Disclosures: Andrew Lai, DO: No financial relationships or conflicts of interest
Case Description: 78-year-old male awoke with sudden onset neck extensor weakness and pain without numbness or dysphagia. He denied recent trauma, prior cervical disorder, or family history of neuromuscular disorders.
Setting: Outpatient Clinic
Patient: Exam showed full strength and sensation in all extremities, with mildly shuffling gait and neck fully flexed. Patient able to actively extend neck to face forward only while seated and by compensating with accessory muscles. No upper motor neuron signs. Assessment/
Results: Patient presented with dropped head syndrome (DHS). Cervicalgia resolved with therapy, but extension strength only improved minimally. Imaging showed mild degenerative change. Electrodiagnostics showed isolated spontaneous activity in the cervical and mid-thoracic paraspinal muscles, and no post-synaptic neuromuscular junction disorder. Genetic testing negative. Because work-up for congenital myopathy, ALS, myasthenia gravis, myotonic dystrophy, autoimmune disease, paraneoplastic syndrome, and endocrine disorders was negative, the patient was diagnosed with isolated neck extensor myopathy (INEM).
Discussion: Dropped head syndrome has been associated with various neuromuscular, congenital, and metabolic disorders. EMG and muscle biopsy may show isolated neck myopathy, which was present in our patient. Our patient was diagnosed with isolated neck extensor myopathy (INEM). To arrive at this diagnosis, other causes of dropped head syndromes need to be ruled out, as discussed above. Treatment options for INEM include therapy, bracing, and fixation surgery if conservative management fails. There is empirical evidence for the use of IVIG, corticosteroids, and immunomodulators. Our patient opted for conservative treatment, resulting in a 30% improvement in neck strength over one year.
Conclusion: DHS is a rare condition often associated with other neuromuscular conditions but can also present as INEM without associated conditions. Our patient only had mild improvements with conservative treatment. Additional research is needed to elucidate management of this rare syndrome.
Level of Evidence: Level V
To cite this abstract in AMA style:
Lai A, Yeh B. Isolated Neck Extensor Myopathy: A Cause of Dropped Head Syndrome in an Elderly Patient [abstract]. PM R. 2020; 12(S1)(suppl 1). https://pmrjabstracts.org/abstract/isolated-neck-extensor-myopathy-a-cause-of-dropped-head-syndrome-in-an-elderly-patient/. Accessed September 7, 2024.« Back to AAPM&R Annual Assembly 2020
PM&R Meeting Abstracts - https://pmrjabstracts.org/abstract/isolated-neck-extensor-myopathy-a-cause-of-dropped-head-syndrome-in-an-elderly-patient/