Objective: NA

Background: The autoantibody Kelch-like protein 11 (KLHL11) has been described previously in several paraneoplastic syndromes presenting as rhombencephalitis with features of ataxia, diplopia, dysarthria, vertigo, hearing loss, and tinnitus. The strongest oncologic association has been with germ-line tumors. Here we present a case report of a seropositive KLHL11 patient presenting as a motor neuron disease mimic without known cancer.

Design/Methods: NA 

Results: A 61-year-old woman presented to an outpatient neurologist for hand weakness. Upon examination, she was noted to have central localizing symptoms including increased tone in the upper extremities, hyperreflexia, down-beating nystagmus, and frontal release signs. Review of her prior imaging was normal and did not explain her exam findings. Repeat examination a few months later showed upper motor and lower motor neuron findings so she was referred for an EMG/NCS and to the ALS center. Unfortunately, she then presented to the hospital with dyspnea and dysphagia. She underwent a broad and extensive workup. In addition to the previous motor findings, she had dysarthria, dysphagia, respiratory weakness, and hyperemotionality, with EMG showing both acute and chronic neurogenic changes. She was discharged with a suspected diagnosis of bulbar onset ALS. Shortly after discharging her serum paraneoplastic panel resulted with a markedly elevated KLHL11 IgG+ (titer >1:7860). She was admitted to the hospital for malignancy workup and initiation of high dose steroids and plasma exchange. Malignancy workup including PET scan did not show any evidence for occult malignancy. During her hospitalization, she showed some improvement of her pseudo-bulbar symptoms and speech, and her strength improved in all extremities.  

Conclusions: Here we present a case of anti-KLHL11 without known malignancy presenting as a neurodegenerative disorder.