To report a diagnostically challenging case of rapidly progressive dementia with complex overlapping cognitive, psychiatric, and motor features.
Rapidly progressive dementia poses a broad diagnostic challenge. We present a patient with rapidly progressive dementia, psychiatric symptoms, and various movement abnormalities (resting and action tremor, stimulus induced myoclonus, and rigidity) who underwent extensive work up and was diagnosed with frontotemporal dementia.
A 66-year-old woman with hypothyroidism presented after months of progressive cognitive and functional decline, abnormal movements, and acute onset unresponsiveness consistent with catatonia. The patient was intubated for airway protection due to her mental status.
Ten months earlier, she developed abrupt psychiatric symptoms that progressed to paranoia and suicidal ideation, requiring psychiatric hospitalization. In the ensuing months, she experienced rapid memory and cognitive decline, from forgetting routine tasks to inability to perform activities of daily living, such as working and cooking. Family reported a progressive tremor of the hands and jaw and fluctuating insomnia and mental status. Weeks before admission, her extremities became markedly rigid, with loss of ambulation and dependence for basic self-care. The day before presenting, she was found unresponsive to verbal and tactile stimuli with a fixed stare and no apparent alertness.
An extensive work up, including brain magnetic resonance imaging, electroencephalography, and cerebral spinal fluid was normal. She was empirically treated with high-dose corticosteroids, plasma exchange, dopaminergic therapy, and a lorazepam challenge with no improvement. The patient’s neurologic status did not improve, and care was transitioned to comfort measures with postmortem brain pathology confirming frontotemporal dementia.
This case highlights the diagnostic complexity of rapidly progressive dementia and the need for a comprehensive and systematic evaluation and diagnostic approach across multiple etiologies. Ultimately, the case demonstrates frontotemporal dementia manifesting as rapidly progressive cognitive and behavioral decline with atypical motor features, initially mimicking psychiatric and autoimmune disorders.