A 68–year–old man with stable lupus nephritis diagnosed in 1999, presented with progressive difficulty with swallowing and speaking since May 2009 requiring percutaneous endoscopic gastrostomy tube placement in August 2010. Muscle atrophy, twitching and cramping developed along with emotional lability. Exam revealed pseudobulbar affect, tongue fasciculations, a marked mixed dysarthria, and marked muscle atrophy with fasciculations in his arms. He had brisk reflexes and Hoffman’s sign was present. Laboratory studies included negative ana titers, lyme and sjogren’s serologies.He had normal copper levels and negative paraneoplastic antibody panel. Electromyography and nerve conduction studies revealed diffuse motor axonopathy involving cranial, cervical and lumbosacral regions. He met clinical criteria for definite ALS. He is currently on riluzole and tolerating it well.
Neurologic manifestations of SLE are common and have protean presentations. ALS is not recognized as a manifestation of SLE. There has been a report of stroke mimicking ALS in SLE but our patient had the classic progression and met clinical criteria for diagnosis of ALS at a time when SLE was in remission. There is only one case report to date in which ALS presented in the course of SLE as in our patient. In another patient ALS was the presenting manifestation of SLE. Autoimmune pathogenesis for ALS has long been contemplated, especially the anti–ganglioside antibodies found in sera of patients with ALS and other autoimmune diseases. Glatiramer acetate is a T lymphocyte inhibitor that is showing some promise in animal models of ALS. Glutamate has also been implicated in the pathology of nerve damage in these patients. Along these lines, ceftriaxone has been tried as an anti–glutamate agent by increasing expression and activity of the glutamate transporter, GLT1, with variable results. A possible autoimmune pathogenesis of ALS prompts the consideration of immunosuppressive therapy in these patients. The lack of correlation between SLE and ALS in medical literature and the suspected autoimmune mechanism of pathogenesis in the latter suggest that this association might be causal in certain patients.
We present the second reported case of ALS developing in a patient with SLE.