INFORMATION ON TS BRAIN

Several types of brain lesions characterize TSC, but like the clinical manifestations, the neutopthologic changes are quite variable.

Cortical Tubers Cortical Hypoplasia Subependymal Nodules Giant Cell Astrocytomas

MANIFESTATIONS

Epileptic seizures, learning disabilities, and psychiatric and behavior problems are the most important neurologic problems of TSC, although patients with milder forms of the disease with little or no neurologic impairment are common.

EPILEPTIC SEIZURES

Epileptic seizures remain one of the most important neurologic problems of TSC, occurring in 80%-90% of recognized patients. Infantile spasms and tonic-clonic seizures are particularly common, but tonic, akinetic, myoclonic, and atypical absence seizures also occur. Older children and adults frequently develop complex partial or other focal seizures, in many instances after suffering more generalized seizures at a younger age. The choice of antiepileptic drugs should be tailored to the patient's age and seizure type. Some patients benefit from surgery if a single site of seizure origin can be pinpointed.

MENTAL HANDICAP

About 45% to 60% of Tuberous Sclerosis Complex patients are learning disabled, although the degree of intellectual dysfunction ranges from borderline to profound. Some children seem to develop normally until the onset of seizures, when their progress slows or they actually lose developmental milestones. Some may regress. Patients whose seizures continue unchecked even after anticonvulsant medication has been started, have a higher likelihood of intellectual impairment. There is also evidence from MRI that patients with severe cerebral disruption from Tuberous Sclerosis Complex tend to have a much greater likelihood of both uncontrolled seizures and learning disabilities, whereas patients with only a few small cerebral cortical lesions are more likely to have better intellectual function and seizures controlled by medication. The degree of neurologic function is probably determined by a combination of the severity of the seizures and the number, size, and location of the cerebral lesions.

PSYCHIATRIC AND BEHAVIOURAL PROBLEMS

Autism, attention deficit disorder, hyperactivity, aggressiveness, and anxiety disorders are found in individuals with Tuberous Sclerosis Complex of varying degrees of intellectual functioning and in isolation or in combination with epilepsy. These behaviour and psychiatric problems are often very disruptive to families, particularly when in conjunction with other medical complications which might accompany TSC. Furthermore, it is often very difficult for families to obtain careful and accurate assessment of the behaviour problems since they are often considered secondary to the Tuberous Sclerosis Complex diagnosis. The important thing to realize is that there is a strong correlation between Tuberous Sclerosis Complex and behavioural and psychiatric problems. The Tuberous Sclerosis Complex patients and their families should be referred to appropriate mental health professionals, for example a psychiatrist, for evaluation and treatment of behaviour problems when needed. Physicians trained as behavioral pediatricians may also be helpful in diagnosing behaviour disorders in very young children, and to provide or offer resources to help families develop early intervention plans. A very important step in treating kids with TSC.

DIAGNOSTIC SCREENING AND FOLLOW-UP

It is common practice to first perform a CT on a patient suspected of having TSC. If the brain lesions are observed, often a MRI will help in establishing a baseline for those lesions that are better observed on MRI than on CT. Repeat CT or MRI will be determined by the physician depending on the health and needs of the patient. Just how often a scan should be performed on an asymptomatic patient is still debated, but many physicians recommend either a CT or MRI at least every 1-3 years until the age of 20, when the risk of formation and growth of a giant cell astrocytoma probably decreases significantly. Additional scans may be needed to address specific clinical situations.

TREATMENT

At present, treatment for the brain lesions of Tuberous Sclerosis Complex is primarily treatment of the symptoms. Antiepileptic drugs or surgery where warranted for seizures, medications for behaviour problems, surgery for the removal of a growing giant cell astrocytoma, etc. Only when a better understanding of the mechanisms of the disease are found will the development of other therapies be possible.