A Case of Imaging-Confirmed Delayed-Onset Olfactory–Gustatory Disturbance Following Traumatic Brain Injury

(Record dated 06-01-2026)

1. Patient Information

Patient: Male
Age: Approximately 30 years
Background: Kiwi
Past Medical History:
No history of upper respiratory tract infection.
No prior smell or taste disturbance related to common cold or infection.

2. Injury History (Clearly Identified Primary Event)

Approximately three months prior, the patient sustained a fall with direct impact of the head onto a concrete surface, resulting in scalp bleeding.

There was no documented loss of consciousness, however the patient subsequently developed clear neurological symptoms, including:

• Transient memory loss

• Slurred or unclear speech

• Slowed response

• Impaired concentration

Due to these symptoms, the patient was hospitalized for over one month and underwent structured rehabilitation, including:

• Speech therapy

• Memory rehabilitation

• Attention training

• Occupational rehabilitation

3. Imaging Evidence (Key Anchor Point)

CT Head (11-12-2025, Greenlane Radiology) demonstrated the following findings:

• Inferior frontal lobes (bilateral):

  • Small areas of previous haemorrhage, now resolved

  • Reducing local oedema

• Lateral right temporal lobe:

  • Small area of previous haemorrhage, now resolved

• Lateral right frontal lobe contusion:

  • Associated oedema reduced

• Trace subdural haemorrhage on the tentorium:

  • Fully resolved

• Left squamous occipital bone fracture (cranial base–related):

  • Persistent

• Left cerebellopontine angle arachnoid cyst:

  • Stable, considered an incidental finding

Key conclusion:
This was a documented traumatic brain injury with cerebral contusions and cranial base fracture, rather than a minor head impact.

4. Delayed Onset of Olfactory and Gustatory Disturbance

During hospitalization and active rehabilitation, the patient did not report any smell or taste disturbance.

Approximately one month after the injury, the patient gradually developed:

• Marked olfactory disturbance

• Significant alteration in taste perception during eating

• Particularly when consuming meat, the patient perceived a strong “chemical” or “offensive” smell

This abnormal perception triggered:

• Intense aversion

• Nausea and retching

• Inability to swallow food, requiring spitting it out

These symptoms persisted for approximately two months, significantly affecting eating behaviour and quality of life.

5. Critical Differentiation of Taste Function (Decisive Findings)

• Sweet taste perception preserved

• Spicy (pungent) sensation preserved

These findings indicate:

• Intact peripheral gustatory pathways (taste buds, chorda tympani, glossopharyngeal nerve)

• Preserved oral somatosensory input (trigeminal nerve–mediated sensation)

Therefore, this presentation does not represent primary taste loss, but rather:

A central disturbance of olfactory–gustatory integration and sensory encoding

6. Associated Symptoms and Exclusion Findings

• Mild headache

• Personality change with increased irritability and reduced patience

• Increased sensation of hunger

7. Case Characterisation (Descriptive, Non-Label-Based)

This case is best characterised as:

An imaging-confirmed delayed-onset olfactory–gustatory integration disorder following traumatic brain injury,
reflecting central sensory encoding dysfunction rather than peripheral sensory loss.

The clinical presentation is consistent with involvement of:

• Inferior frontal (orbitofrontal) regions

• Temporal lobe–associated sensory–emotional integration pathways

during the recovery and neural reorganisation phase after brain injury.

8. Clinical Management Principles (Current Stage)

• Rapid restoration of smell or taste should not be pursued

• Strong sensory stimulation or aggressive interventions should be avoided

• Olfactory–gustatory disturbance should be regarded as part of the central nervous system recovery process

• Time, neural reorganisation, and system-level recovery are considered the primary variables at this stage

9. Remarks – Value as a “Unique Case”

The value of this case does not lie in immediate symptom resolution, but in clearly demonstrating that:

• Olfactory and gustatory disturbances can occur as delayed manifestations after traumatic brain injury

• Radiological resolution does not equate to full functional neural recovery

• Preservation of sweet and spicy perception alongside “chemical” taste distortion is a key indicator of central sensory encoding dysfunction