SPS is an immune-mediated neurological disorder that presents with a spectrum of symptoms and is most commonly associated with anti-glutamic acid decarboxylase (anti-GAD) antibodies. SPS has been associated with lower than expected performance on cognitive testing relative to estimated premorbid intelligence.  Additionally, the presence of anti-GAD antibodies has been associated with an elevated risk of cognitive impairment in patients with diabetes and in animal models.

A retrospective review of medical records from 1997 to 2020 at Johns Hopkins Hospital was performed. SPS patients who had received neuropsychological testing as part of routine clinical care for subjective cognitive complaints were included.  Information about the patient’s demographics, clinical characteristics, medical co-morbidities, medications, and neuropsychological testing reports were extracted. Performance on cognitive and psychological measures were considered impaired if they were reported as “impaired”, or “abnormal”. 

Of 192 patient records reviewed, 21 had past neuropsychological testing, of which 11 were available in the electronic medical record (mean age 47.6 (SD=15.7), mean disease duration 8.3 (SD=6.1) years, 8 (73%) female, 9 (82%) Caucasian). Of those with testing reports available, 7 (64%) patients had impairments in memory, 6 (55%) had impairments in attention, 6 (55%) in executive function, 6 (55%) in motor speed, 5 (54%) in processing speed, 4 (36%) in language and 2 (18%) in visuospatial skills. Seven (64%) had moderate-to-severe depressive or anxiety symptoms on neuropsychological evaluation, but only 5 (45%) were on antidepressants.

Evaluation of subjective cognitive complaints in SPS should include assessment of memory, attention, executive function, motor speed and processing speed. Moderate-to-severe depression and anxiety are common in SPS patients with cognitive impairment. Further understanding of neuropsychological symptoms in SPS is needed to identify interventions and improve quality of life in this population.