimaging, preferably MRI of the brain and orbits with contrast, to evaluate for structural lesions, demyelinating disease, or infiltrative processes.
• Laboratory studies, including thyroid function tests (TSH, free T3, T4) to rule out thyroid ophthalmopathy, acetylcholine receptor antibodies to assess for myasthenia gravis, and inflammatory markers (ESR, CRP).
• Given her history of tremor, a neurological consultation is warranted to evaluate for potential neurodegenerative disorders that might be contributing to her ocular symptoms.
• The skin cancer history raises concern for possible metastatic disease, so a thorough review of her oncologic history and possibly additional imaging may be necessary.

Additional Considerations

• Obtaining previous ophthalmologic records is important for comparison, as the pre-existing amblyopia may have contributed to long-standing visual changes.
• Temporary management of diplopia can include occlusion therapy (eye patch) or prism glasses while the underlying cause is being investigated and treated.
• The patient's symptoms of double vision, nausea, and vomiting, which began suddenly and have persisted, suggest the need for a prompt and comprehensive evaluation to determine the underlying cause and appropriate treatment, as suggested by the guidelines 1 and 1.

From the Research

Recommended Workup

The patient's symptoms of persistent double vision, weakness, fatigue, and occasional headaches, along with a history of tremor, skin cancer, and amblyopia, suggest a complex condition that requires a comprehensive workup. Based on the provided evidence, the following steps are recommended:

• A thorough neurological examination to assess muscle strength, reflexes, and coordination 2, 3, 4, 5
• Laboratory tests to check for the presence of autoantibodies, such as acetylcholine receptor (AChR) antibodies, muscle-specific kinase (MuSK) antibodies, and low-density lipoprotein receptor-related protein 4 (Lrp4) antibodies 2, 3, 4, 5
• Electrophysiological tests, such as repetitive nerve stimulation and single fiber EMG, to assess neuromuscular junction function 2, 4
• Imaging studies, such as MRI or CT scans, to rule out other conditions that may be causing the patient's symptoms 2, 4
• A review of the patient's medication history to identify any potential triggers or contributing factors 3

Considerations

The patient's symptoms and history suggest a possible diagnosis of myasthenia gravis (MG), an autoimmune disease characterized by dysfunction of the neuromuscular junction 2, 3, 4, 5. The presence of autoantibodies and the patient's response to treatment will help confirm the diagnosis. The patient's complexity, as defined by the presence of multiple conditions and non-medical factors, such as socio-economic status and behavior, should be taken into account when developing a treatment plan 6. The patient's history of skin cancer and amblyopia should be considered when evaluating the risk of other conditions, such as thymoma, which is associated with MG 2, 4.

Potential Diagnoses

Based on the patient's symptoms and history, the following potential diagnoses should be considered:

• Myasthenia gravis (MG) 2, 3, 4, 5
• Other neuromuscular disorders, such as muscular dystrophy or amyotrophic lateral sclerosis 2, 4
• Conditions that may be causing the patient's double vision, such as cranial nerve palsy or orbital tumors 2, 4
• Other conditions that may be contributing to the patient's fatigue and weakness, such as anemia or hypothyroidism 2, 4