Temporal Horns of Ventricles

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Definition

The temporal horns are paired structures of the ventricular system extending from the atria of the ventricles to the temporal lobes. They course anteriorly lateral ward and then inferiorly extending within 2.5cms of the tip of the temporal lobes. IKts floor is provided by the hippocampus.

In a normal adult they are not usually visualized, and if they are visualised it is may represent the earliest sign of hydrocephalus or cerebral atrophy.

The vectors of the ventricular System Overlaid on the Brain

The ventricular system is overlaid on a drawing of the brain. Each limb of the horizontal component is situated in a cerebral hemisphere. The angled parts that extend inferiorly represent the temporal horns. The vertical limb includes the third and fourth ventricles

Sagittal View of the Ventricles

The Recesses

The diagram in the sagittal projection reveals the horizontal portion called the lateral ventricle. It is a paired structure that houses the frontal horn, body, and the vertical portion which is composed of the 3rd ventricle, cerebral aqueduct and the 4th ventricle. The lateral ventricle consists of the frontal horn, body, occipital horn, atrium and the temporal horn The foramen of Monro connects the lateral ventricles with the third ventricle. The paired foramina of Luschka are sitiuated anteriorly in the 4th ventricle and they allow CSF to circulate in the subarachnoid spaces. The foramen of Magendie is a single structure and is situated posteriorly and it also enables CSF to enter the subarachnoid space. code brain ventricles lateral ventricles frontal horn body occipital horn atrium temporal horn 3rd ventricle 4th ventricle foramen of Monro formamen of Magendie Foramen of Luschka anatomy normal neuroanatomy diagram conceptual diagram structure principles Davidoff Art Courtesy Ashley Davidoff MD copyright 2010 all rights

Temporal Horns – Part of the Forebrain

Distribution of the Ventricles

The distribution of the ventricular system is demonstrated in this diagram with the forebrain structures (green) including the lateral ventriclesfrontal horns, atria, temporal horns, and third ventricle. The midbrain positioned aqueduct of Sylvius is seen in orange, while the hindbrained positioned 4th ventricle is overlaid in orange

Temporal Horns Extending from the Atria

The atria and temporal horns are demonstrated in this coronal MRI using a STIR sequence. The tmporal horns are easily recognized as an inveted ‘V shaped structure starting roughly in the midline and courses laterally and inferiorly. They start just anterior to the occipital lobes and end in the temporal lobes and these lobes can be recognized as neighbours of this part of the ventricular system.

Choroid Plexus in the Temporal Horns

The reconstructed CTA scan in the coronal plane reveals the choroid plexus (purple) as fine knotty strands extending from the atrium to the temporal horns bilaterally.

Applied Biology

Age related Atrophy

Temporal Horns become Visible (d)

The CT scan of this 92 year old man reveals normal involutional change of the brain including perivntricular lucency(a)suggestive of microangiopathic change, mild dilatation of the ventricles (b) with deepening of the sulci and prominence of the gyri (abc) and ability to identify the temporal horns (d), all signs of brain atrophy. Note also the normal calcification of the choroid plexus in the atria (c) which is found very commonly even in young patients.

Image Courtesy Ashley Davidoff MD 75932c01

Aqueductal Stenosis

The T2 weighted MRI images show dilated lateral ventricles (a), frontal horns and occipital horns (b), temporal horns (c) and 4th ventricle (d) consistent with the known diagnosis of aqueductal stenosis CODE brain lateral ventricles frontal horns occipital horns atria body of temporal horns 4th ventricle aqueduct of Sylvius fx dilated enlarged distended dx hydrocephalus aqueductal stenosis

Courtesy Philips Medical Systems 92408b.8