“Polyradiculoneuritis” as an Atypical Clinical Presentation of Creutzfeldt–Jakob Disease: A Case Report and Review of Literature

(1) Background: Creutzfeldt–Jakob disease (CJD) is a progressive neurodegenerative disorder, characterized by cognitive decline, and motor and psychiatric symptoms; it primarily affects the central nervous system; however, peripheral nervous system involvement has rarely been described, particularly as an atypical presentation. (2) Methods: A 78-year-old Caucasian man, a retired farmer with no family history of neurological disease, presented with diarrhea followed by progressive lower limb weakness, which eventually evolved into encephalopathy and generalized areflexia. An initial diagnosis of inflammatory neuropathy was considered; the diagnostic assessment included blood and cerebrospinal fluid testing, a CT whole body scan, brain MRI, neuropsychological testing, electroencephalography, a nerve conduction study and electromyography. (3) Results: Neurophysiological studies demonstrated an acute asymmetrical sensorimotor, predominantly axonal polyneuropathy, initially suggestive of an axonal form of inflammatory polyradiculoneuritis. This pattern was confirmed on follow-up neurophysiological assessment performed three weeks later. Unexpectedly, the diagnostic course ultimately led to a diagnosis of sporadic Creutzfeldt–Jakob disease, confirmed by post-mortem neuropathological examination. Based on these findings, we conducted a literature review to summarize the current evidence on CJD-related neuropathy. (4) Conclusions: Our case emphasizes the importance of maintaining clinical suspicion for CJD even in patients presenting with progressive lower limb weakness and suggests that peripheral neuropathy may be concomitant or even precede the CNS manifestations. Careful consideration is required to avoid misdiagnosis of inflammatory neuropathy in the context of neurodegenerative diseases such as CJD.