Diagnosis of presumed acute ischemic stroke and associated seizure management in a Congo African grey parrot

Abstract

A 14-year-old Congo African grey parrot (Psittacus erithacus erithacus) was evaluated for an acute onset of falling off of its perch and tonic-clonic movements. Clinical signs were consistent with partial seizures. Findings on whole-body radiography, CBC, and plasma biochemical analysis were unremarkable. Plasma magnesium, ionized calcium, and bile acids concentrations were within reference limits. A magnetic resonance imaging (MRI) examination of the head revealed the presence of a focal hyperintensity at the central to left side of the optic chiasm and a hyperintense focus in the right side of the midbrain area in T2-weighted and FLAIR pulse sequence images. These findings were most consistent with an acute ischemic stroke with 2 brain infarcts. Seizures were initially managed with potassium bromide and phenobarbital administration. On the basis of poor results and difficulties to reach therapeutic blood concentrations, the treatment plan was changed to levetiracetam and zonisamide administration. Blood concentrations were monitored for both drugs, and the frequency of seizures substantially decreased thereafter. A follow-up MRI examination 2 months later revealed resolution of the hyperintense signals. During the 20-month follow-up period, subsequent clusters of seizures were managed by adjusting levetiracetam and zonisamide dosages and adding clonazepam and gabapentin administration to the treatment plan. Regression of intraparenchymal hyperintense lesions and improvement of clinical signs made a diagnosis of acute ischemic stroke most likely. Findings for this Congo African grey parrot indicated that an antemortem diagnosis of an acute ischemic stroke followed by long-term seizure management may be possible in affected psittacines.