Differential Diagnosis

Salient Features Often observed to be absent minded Brief episodes of blank staring and inattention Eye blinking Reflex scratching of head Lip smacking and chewing movements Occurs many times a day then resumes usual activity 10 year old girl Poor academic performance

Differential Diagnosis Nonepileptic syndromes: Syncope Psychogenic seizures Sleep disorders Migraine Seizures: Complex Partial Seizures Absence seizures

Differential Diagnosis Syncope More likely if the event was provoked by acute pain or anxiety or occurred immediately after arising from the lying or sitting position Features suggesting syncope include – preceding light-headedness – sweating – pallor

Differential Diagnosis Psychogenic seizures It is precipitated by underlying psychological distress. Patients with a previous psychiatric history are likely to be at higher risk In general, compared to epileptic seizures, psychogenic seizures display a longer duration, a more waxing and waning nature, and nonphysiologic progression The diagnosis of psychogenic seizures does not exclude a concurrent diagnosis of epilepsy since the two often coexist

Differential Diagnosis Sleep disorders Sleep disorders may result in microsleeps or more prolonged sleep attacks due to any cause of hypersomnolence. The most common cause is disrupted sleep from obstructive sleep apnea, a condition which is common among patients with hypertension, atherosclerosis, and obesity.

Differential Diagnosis Migraine Migraine auras are distinguished from seizures by their more gradual, often visual, warning and longer duration. Associated symptoms include nausea or vomiting, photophobia, and phonophobia. Loss of consciousness is rare.

Differential Diagnosis Nonepileptic syndromes: Syncope Psychogenic seizures Sleep disorders Migraine Seizures: Complex Partial Seizures Absence seizures

Classifications of Seizures Seizures Partial seizures Simple Partial Complex Partial Partial seizures with secondary generalization Primarily Generalized Seizure Absence (petit mal) Tonic-clonic (grand mal) Tonic Atonic Myoclonic Unclassified seizures Neonatal seizures Infantile Spasms Harrison’s Principles of Internal Medicine, 17 th ed.

Differential Diagnosis Partial (or focal) seizures Originate in a localized area of cortex Simple-partial seizures do not affect consciousness and may have motor, sensory, autonomic, or psychiatric symptoms. Complex-partial seizures include alteration in consciousness coupled with automatisms (e.g., lip smacking, chewing, aimless walking, or other complex motor activities).

Differential Diagnosis Generalized seizures Involve diffuse regions of the brain in a bilateral symmetric fashion May occur as a primary disorder or may result from secondary generalization of a partial seizure Tonic-clonic seizures (grand mal) – Sudden loss of consciousness – Loss of postural control – Tonic muscular contraction producing teeth-clenching and rigidity in extension (tonic phase), followed by rhythmic muscular jerking (clonic phase)

Differential Diagnosis Absence seizures – Sudden, brief lapses of consciousness without loss of postural control – Produce automatisms, such as repetitive lip smacking, or mild clonic or myoclonic movements, including mild jerking of the eyelids – Usually begins in childhood ages(4-8) or early adolescence – Seizures can occur hundreds of times per day – Resemble moments of daydreaming or absent-mindedness

Differential Diagnosis Atypical Absence – Lapse of consciousness longer in duration and less abrupt in onset and cessation. – More obvious motor signs are present – Associated with diffused or multifocal abnormalities of the brain – May accompany other signs of neurologic dysfunction such as mental retardation.

Differential Diagnosis Complex Partial Seizures – Transient impairment of ability to maintain normal contact with environment – Impaired recollection of ictal phase – Automatisms show behaviors such as chewing, lip smacking, swallowing – Transition to full recovery may range from seconds to an hour

Differential Diagnosis Typical AbsenceAtypical AbsenceComplex Partial Seizure AuraNeverRareOften AutomatismsLess elaborateMay be more elaborate More elaborate Mean durationUsually < 10 secsAny duration (usually > 10 secs) Usually >10 secs Ictal EEGSynchronous 3Hz or faster spike-and- wave Atypical spike-and- wave, usually 2.5 Hz or slower Focal spikes Postictal confusionNoPossiblyYes Mental StatusNormalLow IQUsually normal PrognosisGoodPoorVariable