Thalamic infarcts in young adults: relationship between clinical-topographic features and pathogenesis

Most reports on thalamic infarcts have focused on clinicoanatomical correlations while the mechanisms of stroke have rarely been investigated. Moreover, most series have included mainly elderly stroke patients, whereas scarce information is available about the etiology of thalamic infarcts in the young.

To investigate the mechanisms of thalamic infarcts according to vascular territory in a series of young adults.

A sample of 24 consecutive patients with thalamic infarcts were found in an unselected series of 129 patients with cerebral infarction aged 18-45 years. Diagnostic investigation included computed tomography and magnetic resonance imaging scans, ultrasonic scanning of the extracranial and intracranial arteries, conventional angiography and magnetic resonance angiography, transthoracic and transesophageal echocardiography and extensive thrombophilic studies. The affected vascular territory within the thalamus was determined using standard templates.

Thalamic infarcts constituted almost one fifth of the ischemic strokes in our series. Ten patients (42%) had infarct in the territory of the thalamogeniculate pedicle (group 1), 10 (42%) in the territory of the paramedian thalamosubthalamic artery (group 2) and 3 (12%) in the territory of the tuberothalamic artery (group 3). In 1 patient (4%), the lesion involved more than one vascular thalamic territory. A significant association between cardioembolism and paramedian infarcts was found when comparing the mechanisms of stroke of group 2 with those of the group including infarcts in other thalamic territories (p = 0.002) and with those of group 1 (p = 0.02).

Our findings provide information about the epidemiology of thalamic infarcts in young adults and point to a differential association between the distribution of infarcts in specific vascular territories and the mechanism of stroke.