A 60-year-old woman comes to the office due to "balance problems while walking." The patient has had 2 falls over the last 2 months associated with tingling in her feet and dull pains in her back and legs. Medical history is notable for type 2 diabetes mellitus; her most recent hemoglobin A1c was 7.6%. Neurological examination reveals decreased muscle strength in both legs, diminished proprioception peripherally in the feet, decreased pain sensation in the feet and ankles, a hyperactive right knee jerk, and an upgoing plantar reflex on the right side. Which of the following is the most appropriate next step in management of this patient's symptoms?

Question

A 60-year-old woman comes to the office due to "balance problems while walking."  The patient has had 2 falls over the last 2 months associated with tingling in her feet and dull pains in her back and legs.  Medical history is notable for type 2 diabetes mellitus; her most recent hemoglobin A1c was 7.6%.  Neurological examination reveals decreased muscle strength in both legs, diminished proprioception peripherally in the feet, decreased pain sensation in the feet and ankles, a hyperactive right knee jerk, and an upgoing plantar reflex on the right side.  Which of the following is the most appropriate next step in management of this patient's symptoms?

Quizplus · Accepted Answer

This patient with diabetes mellitus has back and leg pain associated with weakness, paresthesia in the feet, and right-sided hyperactive knee jerk and upgoing plantar reflex. Although neurologic complications are extremely common in patients with diabetes, patients usually develop distal symmetric polyneuropathy (ie, diabetic neuropathy) that causes a "stocking and glove" pattern of sensory loss, impaired proprioception and vibratory sense, and diminished ankle reflexes. Rarely, motor weakness can occur but is typically a late manifestation (eg, after years) of severe disease and follows a similar distribution. Therefore, several components of this patient's presentation suggest a more serious etiology than simple diabetic neuropathy. The asymmetric hyperactive knee jerk and positive Babinski sign (ie, upgoing plantar reflex) are concerning for an upper motor neuron process (in contrast to diabetic neuropathy, which strictly affects the lower motor neurons). In addition, diabetic neuropathy is unlikely to cause weakness that is present throughout the legs and is of relatively rapid onset (eg, months) as compared to the sensory manifestations. Taken together, these findings make the patient's history of back pain more concerning because it may be indicative of a mass lesion in the spine. The patient should be questioned about recent fevers (concerning for epidural abscess) or weight loss (concerning for malignancy). An MRI of the spine should be performed to evaluate for cord compression. (Choices B and D) Nerve conduction studies and electromyography can be used to confirm a suspected diagnosis of diabetic neuropathy but are not helpful in diagnosing a condition with the spinal cord, as suggested by this patient's upper motor neuron findings. (Choice C) A physical therapy referral would not be the appropriate next step for this patient because it would likely delay the probable diagnosis of cord compression. (Choice E) This patient's hemoglobin A1c is high and in the long term she would likely benefit from tighter blood glucose control. However, the more concerning, immediate issue is the cause of her upper motor neuron findings because delay in diagnosis would likely lead to worsening neurologic deficits. Educational objective: Diabetic neuropathy is a distal, symmetric polyneuropathy that can cause a "stocking and glove" pattern of sensory loss, impaired proprioception and vibratory sense, and diminished ankle reflexes; motor findings may be a late manifestation in severe disease. Hyperactive reflexes and an upgoing plantar reflex are inconsistent with diabetic neuropathy and are suggestive of an upper motor neuron process.

A 60-Year-Old Woman Comes to the Office Due to "Balance