Clinical Reasoning: A Middle-aged Man With Progressive Gait Abnormalities

Progressive spastic paraplegia is the core symptom of hereditary spastic paraplegias (HSPs), a group of monogenic disorders characterized pathologically by degeneration of the corticospinal tract and dorsal column and leading to irreversible neurologic deficits. However, acquired causes, such as structural, vascular, inflammatory, infectious, metabolic, toxic, neurodegenerative, and iatrogenic causes, can also cause acquired spastic paraplegia. We describe the case of a middle-aged man presenting with progressive spastic paraplegia combined with ataxia and parkinsonism. No mutation of HSP genes was detected. After a comprehensive diagnostic workup, hyperintensities in the bilateral basal ganglia, mesencephalon, pons, and cerebellum on T1-weighted images were found, which demonstrated hypointensity on susceptibility-weighted imaging. Furthermore, an increased blood ammonia level and diffuse slow-wave activity in EEG were detected. The patient had a 7-year history of hypertension, alcoholic liver cirrhosis, and transjugular intrahepatic portosystemic shunt operation 2 years before the onset of spastic paraplegia symptoms. Current workup combined with patient history resulted in a diagnosis of acquired hepatocerebral degeneration and hepatic myelopathy.. This case provided a detailed diagnostic approach for progressive spastic paraplegias and exhaustive differential diagnoses of basal ganglia deposits. The take-home message from this case was that acquired causes, especially curable causes, should always be excluded first when dealing with patients with progressive spastic paraplegia.