A 38-year-old woman comes to the emergency department due to worsening clumsiness and shaking in her right arm over the past 5 days. The patient has never had similar symptoms and has no other medical conditions. She takes oral contraceptive pills and occasionally acetaminophen. Temperature is 37 C (98.6 F), blood pressure is 140/85 mm Hg, and pulse is 84/min and regular. BMI is 34 kg/m2. On physical examination, there is right hand dysmetria and a mild right pronator drift but no muscle weakness. MRI of the brain without contrast is shown in the image below:
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Several of the lesions enhance after contrast administration. Which of the following is the most appropriate next step in management of this patient?
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This patient has cerebellar (dysmetria, tremor) and upper motor neuron (pronator drift) dysfunction accompanied by multifocal white matter lesions on MRI consistent with demyelination; this presentation suggests an acute attack of multiple sclerosis (MS). However, definitive diagnosis of MS requires evidence of CNS demyelination exhibiting both dissemination in space (DIS) (ie, lesions in ≥2 distinct locations) and dissemination in time (DIT) (ie, ≥2 attacks with objective findings). When MS is not clinically confirmed (eg, first clinical episode, as in this patient), MRI may establish the diagnosis.
This patient has DIS demonstrated both clinically and radiologically by 2 neurologic deficits (eg, cerebellar, upper motor neuron) and MRI lesions in ≥2 locations (eg, periventricular, juxtacortical) that are MS-typical. However, because this is her first attack, additional evidence for DIT is needed: A single MRI scan that shows both enhancing (ie, active inflammation) and nonenhancing (ie, previous demyelination) lesions (as seen in this patient in whom several lesions enhance after contrast administration) establishes DIT.
Acute MS attacks are treated with high-dose glucocorticoids (eg, methylprednisolone) to accelerate recovery. However, because glucocorticoids cannot reduce long-term disability or relapse risk, all patients with MS should be offered disease-modifying therapy (eg, dimethyl fumarate) to improve long-term outcomes. An acute demyelinating attack not meeting MS criteria (ie, clinically isolated syndrome) is also treated with high-dose glucocorticoids followed by close monitoring for progression to MS.
(Choice A) Acetazolamide decreases cerebrospinal fluid production, which is useful for treating idiopathic intracranial hypertension (IIH). However, IIH typically presents with manifestations of increased intracranial pressure (ICP) (eg, headache, vision changes, papilledema) in patients with obesity; parenchymal abnormalities on neuroimaging are uncommon.
(Choice B) Heparin is used to treat cerebral venous sinus thrombosis, which can occur in patients with prothrombotic conditions (eg, contraceptive use) but typically causes elevated ICP (eg, headache in 90% of patients) and radiographically can cause abnormal venous signal on MRI (rather than multiple enhancing and nonenhancing lesions).
(Choice D) Echocardiography is appropriate for possible cardioembolic stroke (eg, due to atrial fibrillation). However, embolic strokes typically involve cortical arterial territories instead of MS-typical white matter areas, and the resulting neurologic deficits are usually worse at onset rather than gradually worse.
(Choice E) Lumbar puncture (LP) showing oligoclonal (IgG) bands demonstrates ongoing CNS inflammation, which can substitute for clinical/radiologic DIT. However, LP is not required for MS diagnosis when clinical and MRI findings are definitive, as in this patient with both enhancing and nonenhancing lesions (DIT) in multiple locations (DIS).
Educational objective:
Definitive diagnosis of multiple sclerosis requires objective evidence of inflammatory demyelination disseminated in space and time. Acute attacks are treated with high-dose glucocorticoids.