Are Periventricular Lesions Specific for Multiple Sclerosis?

BACKGROUND: The presence of periventricular lesions (PVL) on MRI scans is part of the revised McDonald multiple sclerosis (MS) diagnostic criteria. However, PVL can be found in other neurological diseases including stroke and migraine. Migraine is highly prevalent in patients with MS. OBJECTIVE: To determine if PVL are specific for patients with MS compared to stroke and migraine. METHODS: We studied patients diagnosed with clinically isolated syndrome (CIS), relapsing-remitting MS (RRMS), migraine, and ischemic stroke. The number, location and the volume of PVL were identified on brain MRI scans and analyzed. RESULTS: The number and volume of PVL adjacent to the body and the posterior horn of the lateral ventricles were significantly increased on fluid-attenuated inversion recovery MRI in RRMS compared to migraine. There were no significant differences in the total number and volume of PVL in ischemic stroke patients compared to the age-matched RRMS patients nor in the number and volume of PVL adjacent to the anterior and temporal horns of the lateral ventricles on FLAIR images in migraine compared to CIS or RRMS. CONCLUSION: In contrast to PVL adjacent to the body and the posterior horn of the lateral ventricles, PVL adjacent to the anterior and temporal horns of the lateral ventricles may not be specific for CIS/RRMS when compared to migraine, the disease highly prevalent among patients with MS. PVL are not specific for MS when compared to ischemic stroke.

What proportion of stroke is not explained by classic risk factors?

Ischemic stroke is a complex entity with multiple etiologies and variable clinical manifestations. The most frequent cause of stroke is atherosclerosis of cerebral vasculature followed by cardioembolism. Two thirds of strokes are explained by identifiable risk factors. Age, hypertension, and nonvalvular atrial fibrillation are by far the most frequent and well documented ones. Approximately 5% of strokes are caused by conditions other than atherosclerosis or heart disease, i.e., cervical arteries dissections, nonatherosclerotic vasculopathies, infectious or systemic vasculitis, and collagen vascular diseases. In spite of a thorough diagnostic evaluation, 30% of strokes remain cryptogenic, i.e., no specific cause is identified and the classic risk factors are not present. Identification of unknown environmental or genetic risk factors should be the subject of further research.

Bilateral basal ganglia and cerebellar lesions in an alcoholic hyperosmolar patient.

Bilateral symmetrical basal ganglia lesions may be caused by hypoxic/ischemic injury. However, similar lesions have not been described in the cerebellar cortex. To report a case of bilateral basal ganglia and cerebellar lesions in an alcoholic patient with hyperglycemia and hypotension. A 47-year-old alcoholic man with hypotension of unknown duration and hyperosmolarity had mild weakness of the left upper extremity. Neuroimaging revealed abnormality of bilateral symmetric globus pallidus and inferior cerebellum. Prolonged hypotension with hyperosmolarity may give rise to bilateral basal ganglia and cerebellar lesions.

Spinal cord infarction secondary to nucleus pulposus embolization in pregnancy.

Nucleus pulposus (NP) embolism is an extremely rare cause of spinal cord infarction. To our knowledge, it has not been reported in pregnancy in the English literature. A 41-year-old pregnant woman presented with clinical symptoms initially attributed to a transverse myelitis. After a complicated clinical course, she expired, and was found at autopsy to have NP embolism to the spinal cord. In conclusion NP embolism is a rare cause of spinal cord infarction, and should be considered in the differential of a patient presenting with symptoms compatible with spinal cord infarction in the pregnant as well as nonpregnant state.