EpistemisPhantosmia
Specialty: Neurology.
Why it occurs
- Temporal lobe epilepsy (focal seizure with psychic or olfactory symptoms, classically described as a burning smell or burnt rubber, called uncinate seizure)
- Brain trauma with injury to the fibers of the olfactory bulb and subsequent aberrant regeneration
- Migraine with olfactory aura
- Schizophrenia and other psychotic disorders (olfactory hallucinations associated with delusions of persecution)
- Parkinson's disease or Lewy Body Dementia in prodromal phases
- Chronic paranasal sinus infection with residual neuroepithelial damage
Initial workup
Conventional and sleep deprived electroencephalogram (EEG) to look for spike or spike-wave discharges in mesial temporal regions; high-resolution brain MRI with epilepsy protocol (thin slices targeting the hippocampi and temporal lobes); CT of the paranasal sinuses to rule out chronic sinusitis or lesions of the nasal roof.
red flags
Brief and recurrent phantosmia (seconds in duration) that is accompanied by altered state of consciousness, disconnection from the environment, automatic repetitive movements of the mouth (sucking, chewing) or postictual confusion, suggesting epileptic discharges in the piriform cortex or amygdala.
Standard management
- Carbamazepine (200-800 mg/day) or Oxcarbazepine if temporal focal epilepsy is confirmed
- Valproic acid or Levetiracetam — 500-2000 mg/day
- Preventive treatment of migraine with topiramate or calcium channel blockers if olfactory hallucinations act as a migraine aura.
Educational guidance for study. It is NOT a prescription recommendation. The actual choice depends on the cause, the patient, and current guidelines.
- Area
- Neurology
- Listed causes
- 6
- Treatment options
- 3