5.2 Seizures, Epilepsy & Altered Mental Status
Key Takeaways
- Status epilepticus is defined as continuous seizure activity lasting 5 minutes or longer, or 2 or more discrete seizures without complete recovery of consciousness between events.
- First-line abortive therapy for status epilepticus is intravenous lorazepam (4 mg) or intramuscular midazolam (10 mg); if seizures persist after 5-10 minutes, repeat the dose and administer an IV non-sedating antiepileptic (levetiracetam, fosphenytoin, or valproate).
- Absence seizures characteristically exhibit 3 Hz spike-and-wave complexes on EEG, triggered by hyperventilation, and respond specifically to ethosuximide (T-type calcium channel blocker).
- Delirium is an acute, fluctuating disturbance in attention and awareness diagnosed clinically using the Confusion Assessment Method (CAM), requiring identification of underlying triggers rather than sedative medication.
- In patients presenting with Wernicke encephalopathy, intravenous thiamine (500 mg every 8 hours) must be administered before or concurrently with glucose fluids to prevent irreversible Korsakoff psychosis.
Emergency Management of Status Epilepticus
Status epilepticus is a major neurological emergency associated with neuronal injury and systemic complications. Operationally, status epilepticus is defined as continuous seizure activity lasting ≥5 minutes or ≥2 discrete seizures between which there is incomplete recovery of consciousness. Neuronal injury accelerates rapidly after 30 minutes of continuous seizure activity.
Phased Treatment Protocol
Management follows a strict, time-sensitive algorithm to abort seizure activity rapidly:
| Operational Phase | Timeframe | Interventions & Medications | Dosing & Route |
|---|---|---|---|
| Phase 1: Stabilization | 0 to 5 minutes | Assess airway, breathing, circulation; apply high-flow oxygen; check point-of-care blood glucose; establish IV access | If glucose <60 mg/dL: Administer 50 mL D50W IV + Thiamine 100 mg IV |
| Phase 2: First-Line Therapy | 5 to 20 minutes | Parenteral Benzodiazepines (Rapid abortive agent) | IV Lorazepam: 4 mg IV over 2 min (0.1 mg/kg); OR IM Midazolam: 10 mg IM (>40 kg); OR IV Diazepam: 10 mg IV. May repeat once at 5–10 min if seizures persist |
| Phase 3: Second-Line Urgent Control | 20 to 40 minutes | Non-Sedating IV Antiepileptic Drugs | IV Levetiracetam: 60 mg/kg (max 4500 mg); OR IV Fosphenytoin: 20 mg PE/kg (max 1500 mg PE); OR IV Valproate: 40 mg/kg (max 3000 mg) |
| Phase 4: Refractory Status | >40 minutes | General Anesthesia & Intubation | Continuous IV infusion of Propofol, Midazolam, or Pentobarbital with continuous EEG monitoring targeting burst suppression |
Seizure Classification & Epilepsy Syndromes
Accurate classification of seizures as focal or generalized dictates long-term anti-seizure medication (ASM) selection:
[ Seizure Presentation ]
|
(Clinical History & EEG Evaluation)
|
+---------------------------+---------------------------+
| |
[ Focal Onset ] [ Generalized Onset ]
| |
(Starts in one hemisphere) (Engages both hemispheres)
| |
+-------+-------+ +---------------+--------------+
| | | |
[ Focal Aware ] [ Focal Impaired ] [ Motor (Tonic-Clonic) ] [ Non-Motor (Absence) ]
(No loss of (Epigastric aura, (Tongue biting, post-ictal (3 Hz spike-and-wave;
awareness) lip smacking, amnesia) confusion, 4-6 Hz EEG) ethosuximide responsive)
Common Epilepsy Syndromes & Diagnostic Features
- Absence Seizures: Typically present in school-aged children as sudden, brief (5–15 seconds) episodes of unresponsiveness with blank staring. No post-ictal confusion occurs. Classic EEG finding is 3 Hz generalized spike-and-wave discharges induced by hyperventilation. First-line therapy is ethosuximide (blocks T-type Ca²⁺ channels in the thalamus).
- Juvenile Myoclonic Epilepsy (JME): Characterized by brief, involuntary muscle jerks upon awakening in adolescents, often progressing to generalized tonic-clonic seizures. EEG shows 4–6 Hz polyspike-and-wave complexes. First-line treatment is valproic acid or levetiracetam (avoid valproate in females of childbearing potential due to teratogenicity).
- Temporal Lobe Epilepsy: Most common cause of focal seizures with impaired awareness in adults. Classically preceded by an epigastric rising aura, deja vu, or olfactory hallucinations, followed by automatisms (lip smacking, hand fumbling) and post-ictal confusion. Associated with mesial temporal sclerosis on MRI. First-line agents include oxcarbazepine, carbamazepine, or levetiracetam.
Acute Altered Mental Status & Delirium
Delirium is an acute, fluctuating disturbance in attention, awareness, and cognition that is particularly prevalent among hospitalized elderly patients.
Distinguishing Delirium, Dementia, and Psychosis
| Clinical Feature | Delirium | Dementia | Primary Psychosis |
|---|---|---|---|
| Onset | Acute (hours to days) | Insidious (months to years) | Variable (weeks to months) |
| Course | Fluctuating (symptoms wax/wane) | Progressive, stable | Chronic, unremitting |
| Attention | Markedly impaired (hallmark) | Preserved until late stages | Typically intact |
| Level of Consciousness | Altered (somnolent or hyperactive) | Alert, clear sensorium | Alert, clear sensorium |
| Reversibility | Reversible (upon treating cause) | Irreversible | Manageable with pharmacotherapy |
Confusion Assessment Method (CAM)
Diagnosis of delirium using the CAM requires the presence of:
- Feature 1: Acute Onset and Fluctuating Course AND
- Feature 2: Inattention PLUS EITHER:
- Feature 3: Disorganized Thinking OR
- Feature 4: Altered Level of Consciousness
Management Strategy:
- Non-Pharmacologic Interventions (First-Line): Reorientation protocols, early ambulation, restoring normal sleep-wake cycles, removing unnecessary urinary catheters and physical restraints, and minimizing night-time room intrusions.
- Pharmacologic Interventions: Reserved exclusively for severe agitation posing immediate physical threat to the patient or staff. Low-dose oral haloperidol or atypical antipsychotics (quetiapine) may be used. Avoid benzodiazepines, as they worsen delirium unless treating alcohol withdrawal or benzodiazepine abstinence.
Toxic-Metabolic Encephalopathies
Wernicke Encephalopathy & Korsakoff Syndrome
Wernicke encephalopathy is an acute, reversible neuro-metabolic emergency caused by thiamine (Vitamin B1) deficiency, seen predominantly in chronic alcohol use disorder, severe malnutrition, or hyperemesis gravidarum.
- Classic Triad:
- Encephalopathy (profound confusion, disorientation)
- Ataxia (broad-based gait instability)
- Oculomotor Dysfunction (horizontal nystagmus, bilateral lateral rectus / CN VI palsy)
- Critical Management Rule: Intravenous thiamine (500 mg IV every 8 hours) must be administered BEFORE or concurrently with intravenous glucose solutions. Administering glucose alone accelerates thiamine consumption in the pyruvate dehydrogenase pathway, precipitating irreversible Korsakoff psychosis (characterized by anterograde/retrograde amnesia and confabulation due to destruction of mammillary bodies).
Hepatic Encephalopathy
Reversible neuro-psychiatric impairment resulting from liver failure and portosystemic shunting, causing accumulation of neurotoxins (ammonia, glutamine).
- Clinical Presentation: Asterixis (flapping tremor of outstretched hands), sleep reversal, disorientation, and lethargy.
- First-Line Therapy: Lactulose (titrated to 2–3 soft stools daily; acidifies gut lumen to convert ammonia NH₃ to non-absorbable ammonium NH₄⁺). Rifaximin is added as second-line therapy to eliminate ammonia-producing colonic bacteria.
An 8-year-old child is brought to the clinic by her teacher, who notes that the child frequently stares blankly into space for 10-15 seconds multiple times per day. During these episodes, she does not respond to her name, but immediately resumes her prior activity without post-ictal confusion. An electroencephalogram (EEG) performed during hyperventilation reveals generalized 3 Hz spike-and-wave discharges. What is the drug of choice for this condition?
A 42-year-old male with a history of alcohol use disorder is brought to the emergency department in active generalized tonic-clonic seizure activity. His emergency medical service record indicates continuous seizure activity for 12 minutes without recovery of consciousness. Airway protection and oxygen are initiated. What is the immediate first-line pharmacologic therapy?
An 82-year-old female, 2 days post-operative following total hip arthroplasty, becomes acutely agitated, disoriented to time and place, and reports seeing insects crawling on the hospital walls. Her symptoms fluctuate significantly throughout the day. She has a past medical history of hypertension and osteoarthritis. Physical examination reveals normal vital signs, clear lungs, and no focal neurological deficits. What is the most appropriate management strategy for this patient?