First of all rule out obliquity and improper alignment of pt's head during scanning, the major source of error during assessment of asymmetry of lateral ventricle and cerebral hemispheres.
Next is grading of asymmetry, as mild moderate and severe.
Mild asymmetry is usually seen secondary to off midline septum pellucidum, where rest of the lateral ventricle and its horns are symmetrical, normal and non dilated. Adjacent basal ganglia show normal volume and density.
Prevalence of mild asymmetry of lateral ventricle in our routine opd work load is approximately 5 percent. Headache was the most common symptom in pt with asymmetry of lateral ventricle and were treated conservatively. Seizures was the second common complaint in this group. Giddiness and neuropsychiatric problems like schizophrenia in few. Widening of left lateral ventricle is more common that right. No obvious association found between asymmetry of lateral ventricle with right or left handedness.
To pass if off as normal finding or variant, it should be an isolated finding, without any obvious cause like volume loss due to an adjacent basal ganglionic gliosis or atrophy, without any intra ventricular or para ventricular space occupying lesion, without any trapping lateral ventricular secondary ependymal adhesions.
It is important to differentiate between moderate and severe asymmetry of lateral ventricle from unilateral hydrocephalus which is done by using three different ventricle to brain ratios (V/B ratios).
Conclusion:
Mild asymmetry in lateral ventricle can be passed off as a normal anatomical variation if not associated with any intra ventricular or adjacent parenchymal abnormality; at the most make a note of finding in the report. Moderate and severe degree of asymmetry of lateral ventricle should not be overlooked, search for possible accompanying pathology or association with cognitive disorders.
Related Posts:
Unilateral hydrocephalus
Post shunt lateral ventricle asymmetry
