Positron emission tomography in epileptogenic hypothalamic hamartomas.

Area of Science:

• Neuroscience
• Epileptology
• Medical Imaging

Background:

• Hypothalamic hamartomas (HH) are associated with epilepsy, but the extent of their intrinsic epileptogenicity is debated.
• Similar HH morphology can present with diverse seizure types and cognitive profiles, indicating complex underlying mechanisms.

Purpose of the Study:

• To investigate brain glucose metabolism in patients with epileptogenic HH.
• To identify focal cortical and subcortical dysfunction related to HH using [18F]-fluoro-desoxyglucose positron emission tomography (FDG-PET).
• To correlate metabolic abnormalities with electroclinical findings.

Main Methods:

• Five patients with epileptogenic HH underwent FDG-PET, MRI, and video-EEG monitoring.
• Intra-cranial EEG was performed in one patient.
• FDG-PET findings were compared with interictal and ictal electroclinical data.

Main Results:

• All five patients exhibited focal hypometabolism ipsilateral to the HH and predominant EEG abnormalities.
• Hypometabolic areas varied but generally corresponded to cortical regions involved in ictal discharges.
• These findings suggest HH-driven epileptic networks involve cortical dysfunction.

Conclusions:

• Epileptogenic hypothalamic hamartomas are associated with focal cortical hypometabolism.
• This hypometabolism may indicate regions participating in the broader HH-driven epileptic network.
• Further research is needed to determine if these cortical abnormalities represent ictal propagation or independent seizure onset zones.