---

Microvascular decompression of the fifth cranial nerve (above collage): Such patients present with severe, frequent sharp-lancinating pain (trigeminal neuralgia) often for several months or years. They have typically tried a variety of oral medications and/or other more invasive interventions with little or no relief. Top left image: The axial MRI scan shows the origin or "root entry zone (REZ)" of the fifth cranial (trigeminal) nerve (green arrow) being compressed by a blood vessel (red arrow head). P=brainstem "pons" region. Top right image: The compressive blood vessel (red arrow head) has now been microsurgically dissected and physically separated from the trigeminal nerve origin (yellow arrow head) by Dr Khurana, creating a space between these two structures. By creating this physical separation, the pulsatile/pounding effect of the blood vessel on the trigeminal nerve's origin is significantly diminished, thereby helping to decrease the abnormal "ephaptic" transmission associated with the pain of trigeminal neuralgia ("tic delaroux"). Bottom left image: The ephaptic transmission can be further diminished by gently massaging the relevant nerve root (red circle) in the tips of the bipolar forceps. Bottom right image: At the conclusion of the operation, Dr Khurana has placed a tuft of Teflon microfibres (green arrow) between the offending blood vessel (red arrow head) and the nerve root (yellow arrow head) to keep this space physically "buffered". This patient's symptoms completely resolved after this procedure. A similar technique can be used for patients with hemifacial spasm (persistent facial muscle spasms; microvascular decompression of the seventh cranial nerve) and glossopharyngeal neuralgia (bouts of lancinating pain on swallowing; microvascular decompression of the ninth cranial nerve).

Pituitary macroadenoma (above collage): The pituitary gland is the brain's master hormone-secreting gland and it is located just under the "optic apparatus", i.e., the nerves for vision. Pituitary tumours can present with with hormonal changes (e.g., gigantism or progressively thickening soft tissues - acromegaly - from excess growth hormone secretion; or premature milk expression and irregular periods from excessive prolactin secretion; or Cushing's disease from excess cortisol secretion) and/or impaired vision (tunnel vision or "bitemporal hemianopia"). When pituitary tumours become very large, they can outgrow their blood supply and bleed into themselves. This is referred to as pituitary apoplexy and is often associated with sudden severe headache and loss of visual field (sudden tunnel vision). Top left image: This patient presented with visual field loss over a few months. The tumour appears as the hour-glass shaped white mass in this MRI coronal image. It has bled (the blood pocket is the grey hat between the yellow arrow heads). The optic nerves (yellow arrow heads) are displaced to the sides by the tumour mass. The internal carotid arteries are seen as shadows here (red arrow heads). Top right image: This is another patient's pituitary tumour which is bowing the optic nerves/optic chiasm upwards (yellow arrow heads) resulting in diminished visual field. The carotid artery on each side is shown by the red arrow head. The approach to such tumours is through the nostril (transnasal) and into the air space (sphenoid air sinus; purple arrow) that lies under where the pituitary gland is housed. This is a trans-sphenoidal approach. Note how the space is located close to the internal carotid arteries (red arrow heads). Dr Khurana routinely uses neuronavigation (GPS for the brain) to map out a precise trajectory to the tumour target, thereby avoiding surrounding critical structures. These operations are carried out by Dr Khurana in conjunction with an ENT surgeon. Bottom left image: The pituitary tumour (red circle) is now on view through a speculum carefully inserted along the patient's nostril and magnified by the operating microscope. A suction (grey-white arrow) and a loop-curette (blue arrow) are used to gradually remove the tumour. Bottom right image: After the removal of the tumour, the optic apparatus (yellow arrow heads) is now well decompressed and clearly visible again. The internal carotid arteries (red arrow heads) are not disturbed and the pituitary gland's stalk is now seen (blue arrow) and intact as expected. Some of the patient's own fat can be left in the sphenoid air space as a packing if needed. Patients with recent visual field impairment before surgery typically experience a recovery in this function within hours to days after surgery.

Colloid cyst (above collage): Patients with colloid cysts can present with progressive headaches (obstructive hydrocephalus), blackout spells (intermittent mechanical obstruction or "ball-valve" effect), or sudden death (in 5-10%). Top left image: The MRI coronal image shows a 10 mm colloid cyst (red circle) causing obstruction of the flow of cerebrospinal fluid (CSF) in the fluid-filled inner chambers of the brain called "ventricles". This is hydrocephalus, as seen by the asymmetrical expansion of one of these fluid chambers (green arrows; lateral ventricle). Top right image: Dr Khurana can use either an interhemispheric transcallosal approach or a transfrontocortical approach to access the ventricle and visualise the colloid cyst (green arrows). A key anatomical structure known as the "fornix" serving the functions of memory and learning is seen here (yellow arrow heads), as are veins of this region (red arrow heads). Such structures are vital and should not be disturbed during this very delicate operation. Bottom right image: Dr Khurana has removed this patient's one-cm colloid cyst (green arrows) without any neurological impairment.

Cranioplasty (above collage): Some patients present with skull trauma (physical assault, motor vehicle accident, sporting injury) or with tumours or infections involving skull bones. Such patients may need reconstruction of the skull, and this can be effectively carried out with titanium or a polymer "bone cement" such as methylmethacrylate. Excellent structural and cosmetic results can be achieved with both of these. Top left image: A titanium microplate (blue arrow) has been affixed to a defect in this patient's skull bone via small titanium screws (yellow arrow heads). Top right image: In another patient, a robust acrylic polymer (methyl methacrylate), also referred to as "bone cement", has been carefully moulded to the patient's skull contour and used to replace a larger defect in the patient's skull. Bottom left image: For another patient, a strong titanium plate has been constructed using special computer-CAT scan mapping to exactly fit the patient's skull defect. Bottom right image: The plate has now been screwed into the surrounding skull bone of the patient, and the scalp is then closed over this new strong, cosmetically sound area.

---