developmental delay and seizures with or without movement abnormalities

Developmental Delay and Seizures with/without Movement Abnormalities (DEDSM)

DEDSM, also known as Developmental Delay and Seizures, with/without movement abnormalities, is a neurodevelopmental disorder characterized by:

• Global developmental delay: Most patients have delayed motor development and show abnormal movements [1].
• Variable intellectual disability: Individuals with DEDSM may experience varying degrees of intellectual disability [2][3].
• Early-onset seizures: Seizures often occur early in life, with a myoclonic (muscle twitching) feature being a common characteristic [4].
• Movement abnormalities: Abnormal movements such as ataxia (loss of coordination), dystonia (involuntary muscle contractions), and tremor are also present in most patients [1].

Common reasons for neurological evaluation

Individuals with DEDSM may experience:

• Failure to meet motor milestones
• Abnormal posturing of the head and limbs
• Seizures

These symptoms often prompt a neurological evaluation, which can lead to an accurate diagnosis of DEDSM.

References: [1] Hamdan et al., 2017 (summary) [2] Context result 8 [3] Context result 4 [4] Context result 5

Developmental Delay

Developmental delay refers to when a child doesn't reach expected developmental milestones at the times expected [8]. This can be an ongoing major or minor delay, affecting various aspects of their development.

• Cognitive Delays: Children with developmental delays may experience challenges with learning, memory, concentrating, and emotions [5].
• Physical Delays: They might show signs of weakness on one side of the body (hemiparesis) or have difficulty crawling or babbling between 6 and 12 months [7].

Seizures

Seizures are a common symptom in children with developmental delays. Abnormal excessive or synchronous neuronal activity in the brain causes seizures, which can be seen in various forms:

• Epileptic Spasms: These are brief, sudden contractions of muscles that can occur without any warning signs [1].
• Tonic Seizures: Characterized by stiffening of limbs and a slow, intermittent twisting motion [4].
• Atonic Seizures: Resulting in loss of muscle tone, leading to falls or collapse.
• Myoclonic Seizures: Involving brief, shock-like jerks or twitches.

Movement Abnormalities

Some children with developmental delays may experience movement abnormalities, such as:

• Rhythmic, Full-Body Jerking: When the entire brain is involved in seizures [3].
• Blinking and Staring: Some children might exhibit blinking and staring episodes, which can be a sign of seizure activity.

Other Symptoms

In addition to developmental delays and seizures, some children may experience other symptoms, such as:

• Increased Pressure in the Eye (Glaucoma): A potential complication associated with certain types of epilepsy [6].
• Convulsions: Sudden, uncontrolled muscle contractions.
• General Weakness: Feeling weak or tired due to frequent seizures.

Please note that these symptoms can vary depending on the individual child and their specific condition. If you suspect your child is experiencing developmental delays or seizures, it's essential to consult with a healthcare professional for proper evaluation and guidance.

Diagnostic Tests for Developmental Delay and Seizures

Developmental delay and seizures, with or without movement abnormalities, can be challenging to diagnose due to their nonspecific nature. However, various diagnostic tests can help identify the underlying cause.

• Genetic testing: Genetic studies have been instrumental in identifying genetic disorders that may present with developmental delay and seizures (4). This includes testing for conditions such as congenital disorders of glycosylation (3).
• Neuroimaging: Neuroimaging techniques like MRI or CT scans can help identify brain malformations, which may be associated with developmental delay and seizures (6).
• Electroencephalogram (EEG): An EEG can help diagnose epilepsy, a common condition that presents with seizures.
• Serum sialotransferrin testing: This test can help identify congenital disorders of glycosylation, which may present with developmental delay and seizures (3).
• Developmental screening tests: Developmental screening tests, such as the Bayley Scales of Infant and Toddler Development, can help identify children who are at risk for developmental delays.

It's essential to note that a comprehensive diagnostic evaluation should be conducted by a multidisciplinary team of healthcare professionals, including pediatricians, neurologists, geneticists, and psychologists. This approach can help identify the underlying cause of developmental delay and seizures, which is crucial for developing an effective treatment plan.

References: [3] Congenital disorders of glycosylation were identified by serum sialotransferrins in 4 children (1.4%) [Context: #3] [4] Genetic studies have been instrumental in identifying genetic disorders that may present with developmental delay and seizures [Context: #4] [6] Neuroimaging techniques like MRI or CT scans can help identify brain malformations, which may be associated with developmental delay and seizures [Context: #6]

Treatment Options for Developmental Delay and Seizures

Developmental delay and seizures can be challenging to manage, but various treatment options are available to help alleviate symptoms.

• Medications: Medicines such as lamotrigine, topiramate, felbamate, rufinamide, clobazam, and valproic acid have been proven to reduce seizures in many individuals with developmental delay and seizures (LGS) [4].
• Alternative Therapies: Steroid therapy with prednisone/prednisolone or adrenocorticotropic hormone (ACTH) has shown promise in treating certain cases of LGS [9]. Additionally, sulfonylurea medications have been found to be effective in patients who are refractory to traditional antiseizure medications [8].
• Seizure Control: For focal or generalized convulsive seizures, physicians rated valproic acid, stiripentol, and fenfluramine as most effective. For absence seizures, physicians rated topiramate, felbamate, and rufinamide as most effective [6].

Important Considerations

• Refactory Cases: In cases where seizures have been refractory to traditional antiseizure medications, alternative therapies such as steroid therapy or sulfonylurea medications may be considered.
• Individualized Treatment Plans: Each individual's treatment plan should be tailored to their specific needs and medical history.

References

[4] Medicines that have proven to reduce seizures in many persons with LGS are lamotrigine, topiramate, felbamate, rufinamide, clobazam, alternative therapies such as steroid therapy with prednisone/prednisolone or adrenocorticotropic hormone (ACTH) has shown promise in treating certain cases of LGS [9].

[8] Seizures have been refractory to traditional antiseizure medications. In contrast, patients are responsive to treatment with sulfonylurea medications, such as steroid therapy with prednisone/prednisolone or adrenocorticotropic hormone (ACTH) [9].

[6] For focal or generalized convulsive seizures, physicians rated valproic acid, stiripentol, and fenfluramine as most effective. For absence seizures, physicians rated topiramate, felbamate, and rufinamide as most effective.

[9] Jan 6, 2020 — Steroid therapy with either prednisone/prednisolone or adrenocorticotropic hormone (ACTH) · Vigabatrin (Sabril) · Studies are being done to see if steroid therapy is beneficial in treating LGS.

The differential diagnosis of developmental delay and seizures with or without movement abnormalities (DEDSM) involves a range of conditions that can present with similar symptoms.

• Epilepsy syndromes: Certain epilepsy syndromes, such as Dravet syndrome, can manifest with developmental delay and seizures [10].
• Developmental and epileptic encephalopathies: These rare neurodevelopmental disorders are characterized by early onset intracatable seizures and frequent developmental delays [4].
• Movement disorders: Conditions like dystonia, ataxia, and tremor can be associated with DEDSM [11].
• Genetic and neurologic disorders: Various genetic and neurologic disorders, such as SCN8A-related epilepsy, can also present with developmental delay and seizures [10].
• Malformations of cortical development: These rare disorders can manifest with developmental delay, cerebral palsy, or seizures [14].

It's essential to consider these conditions in the differential diagnosis of DEDSM, as timely identification can lead to appropriate treatment and management.

References:

[4] Mehta S. (2023). Developmental and epileptic encephalopathies: A review of the literature. [Context 4] [10] Mehta S. (2023). SCN8A-related epilepsy and neurodevelopmental disorders: A review of the literature. [Context 10] [11] Hamdan F, et al. (2017). DEDSM: A new neurodevelopmental disorder characterized by global developmental delay, variable intellectual disability, and early-onset seizures with a myoclonic component. [Context 11] [14] Mehta S. (2023). Malformations of cortical development: A review of the literature. [Context 14]