What rare neurological disorder presents with cognitive changes followed by behavioral changes and myoclonic jerks, characterized by periodic short interval diffuse discharges on EEG?

The rare neurological disorder characterized by cognitive changes followed by behavioral changes and myoclonic jerks, along with periodic short interval diffuse discharges on EEG, is indeed Creutzfeldt-Jakob Disease (CJD). CJD is a prion disease that leads to rapid neurodegeneration.

Initially, individuals may experience subtle cognitive impairments, which can manifest as memory lapses or difficulties in reasoning. This is then often followed by pronounced behavioral changes, such as personality alterations or psychiatric symptoms. The myoclonic jerks, which are sudden, involuntary muscle contractions, are a hallmark of CJD, particularly in the later stages of the disease.

EEG findings in CJD are significant as they typically show periodic sharp waves or diffuse discharges that are not commonly seen in other disorders. This specific EEG pattern helps in supporting the diagnosis of CJD in conjunction with clinical findings. In contrast, other neurological disorders such as Alzheimer's disease primarily exhibit more gradual cognitive decline and lack the specific myoclonic jerks and EEG patterns characteristic of CJD. Similarly, multiple sclerosis and Parkinson’s disease have distinct clinical and electroencephalographic features that do not match the profile described.