HYDROCEPHALUS

HYDROCEPHALUS

Definition:
Hydrocephalus is defined as abnormal accumulation of cerebrospinal fluid (CSF) within the ventricles and subarachnoid spaces. It is often associated with dilatation of the ventricular system and increased intracranial pressure (ICP).

Physiology and circulation of CSF

The normal volume of circulating CSF is about 150 ml. The daily production of the CSF is about 450 ml, so the CSF volume is replaced approximately three times daily. CSF is produced by an active process independent of inracranial pressure (ICP). 80% of CSF is produced by the choroid plexus, and the rest is from the parenchyma

Functions of the CSF

1. Protect and support the brain and spinal cord. 2. Maintain homeostasis by acting as a transport medium for transmitters and as a method of removing the end-products of metabolism.

CSF Circulation

lateral ventricles. foramen of Monro third ventricle aqueduct of Sylvius fourth ventricle two foramina of Luschka foramen of Magendie subarachnoid space arachnoid villi venous blood blood stream.

CSF Circulation

CSF Circulation

CSF Circulation

Classification of Hydrocephalus
A. Non-communicating hydrocephalus (Obstructive): results from lesions that obstruct the CSF pathways from the lateral ventricles to the fourth ventricle. B. Communicating hydrocephalus: refers to circumstances in which the intracerebral CSF pathways are patent but there is accumulation of CSF, usually due to impaired CSF absorption.

Epidemiology of Hydrocephalus

The incidence of infantile hydrocephalus is about 3 to 4 per 1000 live birth

Aetiologty of Hydrocephalus

In patients with hydrocephalus, an imbalance has occurred between the normal physiological production of CSF and its absorption. This imbalance can be as a result of overproduction of CSF, an obstruction, or impaired absorption.

Normal Lateral Ventricle Vs Hydrocephalus

Normal Ventricles Vs Hydrocephalus

Normal Brain Vs Hydrocephaluscoronal section

Normal Brain Vs Hydrocephalus

Aetiologty of Hydrocephalus
A. Non-communicating hydrocephalus (Obstructive): 1. Lateral ventricle obstruction by tumours, e.g. basal ganglia glioma, thalamic glioma. 2. Third ventricular obstruction, due to colloid cyst of the 3rd ventricle or glioma of the 3rd ventricle 3.Occlusion of the aqueduct of Sylvius (either primary stenosis or secondary to a tumour). 4. Forth ventricular obstruction due to posterior fossa tumour, e.g. medulloblastoma, ependymoma, acoustic neuroma.

Aetiologty of Hydrocephalus

Communicating hydrocephalus: 1. Failure of absorption of CSF through the arachnoid granulations over the cerebral hemispheres. Sclerosis or scarring of the arachnoid granulations can occur after meningitis (bacterial or tuberculous), subarachnoid haemorrhage (either spontaneous, traumatic or postoperative), or trauma. 2. Oversecretion of CSF (choroid plexus papilloma).

Clinical Features of Hydrocephalus

Neonatal Hydrocephalus (Infantile): Failure to thrive and feeding problems. Enlargement of the head with increasing head circumference. Craniofacial disproportion with expansion of the dome and "low set" ears and eyes. The scalp is thin and glistening. The veins of the scalp are distended. The anterior fontanelle is enlarged, tense, and bulging.

Clinical Features of Hydrocephalus

Neonatal Hydrocephalus (Infantile): 7. Weakness of upward gaze (the setting-sun sign)(3rd ventricular pressure on midbrain tectum). 8. Diastasis of the cranial sutures. 9. Transillumination of the head is usually positive (if cortical mantle is less than 1cm and the patient is under 9 months age). 10. Bradycardia can be seen in extreme cases.

Neonatal Hydrocephalus (Infantile)

Neonatal Hydrocephalus (Infantile)

Neonatal Hydrocephalus (Infantile)

Neonatal Hydrocephalus (Infantile)

Neonatal Hydrocephalus (Infantile)

Clinical Features of Hydrocephalus
Hydrocephalus in older children and adults: Headache. Nausea and vomiting. Deterioration in the level of consciousness. May be associated ataxia. Visual disturbance.

Investigations of Hydrocephalus

A. Skull x-ray: can show 1. Separation of sutures. 2. Features of increased intracranial pressure

Investigations of Hydrocephalus

B. Ultrasound of the brain: can be done through opened anterior fontanelle to see the ventricular system.

Ultrasound of the brain

Investigations of Hydrocephalus
C. CT scan of the Brain: Ventricular dilatation. Can show the cause of obstruction as tumour. D. MRI of the brain: same as CT but no radiation so can be used for follow up.

CT scan of the Brain

CT scan of the Brain

Choroid Plexus Papilloma with Hydrocephalus

Third Ventricle Tumour with Hydrocephalus

MRI HYDROCEPHALUS

MRI Hydrocephalus

Investigations of Hydrocephalus
E. Lumbar puncture: can be done in communicating hydrocephalus for both diagnostic and therapeutic aims.

Management of Hydrocephalus

A. Medical management B. Surgical management

Medical management of Hydrocephalus

By using methods to reduce CSF production, but till now no definite medical treatment is satisfactory.

B. Surgical management

Removal of obstructing lesion e.g. removal of tumour will resolve hydrocephalus. Bypassing obstruction: either by: Endoscopic third ventriculostomy External drainage of CSF Internal diversion (Shunting)

Endoscopic Third Ventriculostomy

Endoscopic Third Ventriculostomy

Types of Internal Shunts
Ventriculo-Peritoneal Shunts. Ventriculo-Atrial Shunts. Ventriculo-Pleural Shunts.

Ventriculo-peritoneal Shunt

Shunted Hydrocephalus

The complications of shunting

Shunt obstruction: Shunt infection. Intracranial haemorrhage either: Intracerebral haemorrhage, or Subdural haematoma.

Complications of Ventriculo-Atrial Shunts

Infective Endocarditis. Volume Overload (Heart Failure). Arrhythmias (SA node).

Complications of Ventriculopleural Shunts:

Pneumothorax and Haemopneumothorax. Pleural Effusion. Pleural Empyema.


DEVELOPMENTAL (CONGENITAL) ANOMALIES OF THE SPINESSPINA BIFIDA (SPINAL DYSRAPHISM)

SPINA BIFIDA

Definition: This is the most common developmental anomaly affecting the spinal column, and it means failure of the neural tube to close fully, so there is split or open spine.

SPINA BIFIDA

SPINA BIFIDA
Types of spina bifida: Spina bifida Occulta Spina bifida Cystica Spina bifida Aperta

Normal Spine

SPINA BIFIDA
Spina bifida Occulta: The posterior vertebral arch has a defect within it, but there is no herniation of the neural tube. This defect is found in 10% of the population. On the skin over the defect various skin changes may be seen, e.g. hairy patch, an area of pigmentation, a fatty lump or a dermal sinus.

Spina bifida occulta

Spina bifida Occulta

SPINA BIFIDA
2. Spina bifida Cystica: In this situation there is skin covering the defect making a cyst like. If this cyst contains CSF only it is called MENINGOCELE. If there is neural tissue within the sac, it is called MYELOMENINGOCELE.

Meningocele

MENINGOCELE

MYELOMENINGOCELE

MYELOMENINGOCELE

SPINA BIFIDA

3. Spina bifida Aperta: The neural tube is open with no skin coverage, through a defect in the posterior vertebral arch. CSF leakage usually occurs so there is a high risk of meningitis.


Spina bifida Aperta

Spina bifida Aperta

SPINA BIFIDA
Aetiology: 90% of cases occur sporadically. Hereditary factors: children of parents with spina bifida have a 5% risk of having the condition. Dietary factors: folic acid administration during pregnancy may lower its incidence. Some Anticonvulsants medications.

SPINA BIFIDA

Clinical Features: Antenatal screening: Post-delivery: General features Spina bifida occulta: Meningocele: Myelomeningocele:

SPINA BIFIDA

Antenatal screening: by using: Detection of alpha-fetoprotein in blood or in amniotic fluid obtained by amniocentesis. The use of ultrasound. Both tests allow the detection of such defects in over 80% of embryos with open neural tube .

Antenatal screening

Antenatal screening

SPINA BIFIDA

b. Post-delivery: General features include: The incidence is ranging from 1 to 8 per 1000 of the population. Most problems tend to occur in the lumbosacral area and are associated with changes in bladder and bowel functions. The higher the lesion the more sever the defect. If the lesion is open then there is associated risk of meningitis. Other associated disorders include Arnold-Chiari malformations type II, and in up to 80% hydrocephalus.

Myelomeningocele+ Hydrocephalus

SPINA BIFIDA
c. Spina bifida occulta: Usually asymptomatic. Accidental finding in X-rays. Lipoma, skin dimple or a tuft of hair over the bifid spine. Rarely urinary incontinence starting at adolescence.

SPINA BIFIDA

d. Meningocele: No neurological manifestations. Cystic translucent swelling with an expansible impulse on coughing. The swelling is compressible.

Meningocele

Meningocele

Meningocele

Meningocele

SPINA BIFIDA

e. Myelomeningocele: Paraplegia, wasting, or contractures, with sensory loss. Trophic disturbances are marked, especially perforating ulcers of foot. Other congenital anomalies associated, mainly hydrocephalus.

Myelomeningocele

Myelomeningocele

Myelomeningocele

SPINA BIFIDA

Investigations: Head circumference measurement to check for an associated hydrocephalus. Plain radiograph of the spine. Ultrasound of the brain to exclude hydrocephalus. CT and/or MRI brain to rule out hydrocephalus.

SPINA BIFIDA

Treatment: Spina bifida occulta requires no treatment in the majority of cases. In the other forms of open spina bifida surgery should be performed as early as possible, and include: Closure of the defect as early as possible to avoid meningitis. The hydrocephalus needs immediate shunting even prior to closure of the defect of spina bifida.

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