The Three Phases of Dravet Syndrome

Dravet syndrome is often described as a journey with three distinct chapters. While every child’s experience is unique—some may have fewer seizure types than others—understanding these phases can help you anticipate changes and prepare your care team. This progression is not a straight line, but rather an evolution of how the condition affects the brain and body over time ^[1][2].

Phase 1: The Febrile Phase (Infancy)

The first chapter typically begins within the first year of life, often between 5 and 8 months of age ^[3][4]. To the outside world, your baby may have seemed perfectly healthy until the first seizure occurred. Many parents find it helpful during this unpredictable phase to pack an “Emergency Go-Bag” to keep by the door for sudden hospital trips.

• Seizure Type: Seizures in this phase are often generalized tonic-clonic (convulsions involving the whole body) or hemiclonic (convulsions on just one side) ^[2][3].
• The Fever Trigger: These seizures are almost always triggered by hyperthermia—an increase in body temperature ^[3]. This can be a high fever from an illness, a warm bath, or even the mild immune response following a routine vaccination ^[5][6].
• The Duration: A hallmark of this phase is status epilepticus, which are seizures that last longer than 5 or 30 minutes ^[2]. Because these early seizures are so long, they often require emergency medical intervention ^[4].

Phase 2: The Worsening Phase (Toddlerhood to Early Childhood)

Often called the “stormy phase,” this period usually begins between ages 1 and 5 ^[3]. This is frequently the most challenging time for families as the seizure profile becomes more complex.

• New Seizure Types: In addition to the fever-triggered convulsions, you may start to see “afebrile” seizures (seizures without a fever) ^[3]. These can include:
  • Myoclonic seizures: Brief, shock-like jerks of a muscle or group of muscles ^[2].
  • Atypical absences: Staring spells where the child appears “checked out” but may still have some slight movement ^[2].
  • Focal seizures: Seizures that start in one specific part of the brain ^[2].
• Developmental Plateau: This is the phase where parents often notice that developmental milestones—like speaking in sentences or complex problem-solving—may slow down or plateau ^[3][7]. This is known as cognitive decline or developmental delay ^[3].
• Motor Changes: You may notice changes in how your child moves. This can include ataxia (clumsiness or lack of coordination) and eventually a “crouch gait,” where the child walks with their knees and hips slightly bent ^[3][2].

Phase 3: The Stabilization Phase (Late Childhood to Adulthood)

As children move into their teenage years and adulthood, the “storm” often begins to self-regulate, though the condition requires lifelong management ^[8].

• Seizure Changes: For many, the frequency of convulsive seizures decreases, and the terrifying, hours-long seizures of infancy become less common ^[8][9]. However, seizures typically do not disappear entirely and may still occur, particularly during sleep ^[10].
• Cognitive and Motor Baseline: While the seizures may stabilize, the intellectual and motor challenges that emerged in Phase 2 generally persist ^[8][9]. Adults with Dravet syndrome usually require some level of ongoing support for daily living ^[11].
• Continued Vigilance: It is vital to continue seeing a specialist in adulthood. Many adults are at risk of being misdiagnosed with other forms of epilepsy, which can lead to them being prescribed medications that are unsafe for Dravet patients ^[10][12].

Every child with Dravet syndrome follows their own timeline. Some children may never experience certain seizure types, while others may find that their “worsening phase” is shorter or less severe thanks to modern treatments ^[3]. The goal of your care team is to manage these transitions with as much stability as possible.