Neuropathic pain as the presenting symptom of adult-onset Alexander’s Disease (P1.154)

Objective: Here we report on an unusual case of adult-onset Alexander’s Disease that came to our clinic as a referral for evaluation of neuropathic pain. Background: Adult onset Alexander’s disease (AOAD) is a rare leukodystrophy which typically presents with myelopathic decline, dysarthria, dysphagia, dysphonia, cerebellar signs, palatal myoclonus, sleep disturbance, or cognitive impairment. The disease is caused by glial fibrillary acidic protein (GFAP) gene mutations. Design/Methods: This patient was seen at our clinic, a tertiary referral center for the greater Los Angeles area. Results: Our patient is a 51 year old Caucasian man referred for evaluation of subtle sensitivity to light touch in the right thigh and leg, without any complaints of weakness or other spinal cord symptoms. Examination was significant for mild weakness and brisk reflexes in the affected leg. Initial workup was broad, including serum studies for autoimmune and vitamin deficiency neuropathies, as well as CSF studies to evaluate for evidence of infectious or inflammatory processes, all of which were negative. Imaging revealed a moderate degree of cerebral, medullary and spinal cord atrophy associated with a T2 hyperintensity in the anterior and lateral medulla. These imaging studies prompted consideration of an adult onset leukodystrophy. Genetic testing for mutation of the GFAP gene was sent, returning positive for a heterozygous mutation. Conclusions: Alexander’s disease is a rare leukodystrophy with both AD and sporadic pattern of inheritance. It is caused by a loss of function mutation in the alpha isoform of glial fibrillary acidic protein (GFAP.) This patient’s neuropathic pain likely represented a central pain syndrome due to the spinal and medullary degeneration. Our case illustrates that neuropathic pain may be a presenting symptoms of Alexander’s disease, and the importance of a broad differential in the workup of a common referral complaint. Disclosure: Dr. Massa has nothing to disclose. Dr. Beaber has nothing to disclose. Dr. Bronstein has nothing to disclose.