Alternating Hemiplegia of Childhood (AHC) » Clinical Presentation and Diagnosis
Age of Onset and SymptomsAHC is a complex clinical condition with predominantly neurological manifestations.
The characteristic symptoms of the disease occur from early infancy. The most frequent first symptoms, that can be noted within the first days after birth, are episodes of abnormal eye movements (AEM). Dystonia and hemiplegia as well as other episodic neurological symptoms, appear in the following months.Sweney at all, 2009 proposed the following criteria for suspected AHC in early infancy:
In the course of the disease other neurological symptoms appear episodes of quadriplegia, dysphagia , autonomic disturbances , abnormal limb movements, epileptic seizures
- focal or unilateral paroxysmal dystonia and/or flaccid hemiplegia in the first 6 months of life
- paroxysmal ocular movements including biocular and monocular nystagmus and/or deviation in the first 3 month of life
- absence of epileptiform changes during ictal events
Electrocardiogram abnormalities are recently reported to be common for AHC patients and suggest that Cardiac dysfunction may be another prominent feature of AHC disease.
- interictal neurologic abnormalities such as tone abnormalities, choreoathetosis, and/or ataxia
- persistent motor deficits such as spastic quadriplegia or hypotonia
- developmental delay and intellectual disability
The type, the duration and the severity of the symptoms are specific for each individual with AHC.