ALTERNATING HEMIPLEGIA OF CHILDHOOD
LIKE HAVING 7 DISEASES AT ONE TIME.
WHAT IS ALTERNATING HEMIPLEGIA OF CHILDHOOD (AHC)?
Alternating hemiplegia of childhood is caused by a mutation of the ATP1A3 gene. This gene is important for maintaining a balance of electrochemicals in the brain. A substitution of the correct protein along this gene is responsible for causing recurrent attacks of paralysis that affect one or both sides of the body. These attacks can range from simple numbness to full loss of function in one or multiple limbs and may last for minutes, hours, or even days. They are usually triggered by overstimulation including but not limited to changes in temperature, water exposure, physical activity, lights, foods, emotional response, odors, fatigue, and medications. The attacks are usually relieved by sleep.
There are only 1,000 diagnosed with AHC in the world, and depending on where the mutation is found, each present differently. In infants these attacks present very similarly to seizures and is often misdiagnosed for epilepsy.
SYMPTOMS OF AHC
AHC is like having seven conditions at one time:
Paralysis like stroke.
Seizures and spells of reduced consciousness like epilepsy.
Low muscle tone like cerebral palsy.
Movement problems and dystonia like Parkinson’s.
Neurodegeneration like Alzheimer’s.
Behavioral issues like ADHD.
Learning challenges like autism.
TREATMENT FOR AHC
Currently, the only treatments for AHC are drugs that attempt to mask the symptoms but do not correct the underlying dysfunction. It is highly unlikely that such a drug would come to fruition. There are too few patients and too large a range of mutations and presentations for drug therapy to be a viable option. The only hope for a viable cure is through gene therapy.
LONG TERM EFFECTS OF AHC
Despite misleading nomenclature, AHC does not end with childhood. Presentation may change as the child grows, but it is not something the child will outgrow. AHC presents differently for each child, some are mildly affected, while others are more severely affected.
Each episode and/or seizure can result in damage to the brain. Over time this can cause the brain to atrophy and loss of previously attained skills. For the majority of patients, gross and fine motor and cognitive abilities are compromised in some capacity.
In severe cases, AHC can cause failure of the autonomic nervous system resulting in sudden and unexplained death.