Postencephalitic parkinsonism
ICD-10 G21.3 is a billable code used to indicate a diagnosis of postencephalitic parkinsonism.
Postencephalitic parkinsonism is a form of parkinsonism that arises following an encephalitic illness, most notably post-influenza encephalitis. This condition is characterized by the classic motor symptoms of Parkinson's disease, including bradykinesia, rigidity, and tremors. The pathophysiology involves damage to the basal ganglia, particularly the substantia nigra, which leads to a deficiency in dopamine production. Patients may also exhibit non-motor symptoms such as cognitive impairment, mood disorders, and autonomic dysfunction. The onset of symptoms can occur weeks to months after the initial encephalitic event, and the severity can vary widely among individuals. Treatment typically involves dopaminergic medications, such as levodopa, which can help alleviate motor symptoms. However, the response to treatment may be less predictable compared to idiopathic Parkinson's disease, and some patients may experience significant side effects or complications from long-term medication use.
Detailed history of encephalitis, neurological examination findings, and treatment response.
Patients presenting with parkinsonian symptoms following a documented encephalitic illness.
Ensure clear documentation of the encephalitic event and its timing relative to the onset of parkinsonism.
Functional assessments, rehabilitation goals, and progress notes.
Patients requiring rehabilitation for mobility issues due to parkinsonism.
Document the impact of parkinsonism on daily activities and rehabilitation outcomes.
Used for follow-up visits for management of parkinsonism symptoms.
Document history of present illness, review of systems, and treatment plan.
Neurology specialists should ensure comprehensive neurological assessments are included.
Postencephalitic parkinsonism is primarily caused by damage to the basal ganglia following an encephalitic illness, often viral in nature, leading to a deficiency in dopamine production.
