Tuberous sclerosis complex: 2026 so far

Kidney benefits were reported more often, and rebound after stopping was described more clearly.

In the months covered, real-world kidney studies gave clearer signals that starting an mTOR inhibitor was linked to fewer angiomyolipoma (AML) hemorrhages (bleeding from a kidney tumor) and fewer embolization procedures (blocking blood flow to stop bleeding). Multiple reports also linked everolimus to AML shrinkage. August added an important durability concern: AML size tended to move back toward baseline after everolimus was discontinued. Separately, stopping and rebound were described in two other settings. One was rebound growth of fetal cardiac rhabdomyomas (heart tumors seen before birth) in some cases after prenatal sirolimus was stopped before birth. The other was worsening after stopping sirolimus in a long follow-up case of severe TSC-associated LAM (lymphangioleiomyomatosis, a lung disease that can damage breathing), with AML rebound also noted after everolimus. In these reports, the benefit seen during treatment was often paired with uncertainty about what happens once the medicine is stopped.

Research covered in: January 2026, February 2026, April 2026, June 2026, August 2026

More real-world add-on data helped set expectations for seizure control and side effects.

So far in 2026, evidence about add-on seizure medicines in TSC grew through both trial summaries and real-world clinic reports. A meta-analysis (a study that combines results from multiple trials) of randomized placebo-controlled trials (studies that compare a treatment to an inactive look-alike) across drug-resistant epilepsies (including TSC) found add-on cannabidiol (CBD) reduced seizure frequency on average. Real-world cohorts in September described a wide range of responses, and side effects were commonly reported but usually described as mild. Observational reports (studies that track what happens in routine care) also linked add-on cenobamate (young adults) and add-on everolimus (small retrospective cohorts, meaning a look back at existing records) to seizure reductions in some people. For cenobamate, some day-to-day measures were also reported as improved. For everolimus, response patterns were described as variable. Overall, these reports suggest add-on options can help some people but not others, and they often come with a need to watch for side effects.

Research covered in: February 2026, May 2026, September 2026

Procedure reports highlighted careful selection, repeat operations, and outcomes beyond seizures.

Between January and September, several reports added detail on what seizure procedures can look like in TSC, especially when medicines are not enough. A multicenter prospective cohort (a study that follows people forward over time) found vagus nerve stimulation (VNS, an implanted device that sends signals to a nerve in the neck) plus medicines had higher seizure response rates than medicines alone in a selected group without a removable seizure focus (a single spot that can be safely removed). Mild surgical complications were reported, and no permanent adverse events were reported. Surgical evidence also highlighted limits over time. A large pediatric series reported seizure freedom more often after a first epilepsy surgery than after repeat procedures. A pooled review (a study combining results across reports) found no significant seizure-freedom difference between MRI-guided laser therapy (using heat to destroy a small target) and open surgery in TSC-only analyses. Taken together, these reports framed procedures as individualized choices, including the possibility of repeat interventions and the possibility that behavior and learning changes may not match seizure freedom.

Research covered in: January 2026, April 2026, July 2026, August 2026, September 2026

Reports linked seizures and behavior challenges with stress and sleep difficulties.

In the months covered, several studies focused on day-to-day impact. In preschool families, parenting stress tracked with behavior challenges, lower adaptive skills (everyday skills like communication and self-care), seizure severity, and medical-related financial strain. Interviews also described fragmented care and a high burden from seizures and TAND (TSC-associated neuropsychiatric disorders, including behavior, learning, and mood symptoms). Cross-sectional surveys (a snapshot at one point in time) reported common mood swings, inattention, and language and learning difficulties. In one dataset, more severe neuropsychiatric profiles were linked to TSC2. Poor sleep was common in an adult cohort and, in that cohort, was associated with anxiety and mental illness and medication use. Longitudinal child cohorts (studies following children over time) described generally delayed cognitive and adaptive functioning, with autism diagnoses often stable over time. A small surgery series suggested neurobehavioral changes after epilepsy surgery could improve or worsen and did not clearly match seizure freedom. These reports repeatedly placed TAND, sleep, and caregiver strain alongside medical monitoring as major parts of what living with TSC can involve.

Research covered in: March 2026, May 2026, June 2026, July 2026, September 2026

More work focused on finding risks that can be missed without specific tests.

So far in 2026, monitoring-focused studies repeatedly emphasized that important risks can be missed without targeted testing. For kidneys, observational cohorts linked higher complication risk to age and lesion burden (how many and how large the growths are). A large AML study (not limited to TSC) tied rupture risk to TSC status and specific imaging features, and it produced a prediction tool with strong performance in its validation group (the separate group used to test the tool). For lungs, a real-world LAM cohort linked sirolimus use to stable lung function and described VEGF-D (a blood marker used in LAM monitoring) falling during treatment, supporting its role as a monitoring marker in that setting. For infants, multiple reports found seizures could be present on EEG (electroencephalogram, a test that records brain electrical activity) without obvious outward signs. One randomized infant study found early vigabatrin reduced certain abnormal interictal EEG patterns (between-seizure EEG changes) mainly in children who did not develop epileptic spasms (a specific infant seizure type). In these reports, imaging, lung function and biomarkers (in LAM), and EEG were repeatedly shown to change what gets detected and followed over time.

Research covered in: February 2026, March 2026, May 2026, June 2026, July 2026