Pseudomenigiocele masquerading as monomelic amyotrophy

Pseudomeningocele is a known cause of myelopathy, however this is classically associated with bilateral symptoms. We discuss a patient presenting with single upper extremity weakness, initially diagnoses as monomelic amyotrophy, which further investigation revealed to be a giant pseudomeningocele. This case illustrates a unique presentation of pseudomeningocele, including prominent changes in MRI, CT myelogram, and EMG. A review of the literature for pseudomeningocele including pathology, diagnosis, imaging, and treatment as well as the initial diagnosis of monomelic amyotrophy is provided.