23- Case 23: Déjà vu and amnesia

Page: 61-62

Correct answer: C. Temporal lobe epilepsy with focal impaired-awareness seizures

Explanation:
This presentation is classic for temporal lobe epilepsy (TLE). The metallic taste and auditory hallucinations represent auras (focal aware seizures), followed by impaired awareness, automatisms, and post-ictal confusion.

Clarification: “Complex partial seizure” is older terminology; the correct modern term is focal impaired-awareness seizure.

A 32-year-old man experiences recurrent episodes beginning with a metallic taste, followed by déjà vu, automatisms (lip smacking), post-episode confusion, and amnesia. What is the most likely diagnosis?

A. Panic disorder
B. Absence epilepsy
C. Temporal lobe epilepsy with focal impaired-awareness seizures
D. Schizophrenia
E. Migraine with aura

Correct answer: C. Stereotyped episodes with aura and post-ictal confusion

Explanation:
Short, stereotyped episodes with a consistent aura, automatisms, and post-ictal confusion with amnesia are highly suggestive of epilepsy rather than psychosis.
Psychotic hallucinations tend to be prolonged, non-stereotyped, and without post-ictal confusion.

Which feature most strongly supports temporal lobe epilepsy over a primary psychotic disorder?

A. Auditory hallucinations
B. Fear during episodes
C. Stereotyped episodes with aura and post-ictal confusion
D. Absence of family psychiatric history
E. Headaches

Correct answer: C. A focal aware seizure (aura)

Explanation:
A metallic taste is a gustatory hallucination, representing a focal aware seizure (aura) arising from the temporal lobe.

Correction: Older texts may call this a “simple partial seizure.”

The metallic taste experienced before the episodes is best described as:

A. A delusion
B. A psychotic hallucination
C. A focal aware seizure (aura)
D. A post-ictal phenomenon
E. A migraine prodrome

Correct answer: C. Repetitive semi-purposeful movements

Explanation:
Automatisms (lip smacking, hand rubbing) occur in 40–80% of temporal lobe seizures and are highly characteristic.

Which finding is most characteristic of focal impaired-awareness seizures arising from the temporal lobe?

A. Sudden loss of postural tone
B. Three-per-second spike-and-wave EEG pattern
C. Repetitive semi-purposeful movements
D. Complete preservation of awareness
E. No post-ictal confusion

Correct answer: B. Lack of aura and post-ictal confusion

Explanation:
Absence seizures:

• Have no aura

• Have no post-ictal confusion

• Are brief and frequent

• Show 3-Hz spike-and-wave EEG

TLE seizures often have an aura, automatisms, and post-ictal confusion.

Which feature helps distinguish absence seizures from temporal lobe epilepsy?

A. Brief duration
B. Lack of aura and post-ictal confusion
C. Impaired awareness
D. Occurrence in adults
E. Repetitive movements

Correct answer: D. MRI brain

Explanation:
MRI is crucial for detecting tumors, hippocampal sclerosis, or vascular malformations and localizing seizure focus.

Clarification: EEG supports diagnosis but has high false-negative rates, especially between seizures.

Which investigation is most useful for identifying a structural cause and localizing the seizure focus in this patient?

A. CT head
B. EEG
C. PET scan
D. MRI brain
E. Lumbar puncture

Correct answer: C. Interictal EEG may be normal

Explanation:
Epileptiform discharges may be intermittent, so interictal EEG can be normal even in true epilepsy.

Why does a normal EEG not exclude temporal lobe epilepsy?

A. EEG only detects generalized seizures
B. Temporal lobe seizures are always subclinical
C. Interictal EEG may be normal
D. EEG is unreliable in adults
E. EEG cannot detect focal seizures

Correct answer: C. Focal impaired-awareness seizure

Explanation:
The seizure begins as a focal aware seizure (aura) and progresses to focal impaired-awareness seizure.

Correction: Older term = “complex partial seizure.”

Which seizure type best describes progression from an aura to loss of awareness with automatisms?

A. Generalized tonic-clonic seizure
B. Focal aware seizure only
C. Focal impaired-awareness seizure
D. Absence seizure
E. Myoclonic seizure

Correct answer: C. Carbamazepine

Explanation:
Carbamazepine is a first-line antiepileptic for focal seizures. Other correct options include lamotrigine, valproate, oxcarbazepine, and topiramate.

Which medication is appropriate first-line treatment for this condition, which is Temporal Lobe Epilepsy (TLE)?

A. Haloperidol
B. Fluoxetine
C. Carbamazepine
D. Lithium
E. Propranolol

Correct answer: B. It is commonly mistaken for anxiety or psychosis

Explanation:
TLE frequently masquerades as psychiatric illness, especially anxiety or psychosis, leading to delayed diagnosis.

Which statement about temporal lobe epilepsy is TRUE?

A. It always begins in childhood
B. It is commonly mistaken for anxiety or psychosis
C. EEG is always diagnostic
D. Seizures are never followed by confusion
E. Surgery is never indicated

Correct answer: C. Temporal lobe seizure phenomena

Explanation:
Déjà vu (false familiarity) and jamais vu (false unfamiliarity) are classic temporal lobe seizure auras, reflecting abnormal activation of memory circuits in the medial temporal lobe.

The patient reports both déjà vu and episodes where familiar people feel completely unfamiliar. These experiences are best described as:

A. Delusional misidentification syndromes
B. Depersonalization and derealization
C. Temporal lobe seizure phenomena
D. Dissociative symptoms
E. Early schizophrenia

Correct answer: C. Post-ictal state

Explanation:
Post-ictal amnesia results from transient cerebral dysfunction after a seizure.

Dissociative amnesia typically occurs in response to psychological trauma and lacks stereotyped episodes or automatisms.

The patient has no memory of his automatisms and experiences confusion afterward. This amnesia is best explained by:

A. Dissociative amnesia
B. Psychogenic fugue
C. Post-ictal state
D. Acute stress reaction
E. Delirium

Correct answer: C. Progressive headache suggests possible mass lesion

Explanation:
Although headaches are common in epilepsy, new or worsening headaches raise concern for tumor, vascular malformation, or other structural pathology, reinforcing the need for MRI.

Why do the patient’s headaches increase concern for an underlying structural cause?

A. Headache is a diagnostic criterion for epilepsy
B. Headache always precedes seizures
C. Progressive headache suggests possible mass lesion
D. Headache excludes primary epilepsy
E. Headache indicates migraine-related seizures

Correct answer: C. The seizures are focal rather than generalized

Explanation:
Many epileptic seizures, especially temporal lobe seizures, do not involve tonic–clonic movements.

Lack of convulsions does not exclude epilepsy.

The absence of witnessed tonic–clonic movements in this patient indicates:

A. The episodes are non-epileptic
B. The diagnosis is psychiatric
C. The seizures are focal rather than generalized
D. EEG will be normal
E. Antiepileptic drugs are unnecessary

Correct answer: C. Presence of hallucinations and fear

Explanation:
Hallucinations, fear, and altered perception during seizures closely resemble panic or psychosis.
The key distinguishing features are episodic nature, aura, automatisms, and post-ictal confusion.

Which factor most strongly contributes to temporal lobe epilepsy being misdiagnosed as a psychiatric disorder?

A. Normal neurological examination
B. Family history of mental illness
C. Presence of hallucinations and fear
D. Poor response to antipsychotics
E. Age of onset

Correct answer: D. Medically refractory focal epilepsy with localized focus

Explanation:
Surgery is considered when seizures are drug-resistant, focal, and localizable, especially in temporal lobe epilepsy.

In which situation is surgical treatment most appropriate for temporal lobe epilepsy?

A. First seizure episode
B. Normal MRI and EEG
C. Seizures controlled with one medication
D. Medically refractory focal epilepsy with localized focus
E. Presence of psychiatric symptoms