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First visit for tuberous sclerosis complex comes months before diagnosis



HOUSTON – Many patients who eventually receive a diagnosis of tuberous sclerosis complex present with related complaints for months, or even years, before their condition is recognized and correctly diagnosed, according to a retrospective study.

The study, presented at the annual meeting of the American Epilepsy Society, found that patients with tuberous sclerosis complex (TSC) first sought care for TSC-related conditions an average of 7 months before they were diagnosed with the condition. Younger patients received the correct diagnosis sooner than did older patients: Treatment for TSC-related conditions preceded the diagnosis for 3.4 months for those aged 4 years or younger, compared with 5.5 months for those aged 25-29 years, and 21 months for those aged 80 years or older.

Seizures and skin conditions were common initial diagnoses among TSC patients, with 27% of patients aged 0-4 years being diagnosed with seizures prior to receiving their TSC diagnosis. The likelihood of prediagnosis visits for seizures decreased to less than 6% for older age groups. Seizures remained common post-TSC diagnosis among younger patients, with 38% of patients aged 0-4 years having any seizure diagnosis, while the rate fell through the lifespan to zero for those aged 80 or older.

James Wheless, MD, and his associates examined claims and enrollment data records from 2,163 patients diagnosed with TSC between January 2000 and December 2011. In addition to the frequently-diagnosed seizures seen in many TSC patients, skin conditions were diagnosed in 16.3% of patients before their eventual TSC diagnosis.

Other early conditions associated with TSC, according to the study’s multivariable analysis, included bone cysts, anxiety, and ADHD. However, wrote Dr. Wheless, chief of the department of pediatric neurology at the University of Tennessee Health Science Center, Memphis, and his coauthors, “at any point in time, patients with seizures were 2.9 times more likely to receive a TSC diagnosis than patients without seizures.”

The study was drawn from U.S. health plan databases that included both commercial and Medicare Advantage enrollees, and included patients through the lifespan. The date of the first recorded TSC diagnosis was the index date, and patients had to have at least 12 months of prediagnosis health plan enrollment to be included, or 6 months for those aged 2 years or younger. Data were collected for all pre-index visits (some of which stretched back to 1993), and for visits in the 12 months after the index visit.

The proportion of female patients ranged from fewer than half for those under 15 years (0-4 years, 46%; 5-9 years, 43%; 10-14 years, 48%) to 64% for those aged 80 years or older (P less than .001).

Dr. Wheless and his coauthors noted that the claims data used for the analysis “may not adequately capture clinical characteristics such as disease severity,” and that some patient data may have been lost if patients were disenrolled for periods of time during the study period.

The findings of the poster may prompt clinicians to consider TSC as a diagnosis; though rare, occurring in 1-2 per 6,000 live births, it’s thought to be an underrecognized disease entity. “Understanding the initial diagnoses experienced by TSC patients may help lead to earlier diagnosis and treatment of TSC,” Dr. Wheless and his coauthors wrote.

Novartis funded the study. Four study authors are employed by Optum, and one is employed by Novartis.

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