A 34-year-old woman comes to the office due to diplopia, clumsiness of the left hand, and numbness of the right foot. Six months ago, the patient had numbness of the right hand, which resolved without treatment. Ten years ago, she was hurt by an explosion at work that resulted in a metallic foreign body in her left eye. She has no other medical problems and takes no medications. The patient has a 10-pack-year smoking history. Both parents are healthy. Vital signs are normal. BMI is 27 kg/m². Neurologic examination shows slowing of left eye adduction and left arm power of 4/5 with mild spasticity. Sensation to pinprick is decreased over the right foot. Cerebrospinal fluid analysis shows mononuclear cell pleocytosis and oligoclonal banding. Which of the following pathologic findings is most likely to be present in this patient's brain?

Question

Quizplus · Accepted Answer

11ec160b_39d1_6bc1_9249_6b79ef57b77f_MD0001_00 This patient with multiple waxing and waning neurologic deficits that cannot be explained by a single lesion most likely has multiple sclerosis (MS). MS is an autoimmune disorder of the central nervous system (CNS) characterized by lesions of focal demyelination. Demyelination involves both cellular and humoral immunity. Helper T cells react with myelin antigens and recruit additional lymphocytes and macrophages. Activated CD8⁺ T cells release cytotoxic granules that injure oligodendrocytes. B cell recruitment leads to the formation of myelin-specific antibodies that activate complement and facilitate myelin breakdown. The result is oligodendrocyte depletion with relative sparing of axons. Diagnosis is largely clinical but is supported by the presence of T2 lesions on MRI (precluded in this patient due to the presence of intraocular metal) or oligoclonal bands on cerebrospinal fluid analysis. Oligoclonal bands represent the intrathecal production of immunoglobulins and are highly sensitive for MS. However, oligoclonal bands are nonspecific and may be seen in any CNS disease involving humoral immunity (eg, vasculitis, infection). (Choice A) Astrocytes undergo hypertrophy and hyperplasia, not shrinkage, in response to CNS injury in a process known as glial scarring. (Choices B and C) Both Lewy body dementia and Alzheimer disease are characterized by protein aggregates in brain tissue. Lewy body dementia causes visual hallucinations, dysautonomia, and parkinsonism and is characterized by eosinophilic inclusions in neurons (Lewy bodies). Alzheimer disease causes progressive memory loss and is characterized by extracellular fibrillar protein accumulation (amyloid). Both diseases are uncommon in young patients and are not associated with focal neurologic deficits. (Choice D) Cerebral vasculitis can resemble MS with neurologic deficits that may wax and wane, and oligoclonal bands can be seen. However, patients typically develop severe headache, and systemic symptoms (eg, fever, fatigue, night sweats) are common. (Choice E) Intracerebral hemorrhaging can cause focal deficits, but symptoms would likely have an acute rather than intermittent or relapsing presentation. In addition, lumbar puncture would typically show xanthochromia (yellow-tinged cerebrospinal fluid from blood product breakdown), not a mononuclear pleocytosis. Educational objective: Multiple sclerosis (MS) is an autoimmune demyelinating disease that results from oligodendrocyte depletion. Within the lesions, inflammatory infiltrates of lymphocytes and macrophages are seen surrounding oligodendrocytes and myelin sheaths. Oligoclonal bands are highly sensitive but nonspecific in patients with MS.

A 34-Year-Old Woman Comes to the Office Due to Diplopia