Phenytoin intoxication and upper facial dyskinesia: An unusual presentation

Orolingual Dyskinesia and Involuntary Neck Movements Caused by Phenytoin Intoxication

“…[1][2][3] Montenegro et al identified one patient with axial and orofacial dyskinesia and two patients with choreoathetosis in a 1-year period, and literature shows that the main findings in phenytoin-intoxicated dyskinesic patients were choreoathetosis, dystonia, orofacial dyskinesia, and ballism, in decreasing order. Besides these, various involuntary movements, such as tremor, asterixis, myoclonus, and dyskinesias have been reported in these patients so far.…”

“…[1][2][3] Montenegro et al identified one patient with axial and orofacial dyskinesia and two patients with choreoathetosis in a 1-year period, and literature shows that the main findings in phenytoin-intoxicated dyskinesic patients were choreoathetosis, dystonia, orofacial dyskinesia, and ballism, in decreasing order. [1][2][3][4][5] Brain damage has been shown to cause sensitization to the toxic effects of phenytoin. 2 The exact pathophysiology of the occurrence of involuntary movement in phenytoin intoxication is still obscure; however, the most likely mechanism seems to be a dopaminergic, cholinergic, and serotonergic imbalance within the basal ganglia system in these patients.…”

“…4 In addition to phenytoin, other anticonvulsants that cause dyskinesia include carbamazepine, gabapentin, felbamate, and valproic acid. 1 Examples include bilateral striatal infarction, globus pallidus calcification, frontal abscess, serious head trauma, operated meningioma, parasagittal glioblastoma, subdural hematoma, and thalamic infarction. [1][2][3][4][5] Brain damage has been shown to cause sensitization to the toxic effects of phenytoin.…”

“…2 The exact pathophysiology of the occurrence of involuntary movement in phenytoin intoxication is still obscure; however, the most likely mechanism seems to be a dopaminergic, cholinergic, and serotonergic imbalance within the basal ganglia system in these patients. 1 After the diagnosis was made, withdrawal of the drug brought about complete disappearance of all the signs within a short time. 1 Examples include bilateral striatal infarction, globus pallidus calcification, frontal abscess, serious head trauma, operated meningioma, parasagittal glioblastoma, subdural hematoma, and thalamic infarction.…”

Teaching Video Neuro Images :Phenytoin-induced orofacial dyskinesias

“…1 Elevation of phenytoin level is not necessary for dyskinesias to develop; dyskinesias usually resolve with drug cessation.…”