What is the best approach to manage a young lady with left-sided body numbness, hypothyroidism (underactive thyroid), and glaucoma?

Management of Left-Sided Body Numbness in a Young Woman with Hypothyroidism and Glaucoma

Immediate Neurological Evaluation is the Priority

The left-sided body numbness requires urgent neurological assessment to rule out stroke, transient ischemic attack, or other central nervous system pathology before attributing symptoms to thyroid dysfunction. While hypothyroidism can cause neurological symptoms including peripheral neuropathy and cranial nerve deficits, unilateral body numbness is atypical and demands immediate evaluation for vascular or structural brain lesions 1.

Diagnostic Algorithm for Neurological Symptoms

Initial Workup

• Obtain brain MRI immediately to exclude stroke, demyelinating disease, or structural lesions causing unilateral sensory deficits 1
• Check thyroid function tests (TSH and free T4) to assess adequacy of hypothyroid treatment, as severe hypothyroidism can manifest with neurological symptoms including cranial neuropathies 1
• Measure serum creatinine and creatinine phosphokinase, as severe hypothyroidism can cause elevated CPK and renal dysfunction that may contribute to neurological symptoms 1
• Consider lumbar puncture if MRI is unremarkable, as hypothyroidism can cause elevated cerebrospinal fluid protein (up to 758 mg/L) and increased CSF/serum albumin ratio without pleocytosis 1

Thyroid-Related Neurological Manifestations

Severe hypothyroidism can present with multiple cranial neuropathies, facial palsy, tongue deviation, and dysarthria, though these typically resolve with levothyroxine replacement 1. However, unilateral body numbness is not a classic presentation and warrants exclusion of other etiologies first.

Hypothyroidism Management Considerations

Assess Treatment Adequacy

• If TSH >10 mIU/L with normal free T4, increase levothyroxine dose by 12.5-25 mcg regardless of symptoms, as this level carries approximately 5% annual risk of progression to overt hypothyroidism 2
• For patients <70 years without cardiac disease, target full replacement dose of approximately 1.6 mcg/kg/day 2
• Recheck TSH and free T4 in 6-8 weeks after any dose adjustment to evaluate response 2

Hypothyroidism as Risk Factor for Glaucoma

Hypothyroidism is an established risk factor for primary open-angle glaucoma, potentially due to decreased cellular metabolism with increased susceptibility to ganglion cell loss and/or alterations in mucopolysaccharides in the trabecular meshwork that increase IOP 3. However, treating hypothyroidism does not reduce glaucoma risk after diagnosis 4.

Glaucoma Management in Context of Hypothyroidism

Continue Standard Glaucoma Treatment

• Maintain target IOP 20% lower than baseline mean IOP measurements for glaucoma suspects 3
• Monitor for optic nerve deterioration with periodic fundus imaging, OCT of optic nerve head and RNFL, and visual field testing 3
• Hypothyroidism treatment may improve glaucoma control in rare cases, as documented in one case report where poorly controlled glaucoma reversed after 1 year of thyroxine therapy 5

Glaucoma Monitoring Considerations

• Patients with hypothyroidism have 1.09 times higher odds of having glaucoma at the time of hypothyroidism diagnosis, but no increased risk after diagnosis 4
• Continue regular ophthalmologic follow-up as hypothyroidism is a recognized risk factor for glaucoma progression 3

Critical Pitfalls to Avoid

• Never attribute unilateral neurological deficits to hypothyroidism alone without excluding stroke or other acute neurological emergencies 1
• Do not delay neuroimaging while waiting for thyroid function test results in a patient with acute unilateral numbness 1
• Avoid starting or increasing levothyroxine before ruling out concurrent adrenal insufficiency, as this can precipitate adrenal crisis 2
• Do not assume glaucoma will improve with thyroid hormone replacement, as this occurs only in exceptional cases 5, 4

Specific Management Based on Thyroid Status

If TSH is Severely Elevated (>10 mIU/L)

• Start levothyroxine at 1.6 mcg/kg/day for young patients without cardiac disease 2, 6
• Neurological symptoms including cranial neuropathies may normalize with adequate levothyroxine replacement over weeks to months 1
• Monitor for symptom improvement at 6-8 week intervals with repeat thyroid function testing 2

If TSH is Adequately Controlled

• Focus investigation on non-thyroid causes of unilateral numbness, as adequately treated hypothyroidism should not cause new neurological deficits 1
• Consider other autoimmune conditions given the association between Hashimoto's thyroiditis and other autoimmune diseases 3

Coordination of Care

Immediate neurology consultation is mandatory for evaluation of unilateral body numbness, with concurrent endocrinology involvement if thyroid function is poorly controlled 1. The glaucoma should continue standard ophthalmologic management with awareness that hypothyroidism is a risk factor for progression 3.