| Non-neurologic specific manifestations |
| Fatigue, anorexia, dizziness, nausea, vomiting, weight loss, tachycardia |
| Common neurological manifestations |
| Learning and memory disturbance, confabulation |
| Altered mental state: mental sluggishness, apathy, inattentiveness and inability to concentrate, spatial and personal disorientation, mild or marked confusion |
| Ocular abnormalities: nystagmus, diplopia, upward gaze paresis, abducens palsy, conjugate gaze palsies |
| Incoordination of gait and trunk ataxia |
| Generalized hyporeflexia |
| Disturbances of consciousness: drowsiness, lethargy, and mild coma |
| Uncommon neurologic manifestations |
| Stupor |
| Dysarthria |
| Hemiparesis, flaccid paraplegia, or quadriplegia |
| Choreic dyskinesias |
| Pupillary abnormalities: anisocoria, sluggish reactivity |
| Optic neuropathy: amaurosis, visual disturbance, papilledema, retinal hemorrhage |
| Epileptic seizures |
| Hearing loss |
| Hallucinations and behavioral disturbances |
| Painful paresthesias: burning, prickling, or tingling |