Abstracts

Rationale: Gerstmann syndrome is an uncommon neurological disorder that classically presents with a tetrad of acalculia, agraphia, finger agnosia, and left-right disorientation. This is usually caused by structural insults to the posterior lobule of the dominant parietal lobe. Thus far, it has most commonly been reported with etiologies such as ischemic stroke, tumor, progressive multifocal leukoencephalopathy, subdural hematoma, multiple sclerosis, cortical atrophy, and systemic lupus erythematosus. Here we present an atypical case of Gerstmann syndrome that presents as focal seizure without focal lesion.

Methods: An 84-year-old female with no previous history of neurological disease such as stroke or seizure presented with acute onset confusion. Examination showed global aphasia with perseveration of speech, but no focal motor or sensory deficits. She also had left-right disorientation, finger agnosia, and acalculia, consistent with Gerstmann syndrome. STAT MRI showed no acute pathology. STAT EEG showed left hemispheric delta slowing. Focal seizure without impaired awareness was suspected, so the patient was immediately started on Keppra. Lumbar puncture was unremarkable for alternative etiology of her symptoms such as meningitis or encephalitis. After initiation of AED, she was gradually able to name objects, but still had finger agnosia and left-right disorientation. By Day 4, her neurological exam was back to baseline, without aphasia or paraphasic errors.

Results: Initial CT head and CT angiogram head & neck showed no acute intracranial abnormality or steno-occlusive disease. MRI brain with and without contrast showed no cortical enhancement, diffusion restriction, T2 hyperintensities, or focal abnormalities. EEG showed continuous focal slowing over the left hemisphere without seizures or epileptiform discharges. Lumbar puncture was unremarkable except for a mild neutrophilic predominance, including a negative viral and bacterial panel. Follow up EEG after symptom resolution, on Day 4, was normal during wakefulness, drowsiness, and sleep.

Conclusions: In patients with acalculia, agraphia, finger agnosia, and left-right disorientation with unremarkable MRI and CSF analysis, focal seizure should be considered as a cause of Gerstmann syndrome. Urgent EEG is necessary to rule out subclinical seizures or nonconvulsive status epilepticus, and prompt AED initiation is warranted. Repeat MRI and EEG may be helpful after resolution of symptoms to support diagnosis.

Funding: Please list any funding that was received in support of this abstract.: No funding.