A 14-year-old girl is brought to the emergency department due to progressive weakness in the lower limbs for 3 weeks. Her parents first noticed clumsiness, which has progressed to difficulty walking over the last week. The patient had a fever, cough, and congestion about 1 month ago and has otherwise been well. She has a history of high plantar arches requiring orthotics and mild scoliosis. The patient takes no medication and has no allergies. Her parents and 2 older siblings are healthy. Vital signs are normal. On examination, she has a wide-based gait and has difficulty maintaining balance without assistance. Strength is 2/5 in the lower extremities and 5/5 in the upper extremities. There is decreased vibratory and position sense in the lower extremities. MRI shows cervical spinal cord atrophy. When discussing the most likely diagnosis with the patient's parents, which of the following statements is most accurate?

Question

A 14-year-old girl is brought to the emergency department due to progressive weakness in the lower limbs for 3 weeks.  Her parents first noticed clumsiness, which has progressed to difficulty walking over the last week.  The patient had a fever, cough, and congestion about 1 month ago and has otherwise been well.  She has a history of high plantar arches requiring orthotics and mild scoliosis.  The patient takes no medication and has no allergies.  Her parents and 2 older siblings are healthy.  Vital signs are normal.  On examination, she has a wide-based gait and has difficulty maintaining balance without assistance.  Strength is 2/5 in the lower extremities and 5/5 in the upper extremities.  There is decreased vibratory and position sense in the lower extremities.  MRI shows cervical spinal cord atrophy.  When discussing the most likely diagnosis with the patient's parents, which of the following statements is most accurate?

Quizplus · Accepted Answer

11ec25c8_d5a5_0075_bc81_07e9dc263c31_MD0003_00 Friedreich ataxia (FA), the most common hereditary form of ataxia, is an autosomal recessive condition that classically presents with progressive ataxia in adolescence. FA is caused by an excessive number of trinucleotide repeat sequences (most commonly GAA) in the frataxin gene. Neurologic findings include dysarthria, limb weakness, loss of deep tendon reflexes, and progressive gait and limb ataxia. Loss of position and vibratory senses occurs due to deterioration of the dorsal spinal column. Skeletal comorbidities include kyphoscoliosis and pes cavus (high-arched feet), as seen in this patient. Hypertrophic cardiomyopathy occurs in most patients, with an increased risk of arrhythmia and heart failure, usually leading to death by age 40. Imaging may reveal cervical spinal cord atrophy. Diagnosis is confirmed by genetic testing. Management is supportive (eg, physical therapy, psychological support), as no disease-modifying therapies are available (Choice D). Prenatal genetic testing and counseling are available for future pregnancies for confirmed cases in siblings or if both parents are known carriers. (Choice A) Ataxia-telangiectasia is also an autosomal recessive, progressive disorder that presents with ataxia in addition to ocular and cutaneous telangiectasias. Patients have DNA repair deficits that increase the risk of malignancy; FA does not predispose patients to cancer. (Choice B) Viral encephalitis can present with ataxia, but patients have fever, seizure, or altered mental status. Imaging reveals brain edema and inflammation. (Choice E) Acute cerebellar ataxia is typically a postinfectious disorder that presents with acute onset of ataxia, nystagmus, and dysarthria. Guillain-Barré syndrome is an immunologic polyneuropathy that classically presents with acute ascending weakness and areflexia. However, neither condition affects vibratory and position senses, and both usually resolve with supportive care, in contrast with Friedreich ataxia. Educational objective: Friedreich ataxia is an autosomal recessive, neurodegenerative disease that typically presents in adolescence with progressive ataxia and loss of position and vibratory senses. Genetic testing reveals an excessive number of trinucleotide repeat sequences. References: Friedreich ataxia. (http://www.ncbi.nlm.nih.gov/pubmed/20301458) Clinical neurogenetics: Friedreich ataxia. (http://www.ncbi.nlm.nih.gov/pubmed/24176426)

A 14-Year-Old Girl Is Brought to the Emergency Department Due