A 56-year-old woman is evaluated for a monthlong history of intermittent weakness of the right foot and a 3-month history of progressive left arm weakness. The patient has no dysphagia, dysarthria, sensory loss, or bowel or bladder impairment. Other medical conditions include type 2 diabetes mellitus, hypercholesterolemia, and hypertension. She takes metformin, atorvastatin, and lisinopril. Temperature is 36.9 C (98.4 F), blood pressure is 130/78 mm Hg, pulse is 80/min, and respirations are 14/min. Neurologic examination reveals normal speech, language, and mental status. Moderate weakness and atrophy of the distal muscles in the right leg and left arm is noted. Fasciculations are present in the right leg. Deep tendon reflexes are brisk in the upper and lower limbs. Sensory examination shows no abnormalities. Laboratory results are as follows: Which of the following would be most helpful in treating this patient's current symptoms?

Question

A 56-year-old woman is evaluated for a monthlong history of intermittent weakness of the right foot and a 3-month history of progressive left arm weakness.  The patient has no dysphagia, dysarthria, sensory loss, or bowel or bladder impairment.  Other medical conditions include type 2 diabetes mellitus, hypercholesterolemia, and hypertension.  She takes metformin, atorvastatin, and lisinopril.  Temperature is 36.9 C (98.4 F), blood pressure is 130/78 mm Hg, pulse is 80/min, and respirations are 14/min.  Neurologic examination reveals normal speech, language, and mental status.  Moderate weakness and atrophy of the distal muscles in the right leg and left arm is noted.  Fasciculations are present in the right leg.  Deep tendon reflexes are brisk in the upper and lower limbs.  Sensory examination shows no abnormalities.  Laboratory results are as follows:  Which of the following would be most helpful in treating this patient's current symptoms?

Quizplus · Accepted Answer

11ec25c8_d58f_caa9_bc81_0709b3fe3fa5_MD0003_00 This patient has progressive weakness and signs of both upper motor neuron (UMN) (ie, hyperreflexia) and lower motor neuron (LMN) (ie, atrophy, fasciculations) deficits. In association with normal sensation, this presentation is consistent with amyotrophic lateral sclerosis (ALS). ALS is diagnosed clinically; although there are no confirmatory laboratory tests, mild creatine kinase (CK) elevation is sometimes seen, which may be due to denervation or hypermetabolism of atrophied muscles. ALS is universally fatal; therefore, management is largely focused on slowing progression and controlling symptoms. Riluzole, a glutamate inhibitor, is a first-line therapy shown to improve survival, possibly by reducing glutamate-mediated excitotoxicity. It is often used in combination with edaravone, an antioxidant, which likely slows disease progression, particularly in patients early in the disease course. Further management includes aggressive respiratory support (eg, noninvasive positive-pressure ventilation), nutritional support, and multidisciplinary symptomatic management. Palliative care strategies are usually introduced early. (Choice A) Patients with poorly controlled diabetes are at increased risk of neuropathy; however, it typically presents as symmetric sensory polyneuropathy (eg, glove and stocking pattern) rather than asymmetric limb weakness. Hyperreflexia, an UMN sign, does not occur. (Choice B) Interferon beta is used to treat multiple sclerosis, which can cause a variety of neurologic deficits (eg, asymmetric extremity weakness) that can be intermittent or progressive. However, neurologic defects result from lesions in the CNS; therefore, atrophy and fasciculations (LMN signs) are typically absent. (Choice C) Hypothyroidism can cause muscle weakness in severe cases. However, although this patient has an elevated TSH level, the free T4 is normal, suggesting subclinical hypothyroidism, which is highly unlikely to cause symptoms. In addition, hyperreflexia and fasciculations are unexpected. (Choice D) Prednisone is used to treat multiple inflammatory myopathies (eg, polymyositis, inclusion body myositis), which can cause muscle weakness and elevated CK. However, myopathies usually cause a symmetric weakness, and hyperreflexia would not occur. (Choice F) Statin-induced myopathy causes muscle weakness and an elevated CK, and management involves statin discontinuation. However, it typically presents with proximal, symmetric muscle weakness and muscle pain. UMN signs are unexpected. Educational objective: Amyotrophic lateral sclerosis presents with both upper and lower motor neuron signs; sensation is typically normal. Medical management includes riluzole (a glutamate inhibitor) and edaravone (an antioxidant), which improves survival and slows disease progression.

A 56-Year-Old Woman Is Evaluated for a Monthlong History of Intermittent