The temporal evolution of neurologic and nonneurologic symptoms can be helpful when attempting to categorize leukoencephalopathies. The age of onset may be neonatal (or prenatal), infantile, late-infantile, childhood, or it may occur in adulthood after a long period of normalcy. Neurologic symptoms may be static, gradually improving over time or progressively declining. The pattern of skill acquisition in children is particularly important because some conditions present with development that is delayed but where children continue to steadily gain skills at their own pace. Other conditions, particularly those associated with progressive destruction of myelin, frequently present with a period of normal development followed by a plateau in skill acquisition then a decline. It is important to note whether there is a regression of skills associated with fever, infections, or head injuries. A careful review of systems aimed at detecting neurologic and nonneurologic symptoms helps generate possible clues for pattern recognition.
A family history of a similarly affected sibling, parent, or family member increases the likelihood of an inherited form of leukoencephalopathy and may suggest the inheritance pattern (autosomal dominant, autosomal recessive, X-linked, or mitochondrial). Some hereditary leukoencephalopathies have primarily been described in specific ethic groups. It is therefore important to enquire about ethnicity and consanguinity.
Semin Neurol. 2012;32(1):29-33. © 2012 Thieme Medical Publishers