A 61-year-old woman presented to the emergency department with neck pain after a fall in the nursing home, where she had lost her balance while trying to move clothing in her closet with her feet. She had a 7-year history of progressive neck, shoulder, and upper extremity weakness and atrophy, for which several diagnoses had been entertained, including amyotrophic lateral sclerosis, person-in-the-barrel syndrome, and upper motor neuron disease of unknown etiology. Electromyography had shown chronic neurogenic changes in the cervical myotomes. There was no history of headache or prior trauma. At presentation, she had severe atrophy of her neck, shoulder, and upper extremity musculature. Occasional fasciculations were noted. Motor examination showed flaccid paralysis (Medical Research Council score of 0 of 5) of the upper extremities except for right thumb abduction (score of 4 of 5) (Video). Lower extremity strength was normal. Deep tendon reflexes were absent in the upper extremities and normal in the lower extremities. Magnetic resonance imaging (MRI) showed an extensive ventral cervicothoracic extradural cerebrospinal fluid (CSF) collection with posterior displacement of the spinal cord (Figure 1A). Brain MRI findings were normal. Digital subtraction myelography localized the ventral CSF leak to the thoracic 11-12 level (Figure 1B). At surgery, through a posterior intradural approach, a ventral dural tear (Figure 2) was found, and this was repaired. The patient recovered well from surgery, and postoperative MRI showed complete resolution of her CSF leak. At last follow-up 40 months postoperatively, stable motor examination findings were noted.