What is the recommended approach to writing a diagnosis for a patient presented with a seizure?

How to Write a Diagnosis for a Patient Presenting with Seizure

The diagnosis should clearly distinguish between provoked (acute symptomatic) versus unprovoked seizures, specify the seizure type based on semiology, and identify any underlying etiology—this classification directly impacts treatment decisions and prognosis. 1

Diagnostic Framework: Provoked vs. Unprovoked Classification

The American College of Emergency Physicians provides a critical temporal distinction that must be documented in your diagnosis: 1

• Provoked (Acute Symptomatic) Seizure: Document when the seizure occurs at the time of or within 7 days of an acute neurologic, systemic, metabolic, or toxic insult 1

  • Examples include hyponatremia, hypocalcemia, alcohol withdrawal, toxic ingestions, encephalitis, or acute CNS mass lesions 1
  • These patients do NOT require long-term antiepileptic therapy—treatment focuses on correcting the underlying cause 2, 3

• Unprovoked Seizure: Document when seizures occur without acute precipitating factors 1

  • This includes remote symptomatic seizures (from CNS/systemic insult >7 days prior) and idiopathic seizures 1
  • Recurrent unprovoked seizures constitute epilepsy 4

Seizure Type Classification in the Diagnosis

Your diagnosis must specify the seizure semiology based on the International League Against Epilepsy classification: 5

For Focal Seizures:

• Document whether awareness was retained or impaired during the seizure 5
• Specify motor characteristics if present: atonic, automatisms, clonic, epileptic spasms, hyperkinetic, myoclonic, or tonic 5
• Note if the seizure became bilateral tonic-clonic (formerly "secondarily generalized") 5
• For nonmotor-onset: document autonomic, behavior arrest, cognitive, emotional, or sensory features 5

For Generalized Seizures:

• Specify motor type: tonic-clonic, tonic, clonic, myoclonic, atonic, or epileptic spasms 5
• For absence seizures: distinguish typical vs. atypical 5

For Unknown Onset:

• Still classify observable features: motor, nonmotor, tonic-clonic, epileptic spasms, or behavior arrest 5

Essential Diagnostic Elements to Document

History-Based Components:

• First seizure vs. recurrent: This distinction determines whether the patient has epilepsy 4, 6
• Witnessed description: Document specific motor movements, duration, level of consciousness, and post-ictal state 6
• Medication compliance in known epilepsy patients (non-compliance is a major precipitant) 2
• Recent medication changes: Tramadol and other drugs lower seizure threshold 2
• Substance use: Alcohol withdrawal, cocaine, stimulants 1
• Sleep deprivation and other triggers 2

Physical Examination Findings:

• Focal neurologic deficits: 81% of patients with focal exam findings had focal CT lesions 1
• However, 17% with normal neurologic exams still had focal CT abnormalities 1
• Signs of infection: Fever, meningismus 1
• Signs of trauma 1

Laboratory-Driven Etiologies to Document:

The American College of Emergency Physicians emphasizes that metabolic abnormalities can be identified by history and physical examination in most cases, but not all: 1

• Hypoglycemia: Check immediately in all seizure patients 7, 2
• Hyponatremia: Most common electrolyte cause 1, 2
• Hypocalcemia: Can trigger seizures at any age, even without prior history 2
• Hypomagnesemia: Particularly in alcohol-related seizures (8 of 18 patients in one series) 1
• Uremia, hyperglycemia 2

Critical caveat: In one study, 3 cases of metabolic abnormalities (hypoglycemia, hyponatremia, hypocalcemia) were NOT predicted by history and physical examination 1

Neuroimaging Findings:

• CT abnormalities were found in 34% of patients overall, highest in those >60 years 1
• Document any mass lesions, stroke, hemorrhage, or structural abnormalities 8, 2
• The American Academy of Neurology recommends MRI as the preferred modality when neuroimaging is obtained 1

Example Diagnostic Statements

Provoked Seizure:

"Provoked generalized tonic-clonic seizure secondary to severe hyponatremia (sodium 118 mEq/L)" 1, 2

Unprovoked Seizure:

"First unprovoked generalized tonic-clonic seizure, etiology undetermined pending outpatient workup" 1

Known Epilepsy:

"Breakthrough focal impaired awareness seizure with secondary generalization in patient with known temporal lobe epilepsy, likely due to medication non-compliance" 2, 5

Remote Symptomatic:

"Unprovoked focal motor seizure (right arm clonic activity) in patient with remote history of left MCA stroke (2 years prior)" 1

Common Pitfalls to Avoid

• Do not diagnose "epilepsy" after a single unprovoked seizure—epilepsy requires recurrent unprovoked seizures 4
• Do not initiate long-term antiepileptic drugs for provoked seizures—treat the underlying cause 2, 3
• Do not use outdated terminology like "grand mal" or "petit mal"—use current ILAE classification 5
• Do not assume normal physical exam rules out structural lesions—17% with normal exams had focal CT findings 1
• Do not overlook non-convulsive status epilepticus in patients with persistent altered consciousness—consider EEG 8, 3