Clinical Reasoning: Middle-aged Man With Progressive Gait Abnormalities

Progressive spastic paraplegia is the core symptom of hereditary spastic paraplegia (HSP), a group of monogenic disorder 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 a 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 work-up, hyperintensities in the bilateral basal ganglia, mesencephalon, pons, and cerebellum on T1-weighted images were found, which demonstrated hypointensity on susceptibility weighted imaging (SWI). Furthermore, an increased blood ammonia level and diffuse slow wave activity in electroencephalogram were detected. Combined with a 7-year history of hypertension and alcoholic liver cirrhosis and the history of Transjugular Intrahepatic Portosystemic Shunt (TIPS) operation two years prior to the symptom of spastic paraplegia, concurrent acquired hepatocerebral degeneration (AHD) and hepatic myelopathy (HM) was finally diagnosed. The current case provided a detailed diagnostic approach for progressive spastic paraplegias and an 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.